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. Extreme Weather and Natural Disasters

    CERN Document Server

    Healey, Justin

    2012-01-01

    Australia is a vast land in which weather varies significantly in different parts of the continent. Recent extreme weather events in Australia, such as the Queensland floods and Victorian bushfires, are brutal reminders of nature's devastating power. Is global warming increasing the rate of natural disasters? What part do La Niña and El Niño play in the extreme weather cycle? Cyclones, floods, severe storms, bushfires, landslides, earthquakes, tsunamis - what are the natural and man-made causes of these phenomena, how predictable are they, and how prepared are we for the impacts of natural dis

  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. Predicting Predictable about Natural Catastrophic Extremes

    Science.gov (United States)

    Kossobokov, Vladimir

    2015-04-01

    By definition, an extreme event is rare one in a series of kindred phenomena. Usually (e.g. in Geophysics), it implies investigating a small sample of case-histories with a help of delicate statistical methods and data of different quality, collected in various conditions. Many extreme events are clustered (far from independent) and follow fractal or some other "strange" distribution (far from uniform). Evidently, such an "unusual" situation complicates search and definition of reliable precursory behaviors to be used for forecast/prediction purposes. Making forecast/prediction claims reliable and quantitatively probabilistic in the frames of the most popular objectivists' viewpoint on probability requires a long series of "yes/no" forecast/prediction outcomes, which cannot be obtained without an extended rigorous test of the candidate method. The set of errors ("success/failure" scores and space-time measure of alarms) and other information obtained in such a control test supplies us with data necessary to judge the candidate's potential as a forecast/prediction tool and, eventually, to find its improvements. This is to be done first in comparison against random guessing, which results confidence (measured in terms of statistical significance). Note that an application of the forecast/prediction tools could be very different in cases of different natural hazards, costs and benefits that determine risks, and, therefore, requires determination of different optimal strategies minimizing reliable estimates of realistic levels of accepted losses. In their turn case specific costs and benefits may suggest a modification of the forecast/prediction tools for a more adequate "optimal" application. Fortunately, the situation is not hopeless due to the state-of-the-art understanding of the complexity and non-linear dynamics of the Earth as a Physical System and pattern recognition approaches applied to available geophysical evidences, specifically, when intending to predict

  5. Geophysical Hazards and Preventive Disaster Management of Extreme Natural Events

    Science.gov (United States)

    Ismail-Zadeh, A.; Takeuchi, K.

    2007-12-01

    Geophysical hazard is potentially damaging natural event and/or phenomenon, which may cause the loss of life or injury, property damage, social and economic disruption, or environmental degradation. Extreme natural hazards are a key manifestation of the complex hierarchical nonlinear Earth system. An understanding, accurate modeling and forecasting of the extreme hazards are most important scientific challenges. Several recent extreme natural events (e.g., 2004 Great Indian Ocean Earthquake and Tsunami and the 2005 violent Katrina hurricane) demonstrated strong coupling between solid Earth and ocean, and ocean and atmosphere. These events resulted in great humanitarian tragedies because of a weak preventive disaster management. The less often natural events occur (and the extreme events are rare by definition), the more often the disaster managers postpone the preparedness to the events. The tendency to reduce the funding for preventive disaster management of natural catastrophes is seldom follows the rules of responsible stewardship for future generations neither in developing countries nor in highly developed economies where it must be considered next to malfeasance. Protecting human life and property against earthquake disasters requires an uninterrupted chain of tasks: from (i) understanding of physics of the events, analysis and monitoring, through (ii) interpretation, modeling, hazard assessment, and prediction, to (iii) public awareness, preparedness, and preventive disaster management.

  6. Stability of extremal metrics under complex deformations

    CERN Document Server

    Rollin, Yann; Tipler, Carl

    2011-01-01

    Let $(\\mathcal {X},\\Omega)$ be a closed polarized complex manifold, $g$ be an extremal metric on $\\mathcal X$ that represents the K\\"ahler class $\\Omega$, and $G$ be a compact connected subgroup of the isometry group $Isom(\\mathcal{X},g)$. Assume that the Futaki invariant relative to $G$ is nondegenerate at $g$. Consider a smooth family $(\\mathcal{M}\\to B)$ of polarized complex deformations of $(\\mathcal{X},\\Omega)\\simeq (\\mathcal{M}_0,\\Theta_0)$ provided with a holomorphic action of $G$. Then for every $t\\in B$ sufficiently small, there exists an $h^{1,1}(\\cX)$-dimensional family of extremal K\\"ahler metrics on $\\mathcal{M}_t$ whose K\\"ahler classes are arbitrarily close to $\\Theta_t$. We apply this deformation theory to analyze the Mukai-Umemura 3-fold and its complex deformations. In particular, we prove that there are certain complex deformation of the Mukai-Umemura 3-folds which have extremal metric of non constant scalar curvature with Kaehler class $c_1$.

  7. 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

  8. Nonthermal nature of extremal Kerr black holes

    CERN Document Server

    Rothman, T

    2000-01-01

    Liberati, Rothman and Sonego have recently showed that objects collapsing into extremal Reissner-Nordstrom black holes do not behave as thermal objects at any time in their history. In particular, a temperature, and hence thermodynamic entropy, are undefined for them. I demonstrate that the analysis goes through essentially unchanged for Kerr black holes.

  9. Nonthermal nature of incipient extremal black holes

    Science.gov (United States)

    Liberati, Stefano; Rothman, Tony; Sonego, Sebastiano

    2000-07-01

    We examine particle production from spherical bodies collapsing into extremal Reissner-Nordström black holes. Kruskal coordinates become ill defined in the extremal case, but we are able to find a simple generalization of them that is good in this limit. The extension allows us to calculate the late-time world line of the center of the collapsing star, thus establishing a correspondence with a uniformly accelerated mirror in Minkowski spacetime. The spectrum of created particles associated with such uniform acceleration is nonthermal, indicating that a temperature is not defined. Moreover, the spectrum contains a constant that depends on the history of the collapsing object. At first sight this points to a violation of the no-hair theorems; however, the expectation value of the stress-energy-momentum tensor is zero and its variance vanishes as a power law at late times. Hence, both the no-hair theorems and the cosmic censorship conjecture are preserved. The power-law decay of the variance is in distinction to the exponential falloff of a nonextremal black hole. Therefore, although the vanishing of the stress tensor's expectation value is consistent with a thermal state at zero temperature, the incipient black hole does not behave as a thermal object at any time and cannot be regarded as the thermodynamic limit of a nonextremal black hole, regardless of the fact that the final product of collapse is quiescent.

  10. Nonthermal nature of incipient extremal black holes

    CERN Document Server

    Liberati, S; Sonego, S

    2000-01-01

    We examine particle production from spherical bodies collapsing into extremalReissner-Nordstr\\"om black holes. Kruskal coordinates become ill-defined in theextremal case, but we are able to find a simple generalization of them that isgood in this limit. The extension allows us to calculate the late-timeworldline of the center of the collapsing star, thus establishing acorrespondence with a uniformly accelerated mirror in Minkowski spacetime. Thespectrum of created particles associated with such uniform acceleration isnonthermal, indicating that a temperature is not defined. Moreover, thespectrum contains a constant that depends on the history of the collapsingobject. At first sight this points to a violation of the no-hair theorems;however, the expectation value of the stress-energy-momentum tensor is zero andits variance vanishes as a power law at late times. Hence, both the no-hairtheorems and the cosmic censorship conjecture are preserved. Furthermore,because the incipient black hole does not behave as a t...

  11. 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.

  12. Dancing with Nature: Rhythm and Harmony in Extreme Sport Participation

    Science.gov (United States)

    Brymer, Eric; Gray, Tonia

    2009-01-01

    Research on extreme sports has downplayed the importance of the athletes' connection to the natural world. This neglect stems, in part, from the assumption that these activities derive their meaning primarily from risk. The authors' long-term research reveals that the interplay between adventure athletes and the natural world is, in fact, crucial…

  13. PRACE resources to study extreme natural events: the SCENE project

    Science.gov (United States)

    Fiori, Elisabetta; Galizia, Antonella; Danovaro, Emanuele; Clematis, Andrea; Bedrina, Tatiana; Parodi, Antonio

    2014-05-01

    Forecasting severe storms and floods is one of the main challenges of 21th century. Floods are the most dangerous meteorological hazard in the Mediterranean basins due to both the number of people affected and to the relatively high frequency by which human activities and goods suffer damages and losses. The numerical simulations of extreme events which happen over small basins as the Mediterranean ones are need a very fine-resolution in space and time and as a consequence considerable memory and computational power are required. Since the resources provided by the PRACE project represent the solution for satisfying such requirements, the Super Computing of Extreme Natural Events (SCENE) project has been proposed. SCENE aims to provide an advanced understanding of the intrinsic predictability of severe precipitation processes and the associated predictive ability of high-resolution meteorological models with a special focus on flash flood-producing storms in regions of complex orography (e.g. Mediterranean area) through the assessment of the role of both the convective and microphysical processes. The meteorological model considered in the project is the Weather Research and Forecasting (WRF) model, a state of the art mesoscale numerical weather prediction system designed to serve both operational forecasting and atmospheric research needs. Thus, among all the parameterizations available in the WRF model, the WRF Single-Moment 6-Class Scheme and the Thompson microphysics scheme will be adopted for the numerical simulations in combination with three different approaches for the treatment of the convective processes, that is the use of explicit method, Betts-Miller-Janjic Scheme and Kain-Fritsch. As for flash-flood producing storms, the project considers the recent sequence of extreme events occurred in the north-western portion of the Mediterranean sea; some of these events are the so-called critical cases of the DRIHM project (www.drihm.eu), i.e. selected severe

  14. Methane Leaks from Natural Gas Systems Follow Extreme Distributions.

    Science.gov (United States)

    Brandt, Adam R; Heath, Garvin A; Cooley, Daniel

    2016-11-15

    Future energy systems may rely on natural gas as a low-cost fuel to support variable renewable power. However, leaking natural gas causes climate damage because methane (CH4) has a high global warming potential. In this study, we use extreme-value theory to explore the distribution of natural gas leak sizes. By analyzing ∼15 000 measurements from 18 prior studies, we show that all available natural gas leakage data sets are statistically heavy-tailed, and that gas leaks are more extremely distributed than other natural and social phenomena. A unifying result is that the largest 5% of leaks typically contribute over 50% of the total leakage volume. While prior studies used log-normal model distributions, we show that log-normal functions poorly represent tail behavior. Our results suggest that published uncertainty ranges of CH4 emissions are too narrow, and that larger sample sizes are required in future studies to achieve targeted confidence intervals. Additionally, we find that cross-study aggregation of data sets to increase sample size is not recommended due to apparent deviation between sampled populations. Understanding the nature of leak distributions can improve emission estimates, better illustrate their uncertainty, allow prioritization of source categories, and improve sampling design. Also, these data can be used for more effective design of leak detection technologies.

  15. Strong asymptotics for Lp extremal polynomials off a complex curve

    Directory of Open Access Journals (Sweden)

    Rabah Khaldi

    2004-01-01

    Full Text Available We study the asymptotic behavior of Lp(σ extremal polynomials with respect to a measure of the form σ=α+γ, where α is a measure concentrated on a rectifiable Jordan curve in the complex plane and γ is a discrete measure concentrated on an infinite number of mass points.

  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. Safety evaluation of natural flavour complexes

    NARCIS (Netherlands)

    Smith, R.L.; Adams, T.B.; Cohen, S.M.; Doull, J.; Feron, V.J.; Goodman, J.I.; Hall, R.L.; Marnett, L.J.; Portoghese, P.S.; Waddell, W.J.; Wagner, B.M.

    2004-01-01

    Natural flavour complexes (NFCs) are chemical mixtures obtained by applying physical separation methods to botanical sources. Many NFCs are derived from foods. In the present paper, a 12-step procedure for the safety evaluation of NFCs, 'the naturals paradigm', is discussed. This procedure, which is

  18. Safety evaluation of natural flavour complexes

    NARCIS (Netherlands)

    Smith, R.L.; Adams, T.B.; Cohen, S.M.; Doull, J.; Feron, V.J.; Goodman, J.I.; Hall, R.L.; Marnett, L.J.; Portoghese, P.S.; Waddell, W.J.; Wagner, B.M.

    2004-01-01

    Natural flavour complexes (NFCs) are chemical mixtures obtained by applying physical separation methods to botanical sources. Many NFCs are derived from foods. In the present paper, a 12-step procedure for the safety evaluation of NFCs, 'the naturals paradigm', is discussed. This procedure, which is

  19. Complexity measurement of natural and artificial languages

    CERN Document Server

    Febres, Gerardo; Gershenson, Carlos

    2013-01-01

    We compared entropy for texts written in natural languages (English, Spanish) and artificial languages (computer software) based on a simple expression for the entropy as a function of message length and specific word diversity. Code text written in artificial languages showed higher entropy than text of similar length expressed in natural languages. Spanish texts exhibit more symbolic diversity than English ones. Results showed that algorithms based on complexity measures differentiate artificial from natural languages, and that text analysis based on complexity measures allows the unveiling of important aspects of their nature. We propose specific expressions to examine entropy related aspects of tests and estimate the values of entropy, emergence, self-organization and complexity based on specific diversity and message length.

  20. Local Natural Connectivity in Complex Networks

    Institute of Scientific and Technical Information of China (English)

    SHANG Yi-Lun

    2011-01-01

    @@ In network theory, a complex network represents a system whose evolving structure and dynamic behavior contribute to its robustness.The natural connectivity is recently proposed as a spectral measure to characterize the robustness of complex networks.We decompose the natural connectivity of a network as local natural connectivity of its connected components and quantify their contributions to the network robustness.In addition, we compare the natural connectivity of a network with that of an induced subgraph of it based on interlacing theorems.As an application, we derive an inequality for eigenvalues of ErdSs-Renyi random graphs.%In network theory, a complex network represents a system whose evolving structure and dynamic behavior contribute to its robustness. The natural connectivity is recently proposed as a spectral measure to characterize the robustness of complex networks. We decompose the natural connectivity of a network as local naturai connectivity of its connected components and quantify their contributions to the network robustness. In addition, we compare the naturai connectivity of a network with that of an induced subgraph of it based on interlacing theorems. As an application, we derive an inequality for eigenvalues of Erdos-Renyi random graphs.

  1. Complex network based techniques to identify extreme events and (sudden) transitions in spatio-temporal systems

    CERN Document Server

    Marwan, Norbert

    2015-01-01

    We present here two promising techniques for the application of the complex network approach to continuous spatio-temporal systems that have been developed in the last decade and show large potential for future application and development of complex systems analysis. First, we discuss the transforming of a time series from such systems to a complex network. The natural approach is to calculate the recurrence matrix and interpret such as the adjacency matrix of an associated complex network, called recurrence network. Using complex network measures, such as transitivity coefficient, we demonstrate that this approach is very efficient for identifying qualitative transitions in observational data, e.g., when analyzing paleoclimate regime transitions. Second, we demonstrate the use of directed spatial networks constructed from spatio-temporal measurements of such systems that can be derived from the synchronized-in-time occurrence of extreme events in different spatial regions. Although there are many possibiliti...

  2. 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.

  3. 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.

  4. New Clues on the Nature of Extremely Red Galaxies

    CERN Document Server

    Cimatti, A; Alighieri, S S; Pozzetti, L; Mannucci, F; Renzini, A; Oliva, E; Zamorani, G; Andreani, P; Röttgering, H J A

    1999-01-01

    We present near-infrared VLT-UT1+ISAAC spectroscopy of a sample of 9 extremely red galaxies (ERGs) with R-K>5 and K0.8. We discuss the general implications of our findings in relation with the problem of the formation of early type galaxies.

  5. Tardigrades living in extreme environments have naturally selected prerequisites useful to space conquer

    Science.gov (United States)

    Guidetti, Roberto; Tiziana, Altiero; Cesari, Michele; Rizzo, Angela Maria; Bertolani, Roberto; Galletta, Giuseppe; Dalessandro, Maurizio; Rebecchi, Lorena

    Extreme habitats are highly selective and can host only living organisms possessing specific adaptations to stressors. Among extreme habitats, space environment has particular charac-teristics of radiations, vacuum, microgravity and temperature, which induce rapid changes in living systems. Consequently, the response of multicellular complex organisms, able to colo-nize extreme environments, to space stresses can give very useful information on the ability to withstand a single stress or stress combinations. This knowledge on changes in living systems in space, with their similarity to the ageing processes, offers the opportunity to improve human life both on Earth and in space. Even though experimentation in space has often been carried out using unicellular organisms, multicellular organisms are very relevant in order to develop the appropriate countermeasures to avoid the risks imposed by environmental space in humans. The little attention received by multicellular organisms is probably due, other than to difficul-ties in the manipulation of biological materials in space, to the presence of only few organisms with the potential to tolerate environmental space stresses. Among them, tardigrades are small invertebrates representing an attractive animal model to study adaptive strategies for surviving extreme environments, including space environment. Tardigrades are little known microscopic aquatic animals (250-800 m in body length) distributed in different environments (from the deep sea to high mountains and deserts all over the world), and frequently inhabiting very unstable and unpredictable habitats (e.g. interstices of mosses, lichens, leaf litter, freshwater ponds, cryoconite holes). Their ability to live in the extreme environments is related to a wide variety of their life histories and adaptive strategies. A widespread and crucial strategy is cryptobiosis, a form of quiescence. It includes strategies such as anhydrobiosis and cryobiosis, characterized by

  6. Nature of the Extreme Ultraluminous X-ray Sources

    CERN Document Server

    Wiktorowicz, Grzegorz; Sadowski, Aleksander; Belczynski, Krzysztof

    2015-01-01

    In this proof-of-concept study we demonstrate how a binary system can easily form an extreme ULX source with the X-ray luminosity of L_x > 10^42 erg/s. Formation efficiencies and lifetimes of such objects are high enough to potentially explain all observed extreme ULXs. These systems are not only limited to binaries with stellar-origin black hole accretors. Noteworthy, we have also identified such objects with neutron stars. Typically, a 10 Msun black hole is fed by a massive (~10 Msun) Hertzsprung gap donor with Roche lobe overflow rate of ~10^-3 Msun/yr (~2600 Mdot_Edd). For neutron star systems the typical donors are evolved low-mass (~2 Msun) helium stars with Roche lobe overflow rate of ~10^-2 Msun/yr. We base our study purely on the available Roche lobe overflow rate in a binary system and show that if only even a small fraction (>10^-3) of the overflow reaches the BH, the source will be super-Eddington. Our study does not prove that any particular extreme ULX (e.g., HLX-1) is a regular binary system wi...

  7. 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

  8. Extreme events in multilayer, interdependent complex networks and control

    Science.gov (United States)

    Chen, Yu-Zhong; Huang, Zi-Gang; Zhang, Hai-Feng; Eisenberg, Daniel; Seager, Thomas P.; Lai, Ying-Cheng

    2015-11-01

    We investigate the emergence of extreme events in interdependent networks. We introduce an inter-layer traffic resource competing mechanism to account for the limited capacity associated with distinct network layers. A striking finding is that, when the number of network layers and/or the overlap among the layers are increased, extreme events can emerge in a cascading manner on a global scale. Asymptotically, there are two stable absorption states: a state free of extreme events and a state of full of extreme events, and the transition between them is abrupt. Our results indicate that internal interactions in the multiplex system can yield qualitatively distinct phenomena associated with extreme events that do not occur for independent network layers. An implication is that, e.g., public resource competitions among different service providers can lead to a higher resource requirement than naively expected. We derive an analytical theory to understand the emergence of global-scale extreme events based on the concept of effective betweenness. We also articulate a cost-effective control scheme through increasing the capacity of very few hubs to suppress the cascading process of extreme events so as to protect the entire multi-layer infrastructure against global-scale breakdown.

  9. Complex multifractal nature in Mycobacterium tuberculosis genome

    Science.gov (United States)

    Mandal, Saurav; Roychowdhury, Tanmoy; Chirom, Keilash; Bhattacharya, Alok; Brojen Singh, R. K.

    2017-04-01

    The mutifractal and long range correlation (C(r)) properties of strings, such as nucleotide sequence can be a useful parameter for identification of underlying patterns and variations. In this study C(r) and multifractal singularity function f(α) have been used to study variations in the genomes of a pathogenic bacteria Mycobacterium tuberculosis. Genomic sequences of M. tuberculosis isolates displayed significant variations in C(r) and f(α) reflecting inherent differences in sequences among isolates. M. tuberculosis isolates can be categorised into different subgroups based on sensitivity to drugs, these are DS (drug sensitive isolates), MDR (multi-drug resistant isolates) and XDR (extremely drug resistant isolates). C(r) follows significantly different scaling rules in different subgroups of isolates, but all the isolates follow one parameter scaling law. The richness in complexity of each subgroup can be quantified by the measures of multifractal parameters displaying a pattern in which XDR isolates have highest value and lowest for drug sensitive isolates. Therefore C(r) and multifractal functions can be useful parameters for analysis of genomic sequences.

  10. Natural Time Analysis and Complex Networks

    Science.gov (United States)

    Sarlis, Nicholas; Skordas, Efthimios; Lazaridou, Mary; Varotsos, Panayiotis

    2013-04-01

    Here, we review the analysis of complex time series in a new time domain, termed natural time, introduced by our group [1,2]. This analysis conforms to the desire to reduce uncertainty and extract signal information as much as possible [3]. It enables [4] the distinction between the two origins of self-similarity when analyzing data from complex systems, i.e., whether self-similarity solely results from long-range temporal correlations (the process's memory only) or solely from the process's increments infinite variance (heavy tails in their distribution). Natural time analysis captures the dynamical evolution of a complex system and identifies [5] when the system enters a critical stage. Hence, this analysis plays a key role in predicting forthcoming catastrophic events in general. Relevant examples, compiled in a recent monograph [6], have been presented in diverse fields, including Solid State Physics [7], Statistical Physics (for example systems exhibiting self-organized criticality [8]), Cardiology [9,10], Earth Sciences [11] (Geophysics, Seismology), Environmental Sciences (e.g. see Ref. [12]), etc. Other groups have proposed and developed a network approach to earthquake events with encouraging results. A recent study [13] reveals that this approach is strengthened if we combine it with natural time analysis. In particular, we find [13,14] that the study of the spatial distribution of the variability [15] of the order parameter fluctuations, defined in natural time, provides important information on the dynamical evolution of the system. 1. P. Varotsos, N. Sarlis, and E. Skordas, Practica of Athens Academy, 76, 294-321, 2001. 2. P.A. Varotsos, N.V. Sarlis, and E.S. Skordas, Phys. Rev. E, 66, 011902 , 2002. 3. S. Abe, N.V. Sarlis, E.S. Skordas, H.K. Tanaka and P.A. Varotsos, Phys. Rev. Lett. 94, 170601, 2005. 4. P.A. Varotsos, N.V. Sarlis, E.S. Skordas, H.K. Tanaka and M.S. Lazaridou, Phys. Rev. E, 74, 021123, 2006. 5. P.Varotsos, N. V. Sarlis, E. S. Skordas

  11. Predicting climate extremes – a complex network approach

    Directory of Open Access Journals (Sweden)

    M. Weimer

    2015-10-01

    Full Text Available Regional decadal predictions have emerged in the past few years as a research field with high application potential, especially for extremes like heat and drought periods. However, up to now the prediction skill of decadal hindcasts, as evaluated with standard methods is moderate, and for extreme values even rarely investigated. In this study, we use hindcast data from a regional climate model (CCLM for 8 regions in Europe to construct time evolving climate networks and use the network correlation threshold (link strength as a predictor for heat periods. We show that the skill of the network measure to predict the low frequency dynamics of heat periods is similar to the one of the standard approach, with the potential of being even better in some regions.

  12. Extreme sensory processing patterns show a complex association with depression, and impulsivity, alexithymia, and hopelessness.

    Science.gov (United States)

    Serafini, Gianluca; Gonda, Xenia; Canepa, Giovanna; Pompili, Maurizio; Rihmer, Zoltan; Amore, Mario; Engel-Yeger, Batya

    2017-03-01

    The involvement of extreme sensory processing patterns, impulsivity, alexithymia, and hopelessness was hypothesized to contribute to the complex pathophysiology of major depression and bipolar disorder. However, the nature of the relation between these variables has not been thoroughly investigated. This study aimed to explore the association between extreme sensory processing patterns, impulsivity, alexithymia, depression, and hopelessness. We recruited 281 euthymic participants (mean age=47.4±12.1) of which 62.3% with unipolar major depression and 37.7% with bipolar disorder. All participants completed the Adolescent/Adult Sensory Profile (AASP), Toronto Alexithymia Scale (TAS-20), second version of the Beck Depression Inventory (BDI-II), Barratt Impulsivity Scale (BIS), and Beck Hopelessness Scale (BHS). Lower registration of sensory input showed a significant correlation with depression, impulsivity, attentional/motor impulsivity, and alexithymia. It was significantly more frequent among participants with elevated hopelessness, and accounted for 22% of the variance in depression severity, 15% in greater impulsivity, 36% in alexithymia, and 3% in hopelessness. Elevated sensory seeking correlated with enhanced motor impulsivity and decreased non-planning impulsivity. Higher sensory sensitivity and sensory avoiding correlated with depression, impulsivity, and alexithymia. The study was limited by the relatively small sample size and cross-sectional nature of the study. Furthermore, only self-report measures that may be potentially biased by social desirability were used. Extreme sensory processing patterns, impulsivity, alexithymia, depression, and hopelessness may show a characteristic pattern in patients with major affective disorders. The careful assessment of sensory profiles may help in developing targeted interventions and improve functional/adaptive strategies. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Approach of Complexity in Nature: Entropic Nonuniqueness

    Directory of Open Access Journals (Sweden)

    Constantino Tsallis

    2016-08-01

    Full Text Available Boltzmann introduced in the 1870s a logarithmic measure for the connection between the thermodynamical entropy and the probabilities of the microscopic configurations of the system. His celebrated entropic functional for classical systems was then extended by Gibbs to the entire phase space of a many-body system and by von Neumann in order to cover quantum systems, as well. Finally, it was used by Shannon within the theory of information. The simplest expression of this functional corresponds to a discrete set of W microscopic possibilities and is given by S B G = − k ∑ i = 1 W p i ln p i (k is a positive universal constant; BG stands for Boltzmann–Gibbs. This relation enables the construction of BGstatistical mechanics, which, together with the Maxwell equations and classical, quantum and relativistic mechanics, constitutes one of the pillars of contemporary physics. The BG theory has provided uncountable important applications in physics, chemistry, computational sciences, economics, biology, networks and others. As argued in the textbooks, its application in physical systems is legitimate whenever the hypothesis of ergodicity is satisfied, i.e., when ensemble and time averages coincide. However, what can we do when ergodicity and similar simple hypotheses are violated, which indeed happens in very many natural, artificial and social complex systems. The possibility of generalizing BG statistical mechanics through a family of non-additive entropies was advanced in 1988, namely S q = k 1 − ∑ i = 1 W p i q q − 1 , which recovers the additive S B G entropy in the q→ 1 limit. The index q is to be determined from mechanical first principles, corresponding to complexity universality classes. Along three decades, this idea intensively evolved world-wide (see the Bibliography in http://tsallis.cat.cbpf.br/biblio.htm and led to a plethora of predictions, verifications and applications in physical systems and elsewhere. As expected

  14. 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

  15. 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

  16. Ensuring Resilience of Natural Resources under Exposure to Extreme Climate Events

    OpenAIRE

    Brent Jacobs; Louise Boronyak-Vasco; Kristy Moyle; Peat Leith

    2016-01-01

    Natural resources directly support rural livelihoods and underpin much of the wealth of rural and regional Australia. Climate change manifesting as increasing frequency and or severity of extreme weather events poses a threat to sustainable management of natural resources because the recurrence of events may exceed the resilience of natural systems or the coping capacity of social systems. We report the findings of a series of participatory workshops with communities in eight discrete landsca...

  17. 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.

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

    Science.gov (United States)

    Smolka, Anselm

    2006-08-15

    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

  19. 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

  20. Complex links between natural tuberculosis and porcine circovirus type 2 infection in wild boar

    OpenAIRE

    Iratxe Díez-Delgado; Mariana Boadella; MariPaz Martín-Hernando; José Angel Barasona; Beatriz Beltrán-Beck; David González-Barrio; Marina Sibila; Joaquín Vicente; Garrido, Joseba M; Joaquim Segalés; Christian Gortazar

    2014-01-01

    Individuals in natural populations are exposed to a diversity of pathogens which results in coinfections. The aim of this study was to investigate the relation between natural infection with tuberculosis (TB) due to infection by bacteria of the Mycobacterium tuberculosis complex and porcine circovirus type 2 (PCV2) in free-ranging Eurasian wild boar (Sus scrofa). Apparent prevalence for TB lesions and PCV2 infection was extremely high in all age classes, including piglets (51% for TB; 85.7% f...

  1. Complex Estimation Of Natural Resources In Innovative Forms Of Natural Resources Management

    OpenAIRE

    Dmitry Klynovy

    2012-01-01

    The theoretical and methodological base and practical opportunities of the complex estimation of natural resources are determined as a factor of capitalisation of the natural-resources relations in the system of innovative forms of natural resources use.

  2. Ensuring Resilience of Natural Resources under Exposure to Extreme Climate Events

    Directory of Open Access Journals (Sweden)

    Brent Jacobs

    2016-06-01

    Full Text Available Natural resources directly support rural livelihoods and underpin much of the wealth of rural and regional Australia. Climate change manifesting as increasing frequency and or severity of extreme weather events poses a threat to sustainable management of natural resources because the recurrence of events may exceed the resilience of natural systems or the coping capacity of social systems. We report the findings of a series of participatory workshops with communities in eight discrete landscapes in South East New South Wales, Australia. The workshops focused on how natural resource management (NRM is considered in the Prevent-Prepare-Respond-Recover emergency management cycle. We found that NRM is generally considered only in relation to the protection of life and property and not for the intrinsic value of ecosystem services that support communities. We make three recommendations to improve NRM under extreme climate events. Firstly, the support to communities offered by emergency management agencies could be bolstered by guidance material co-produced with government NR agencies. Secondly, financial assistance from government should specifically target the restoration and maintenance of green infrastructure to avoid loss of social-ecological resilience. Thirdly, action by natural resource dependent communities should be encouraged and supported to better protect ecosystem services in preparation for future extreme events.

  3. Adaptation potential of naturally ventilated barns to high temperature extremes: The OptiBarn project

    Science.gov (United States)

    Menz, Christoph

    2016-04-01

    Climate change interferes with various aspects of the socio-economic system. One important aspect is its influence on animal husbandry, especially dairy faming. Dairy cows are usually kept in naturally ventilated barns (NVBs) which are particular vulnerable to extreme events due to their low adaptation capabilities. An effective adaptation to high outdoor temperatures for example, is only possible under certain wind and humidity conditions. High temperature extremes are expected to increase in number and strength under climate change. To assess the impact of this change on NVBs and dairy cows also the changes in wind and humidity needs to be considered. Hence we need to consider the multivariate structure of future temperature extremes. The OptiBarn project aims to develop sustainable adaptation strategies for dairy housings under climate change for Europe, by considering the multivariate structure of high temperature extremes. In a first step we identify various multivariate high temperature extremes for three core regions in Europe. With respect to dairy cows in NVBs we will focus on the wind and humidity field during high temperature events. In a second step we will use the CORDEX-EUR-11 ensemble to evaluate the capability of the RCMs to model such events and assess their future change potential. By transferring the outdoor conditions to indoor climate and animal wellbeing the results of this assessment can be used to develop technical, architectural and animal specific adaptation strategies for high temperature extremes.

  4. Oxomanganese complexes for natural and artificial photosynthesis.

    Science.gov (United States)

    Rivalta, Ivan; Brudvig, Gary W; Batista, Victor S

    2012-04-01

    The oxygen-evolving complex (OEC) of Photosystem II (PSII) is an oxomanganese complex that catalyzes water-splitting into O2, protons and electrons. Recent breakthroughs in X-ray crystallography have resolved the cuboidal OEC structure at 1.9 Å resolution, stimulating significant interest in studies of structure/function relations. This article summarizes recent advances on studies of the OEC along with studies of synthetic oxomanganese complexes for artificial photosynthesis. Quantum mechanics/molecular mechanics hybrid methods have enabled modeling the S1 state of the OEC, including the ligation proposed by the most recent X-ray data where D170 is bridging Ca and the Mn center outside the CaMn3 core. Molecular dynamics and Monte Carlo simulations have explored the structural/functional roles of chloride, suggesting that it regulates the electrostatic interactions between D61 and K317 that might be critical for proton abstraction. Furthermore, structural studies of synthetic oxomanganese complexes, including the [H2O(terpy)MnIII(μ-O)2MnIV(terpy)OH2]3+ (1, terpy=2,2':6',2″-terpyridine) complex, provided valuable insights on the mechanistic influence of carboxylate moieties in close contact with the Mn catalyst during oxygen evolution. Covalent attachment of 1 to TiO2 has been achieved via direct deposition and by using organic chromophoric linkers. The (III,IV) oxidation state of 1 attached to TiO2 can be advanced to (IV,IV) by visible-light photoexcitation, leading to photoinduced interfacial electron transfer. These studies are particularly relevant to the development of artificial photosynthetic devices based on inexpensive materials.

  5. 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.

  6. Observational Constraints of Stellar Collapse: Diagnostic Probes of Nature's Extreme Matter Experiment

    CERN Document Server

    Fryer, C L; Grefenstette, B W; Wong, T -W

    2014-01-01

    Supernovae are Nature's high-energy, high density laboratory experiments, reaching densities in excess of nuclear densities and temperatures above 10MeV. 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 needed to use them to learn about the supernova engine, and ultimate nuclear physics.

  7. Limits to the thermal tolerance of corals adapted to a highly fluctuating, naturally extreme temperature environment

    Science.gov (United States)

    Schoepf, Verena; Stat, Michael; Falter, James L.; McCulloch, Malcolm T.

    2015-12-01

    Naturally extreme temperature environments can provide important insights into the processes underlying coral thermal tolerance. We determined the bleaching resistance of Acropora aspera and Dipsastraea sp. from both intertidal and subtidal environments of the naturally extreme Kimberley region in northwest Australia. Here tides of up to 10 m can cause aerial exposure of corals and temperatures as high as 37 °C that fluctuate daily by up to 7 °C. Control corals were maintained at ambient nearshore temperatures which varied diurnally by 4-5 °C, while treatment corals were exposed to similar diurnal variations and heat stress corresponding to ~20 degree heating days. All corals hosted Symbiodinium clade C independent of treatment or origin. Detailed physiological measurements showed that these corals were nevertheless highly sensitive to daily average temperatures exceeding their maximum monthly mean of ~31 °C by 1 °C for only a few days. Generally, Acropora was much more susceptible to bleaching than Dipsastraea and experienced up to 75% mortality, whereas all Dipsastraea survived. Furthermore, subtidal corals, which originated from a more thermally stable environment compared to intertidal corals, were more susceptible to bleaching. This demonstrates that while highly fluctuating temperatures enhance coral resilience to thermal stress, they do not provide immunity to extreme heat stress events.

  8. Limits to the thermal tolerance of corals adapted to a highly fluctuating, naturally extreme temperature environment.

    Science.gov (United States)

    Schoepf, Verena; Stat, Michael; Falter, James L; McCulloch, Malcolm T

    2015-12-02

    Naturally extreme temperature environments can provide important insights into the processes underlying coral thermal tolerance. We determined the bleaching resistance of Acropora aspera and Dipsastraea sp. from both intertidal and subtidal environments of the naturally extreme Kimberley region in northwest Australia. Here tides of up to 10 m can cause aerial exposure of corals and temperatures as high as 37 °C that fluctuate daily by up to 7 °C. Control corals were maintained at ambient nearshore temperatures which varied diurnally by 4-5 °C, while treatment corals were exposed to similar diurnal variations and heat stress corresponding to ~20 degree heating days. All corals hosted Symbiodinium clade C independent of treatment or origin. Detailed physiological measurements showed that these corals were nevertheless highly sensitive to daily average temperatures exceeding their maximum monthly mean of ~31 °C by 1 °C for only a few days. Generally, Acropora was much more susceptible to bleaching than Dipsastraea and experienced up to 75% mortality, whereas all Dipsastraea survived. Furthermore, subtidal corals, which originated from a more thermally stable environment compared to intertidal corals, were more susceptible to bleaching. This demonstrates that while highly fluctuating temperatures enhance coral resilience to thermal stress, they do not provide immunity to extreme heat stress events.

  9. Natural and artefactual aneuploidy in human lymphocytes in extreme old age.

    Science.gov (United States)

    Lezhava, T; Khmaladze, E; Lokhadze, T; Buadze, T

    2008-04-01

    At present it is generally believed that aging is accompanied by an increase in the numbers of cells with altered chromosome sets. However, the problem of aneuploidy in extreme old age (80 years and over) has hardly been subjected to systematic investigation. The purpose of this study was to examine quantitative chromosome changes and relationship between "artefactual" and "natural" aneuploidy in subjects from 80 to 114 years of age using karyotype analyses. Chromosomes were studied in 1136 karyotypes of relatively round metaphases from 40 lymphocyte cultures obtained from 40 apparently normal subjects aged from 80 to 114 ( including 26 men and 14 women). 964 karyotypes from 48 donors aged 20 to 48 served as control. Lymphocytes were cultivation by modification method (Lezhava, 2006). It is suggested that the probability of natural aneuploidy rises substantially among elderly women; while that of artefactual aneuploidy is increased among elderly men; the problem of natural aneuploidy in males remains unclear.

  10. 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.

  11. Dismounted complex blast injuries: patterns of injuries and resource utilization associated with the multiple extremity amputee.

    Science.gov (United States)

    Fleming, Mark; Waterman, Scott; Dunne, James; D'Alleyrand, Jean-Claude; Andersen, Romney C

    2012-01-01

    The objective of this report is to analyze the resource utilization and injury patterns of complex dismounted blast injuries. A retrospective review of U.S. service members injured in combat between 2007 and 2010 was conducted. Data analyzed included age, injury mechanism, amputated limbs, number and type of associated injuries, blood products utilized, intensive care unit length of stay (ILOS), hospital length of stay (HLOS) and the Injury Severity Score (ISS). Patients were stratified based on the number of amputations. Sixty-three patients comprised the multiple extremity amputation (MEA) group. Ninety-eight percent sustained injuries from an improvised explosive device (IED) and 96% were dismounted. The ISS, number of surgical encounters, blood products utilized and ILOS were all clinically significantly different than controls. Care of multiple extremity amputees involves the utilization of significant resources. This knowledge may better help surgeons and administrators allocate assets at hospitals, both military and civilian, who care for this complex and challenging patient population.

  12. Targeted isolation of proteins from natural microbial communities living in an extreme environment.

    Science.gov (United States)

    Singer, Steven W

    2012-01-01

    Microorganisms from extreme environments are often very difficult to cultivate, precluding detailed study by biochemical and physiological techniques. Recent advances in genomic sequencing and proteomic measurements of samples obtained from natural communities have allowed new access to these uncultivated extremophiles and identified abundant proteins that can be isolated directly from natural samples. Here we report the isolation of two abundant heme proteins from low-diversity biofilm microbial communities that thrive in very acidic (pH ~ 1), metal-rich water in a subsurface mine. Purification and detailed characterization of these proteins has afforded new insight into the possible mechanism of Fe(II) oxidation by Leptospirillum Group II, the dominant population in most of these biofilms, and demonstrated that the abundance and posttranslational modifications of one of these proteins is dependent on the lifecycle of the biofilm.

  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. Impact of the extreme 2009 wildfire Victoria the wettability of naturally highly water repellent soils

    Science.gov (United States)

    Doerr, Stefan H.; Shakesby, Richard A.; Sheridan, Gary J.; Lane, Patrick Nj; Smith, Hugh G.; Bell, Tina; Blake, William H.

    2010-05-01

    The recent catastrophic wildfires near Melbourne, which peaked on Feb. 7 2009, burned ca 400,000 ha and caused the tragic loss of 173 people. They occurred during unprecedented extreme fire weather where dry northerly winds gusting up to 100 km/h coincided with the highest temperatures ever recorded in this region. These conditions, combined with the very high biomass of mature eucalypt forests, very low fuel moisture conditions and steep slopes, generated extreme burning conditions. A rapid response project was launched under the NERC Urgency Scheme aimed at determining the effects of this extreme event on soil properties. Three replicate sites each were sampled for extremely high burn severity, high burn severity and unburnt control terrain, within mature mixed-species eucalypt forests near Marysville in April 2009. Ash and surface soil (0-2.5 cm and 2.5-5 cm) were collected at 20 sample grid points at each site. Here we report on outcomes from Water Drop Penetration Time (WDPT) tests carried out on soil samples to determine the impact of this extreme event on the wettability of a naturally highly water repellent soil. Field assessment suggested that the impact of this extreme wildfire on the soil was less than might be supposed given the extreme burn severity (indicated by the complete elimination of the ground vegetation). This was confirmed by the laboratory results. No major difference in WDPT was detected between (i) burned and control samples, and (ii) between surface and subsurface WDPT patterns, indicating that soil temperatures in the top 0-2.5 cm did not exceed ~200° C. Seedling germination in burned soil was reduced by at least 2/3 compared to the control samples, however, this reduction is indicative an only modest heat input into the soil. The limited heat input into the soil stands in stark contrast to the extreme burn severity (based on vegetation destruction parameters). We speculate that limited soil heating resulted perhaps from the unusually

  15. 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.

  16. 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…

  17. 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…

  18. 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.

  19. Investigation of vegetation-induced drag parameterizations for natural and nature-based extreme events coastal protection in the Chesapeake Bay

    Science.gov (United States)

    Maldonado, S.; Suckale, J.; Ferreira, C.; Arkema, K.

    2016-12-01

    Increasing intensity and frequency of extreme meteorological events around the world highlight the need for resilient coastal defenses. For more than a century, it has been recognized that coastal ecosystems such as marshes and mangroves may mitigate the damage caused by natural hazards such as storms. Aquatic vegetation can potentially attenuate waves and currents through drag forces, with strong implications for sediment transport processes and hence morphological evolution. However, although observations exist that support such a theory, an accurate quantification of the protective role of coastal ecosystems remains a standing challenge for the scientific community, which manifests itself in the large, diverse set of available empirical expressions for parameterizing the fluid-vegetation interaction. We propose a comparison of different state-of-the-art parameterizations for the effect of vegetation on hydrodynamics (particularly, the drag coefficient), with varying degrees of complexity and number of required input variables. The inter-comparison of such alternatives, when validated against field data, can lead to a modeling framework that optimizes the trade-offs between complexity, input requirements and uncertainty in the results. We focus our numerical study on storm events in the marshes and wetlands of Chesapeake Bay. We simulate the hydrodynamics via the Non-Linear Shallow Water Equations, which are in turn solved numerically through a Finite Volume scheme. The simulations are complemented by an ongoing 2-years field campaign, where we continuously collect hydrodynamic measurements such as free surface elevation and vertical velocity profiles, biophysical characteristics of the vegetation and high-resolution topo-bathymetric data of the site. Field measurements are used for calibration and validation purposes. We also investigate some implications on sediment transport processes. We expect that results from our study can support policy makers and

  20. Complex extreme learning machine applications in terahertz pulsed signals feature sets.

    Science.gov (United States)

    Yin, X-X; Hadjiloucas, S; Zhang, Y

    2014-11-01

    This paper presents a novel approach to the automatic classification of very large data sets composed of terahertz pulse transient signals, highlighting their potential use in biochemical, biomedical, pharmaceutical and security applications. Two different types of THz spectra are considered in the classification process. Firstly a binary classification study of poly-A and poly-C ribonucleic acid samples is performed. This is then contrasted with a difficult multi-class classification problem of spectra from six different powder samples that although have fairly indistinguishable features in the optical spectrum, they also possess a few discernable spectral features in the terahertz part of the spectrum. Classification is performed using a complex-valued extreme learning machine algorithm that takes into account features in both the amplitude as well as the phase of the recorded spectra. Classification speed and accuracy are contrasted with that achieved using a support vector machine classifier. The study systematically compares the classifier performance achieved after adopting different Gaussian kernels when separating amplitude and phase signatures. The two signatures are presented as feature vectors for both training and testing purposes. The study confirms the utility of complex-valued extreme learning machine algorithms for classification of the very large data sets generated with current terahertz imaging spectrometers. The classifier can take into consideration heterogeneous layers within an object as would be required within a tomographic setting and is sufficiently robust to detect patterns hidden inside noisy terahertz data sets. The proposed study opens up the opportunity for the establishment of complex-valued extreme learning machine algorithms as new chemometric tools that will assist the wider proliferation of terahertz sensing technology for chemical sensing, quality control, security screening and clinic diagnosis. Furthermore, the proposed

  1. Revealing the macromolecular targets of complex natural products

    Science.gov (United States)

    Reker, Daniel; Perna, Anna M.; Rodrigues, Tiago; Schneider, Petra; Reutlinger, Michael; Mönch, Bettina; Koeberle, Andreas; Lamers, Christina; Gabler, Matthias; Steinmetz, Heinrich; Müller, Rolf; Schubert-Zsilavecz, Manfred; Werz, Oliver; Schneider, Gisbert

    2014-12-01

    Natural products have long been a source of useful biological activity for the development of new drugs. Their macromolecular targets are, however, largely unknown, which hampers rational drug design and optimization. Here we present the development and experimental validation of a computational method for the discovery of such targets. The technique does not require three-dimensional target models and may be applied to structurally complex natural products. The algorithm dissects the natural products into fragments and infers potential pharmacological targets by comparing the fragments to synthetic reference drugs with known targets. We demonstrate that this approach results in confident predictions. In a prospective validation, we show that fragments of the potent antitumour agent archazolid A, a macrolide from the myxobacterium Archangium gephyra, contain relevant information regarding its polypharmacology. Biochemical and biophysical evaluation confirmed the predictions. The results obtained corroborate the practical applicability of the computational approach to natural product ‘de-orphaning’.

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

    Directory of Open Access Journals (Sweden)

    Rodica Ioana Lung

    Full Text Available 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.

  3. Analysis of spatial and temporal extreme monsoonal rainfall over South Asia using complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Malik, Nishant [Potsdam Institute for Climate Impact Research, P.O. Box 60 12 03, Potsdam (Germany); University of Potsdam, Institute of Physics, Potsdam-Golm (Germany); Bookhagen, Bodo [University of California Santa Barbara, Department of Geography, Santa Barbara, CA (United States); Marwan, Norbert [Potsdam Institute for Climate Impact Research, P.O. Box 60 12 03, Potsdam (Germany); Kurths, Juergen [Potsdam Institute for Climate Impact Research, P.O. Box 60 12 03, Potsdam (Germany); Humboldt University, Department of Physics, Berlin (Germany)

    2012-08-15

    We present a detailed analysis of summer monsoon rainfall over the Indian peninsular using nonlinear spatial correlations. This analysis is carried out employing the tools of complex networks and a measure of nonlinear correlation for point processes such as rainfall, called event synchronization. This study provides valuable insights into the spatial organization, scales, and structure of the 90th and 94th percentile rainfall events during the Indian summer monsoon (June-September). We furthermore analyse the influence of different critical synoptic atmospheric systems and the impact of the steep Himalayan topography on rainfall patterns. The presented method not only helps us in visualising the structure of the extreme-event rainfall fields, but also identifies the water vapor pathways and decadal-scale moisture sinks over the region. Furthermore a simple scheme based on complex networks is presented to decipher the spatial intricacies and temporal evolution of monsoonal rainfall patterns over the last 6 decades. (orig.)

  4. 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.

  5. Autocatalysis as the Natural Philosophy Underlying Complexity and Biological Evolution

    Directory of Open Access Journals (Sweden)

    Güngör Gündüz

    2011-06-01

    Full Text Available The importance and different aspects of autocatalysis in evolution was analyzed. The behaviour of autocatalytic reactions mainly the Lotka-Volterra and the Schlögl equations were discussed in terms of phase change, entropy, and their oscillation frequency. The increase of complexity as the general direction of evolution was examined on some patterns in terms of both their entropy and information content. In addition, the relation between stability and functionality, stability and cohesion were discussed. It was concluded that evolution drifts in the direction of increasing complexity as a kind of natural philosophy to counteract the increase of entropy in the universe.

  6. 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

  7. The natural history of epilepsy in tuberous sclerosis complex

    OpenAIRE

    Chu, Catherine Jean; Major, Philippe; Camposano, Susana; Muzykewicz, David; Thiele, Elizabeth Anne

    2009-01-01

    Background: Although epilepsy affects most patients with tuberous sclerosis complex (TSC), little is known about the natural history of epilepsy in this genetic disease. Methods: A retrospective chart review of all patients with TSC seen between January 2002 and October 2008. Charts were reviewed for a history of infantile spasms (IS), seizure other than IS, refractory epilepsy, Lennox-Gastaut syndrome (LGS), anticonvulsant medication use, ages of seizure onset, last seizure, last clinic ...

  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. 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

    The majority of experimental studies of the effects of population bottlenecks on fitness are performed under laboratory conditions, which do not account for the environmental complexity that populations face in nature. In this study, we test inbreeding depression in multiple replicates of inbred...... 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...... 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...

  10. A Structural Algorithm for Complex Natural Languages Parse Generation

    Directory of Open Access Journals (Sweden)

    Enikuomehin, A. O.

    2013-06-01

    Full Text Available In artificial intelligence, the study of how humans understand natural languages is cognitive based and such science is essential in the development of a modern day embedded robotic systems. Such systems should have the capability to process natural languages and generate meaningful output. As against machines, humans have the ability to understand a natural language sentence due to the in-born facility inherent in them and such is used to process it. Robotics requires appropriate PARSE systems to be developed in order to handle language based operations. In this paper, we present a new method of generating parse structures on complex natural language using algorithmic processes. The paper explores the process of generating meaning via parse structure and improves on the existing results using well established parsing scheme. The resulting algorithm was implemented in Java and a natural language interface for parse generation is presented. The result further shows that tokenizing sentences into their respective units affects the parse structure in the first instance and semantic representation in the larger scale. Efforts were made to limit the rules used in the generation of the grammar since natural language rules are almost infinite depending on the language set. (Abstract

  11. 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.

  12. Divisibility patterns of natural numbers on a complex network

    Science.gov (United States)

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

    2015-09-01

    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.

  13. The geometric nature of weights in real complex networks

    Science.gov (United States)

    Allard, Antoine; Serrano, M. Ángeles; García-Pérez, Guillermo; Boguñá, Marián

    2017-01-01

    The topology of many real complex networks has been conjectured to be embedded in hidden metric spaces, where distances between nodes encode their likelihood of being connected. Besides of providing a natural geometrical interpretation of their complex topologies, this hypothesis yields the recipe for sustainable Internet's routing protocols, sheds light on the hierarchical organization of biochemical pathways in cells, and allows for a rich characterization of the evolution of international trade. Here we present empirical evidence that this geometric interpretation also applies to the weighted organization of real complex networks. We introduce a very general and versatile model and use it to quantify the level of coupling between their topology, their weights and an underlying metric space. Our model accurately reproduces both their topology and their weights, and our results suggest that the formation of connections and the assignment of their magnitude are ruled by different processes.

  14. Complexation by natural heterogeneous compounds: Site occupation distribution functions, a normalized description of metal complexation

    Science.gov (United States)

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

    1990-06-01

    This paper presents a new conceptual approach to interpreting titration curves of metal complexation by physically and chemically heterogeneous natural complexants such as humic acids, clays, complete soils, or sediments. The physico-chemical and analytical difficulties encountered with such systems are reviewed by comparison with a system containing only a few simple ligands, followed by discussion of the new approach on the same basis. It is shown that interpretation of heterogeneous complexant properties necessitates a preliminary transformation of experimental raw data into a function sufficiently normalized so as to allow comparison of results obtained under different conditions. A normalized function called a Site Occupation Distribution Function (SODF) and its potential usefulness is described here. The SODF is a readily computable function which relates the complexation buffer intensity of the system to the differential free energy of the complexation sites present. Its major interest is that it enables one to obtain both a rigorous mathematical description of the complexant properties (even when highly heterogeneous) at the macroscopic level and, in certain cases, an estimation of the molecular-scale behavior of particular site types. The relationship of the SODF to other distribution functions proposed in the literature is discussed and applications are exemplified using simulated and real natural systems. In particular, its utility is discussed in detail for (1) discriminating between different site types (major, minor, dominant, background), (2) evaluating the degree of heterogeneity of an unknown complexant system, (3) estimating the nature and true thermodynamic constants of complexes, and (4) yielding a rigorous definition of "complexation capacity."

  15. 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.

  16. Revealing the Nature of Extreme Coronal-line Emitter SDSS J095209.56+214313.3

    CERN Document Server

    Palaversa, Lovro; Sesar, Branimir; Stuart, J Scott; Wozniak, Przemyslaw; Holl, Berry; Ivezić, Željko

    2015-01-01

    Extreme coronal-line emitter (ECLE) SDSSJ095209.56+214313.3, known by its strong, fading, high ionization lines, has been a long standing candidate for a tidal disruption event, however a supernova origin has not yet been ruled out. Here we add several new pieces of information to the puzzle of the nature of the transient that powered its variable coronal lines: 1) an optical light curve from the Lincoln Near Earth Asteroid Research (LINEAR) survey that serendipitously catches the optical flare, and 2) late-time observations of the host galaxy with the Swift Ultraviolet and Optical Telescope (UVOT) and X-ray telescope (XRT) and the ground-based Mercator telescope. The well-sampled, $\\sim10$-year long, unfiltered LINEAR light curve constrains the onset of the flare to a precision of $\\pm5$ days and enables us to place a lower limit on the peak optical magnitude. Difference imaging allows us to estimate the location of the flare in proximity of the host galaxy core. Comparison of the \\textsl{GALEX} data (early ...

  17. 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...

  18. Analysis and Modelling of Extreme Wind Speed Distributions in Complex Mountainous Regions

    Science.gov (United States)

    Laib, Mohamed; Kanevski, Mikhail

    2016-04-01

    Modelling of wind speed distributions in complex mountainous regions is an important and challenging problem which interests many scientists from several fields. In the present research, high frequency (10 min) Swiss wind speed monitoring data (IDAWEB service, Meteosuisse) are analysed and modelled with different parametric distributions (Weibull, GEV, Gamma, etc.) using maximum likelihood method. In total, 111 stations placed in different geomorphological units and at different altitude (from 203 to 3580 meters) are studied. Then, this information is used for training machine learning algorithms (Extreme Learning Machines, Support vector machine) to predict the distribution at new places, potentially useful for aeolian energy generation. An important part of the research deals with the construction and application of a high dimensional input feature space, generated from digital elevation model. A comprehensive study was carried out using feature selection approach to get the best model for the prediction. The main results are presented as spatial patterns of distributions' parameters.

  19. Complex links between natural tuberculosis and porcine circovirus type 2 infection in wild boar.

    Science.gov (United States)

    Díez-Delgado, Iratxe; Boadella, Mariana; Martín-Hernando, MariPaz; Barasona, José Angel; Beltrán-Beck, Beatriz; González-Barrio, David; Sibila, Marina; Vicente, Joaquín; Garrido, Joseba M; Segalés, Joaquim; Gortazar, Christian

    2014-01-01

    Individuals in natural populations are exposed to a diversity of pathogens which results in coinfections. The aim of this study was to investigate the relation between natural infection with tuberculosis (TB) due to infection by bacteria of the Mycobacterium tuberculosis complex and porcine circovirus type 2 (PCV2) in free-ranging Eurasian wild boar (Sus scrofa). Apparent prevalence for TB lesions and PCV2 infection was extremely high in all age classes, including piglets (51% for TB; 85.7% for PCV2). Modeling results revealed that the relative risk of young (less than 2 years old) wild boar to test positive to PCV2 PCR was negatively associated with TB lesion presence. Also, an interaction between TB, PCV2, and body condition was evidenced: in wild boar with TB lesions probability of being PCV2 PCR positive increased with body condition, whereas this relation was negative for wild boar without TB lesions. This study provides insight into the coinfections occurring in free-ranging host populations that are naturally exposed to several pathogens at an early age. Using TB and PCV2 as a case study, we showed that coinfection is a frequent event among natural populations that takes place early in life with complex effects on the infections and the hosts.

  20. Complex Links between Natural Tuberculosis and Porcine Circovirus Type 2 Infection in Wild Boar

    Directory of Open Access Journals (Sweden)

    Iratxe Díez-Delgado

    2014-01-01

    Full Text Available Individuals in natural populations are exposed to a diversity of pathogens which results in coinfections. The aim of this study was to investigate the relation between natural infection with tuberculosis (TB due to infection by bacteria of the Mycobacterium tuberculosis complex and porcine circovirus type 2 (PCV2 in free-ranging Eurasian wild boar (Sus scrofa. Apparent prevalence for TB lesions and PCV2 infection was extremely high in all age classes, including piglets (51% for TB; 85.7% for PCV2. Modeling results revealed that the relative risk of young (less than 2 years old wild boar to test positive to PCV2 PCR was negatively associated with TB lesion presence. Also, an interaction between TB, PCV2, and body condition was evidenced: in wild boar with TB lesions probability of being PCV2 PCR positive increased with body condition, whereas this relation was negative for wild boar without TB lesions. This study provides insight into the coinfections occurring in free-ranging host populations that are naturally exposed to several pathogens at an early age. Using TB and PCV2 as a case study, we showed that coinfection is a frequent event among natural populations that takes place early in life with complex effects on the infections and the hosts.

  1. REVEALING THE NATURE OF EXTREME CORONAL-LINE EMITTER SDSS J095209.56+214313.3

    Energy Technology Data Exchange (ETDEWEB)

    Palaversa, Lovro; Holl, Berry [Observatoire astronomique de l’Université de Genève, 51 chemin des Maillettes, CH-1290 Sauverny (Switzerland); Gezari, Suvi [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Sesar, Branimir [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Stuart, J. Scott [Lincoln Laboratory, Massachusetts Institute of Technology, 244 Wood Street, Lexington, MA 02420-9108 (United States); Wozniak, Przemyslaw [Los Alamos National Laboratory, 30 Bikini Atoll Road, Los Alamos, NM 87545-0001 (United States); Ivezić, Željko, E-mail: lovro.palaversa@unige.ch [University of Washington, Department of Astronomy, P.O. Box 351580, Seattle, WA 98195-1580 (United States)

    2016-03-10

    Extreme coronal-line emitter (ECLE) SDSS J095209.56+214313.3, known by its strong, fading, high-ionization lines, has been a long-standing candidate for a tidal disruption event; however, a supernova (SN) origin has not yet been ruled out. Here we add several new pieces of information to the puzzle of the nature of the transient that powered its variable coronal lines: (1) an optical light curve from the Lincoln Near Earth Asteroid Research (LINEAR) survey that serendipitously catches the optical flare, and (2) late-time observations of the host galaxy with the Swift Ultraviolet and Optical Telescope (UVOT) and X-ray telescope (XRT) and the ground-based Mercator telescope. The well-sampled, ∼10 yr long, unfiltered LINEAR light curve constrains the onset of the flare to a precision of ±5 days and enables us to place a lower limit on the peak optical magnitude. Difference imaging allows us to estimate the location of the flare in proximity of the host galaxy core. Comparison of the GALEX data (early 2006) with the recently acquired Swift UVOT (2015 June) and Mercator observations (2015 April) demonstrates a decrease in the UV flux over a ∼10 yr period, confirming that the flare was UV-bright. The long-lived UV-bright emission, detected 1.8 rest-frame years after the start of the flare, strongly disfavors an SN origin. These new data allow us to conclude that the flare was indeed powered by the tidal disruption of a star by a supermassive black hole and that tidal disruption events are in fact capable of powering the enigmatic class of ECLEs.

  2. 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.

  3. The role of Natural Flood Management in managing floods in large scale basins during extreme events

    Science.gov (United States)

    Quinn, Paul; Owen, Gareth; ODonnell, Greg; Nicholson, Alex; Hetherington, David

    2016-04-01

    There is a strong evidence database showing the negative impacts of land use intensification and soil degradation in NW European river basins on hydrological response and to flood impact downstream. However, the ability to target zones of high runoff production and the extent to which we can manage flood risk using nature-based flood management solution are less known. A move to planting more trees and having less intense farmed landscapes is part of natural flood management (NFM) solutions and these methods suggest that flood risk can be managed in alternative and more holistic ways. So what local NFM management methods should be used, where in large scale basin should they be deployed and how does flow is propagate to any point downstream? Generally, how much intervention is needed and will it compromise food production systems? If we are observing record levels of rainfall and flow, for example during Storm Desmond in Dec 2015 in the North West of England, what other flood management options are really needed to complement our traditional defences in large basins for the future? In this paper we will show examples of NFM interventions in the UK that have impacted at local scale sites. We will demonstrate the impact of interventions at local, sub-catchment (meso-scale) and finally at the large scale. These tools include observations, process based models and more generalised Flood Impact Models. Issues of synchronisation and the design level of protection will be debated. By reworking observed rainfall and discharge (runoff) for observed extreme events in the River Eden and River Tyne, during Storm Desmond, we will show how much flood protection is needed in large scale basins. The research will thus pose a number of key questions as to how floods may have to be managed in large scale basins in the future. We will seek to support a method of catchment systems engineering that holds water back across the whole landscape as a major opportunity to management water

  4. Nonlinear problems of complex natural systems: Sun and climate dynamics.

    Science.gov (United States)

    Bershadskii, A

    2013-01-13

    The universal role of the nonlinear one-third subharmonic resonance mechanism in generation of strong fluctuations in complex natural dynamical systems related to global climate is discussed using wavelet regression detrended data. The role of the oceanic Rossby waves in the year-scale global temperature fluctuations and the nonlinear resonance contribution to the El Niño phenomenon have been discussed in detail. The large fluctuations in the reconstructed temperature on millennial time scales (Antarctic ice core data for the past 400,000 years) are also shown to be dominated by the one-third subharmonic resonance, presumably related to the Earth's precession effect on the energy that the intertropical regions receive from the Sun. The effects of galactic turbulence on the temperature fluctuations are also discussed.

  5. Identifying anthropogenic and natural influences on extreme pollution of respirable suspended particulates in Beijing using backward trajectory analysis.

    Science.gov (United States)

    Song, Yu; Miao, Weijie; Liu, Bing; Dai, Wei; Cai, Xuhui

    2008-06-15

    In China, daily respirable suspended particulate (RSP, particles with aerodynamic diameters less than 10 microm) concentrations exceeding 420 microg m(-3) are considered "hazardous" to health. These can lead to the premature onset of certain diseases and premature death of sick and elderly people; even healthy people are warned to avoid outdoor activity when RSP concentrations are high. Such high pollution levels are defined as extreme RSP pollution events. Recent epidemiological studies have shown that a distinct difference exists between the health effects caused by natural sources and anthropogenic sources, mandating knowledge of the source of extreme RSP pollution. Twenty-six extreme RSP pollution events were recorded in Beijing from January 2003 to December 2006. The HYSPLIT4 (Hybrid Single Particle Lagrangian Integrated Trajectory) model (Version 4) was used to discriminate the sources of these extreme RSP pollution events. The model found that twelve events were caused from natural sources (dust storms), nine events from anthropogenic sources (e.g., vehicles and industrial activities, etc.) under quasi-quiescent weather, and five events were from mixed causes. Identifying such events will be valuable in epidemiological studies on air pollution in Beijing.

  6. 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

  7. Complex nature of enterococcal pheromone-responsive plasmids.

    Science.gov (United States)

    Wardal, Ewa; Sadowy, Ewa; Hryniewicz, Waleria

    2010-01-01

    Pheromone-responsive plasmids constitute a unique group of approximately 20 plasmids identified, as yet, only among enterococcal species. Several of their representatives, e.g. pAD1, pCF10, pPD1 and pAM373 have been extensively studied. These plasmids possess a sophisticated conjugation mechanism based on response to sex pheromones--small peptides produced by plasmid-free recipient cells. Detailed analysis of regulation and function of the pheromone response process revealed its great complexity and dual role--in plasmid conjugation and modulation of enterococcal virulence. Among other functional modules identified in pheromone plasmids, the stabilization/partition systems play a crucial role in stable maintenance of the plasmid molecule in host bacteria. Among them, the par locus of pAD1 is one of the exceptional RNA addiction systems. Pheromone-responsive plasmids contribute also to enterococcal phenotype being an important vehicle of antibiotic resistance in this genus. Both types of acquired vancomycin resistance determinants, vanA and vanB, as well many other resistant phenotypes, were found to be located on these plasmids. They also encode two basic agents of enterococcal virulence, i.e. aggregation substance (AS) and cytolysin. AS participates in mating-pair formation during conjugation but can also facilitate the adherence ofenterococci to human tissues during infection. The second protein, cytolysin, displays hemolytic activity and helps to invade eukaryotic cells. There are still many aspects of the nature of pheromone plasmids that remain unclear and more detailed studies are needed to understand their uniqueness and complexity.

  8. Nonlinear problems of complex natural systems: Sun and climate dynamics

    CERN Document Server

    Bershadskii, A

    2012-01-01

    Universal role of the nonlinear one-third subharmonic resonance mechanism in generation of the strong fluctuations in such complex natural dynamical systems as global climate and global solar activity is discussed using wavelet regression detrended data. Role of the oceanic Rossby waves in the year-scale global temperature fluctuations and the nonlinear resonance contribution to the El Nino phenomenon have been discussed in detail. The large fluctuations of the reconstructed temperature on the millennial time-scales (Antarctic ice cores data for the past 400,000 years) are also shown to be dominated by the one-third subharmonic resonance, presumably related to Earth precession effect on the energy that the intertropical regions receive from the Sun. Effects of Galactic turbulence on the temperature fluctuations are discussed in this content. It is also shown that the one-third subharmonic resonance can be considered as a background for the 11-years solar cycle, and again the global (solar) rotation and chaoti...

  9. Natural radioelement concentration in the Troodos Ophiolite Complex of Cyprus

    CERN Document Server

    Tzortzis, M; Tzortzis, Michalis; Tsertos, Haralabos

    2004-01-01

    High-resolution gamma-ray spectrometry was exploited to determine naturally occurring thorium (Th), uranium (U) and potassium (K) elemental concentrations in the whole area covered by the Troodos Ophiolite Complex of Cyprus. For that purpose, a total of 59 samples from surface soils and 10 from the main rock formations of the region of interest were analysed. Elemental concentrations were determined for Th (range from 2.5x10^-3 ppm to 2.0 ppm), U (from 8.1x10^-4 ppm to 0.6 ppm), and K (from 1.3x10^-4 % to 1.0 %). The average values (A.M +- S.D.) derived are (0.24 +- 0.34) ppm, (0.10 +- 0.10) ppm and (0.21 +- 0.24) %, for Th, U, and K, respectively, in the soils, and (0.52 +- 0.17) ppm, (0.17 +- 0.11) ppm and (0.49 +- 0.87) % in the rocks. From these values, a radioactivity (radioelement) loss of nearly 50% is estimated in the underlying surface soils due to bleaching and eluviation during weathering of the rocks. The measured Th/U ratio exhibits values between 2 and 4, whereas the K/Th ratio is highly variabl...

  10. Extreme Rainfall Events and Associated Natural Hazards in Alaknanda Valley, Indian Himalayan Region

    Institute of Scientific and Technical Information of China (English)

    JOSHI Varun; KUMAR Kireet

    2006-01-01

    Entire Himalayan region is vulnerable to rain-induced (torrential rainfall) hazards in the form of flash flood, cloudburst or glacial lake outburst flood. Flash floods and cloudburst are generally caused by high intensity rainfall followed by debris flow or landslide often resulting into blockade of river channels. The examples of some major disasters caused by torrential rainfall events in last fifty years are the flash floods of 1968 in Teesta valley, in 1993 and 20o0 in Sntlej valley, in 1978 in Bhagirathi and in 197o in Alaknanda river valleys. The formation of landslide dams and subsequent breaching is also associated with such rainfall events. These dams may persist for years or may burst within a short span of its formation. Due to sudden surge of water level in the river valleys, havoc and panic are created in the down stream. In Alaknanda valley, frequencies of such extreme rainfall events are found to be increasing in last two decades. However, the monthly trend of extreme rainfall events has partly indicated this increase. In most of the years extreme rainfall events and cloudburst disaster were reported in August during the later part of the monsoon season.

  11. Natural Gradient Descent for Training Stochastic Complex-Valued Neural Networks

    Directory of Open Access Journals (Sweden)

    Tohru Nitta

    2014-08-01

    Full Text Available In this paper, the natural gradient descent method for the multilayer stochastic complex-valued neural networks is considered, and the natural gradient is given for a single stochastic complex-valued neuron as an example. Since the space of the learnable parameters of stochastic complex-valued neural networks is not the Euclidean space but a curved manifold, the complex-valued natural gradient method is expected to exhibit excellent learning performance.

  12. Management of Complex Extremity Injuries: Tourniquets, Compartment Syndrome Detection, Fasciotomy, and Amputation Care

    Science.gov (United States)

    2012-01-01

    E mail address: robert.rush1@us.army.mil KEYWORDS Extremity injury Mangled extremity Amputation Compartment syndrome Fasciotomy Prosthesis ...definitive repair. For ray amputations of the foot , removing the big toe in most cases is worse than a transmetatarsal amputation due to lack of...from lack of total contact with the prosthesis and requires refitting. Heterotopic ossification (HO), the aberrant formation of mature, lamellar bone in

  13. Coping with Extreme Hazard Events: Emerging Themes in Natural and Technological Disaster Research.

    Science.gov (United States)

    Pijawka, K. David; And Others

    1988-01-01

    Notes that deaths from natural and technological disasters are increasing in United States. Reviews key findings in areas of vulnerability to natural hazards, disaster behavior and risk perception, societal concern over technological hazard, and social-psychological effects of disasters. Calls for research examining the role of media and measuring…

  14. Rainfall extremes, weather and climatic characterization over complex terrain: A data-driven approach based on signal enhancement methods and extreme value modeling

    Science.gov (United States)

    Pineda, Luis E.; Willems, Patrick

    2017-04-01

    Weather and climatic characterization of rainfall extremes is both of scientific and societal value for hydrometeorogical risk management, yet discrimination of local and large-scale forcing remains challenging in data-scarce and complex terrain environments. Here, we present an analysis framework that separate weather (seasonal) regimes and climate (inter-annual) influences using data-driven process identification. The approach is based on signal-to-noise separation methods and extreme value (EV) modeling of multisite rainfall extremes. The EV models use a semi-automatic parameter learning [1] for model identification across temporal scales. At weather scale, the EV models are combined with a state-based hidden Markov model [2] to represent the spatio-temporal structure of rainfall as persistent weather states. At climatic scale, the EV models are used to decode the drivers leading to the shift of weather patterns. The decoding is performed into a climate-to-weather signal subspace, built via dimension reduction of climate model proxies (e.g. sea surface temperature and atmospheric circulation) We apply the framework to the Western Andean Ridge (WAR) in Ecuador and Peru (0-6°S) using ground data from the second half of the 20th century. We find that the meridional component of winds is what matters for the in-year and inter-annual variability of high rainfall intensities alongside the northern WAR (0-2.5°S). There, low-level southerly winds are found as advection drivers for oceanic moist of the normal-rainy season and weak/moderate the El Niño (EN) type; but, the strong EN type and its unique moisture surplus is locally advected at lowlands in the central WAR. Moreover, the coastal ridges, south of 3°S dampen meridional airflows, leaving local hygrothermal gradients to control the in-year distribution of rainfall extremes and their anomalies. Overall, we show that the framework, which does not make any prior assumption on the explanatory power of the weather

  15. 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

  16. State-of-art methodology of marine natural products chemistry: structure determination with extremely small sample amounts.

    Science.gov (United States)

    Murata, M; Oishi, T; Yoshida, M

    2006-01-01

    Structure elucidation studies on natural products are reviewed emphasizing extremely small sample amounts. Previous studies on insect pheromones, periplanones, and bean-originating kairomones, glycinoeclepins, are described briefly. Recent examples are selected from marine natural products such as ciguatoxin, dolastatin-3, and aurisides. A more detailed description is given of a sperm-activating and attracting factor (SAAF), which may be the smallest sample amount used in the structure elucidation of novel non-peptidic natural products. SAAF was isolated from the eggs of the ascidian, Ciona intestinalis, and its structure was deduced with only approximately 4 microg (6 nmol) of sample. Based upon the proposed structure, two epimers were synthesized from chenodeoxycholic acid in 17 steps, leading to the identification of SAAF as a novel sterol sulfate.

  17. 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...

  18. 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

  19. Ignoring Extreme Opinions in Complex Networks: The Impact of Heterogeneous Thresholds

    CERN Document Server

    Sundaram, Shreyas

    2016-01-01

    We consider a class of opinion dynamics on networks where at each time-step, each node in the network disregards the opinions of a certain number of its most extreme neighbors and updates its own opinion as a weighted average of the remaining opinions. When all nodes disregard the same number of extreme neighbors, previous work has shown that consensus will be reached if and only if the network satisfies certain topological properties. In this paper, we consider the implications of allowing each node to have a personal threshold for the number of extreme neighbors to ignore. We provide graph conditions under which consensus is guaranteed for such dynamics. We then study random networks where each node's threshold is drawn from a certain distribution, and provide conditions on that distribution, together with conditions on the edge formation probability, that guarantee that consensus will be reached asymptotically almost surely.

  20. Second-order complex linear differential equations with special functions or extremal functions as coefficients

    Directory of Open Access Journals (Sweden)

    Xiubi Wu

    2015-05-01

    Full Text Available The classical problem of finding conditions on the entire coefficients A(z and B(z guaranteeing that all nontrivial solutions of $f''+A(zf'+B(zf=0$ are of infinite order is discussed. Two distinct approaches are used. In the first approach the coefficient A(z itself is a solution of a differential equation $w''+P(zw=0$, where P(z is a polynomial. This assumption yields stability on the behavior of A(z via Hille's classical method on asymptotic integration. In this case A(z is a special function of which the Airy integral is one example. The second approach involves extremal functions. It is assumed that either A(z is extremal for Yang's inequality or B(z is extremal for Denjoy's conjecture. A combination of these two approaches is also discussed.

  1. Experimental evolution can unravel the complex causes of natural selection in clinical infections.

    Science.gov (United States)

    Brockhurst, Michael A

    2015-06-01

    It is increasingly clear that rapid evolutionary dynamics are an important process in microbial ecology. Experimental evolution, wherein microbial evolution is observed in real-time, has revealed many instances of appreciable evolutionary change occurring on very short timescales of a few days or weeks in response to a variety of biotic and abiotic selection pressures. From clinical infections, including the chronic bacterial lung infections associated with cystic fibrosis that form a focus of my research, there is now abundant evidence suggesting that rapid evolution by infecting microbes contributes to host adaptation, treatment failure and worsening patient prognosis. However, disentangling the drivers of natural selection in complex infection environments is extremely challenging and limits our understanding of the selective pressures acting upon microbes in infections. Controlled evolution experiments can make a vital contribution to this by determining the causal links between predicted drivers of natural selection and the evolutionary responses of microbes. Integration of experimental evolution into studies of clinical infections is a key next step towards a better understanding of the causes and consequences of rapid microbial evolution in infections, and discovering how these evolutionary processes might be influenced to improve patient health.A video of this Prize Lecture, presented at the Society for General Microbiology Annual Conference 2015, can be viewed via this link: Michael A. Brockhurst https://www.youtube.com/watch?v=N1bodVSl27E.

  2. Frequency and Heterogeneous Nature of Complex Clauses in Italian Non-Literary Texts

    Directory of Open Access Journals (Sweden)

    Darja Mertelj

    2009-12-01

    Full Text Available Although it might seem that syntactically complex clauses rarely appear in everyday language and/or belong to higher language, they are also used in the context of a less demanding and less controlled verbal communication environment. The aim of this paper is to present their syntactically heterogeneous nature in some representative Italian texts, along with potential difficulties Slovenian learners may have when dealing with them. The analysis focuses on subordinate clauses introduced by the conjunctions se, anche se and come se which can introduce various subordinate clauses, most being notorious for Slovenian (and other Slavic learners. Interference errors occur constantly, in particular as far as the appropriate use of verbal forms is concerned. It was found that all the subordinates in question appear in Italian text constantly, but they are not extremely common; their use is also not correlated to the type of text involved, but to the writer/speaker’s communication  goals. Due to their sporadic appearance and highly heterogeneous nature, they cannot represent a stable input for learners in order to enable their successful unconscious acquisition. That is why at least the prototypical usage of syntactic patterns should be included in the conscious learning of Italian as a foreign language despite their reduced importance attributed by recent tendencies in the field of foreign language methodologies.

  3. 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...

  4. The nature of 4-aminophthalimide-cyclodextrin inclusion complexes

    Energy Technology Data Exchange (ETDEWEB)

    Soujanya, T.; Krishna, T.S.R.; Samanta, A. [Univ. of Hyderabad (India)

    1992-10-15

    The complexation between 4-aminophthalimide and cyclodextrin has been investigated in aqueous solution using steady-state and time-resolved fluorescence techniques. While 1:1 complex formation with {alpha} or {Beta}-cyclodextrin is evident from the presence of the isosbestic point in absorption and analysis of fluorescence spectral data, the binding is rather weak with {gamma}-cyclodextrin and more than one type of complex are indicated. The complexes of {alpha}- and {Beta}-cyclodextrins have been characterized through the measurement of fluorescence spectra, quantum yields, and lifetimes. On the basis of the available experimental data and the results of AM1 calculation on the probe molecule, possible structures of these complexes are suggested. 30 refs., 7 figs., 3 tabs.

  5. Extremos geográficos de la distribución natural de Austrocedrus chilensis (Cupressaceae Geographic extremes of the natural range of Austrocedrus chilensis (Cupressaceae

    Directory of Open Access Journals (Sweden)

    Mario J. Pastorino

    2006-12-01

    Full Text Available El "Ciprés de la Cordillera " ( Austrocedrus chilensis (D.Don Pic. Ser. et Bizzarri es la conífera nativa de mayor importancia económica de los bosques templados de Argentina. Se han detectado en la bibliografía imprecisiones respecto al rango latitudinal en el que se desarrolla, las que motivaron este estudio. Se determinaron los extremos de ese rango en base a antecedentes bibliográficos, información provista por pobladores y expertos regionales, y reconocimientos en el campo. El extremo septentrional se ubica a los 32º 39' S (Región V de Valparaíso, Chile, y el extremo austral se halla a los 43º 44' S (Provincia de Chubut, Argentina, lo que representa una distancia de unos 1230 km . Esta variación latitudinal y el carácter fragmentario de su distribución natural apoyan la hipótesis de la existencia de ecotipos en la especie.The "Patagonian Cypress" ( Austrocedrus chilensis (D.Don Pic. Ser. et Bizzarri is the most economically important native conifer of the temperate forests of Argentina. Some inaccuracy was detected in the bibliography with respect to its latitudinal range, what motivates the present study. The location of the latitudinal extremes was determined based on bibliographic antecedents, local settlers' and experts' information, and field surveys. The northernmost extreme is located at 32º 39' S (Region V of Valparaíso, Chile, while the southernmost extreme at 43º 44' S (Chubut Province, Argentina. This 11 latitudinal grades range represents a distance of 1230 km. This broad latitudinal range and the fragmentary feature of its natural distribution area support the hypothesis of ecotypes for this species.

  6. Adiabatic expansion effect of natural gas at the downstream extremity of the pipeline

    Science.gov (United States)

    Kessal, Mohand; Amara, Khadidja; Belaidi, Idir

    2017-02-01

    Two numerical simulation examples of natural gas transients are studied, based on the conservation equations of fluid mechanics and energy, discribed by the flow parameters, pressure (P) and the speed (V) and temperature (T) in a gas pipeline. The considered exemple is under static pressure, at which two boundary conditions are applied to its downstream end, whith an adiabatic discharge to the atmosphere. Obtained results have shown the parameters variation induced by the conditions of these instantaneous gas output conditions.

  7. On the Nature of the Extreme-Ultraviolet Late Phase of Solar Flares

    CERN Document Server

    Li, Y; Guo, Y; Dai, Y

    2014-01-01

    The extreme-ultraviolet (EUV) late phase of solar flares is a second peak of warm coronal emissions (e.g., Fe XVI) for many minutes to a few hours after the GOES soft X-ray peak. It was first observed by the EUV Variability Experiment (EVE) on board the Solar Dynamics Observatory (SDO). The late phase emission originates from a second set of longer loops (late phase loops) that are higher than the main flaring loops. It is suggested as being caused by either additional heating or long-lasting cooling. In this paper, we study the role of long-lasting cooling and additional heating in producing the EUV late phase using the "enthalpy-based thermal evolution of loops" (EBTEL) model. We find that a long cooling process in late phase loops can well explain the presence of the EUV late phase emission, but we cannot exclude the possibility of additional heating in the decay phase. Moreover, we provide two preliminary methods based on the UV and EUV emissions from the Atmospheric Imaging Assembly (AIA) on board SDO to...

  8. 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.

  9. Scan patterns when viewing natural scenes: Emotion, complexity, and repetition

    OpenAIRE

    Bradley, Margaret M.; Houbova, Petra; Miccoli,Laura; Costa, Vincent D.; Lang, Peter J.

    2011-01-01

    Eye movements were monitored during picture viewing and effects of hedonic content, perceptual composition, and repetition on scanning assessed. In Experiment 1, emotional and neutral pictures that were figure-ground compositions or more complex scenes were presented for a 6 s free viewing period. Viewing emotional pictures or complex scenes prompted more fixations and broader scanning of the visual array, compared to neutral pictures or simple figure-ground compositions. Effects of emotion a...

  10. Extreme conservation of noncoding DNA near HoxD complex of vertebrates

    Directory of Open Access Journals (Sweden)

    Tripathi Anshuman

    2004-10-01

    Full Text Available Abstract Background Homeotic gene complexes determine the anterior-posterior body axis in animals. The expression pattern and function of hox genes along this axis is colinear with the order in which they are organized in the complex. This 'chromosomal organization and functional correspondence' is conserved in all bilaterians investigated. Genomic sequences covering the HoxD complex from several vertebrate species are now available. This offers a comparative genomics approach to identify conserved regions linked to this complex. Although the molecular basis of 'colinearity' of Hox complexes is not yet understood, it is possible that there are control elements within or in the proximity of these complexes that establish and maintain the expression patterns of hox genes in a coordinated fashion. Results We have compared DNA sequence flanking the HoxD complex of several primate, rodent and fish species. This analysis revealed an unprecedented conservation of non-coding DNA sequences adjacent to the HoxD complex from fish to human. Stretches of hundreds of base pairs in a 7 kb region, upstream of HoxD complex, show 100% conservation across the vertebrate species. Using PCR primers from the human sequence, these conserved regions could be amplified from other vertebrate species, including other mammals, birds, reptiles, amphibians and fish. Our analysis of these sequences also indicates that starting from the conserved core regions, more sequences have been added on and maintained during evolution from fish to human. Conclusion Such a high degree of conservation in the core regions of this 7 kb DNA, where no variation occurred during ~500 million years of evolution, suggests critical function for these sequences. We suggest that such sequences are likely to provide molecular handle to gain insight into the evolution and mechanism of regulation of associated gene complexes.

  11. Transcriptional control of anthocyanin biosynthetic genes in extreme phenotypes for berry pigmentation of naturally occurring grapevines

    Directory of Open Access Journals (Sweden)

    Castellarin Simone D

    2007-08-01

    Full Text Available Abstract Background Fruit coloration of red-skinned grapevines is mainly due to anthocyanin pigments. We analysed a panel of nine cultivars that included extreme phenotypes for berry colour, ranging from green (absence of anthocyanins to red, purple, violet and blue. Expression of six genes of the anthocyanin pathway coding for flavanone-hydroxylase (F3H, flavonoid 3'-hydroxylase (F3'H, flavonoid 3',5'-hydroxylase (F3'5'H, UDP-glucose:flavonoid-3-O-glucosyltransferase (UFGT, glutathione-S-transferase (GST, O-methyltransferase (OMT and four transcription factors (MybA, MybB, MybC, MybD was analysed by quantitative RT-PCR at four developmental stages from before the onset of ripening until full maturity and compared to anthocyanin metabolites. Results Total anthocyanin content at full maturity correlated well with the cumulative expression of F3H, UFGT and GST throughout ripening. Transcripts of the last two genes were absent in the green-skinned cultivar 'Sauvignonasse', also known as 'Tocai friulano', and were at least 10-fold less abundant in pale red cultivars, such as 'Pinot gris' and 'Gewürztraminer', compared to fully coloured cultivars. Predominance of tri-hydroxylated anthocyanins (delphinidin, petunidin and malvidin in cultivars bearing dark berries with violet and blue hue was associated with higher ratios of F3'5'H/F3'H transcription, compared to red-skinned cultivars. Higher levels of OMT transcripts were observed in berries of cultivars that accumulated methoxylated forms of anthocyanins more abundantly than non-methoxylated forms. Conclusion Colour variation of the grape berry conforms to a peculiar pattern of genotype-specific expression of the whole set of anthocyanin genes in a direct transcript-metabolite-phenotype relationship. Cumulative mRNA levels of the structural genes and their relative abundance throughout ripening explained per se the final phenotype for anthocyanin content, anthocyanin composition, colour intensity

  12. 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.

  13. Composite Centrality: A Natural Scale for Complex Evolving Networks

    CERN Document Server

    Joseph, Andreas

    2012-01-01

    We derive a composite centrality measure for general weighted and directed complex networks, based on measure standardisation and invariant statistical inheritance. Different inheritance schemes generate different intermediate abstract measures providing additional information, while the overall composite centrality measure tends to the standard log-normal distribution. This offers a unified scale to measure node and edge centralities for complex evolving networks inside a uniform framework. Considering the two real-world cases of the world trade web and the world migration web, both during a time span of 40 years, we propose a standard framework and demonstrate its remarkable normative power and accuracy. We demonstrate the applicability of the proposed framework to large and arbitrary complex systems by the means of numerical simulations.

  14. 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...

  15. Complex Systems Theory to understand extremely low frequency magnetic fields interaction with immune cells

    Science.gov (United States)

    Vázquez-Coutiño, G. A.; Serrano-Luna, G.; Cañedo-Dorantes, L.; Godina-Nava, J. J.; Rodríguez-Segura, M. A.

    2003-09-01

    Well-documented studies about the interaction of extremely low frequency electromagnetic fields (ELF) with lymphocytes provide elements for the development of non-linear theoretical models. The Eichwald-Kaiser model of calcium oscillations was tested with a rectified cosine function at a frequency of 120 Hz. A change in dynamical behavior of calcium oscillations, from periodic in the normal case (without perturbation, what corresponds to a limit cycle) to the existence of very small micro-oscillations and a strange attractor in the perturbed case was found. It is concluded that the ELF configuration used in this model, alters the dynamical behavior of calcium oscillations in lymphocytes.

  16. 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

  17. Risk prediction of Critical Infrastructures against extreme natural hazards: local and regional scale analysis

    Science.gov (United States)

    Rosato, Vittorio; Hounjet, Micheline; Burzel, Andreas; Di Pietro, Antonio; Tofani, Alberto; Pollino, Maurizio; Giovinazzi, Sonia

    2016-04-01

    Natural hazard events can induce severe impacts on the built environment; they can hit wide and densely populated areas, where there is a large number of (inter)dependent technological systems whose damages could cause the failure or malfunctioning of further different services, spreading the impacts on wider geographical areas. The EU project CIPRNet (Critical Infrastructures Preparedness and Resilience Research Network) is realizing an unprecedented Decision Support System (DSS) which enables to operationally perform risk prediction on Critical Infrastructures (CI) by predicting the occurrence of natural events (from long term weather to short nowcast predictions, correlating intrinsic vulnerabilities of CI elements with the different events' manifestation strengths, and analysing the resulting Damage Scenario. The Damage Scenario is then transformed into an Impact Scenario, where punctual CI element damages are transformed into micro (local area) or meso (regional) scale Services Outages. At the smaller scale, the DSS simulates detailed city models (where CI dependencies are explicitly accounted for) that are of important input for crisis management organizations whereas, at the regional scale by using approximate System-of-Systems model describing systemic interactions, the focus is on raising awareness. The DSS has allowed to develop a novel simulation framework for predicting earthquakes shake maps originating from a given seismic event, considering the shock wave propagation in inhomogeneous media and the subsequent produced damages by estimating building vulnerabilities on the basis of a phenomenological model [1, 2]. Moreover, in presence of areas containing river basins, when abundant precipitations are expected, the DSS solves the hydrodynamic 1D/2D models of the river basins for predicting the flux runoff and the corresponding flood dynamics. This calculation allows the estimation of the Damage Scenario and triggers the evaluation of the Impact Scenario

  18. 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.

  19. Persistence of an extreme male-biased adult sex ratio in a natural population of polyandrous bird.

    Science.gov (United States)

    Kosztolányi, A; Barta, Z; Küpper, C; Székely, T

    2011-08-01

    In a number of insects, fishes and birds, the conventional sex roles are reversed: males are the main care provider, whereas females focus on matings. The reversal of typical sex roles is an evolutionary puzzle, because it challenges the foundations of sex roles, sexual selection and parental investment theory. Recent theoretical models predict that biased parental care may be a response to biased adult sex ratios (ASRs). However, estimating ASR is challenging in natural populations, because males and females often have different detectabilities. Here, we use demographic modelling with field data from 2101 individuals, including 579 molecularly sexed offspring, to provide evidence that ASR is strongly male biased in a polyandrous bird with male-biased care. The model predicts 6.1 times more adult males than females (ASR=0.860, proportion of males) in the Kentish plover Charadrius alexandrinus. The extreme male bias is consistent between years and concordant with experimental results showing strongly biased mating opportunity towards females. Based on these results, we conjecture that parental sex-role reversal may occur in populations that exhibit extreme male-biased ASR.

  20. 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.

  1. Formation, Characterization and Stability of Natural Antimicrobial-Cyclodextrin Complexes

    OpenAIRE

    Samperio, Cristian

    2009-01-01

    As a response of the need for a natural antimicrobial to replace sodium benzoateâ s use as a preservative in beverages, twenty eight compounds known to have antimicrobial activity were evaluated to quantify their solubility. Twenty three of the compounds evaluated are components of plant essential oils and the remaining five compounds are alkyl esters of para-hydroxybenzoic acid. The test compounds were evaluated for aqueous solubility as well as their solubility in an acid-based beverage mi...

  2. The complex nature of autonomy A natureza complexa da autonomia

    Directory of Open Access Journals (Sweden)

    Vera Lúcia Menezes de Oliveira e Paiva

    2008-01-01

    Full Text Available Drawing on Complexity Theory and on the literature of autonomy, the discussions herein presented will center around the language learner process of autonomy as a complex system. As empirical evidence to defend our assumptions, a corpus of 80 English language learning narratives, collected in Brazil, were examined and interwined with the theoretical discussion.Tendo a teoria da complexidade e a literatura sobre autonomia como suporte, apresentamos uma discussão sobre o processo de autonomia do aprendiz de língua estrangeira como um sistema complexo. Para defender nossa proposta, utilizamos como evidências empíricas, em diálogo com a discussão teórica, um corpus de 80 narrativas de aprendizagem de língua inglesa, coletadas no Brasil.

  3. Scan patterns when viewing natural scenes: emotion, complexity, and repetition.

    Science.gov (United States)

    Bradley, Margaret M; Houbova, Petra; Miccoli, Laura; Costa, Vincent D; Lang, Peter J

    2011-11-01

    Eye movements were monitored during picture viewing, and effects of hedonic content, perceptual composition, and repetition on scanning assessed. In Experiment 1, emotional and neutral pictures that were figure-ground compositions or more complex scenes were presented for a 6-s free viewing period. Viewing emotional pictures or complex scenes prompted more fixations and broader scanning of the visual array, compared to neutral pictures or simple figure-ground compositions. Effects of emotion and composition were independent, supporting the hypothesis that these oculomotor indices reflect enhanced information seeking. Experiment 2 tested an orienting hypothesis by repeatedly presenting the same pictures. Although repetition altered specific scan patterns, emotional, compared to neutral, picture viewing continued to prompt oculomotor differences, suggesting that motivationally relevant cues enhance information seeking in appetitive and defensive contexts. Copyright © 2011 Society for Psychophysiological Research.

  4. Hydro-Meteocean Nature of some Extreme Flood Events and Some Consequences

    Science.gov (United States)

    Diez, J. Javier

    2013-04-01

    The Santa Irene flood event, at the end of October 1982, is one of the most dramatically widely reported flood events in Spain. Its renown is mainly due to the collapse of the Tous dam, but its main message is to be the paradigm of the incidence of the maritime/littoral weather and its temporal sea level rise on the coastal plains inland floods. Looking at damages the paper analyzes the adapted measures from the point of view of the aims of the FP7 SMARTeST Project related to the Flood Resilience improvement in urban areas through looking for Technologies, Systems and Tools an appropriate "road to de market". The event, as frequently, was due to a meteorological phenomenon known as "gota fría" (cold drop), a relatively frequent and intense rainy phenomenon on the Iberian Peninsula, particularly on the Spanish east to southeast inlands and coasts. There are some circumstances that can easily come together to unleash the cold drop there: cold and dry polar air masses coming onto the whole Iberian Peninsula and the north of Africa, high sea water temperatures, and low atmospheric pressure (cyclone) areas in the western Mediterranean basin; these circumstances are quite common during the autumn season there, and, as it happens, in other places around the world (East/Southeast Africa). Their occurrence, however shows a great space-temporal variability (in a similar way to hurricanes, on Caribbean and western North-Atlantic areas, or to typhoons do). As a matter of fact, all of these equivalent though different phenomena may have different magnitude each time. This paper describes the results of a detailed analysis and reflection about this cold drop phenomenon as a whole, on the generation of its rains and on the different natures and consequences of its flood. This paper explains also the ways in which the maritime weather in front of the basin and the consequent sea level govern floods on the lowest zone of any hydrographical basin, showing that event as a real

  5. Manganese complexes with bicarbonate and sulfate in natural water

    Science.gov (United States)

    Hem, J.D.

    1963-01-01

    The association constant for the dissolved species MnHCO3+ was experimentally determined to be 63. From this value and a published constant for the species MNSO4 aq., a diagram was prepared showing per cent of dissolved manganese complexed in the presence of 10 to 10,000 p.p.m. bicarbonate and 1.0 to 10,000 p.p.m. sulfate. The rate of oxidation of Mn+2 in aerated water is greatly increased by increasing pH, and is retarded when SO4-2and HCO3- are present.

  6. 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 freq

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

    Directory of Open Access Journals (Sweden)

    Emily A. Martin

    2015-07-01

    Full Text Available 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

  8. 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

  9. 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...... these two plant species interesting gateways for addressing these questions of evolution. The presented research demonstrates that the biosynthetic pathway for the hydroxynitrile glucoside alliarinoside in A. petiolata does not follow the general scheme for hydroxynitrile glucoside biosynthesis in other...

  10. Turing Systems: A General Model for Complex Patterns in Nature

    Science.gov (United States)

    Barrio, R. A.

    More than half a century ago Alan Turing showed that a system of nonlinear reaction-diffusion equations could produce spatial patterns that are stationary and robust, a phenomenon known as "diffusion driven instability". This remarkable fact was largely ignored for twenty years. However, in the last decade, Turing systems have been a matter of intense and active research, because they are suitable to model a wide variety of phenomena found in Nature, ranging from Turing's original idea of describing morphogenesis from an egg, and applications to the colouring of skins of animals, to the physics of chemical reactors and catalyzers, the physiology of the heart, semiconductor devices, and even to geological formations. In this paper I review the main properties of the Turing instability using a generic reaction-diffusion model, and I give examples of recent applications of Turing models to different problems of pattern formation.

  11. Study of complex properties of binary system of ethanol-methanol at extreme concentrations

    CERN Document Server

    Nilavarasi, K; Madhurima, V

    2016-01-01

    At low concentrations of methanol in ethanol-methanol binary system, the molecular interactions are seen to be uniquely complex. It is observed that the ethanol aggregates are not strictly hydrogen-bonded complexes; dispersion forces also play a dominant role in the self- association of ethanol molecules. On the addition of small amount of methanol to ethanol, the dipolar association of ethanol is destroyed. The repulsive forces between the two moieties dominate the behavior of the binary system at lower concentration of methanol. At higher concentration of methanol (> 30%), the strength and extent (number) of formation of hydrogen bonds between ethanol and methanol increases. The geometry of molecular structure at high concentration favors the fitting of component molecules with each other. Intermolecular interactions in the ethanol-methanol binary system over the entire concentration range were investigated in detail using broadband dielectric spectroscopy, FTIR, surface tension and refractive index studies...

  12. Chemical constituents of marijuana: the complex mixture of natural cannabinoids.

    Science.gov (United States)

    Elsohly, Mahmoud A; Slade, Desmond

    2005-12-22

    The cannabis plant (Cannabis sativa L.) and products thereof (such as marijuana, hashish and hash oil) have a long history of use both as a medicinal agent and intoxicant. Over the last few years there have been an active debate regarding the medicinal aspects of cannabis. Currently cannabis products are classified as Schedule I drugs under the Drug Enforcement Administration (DEA) Controlled Substances act, which means that the drug is only available for human use as an investigational drug. In addition to the social aspects of the use of the drug and its abuse potential, the issue of approving it as a medicine is further complicated by the complexity of the chemical make up of the plant. This manuscript discusses the chemical constituents of the plant with particular emphasis on the cannabinoids as the class of compounds responsible for the drug's psychological properties.

  13. Organized simultaneous displays facilitate learning of complex natural science categories.

    Science.gov (United States)

    Meagher, Brian J; Carvalho, Paulo F; Goldstone, Robert L; Nosofsky, Robert M

    2017-02-24

    Subjects learned to classify images of rocks into the categories igneous, metamorphic, and sedimentary. In accord with the real-world structure of these categories, the to-be-classified rocks in the experiments had a dispersed similarity structure. Our central hypothesis was that learning of these complex categories would be improved through observational study of organized, simultaneous displays of the multiple rock tokens. In support of this hypothesis, a technique that included the presentation of the simultaneous displays during phases of the learning process yielded improved acquisition (Experiment 1) and generalization (Experiment 2) compared to methods that relied solely on sequential forms of study and testing. The technique appears to provide a good starting point for application of cognitive-psychology principles of effective category learning to the science classroom.

  14. Vegetation patterns and nature reserve construction in an extremely-arid desert in Anxi, NW China's Gansu Province.

    Science.gov (United States)

    Liu, Hong-Yan; Xu, Li-Hong; Chen, Chang-Du; Cui, Hai-Ting; Xu, Xing-Ying

    2002-07-01

    Anxi County is located in the northwestern part of the Hexi Corridor in Gansu Province and has the sole national level nature reserve of extremely-arid desert in China. Phytosociological methods (Braun-Blanquet, 1964) are used to classify plant community types in this area. Eleven are distinguished, including six of deserts, four of cases and one transitional type between deserts and cases. Direct gradient analysis (DCA) is employed to correlate the distribution of plant communities to physiogeographic conditions. This study makes clear that water is the most important ecological factor for the distribution of plant species and communities in this area. The effects of water have been demonstrated in different ways. A vegetation gradient from lower altitude to higher altitude in the southern part of the reserve is driven by a precipitation gradient. The effects of the depth of ground water table contribute to the differentiation of vegetation from desert to oasis in the flat area. In a finer scale, the washed gullies have obviously higher species richness and also higher vegetation cover than the surround gobi surfaces, possibly caused by the effects of floods. The vegetation patterns demonstrate that the area of Anxi County is a complete landscape unit. The range of the current nature reserve is not large enough for the purpose of conserving the unique biodiversity in this area.

  15. Nature and severity of lung function abnormalities in extremely pre-term children at 11 years of age.

    Science.gov (United States)

    Lum, S; Kirkby, J; Welsh, L; Marlow, N; Hennessy, E; Stocks, J

    2011-05-01

    Advances in neonatal care have resulted in increased survival of children born extremely pre-term (EP). Nevertheless the incidence of bronchopulmonary dysplasia and long-term respiratory morbidity remains high. We investigated the nature of pathophysiological changes at 11 yrs of age to ascertain whether respiratory morbidity in EP children primarily reflects alterations in the lung periphery or more centralised airway function in this population. Spirometry, plethysmography, diffusing capacity, exhaled nitric oxide, multiple-breath washout, skin tests and methacholine challenge were used during laboratory-based assessments in a subgroup of the 1995 EPICure cohort and in controls. Results were obtained in 49 EP and 52 control children. Lung function abnormalities were found in 78% of EP children, with evidence of airway obstruction, ventilation inhomogeneity, gas trapping and airway hyperresponsiveness. Levels of atopy and exhaled nitric oxide were similar between the groups. Prior wheeze was associated with significant reductions in forced flows and volumes. By contrast, abnormalities of the lung periphery appear to be mediated primarily through EP birth per se. The prevalence of lung function abnormalities, which is largely obstructive in nature and likely to have long-term implications, remains high among 11-yr-old children born EP. Spirometry proved an effective means of detecting these persistent abnormalities.

  16. Vegetation patterns and nature reserve construction in an extremely-arid desert in Anxi,NW China's Gansu Province

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Anxi County is located in the northwestern part of the Hexi Corridor in Gansu Province and has the sole national level nature reserve of extremely-arid desert in China.Phytosociological methods (Braun-Blanquet,1964) are used to classify plant community types in this area.Eleven are distinguished,including six of deserts,four of oases and one transitional type between deserts and oases.Direct gradient analysis ( DCA ) is employed to correlate the distribution of plant communities to physiogeographic conditions.This study makes clear that water is the most important ecological factor for the distribution of plant species and communities in this area.The effects of water have been demonstrated in different ways.A vegetation gradient from lower altitude to higher altitude in the southern part of the reserve is driven by a precipitation gradient.The effects of the depth of ground water table contribute to the differentiation of vegetation from desert to oasis in the flat area.In a finer scale,the washed gullies have obviously higher species richness and also higher vegetation cover than the surround gobi surfaces,possibly caused by the effects of floods.The vegetation patterns demonstrate that the area of Anxi County is a complete landscape unit.The range of the current nature reserve is not large enough for the purpose of conserving the unique biodiversity in this area.

  17. 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.

  18. 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 translation...... in the catalytic efficiency of serine attachment to tRNA, but had no effect on the activity of MtArgRS. Further, the most pronounced improvements in the aminoacylation activity of MtSerRS induced by MtArgRS were observed under conditions of elevated temperature and osmolarity. These data indicate that formation...

  19. Anthropogenic changes to seawater buffer capacity combined with natural reef metabolism induce extreme future coral reef CO2 conditions.

    Science.gov (United States)

    Shaw, Emily C; McNeil, Ben I; Tilbrook, Bronte; Matear, Richard; Bates, Michael L

    2013-05-01

    Ocean acidification, via an anthropogenic increase in seawater carbon dioxide (CO2 ), is potentially a major threat to coral reefs and other marine ecosystems. However, our understanding of how natural short-term diurnal CO2 variability in coral reefs influences longer term anthropogenic ocean acidification remains unclear. Here, we combine observed natural carbonate chemistry variability with future carbonate chemistry predictions for a coral reef flat in the Great Barrier Reef based on the RCP8.5 CO2 emissions scenario. Rather than observing a linear increase in reef flat partial pressure of CO2 (pCO2 ) in concert with rising atmospheric concentrations, the inclusion of in situ diurnal variability results in a highly nonlinear threefold amplification of the pCO2 signal by the end of the century. This significant nonlinear amplification of diurnal pCO2 variability occurs as a result of combining natural diurnal biological CO2 metabolism with long-term decreases in seawater buffer capacity, which occurs via increasing anthropogenic CO2 absorption by the ocean. Under the same benthic community composition, the amplification in the variability in pCO2 is likely to lead to exposure to mean maximum daily pCO2 levels of ca. 2100 μatm, with corrosive conditions with respect to aragonite by end-century at our study site. Minimum pCO2 levels will become lower relative to the mean offshore value (ca. threefold increase in the difference between offshore and minimum reef flat pCO2 ) by end-century, leading to a further increase in the pCO2 range that organisms are exposed to. The biological consequences of short-term exposure to these extreme CO2 conditions, coupled with elevated long-term mean CO2 conditions are currently unknown and future laboratory experiments will need to incorporate natural variability to test this. The amplification of pCO2 that we describe here is not unique to our study location, but will occur in all shallow coastal environments where high

  20. Chromium(III) complexes of naturally occurring ligands

    Science.gov (United States)

    El-Shahawi, M. S.

    1995-02-01

    Chromium(III) complexes prepared from CrCl 3Py 3 and anhydrous CrCl 3 with L(-)-threonine, nicotinic acid, glycine, D(-)-penicillamine, L(-)-cysteine and L(-)-cystine have been characterized. The magnetic moments (3.4-4.05 B.M.) are close to the spin only value for a d3 chromium(III) ion in octahedral or pseudo octahedral symmetry. In the electronic spectra two sharp peaks are observed at (15.9-19.8) × 10 3 and (22.0-26.7) × 10 3 cm -1 and are assigned to d-d transitions in the pseudo octahedral configuration. The parameters ( Dq, B, β35) and the interelectronic repulsion parameter with the ionic charge, Z∗, are calculated and place the ligand in the middle of the spectrochemical series. In the circular dichroism spectra three Cotton effects are observed in the forbidden band of the optically active chelates and are assigned to the 2E( 2Eg), 2A 2( 2T 1g) and2E( 2T 1g) while that in the spin allowed band are a result of the splitting of the 4A 2g( 4T 2g) to 4A 1( 4T 2g) and4E( 4T 2g) transitions. The structure of threonine, cystine and cysteine chelates are likely to be fac since strong and well defined Cotton effects are observed. The Cotton effects of penicillamine chelates are weak suggesting formation of the mer structure. Prolonged heating or bubbling air through the solution of CrCl 3Py 3 containing L(-)-threonine, glycine or nicotinic acid for several hours enhances chromium(VI) formation.

  1. Extreme evolutionary disparities seen in positive selection across seven complex diseases.

    Directory of Open Access Journals (Sweden)

    Erik Corona

    Full Text Available Positive selection is known to occur when the environment that an organism inhabits is suddenly altered, as is the case across recent human history. Genome-wide association studies (GWASs have successfully illuminated disease-associated variation. However, whether human evolution is heading towards or away from disease susceptibility in general remains an open question. The genetic-basis of common complex disease may partially be caused by positive selection events, which simultaneously increased fitness and susceptibility to disease. We analyze seven diseases studied by the Wellcome Trust Case Control Consortium to compare evidence for selection at every locus associated with disease. We take a large set of the most strongly associated SNPs in each GWA study in order to capture more hidden associations at the cost of introducing false positives into our analysis. We then search for signs of positive selection in this inclusive set of SNPs. There are striking differences between the seven studied diseases. We find alleles increasing susceptibility to Type 1 Diabetes (T1D, Rheumatoid Arthritis (RA, and Crohn's Disease (CD underwent recent positive selection. There is more selection in alleles increasing, rather than decreasing, susceptibility to T1D. In the 80 SNPs most associated with T1D (p-value <7.01 x 10(-5 showing strong signs of positive selection, 58 alleles associated with disease susceptibility show signs of positive selection, while only 22 associated with disease protection show signs of positive selection. Alleles increasing susceptibility to RA are under selection as well. In contrast, selection in SNPs associated with CD favors protective alleles. These results inform the current understanding of disease etiology, shed light on potential benefits associated with the genetic-basis of disease, and aid in the efforts to identify causal genetic factors underlying complex disease.

  2. 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.

  3. Censusing natural microgametophyte populations: variable spatial mosaics and extreme fine-graininess in winter-flowering Helleborus foetidus (Ranunculaceae).

    Science.gov (United States)

    Herrera, Carlos M

    2002-10-01

    Little is known about patterns and correlates of variation in microgametophyte populations for naturally pollinated plants, yet this information is critical for evaluating the prevalence and potential evolutionary significance of gametophyte competition in the wild. This paper analyzes spatial and temporal variation in microgametophyte populations (= number of pollen tubes per style) for the winter-flowering, perennial herb Helleborus foetidus (Ranunculaceae), based on data from 29 populations in three regions of the Iberian Peninsula collected over two consecutive years. Mean size of microgametophyte populations varied significantly at a wide range of spatial scales, including among regions, among populations within regions, among individual plants within populations, among flowers of the same plant, and among pistils of the same flower (H. foetidus flowers are apocarpous). Differences between regions were quantitatively negligible. Differences between populations in the same region were moderate to low, and their sign and magnitude were inconsistent between years. Roughly half of total variance in microgametophyte numbers was accounted for by variation within individual plants, and the largest part of this component was due to differences between the pistils of the same flower. These results reveal extreme spatial fine-graininess and marked stochasticity in the spatial variation of H. foetidus microgametophyte populations and suggest that opportunities for consistent selection on male gametophyte competitive ability are probably negligible in this species.

  4. [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.

  5. Nonlinearity, chaos, and complexity the dynamics of natural and social systems

    CERN Document Server

    Bertuglia, Cristoforo Sergio

    2005-01-01

    Covering a broad range of topics, this text provides a comprehensive survey of the modelling of chaotic dynamics and complexity in the natural and social sciences. Its attention to models in both the physical and social sciences and the detailed philosophical approach make this an unique text in the midst of many current books on chaos and complexity. Including an extensive index and bibliography along with numerous examples and simplified models, this is an ideal course. text. - ;Covering a broad range of topics, this text provides a comprehensive survey of the modelling of chaotic dynamics and complexity in the natural and social sciences. Its attention to models in both the physical and social sciences and the detailed philosophical approach make this an unique text in the midst of many current books on chaos and complexity. Part 1 deals with the mathematical model as an instrument of investigation. The general meaning of modelling and, more specifically, questions concerning linear modelling are discussed...

  6. Rheological principles of development hetero-modulus and hetero-viscous complex materials with extreme dynamic strength

    Science.gov (United States)

    Gömze, L. A.; Gömze, L. N.

    2017-02-01

    Materials with different crystalline and morphological compositions have different chemical, physical, mechanical and rheological properties, including wear protection, melting temperature, module of elasticity and viscosity. Examining the material structures and behaviors of differentceramic bodies and CMCs under high speed collisions in several years the authors have understood the advantages of hetero-modulus and hetero-viscous complex material systems to absorb and dissipate the kinetic energy of objects during high speed collisions. Applying the rheo-mechanical principles the authors successfully developed a new family of hetero-modulus and hetero-viscous alumina matrix composite materials with extreme mechanical properties including dynamic strength. These new corundum-matrix composite materials reinforced with Si2ON 2, Si3N4 , SiAlON and AlN submicron and nanoparticles have excellent dynamic strength during collisions with high density metallic bodies with speeds about 1000 m/sec or more. At the same time in the alumina matrix composites can be observed a phase transformation of submicron and nanoparticles of alpha and beta silicone-nitride crystals into cubicc-Si3N4 diamond-like particles can be observed, when the high speed collision processes are taken place in vacuum or oxygen-free atmosphere. Using the rheological principles and the energy engorgement by fractures, heating and melting of components the authors successfully developed several new hetero-modulus, hetero-viscous and hetero-plastic complex materials. These materials generally are based on ceramic matrixes and components having different melting temperatures and modules of elasticity from low values like carbon and light metals (Mg, Al, Ti, Si) up to very high values like boride, nitride and carbide ceramics. Analytical methods applied in this research were scanning electron microscopy, X-ray diffractions and energy dispersive spectrometry. Digital image analysis was applied to microscopy

  7. 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.

  8. Performing Complex Tasks by Users With Upper-Extremity Disabilities Using a 6-DOF Robotic Arm: A Study.

    Science.gov (United States)

    Al-Halimi, Reem K; Moussa, Medhat

    2017-06-01

    In this paper, we report on the results of a study that was conducted to examine how users suffering from severe upper-extremity disabilities can control a 6 degrees-of-freedom (DOF) robotics arm to complete complex activities of daily living. The focus of the study is not on assessing the robot arm but on examining the human-robot interaction patterns. Three participants were recruited. Each participant was asked to perform three tasks: eating three pieces of pre-cut bread from a plate, drinking three sips of soup from a bowl, and opening a right-handed door with lever handle. Each of these tasks was repeated three times. The arm was mounted on the participant's wheelchair, and the participants were free to move the arm as they wish to complete these tasks. Each task consisted of a sequence of modes where a mode is defined as arm movement in one DOF. Results show that participants used a total of 938 mode movements with an average of 75.5 (std 10.2) modes for the eating task, 70 (std 8.8) modes for the soup task, and 18.7 (std 4.5) modes for the door opening task. Tasks were then segmented into smaller subtasks. It was found that there are patterns of usage per participant and per subtask. These patterns can potentially allow a robot to learn from user's demonstration what is the task being executed and by whom and respond accordingly to reduce user effort.

  9. 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.

  10. 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

  11. Coevolution in Complex Networks : An analysis of socio-natural interactions for wetlands management

    NARCIS (Netherlands)

    Gilbert, A.J.

    2006-01-01

    Coevolution between natural and social systems comprises interaction, reciprocal dynamics and reciprocal adaptation. The notion derives primarily from evolutionary biology, but also from the study of complex systems. This dissertation aims to: “develop the means to assess the effects of different hu

  12. Detection Limits for Natural Circular Dichroism of Chiral Complexes in the X-ray Range

    NARCIS (Netherlands)

    Goulon, José; Sette, Francesco; Moise, Claude; Fontaine, Alain; Perey, Danièle; Rudolf, Petra; Baudelet, François

    1993-01-01

    Whereas both Magnetic Circular Dichroism and Faraday Rotation studies have been successfully carried out at the K-, L- and M- absorption edges of metal atoms in ferromagnetic systems, Natural optical activity of chiral complexes has not yet been detected quite unambiguously in the X-ray range. We re

  13. Detection Limits for Natural Circular Dichroism of Chiral Complexes in the X-ray Range

    NARCIS (Netherlands)

    Goulon, José; Sette, Francesco; Moise, Claude; Fontaine, Alain; Perey, Danièle; Rudolf, Petra; Baudelet, François

    1993-01-01

    Whereas both Magnetic Circular Dichroism and Faraday Rotation studies have been successfully carried out at the K-, L- and M- absorption edges of metal atoms in ferromagnetic systems, Natural optical activity of chiral complexes has not yet been detected quite unambiguously in the X-ray range. We

  14. Towards theory driven structure elucidation of complex natural products: mandelalides and coibamide A.

    Science.gov (United States)

    Snyder, Kevin M; Sikorska, Justyna; Ye, Tao; Fang, Lijing; Su, Wu; Carter, Rich G; McPhail, Kerry L; Cheong, Paul H-Y

    2016-06-28

    The effectiveness of computational tools in determining relative configurations of complex molecules is investigated, using natural products mandelalides A-D and coibamide A, towards a generalized recipe for the scientific community at large. Ultimately, continuing efforts in this vein will accelerate and strengthen relative structure elucidation of complex molecules, such as natural products. Molecular mechanics conformational search, quantum mechanical NMR chemical shift predictions, and DP4 analyses led to confirmation of the revised structures of mandelalides A-D and coibamide A. All chiral centers in the northern hemisphere of mandelalides A-D are inverted with respect to the originally proposed structures, in agreement with recent total syntheses of mandelalide A by Ye, Fürstner & Carter. In the case of coibamide A, it was found that Fang & Su's revision, in which both the macrocycle [MeAla(11)] and the side chain [HIV(2)] residues are inverted from l to d, was consistent with the authentic natural product and computations.

  15. The Continuing Development of E. coli as a Heterologous Host for Complex Natural Product Biosynthesis.

    Science.gov (United States)

    Zhang, Haoran; Fang, Lei; Osburne, Marcia S; Pfeifer, Blaine A

    2016-01-01

    Heterologous biosynthesis of natural products is meant to enable access to the vast array of valuable properties associated with these compounds. Often motivated by limitations inherent in native production hosts, the heterologous biosynthetic process begins with a candidate host regarded as technically advanced relative to original producing organisms. Given this requirement, E. coli has been a top choice for heterologous biosynthesis attempts as associated recombinant tools emerged and continue to develop. However, success requires overcoming challenges associated with natural product formation, including complex biosynthetic pathways and the need for metabolic support. These two challenges have been heavily featured in cellular engineering efforts completed to position E. coli as a viable surrogate host. This chapter outlines steps taken to engineer E. coli with an emphasis on genetic manipulations designed to support the heterologous production of polyketide, nonribosomal peptide, and similarly complex natural products.

  16. A ring-distortion strategy to construct stereochemically complex and structurally diverse compounds from natural products

    Science.gov (United States)

    Huigens, Robert W., III; Morrison, Karen C.; Hicklin, Robert W.; Flood, Timothy A., Jr.; Richter, Michelle F.; Hergenrother, Paul J.

    2013-03-01

    High-throughput screening is the dominant method used to identify lead compounds in drug discovery. As such, the makeup of screening libraries largely dictates the biological targets that can be modulated and the therapeutics that can be developed. Unfortunately, most compound-screening collections consist principally of planar molecules with little structural or stereochemical complexity, compounds that do not offer the arrangement of chemical functionality necessary for the modulation of many drug targets. Here we describe a novel, general and facile strategy for the creation of diverse compounds with high structural and stereochemical complexity using readily available natural products as synthetic starting points. We show through the evaluation of chemical properties (which include fraction of sp3 carbons, ClogP and the number of stereogenic centres) that these compounds are significantly more complex and diverse than those in standard screening collections, and we give guidelines for the application of this strategy to any suitable natural product.

  17. Responses of Natural Vegetation to Different Stages of Extreme Drought during 2009–2010 in Southwestern China

    Directory of Open Access Journals (Sweden)

    Xiang Zhao

    2015-10-01

    Full Text Available An extreme drought event is usually a long-term process with different stages. Although it is well known that extreme droughts that have occurred frequently in recent years can substantially affect vegetation growth, few studies have revealed the characteristics of vegetation responses for different stages of an extreme drought event. Especially, studies should address when the vegetation growth was disturbed and how it recovered through an extreme drought event. In this study, we used the Normalized Difference Vegetation Index (NDVI and Palmer Drought Severity Index (PDSI to evaluate the response of vegetation to different stages of a severe drought event during 2009–2010 throughout Southwestern China. The PDSI time series indicated that the drought can be divided into three stages, including an initial stage represented by moderate drought (S1, a middle stage represented by continual severe drought (S2, and a final recovery stage (S3. The results revealed that the drought during the initial stage inhibited the growth of grassland and woody savanna, however, forest growth did not decrease during the first stage of droughts, and there was even a trend towards higher NDVI values. The continual severe drought in the middle stage inhibited growth for all vegetation types, and the woody savanna was affected most severely. In the final stage, all vegetation types underwent recovery, including the grassland that had endured the most severe drought. This study provides observational evidence and reveals that the responses of forest to the extreme drought are different from grassland and woody savanna in the different drought stages.

  18. 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.

    2015-05-01

    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.

  19. Strength and nature of hydrogen bonding interactions in mono- and di-hydrated formamide complexes.

    Science.gov (United States)

    Angelina, Emilio L; Peruchena, Nélida M

    2011-05-12

    In this work, mono- and di-hydrated complexes of the formamide were studied. The calculations were performed at the MP2/6-311++G(d,p) level of approximation. The atoms in molecules theory (AIM), based on the topological properties of the electronic density distribution, was used to characterize the different types of bonds. The analysis of the hydrogen bonds (H-bonds) in the most stable mono- and di-hydrated formamide complexes shows a mutual reinforcement of the interactions, and some of these complexes can be considered as "bifunctional hydrogen bonding hydration complexes". In addition, we analyzed how the strength and the nature of the interactions, in mono-hydrated complexes, are modified by the presence of a second water molecule in di-hydrated formamide complexes. Structural changes, cooperativity, and electron density redistributions demonstrate that the H-bonds are stronger in the di-hydrated complexes than in the corresponding mono-hydrated complexes, wherein the σ- and π-electron delocalization were found. To explain the nature of such interactions, we carried out the atoms in molecules theory in conjunction with reduced variational space self-consistent field (RVS) decomposition analysis. On the basis of the local Virial theorem, the characteristics of the local electron energy density components at the bond critical points (BCPs) (the 1/4∇ (2)ρ(b) component of electron energy density and the kinetic energy density) were analyzed. These parameters were used in conjunction with the electron density and the Laplacian of the electron density to analyze the characteristics of the interactions. The analysis of the interaction energy components for the systems considered indicates that the strengthening of the hydrogen bonds is manifested by an increased contribution of the electrostatic energy component represented by the kinetic energy density at the BCP.

  20. 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

    2005-02-04

    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.

  1. 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. PMID:28278280

  2. The complex of looped diagrams and natural operations on Hochschild homology

    DEFF Research Database (Denmark)

    Klamt, Angela

    In this thesis natural operations on the (higher) Hochschild complex of a given family of algebras are investigated. We give a description of all formal operations (in the sense of Wahl) for the class of commutative algebras using Loday's lambda operation, Connes' boundary operator and shue produ...... of formal operations on Hochschild homology to higher Hochschild homology. We also generalize statements about the formal operations and give smaller models for the formal operations on higher Hochschild homology in certain cases....

  3. The nature of arsenic-phytochelatin complexes in Holcus lanatus and Pteris cretica.

    Science.gov (United States)

    Raab, Andrea; Feldmann, Jörg; Meharg, Andrew A

    2004-03-01

    We have developed a method to extract and separate phytochelatins (PCs)-metal(loid) complexes using parallel metal(loid)-specific (inductively coupled plasma-mass spectrometry) and organic-specific (electrospray ionization-mass spectrometry) detection systems-and use it here to ascertain the nature of arsenic (As)-PC complexes in plant extracts. This study is the first unequivocal report, to our knowledge, of PC complex coordination chemistry in plant extracts for any metal or metalloid ion. The As-tolerant grass Holcus lanatus and the As hyperaccumulator Pteris cretica were used as model plants. In an in vitro experiment using a mixture of reduced glutathione (GS), PC(2), and PC(3), As preferred the formation of the arsenite [As((III))]-PC(3) complex over GS-As((III))-PC(2), As((III))-(GS)(3), As((III))-PC(2), or As((III))-(PC(2))(2) (GS: glutathione bound to arsenic via sulphur of cysteine). In H. lanatus, the As((III))-PC(3) complex was the dominant complex, although reduced glutathione, PC(2), and PC(3) were found in the extract. P. cretica only synthesizes PC(2) and forms dominantly the GS-As((III))-PC(2) complex. This is the first evidence, to our knowledge, for the existence of mixed glutathione-PC-metal(loid) complexes in plant tissues or in vitro. In both plant species, As is dominantly in non-bound inorganic forms, with 13% being present in PC complexes for H. lanatus and 1% in P. cretica.

  4. Thiopyridazine-Based Copper Boratrane Complexes Demonstrating the Z-type Nature of the Ligand.

    Science.gov (United States)

    Holler, Stefan; Tüchler, Michael; Belaj, Ferdinand; Veiros, Luis F; Kirchner, Karl; Mösch-Zanetti, Nadia C

    2016-05-16

    In Z-type ligands the electrons for the coordination bond are formally provided by the metal. They represent an important addition to the much more extensively used L- and X-type σ-donor ligands for the development of transition metal complexes with new reactivities. We report here a new boron Z-type ligand with three tethering thiopyridazinyl donors forming exclusively complexes that feature a metal boron bond. Rational substitution pattern in the backbone of the pyridazinyl heterocycle led to a well-behaved ligand system that allowed preparation of a series of copper boratrane complexes in high yields. They are found to be more soluble in common organic solvents allowing reactivity studies in contrast to previous complexes with this type of ligand. Thus, copper complexes [Cu{B(Pn(Me,tBu))3}X] with X = Cl, OTf, N3, and κN-NCS are reported. Solution behavior was explored, and the molecular structures were determined by single-crystal X-ray diffraction analyses. The thiocyanate ligand is found to coordinate via its nitrogen atom pointing to a high oxidation state of the copper. Density functional theory calculations indicate a high positive charge on copper and a strong copper-boron interaction. Thus, here reported complexes deliver synthetic evidence for the Z-type nature of the ligand. These findings are important for further dissemination of these types of ligands in coordination chemistry.

  5. The Complexity of Monotone Hybrid Logics over Linear Frames and the Natural Numbers

    CERN Document Server

    Göller, Stefan; Mundhenk, Martin; Schneider, Thomas; Thomas, Michael; Weiss, Felix

    2012-01-01

    Hybrid logic with binders is an expressive specification language. Its satisfiability problem is undecidable in general. If frames are restricted to the natural numbers or general linear orders, then satisfiability is known to be decidable, but of non-elementary complexity. In this paper, we consider monotone hybrid logics (i.e., the Boolean connectives are conjunction and disjunction only) over the natural numbers and general linear orders. We show that the satisfiability problem remains non-elementary over linear orders, but its complexity drops to PSPACE-completeness over natural numbers. We categorize the strict fragments arising from different combinations of modal and hybrid operators into NP-complete and tractable, and show that the latter cases are complete for NC1 or LOGSPACE. Interestingly, NP-completeness depends only on the fragment and not on the frame. For the cases above NP, satisfiability over linear orders is harder than over natural numbers, while below NP it is at most as hard. In addition ...

  6. How extreme are extremes?

    Science.gov (United States)

    Cucchi, Marco; Petitta, Marcello; Calmanti, Sandro

    2016-04-01

    High temperatures have an impact on the energy balance of any living organism and on the operational capabilities of critical infrastructures. Heat-wave indicators have been mainly developed with the aim of capturing the potential impacts on specific sectors (agriculture, health, wildfires, transport, power generation and distribution). However, the ability to capture the occurrence of extreme temperature events is an essential property of a multi-hazard extreme climate indicator. Aim of this study is to develop a standardized heat-wave indicator, that can be combined with other indices in order to describe multiple hazards in a single indicator. The proposed approach can be used in order to have a quantified indicator of the strenght of a certain extreme. As a matter of fact, extremes are usually distributed in exponential or exponential-exponential functions and it is difficult to quickly asses how strong was an extreme events considering only its magnitude. The proposed approach simplify the quantitative and qualitative communication of extreme magnitude

  7. Natural frequencies improve Bayesian reasoning in simple and complex inference tasks.

    Science.gov (United States)

    Hoffrage, Ulrich; Krauss, Stefan; Martignon, Laura; Gigerenzer, Gerd

    2015-01-01

    Representing statistical information in terms of natural frequencies rather than probabilities improves performance in Bayesian inference tasks. This beneficial effect of natural frequencies has been demonstrated in a variety of applied domains such as medicine, law, and education. Yet all the research and applications so far have been limited to situations where one dichotomous cue is used to infer which of two hypotheses is true. Real-life applications, however, often involve situations where cues (e.g., medical tests) have more than one value, where more than two hypotheses (e.g., diseases) are considered, or where more than one cue is available. In Study 1, we show that natural frequencies, compared to information stated in terms of probabilities, consistently increase the proportion of Bayesian inferences made by medical students in four conditions-three cue values, three hypotheses, two cues, or three cues-by an average of 37 percentage points. In Study 2, we show that teaching natural frequencies for simple tasks with one dichotomous cue and two hypotheses leads to a transfer of learning to complex tasks with three cue values and two cues, with a proportion of 40 and 81% correct inferences, respectively. Thus, natural frequencies facilitate Bayesian reasoning in a much broader class of situations than previously thought.

  8. 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.

  9. 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.

  10. First observation of natural circular dichroism spectra in the extreme ultraviolet region using a polarizing undulator-based optical system and its polarization characteristics.

    Science.gov (United States)

    Tanaka, Masahito; Yagi-Watanabe, Kazutoshi; Kaneko, Fusae; Nakagawa, Kazumichi

    2009-07-01

    Natural circular dichroism (CD) spectra in the extreme ultraviolet (EUV) region down to a wavelength of 80 nm have been observed for the first time, using an alanine thin film deposited on sodium salicylate coated glass as a sample. Calibrated EUV-CD spectra of L-alanine exhibited a large negative peak at around 120 nm and a positive CD signal below 90 nm, which were roughly predicted by theoretical calculations. A CD measurement system with an Onuki-type polarizing undulator was used to obtain the EUV-CD spectra. This CD system, the development of which took five years, can be used to observe even weak natural CD spectra. The polarization characteristics of this system were also evaluated in order to calibrate the recorded CD spectra.

  11. Trace Metal-Humic Complexes in Natural Waters: Insights From Speciation Experiments

    Science.gov (United States)

    Stern, J. C.; Salters, V.; Sonke, J.

    2006-12-01

    The DOM cycle is intimately linked to the cycling and bioavailability of trace metals in aqueous environments. The presence or absence of DOM in the water column can determined whether trace elements will be present in limited quantities as a nutrient, or in surplus quantities as a toxicant. Humic substances (HS), which represent the refractory products of DOM degradation, strongly affect the speciation of trace metals in natural waters. To simulate metal-HS interactions in nature, experiments must be carried out using trace metal concentrations. Sensitive detection systems such as ICP-MS make working with small (nanomolar) concentrations possible. Capillary electrophoresis coupled with ICP-MS (CE-ICP-MS) has recently been identified as a rapid and accurate method to separate metal species and calculate conditional binding constants (log K_c) of metal-humic complexes. CE-ICP-MS was used to measure partitioning of metals between humic substances and a competing ligand (EDTA) and calculate binding constants of rare earth element (REE) and Th, Hf, and Zr-humic complexes at pH 3.5-8 and ionic strength of 0.1. Equilibrium dialysis ligand exchange (EDLE) experiments to validate the CE-ICP-MS method were performed to separate the metal-HS and metal-EDTA species by partitioning due to size exclusion via diffusion through a 1000 Da membrane. CE-ICP-MS experiments were also conducted to compare binding constants of REE with humic substances of various origin, including soil, peat, and aquatic DOM. Results of our experiments show an increase in log K_c with decrease in ionic radius for REE-humic complexes (the lanthanide contraction effect). Conditional binding constants of tetravalent metal-humic complexes were found to be several orders of magnitude higher than REE-humic complexes, indicating that tetravalent metals have a very strong affinity for humic substances. Because thorium is often used as a proxy for the tetravalent actinides, Th-HS binding constants can allow us

  12. Complexes of metals with humus substances as natural biocolloids: mechanism and size

    Science.gov (United States)

    Dinu, Marina; Shkinev, Valery; Linnik, Vitaly

    2014-05-01

    Metal complexes with humus substances in the soil are natural biocolloids, which are characterized by the size of the nano- to milli grams. Physical state of the compound functional features humus substances (HS), the nature of metal - all these parameters define different mechanisms transportation of the metal in the soil profile. To assess changes in the composition humus substances complexes with metals and molecular weights humus substances used methods ultrotsentrifugation and filtration (ultrafiltration alkali metals do not stay in any of the fractions and to migrate as the ions (40-50 cm). Alkali- earth metals, on the contrary, delayed a layer ( 2-7 cm), most humified layer, explained by the appearance of active d- orbital of the metal cations, and their greater ability to form complexes than alkali metals. Aluminum content of elements of the subgroup represented by several peaks, mainly in the upper layers of the soil in those areas where the most represented type of fulvic humus substances. High concentration of iron in all studied soil layers. An exception is the 15-35 cm layer which contains humic substance in large quantities compared with fulvic acids, that may explain the decrease in the affinity of the metal to the functional groups and less strong sorption communication mechanism. Metal concentrations of nickel and cobalt are practically unchanged with soil depth. Indicating that almost the same ability to bind to humic and fulvic acids. In samples of 5-8 cm identified reduction of zinc and copper ions in the filtrates from 8 microns to 100 kDa. However, complexes with zinc ions of HS molecular weight less than 100 kDa in all filtrates predominates, particularly fulvic type complexes. Lead ions are predominantly high molecular weight complexes of over 1000 kD, so the filtrate was less than 100 kDa lead content is minimal. The content of zinc ion in layers 8-11 sharply decreases with decreasing pore size of the filter is comparable to the reduction

  13. 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.

  14. Cosmetic benefits of natural ingredients: mushrooms, feverfew, tea, and wheat complex.

    Science.gov (United States)

    Bowe, Whitney P

    2013-09-01

    Natural ingredients are frequently used in an effort to address cosmetic concerns such as fine lines, wrinkles, uneven tone, and texture. Many of these ingredients found in nature possess potent antioxidant as well as anti-inflammatory properties. Some, such as mushroom extracts, are even capable of accelerating the skin turnover rate and repairing dermal molecular components that provide structure and elasticity to the skin. Others, such as green tea, provide photoprotection against ultraviolet-induced DNA damage. In this manuscript, the cosmetic benefits of mushrooms, feverfew, and tea are discussed in the context of their ability to improve the appearance of the skin. The healing effects that wheat complex can have on damaged hair are also addressed.

  15. Whole-genome resequencing of extreme phenotypes in collared flycatchers highlights the difficulty of detecting quantitative trait loci in natural populations.

    Science.gov (United States)

    Kardos, Marty; Husby, Arild; McFarlane, S Eryn; Qvarnström, Anna; Ellegren, Hans

    2016-05-01

    Dissecting the genetic basis of phenotypic variation in natural populations is a long-standing goal in evolutionary biology. One open question is whether quantitative traits are determined only by large numbers of genes with small effects, or whether variation also exists in large-effect loci. We conducted genomewide association analyses of forehead patch size (a sexually selected trait) on 81 whole-genome-resequenced male collared flycatchers with extreme phenotypes, and on 415 males sampled independent of patch size and genotyped with a 50K SNP chip. No SNPs were genomewide statistically significantly associated with patch size. Simulation-based power analyses suggest that the power to detect large-effect loci responsible for 10% of phenotypic variance was 0.8 for resequencing of extreme phenotypes (N = 243), but power remained 0.8 when analysing 415 randomly sampled phenotypes. However, power of the 50K SNP chip to detect large-effect loci was nearly 0.8 in simulations with a small effective population size of 1500. These results suggest that reliably detecting large-effect trait loci in large natural populations will often require thousands of individuals and near complete sampling of the genome. Encouragingly, far fewer individuals and loci will often be sufficient to reliably detect large-effect loci in small populations with widespread strong linkage disequilibrium.

  16. 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.

  17. 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.

  18. Synthetic Detergents: Their Influence upon Iron-Binding Complexes of Natural Waters.

    Science.gov (United States)

    Kent, F; Hooper, F F

    1966-07-29

    Organic compounds extracted from Michigan lakes and streams and added to algal cultures increase the growth rate of the green alga (Chlamydomonas reinhardi) when iron is present. Two-dimensional paper chromatography has shown that the iron is complexed by organic fractions containing an amine group. When isolated from natural waters containing a concentration of over 0.3 part per million alkyl benzene sulfonate, these compounds do not show an iron-binding capacity. Separation of this sulfonate from the amine complexes restores the iron-binding capability. These findings suggest that detergents may influence the mobility of iron by reducing the number of binding sites, and in this way may have an important secondary effect upon the primary production of lakes and streams.

  19. Regulation of flowering in rice: two florigen genes, a complex gene network, and natural variation.

    Science.gov (United States)

    Tsuji, Hiroyuki; Taoka, Ken-ichiro; Shimamoto, Ko

    2011-02-01

    Photoperiodic control of flowering time consists of a complicated network that converges into the generation of a mobile flowering signal called florigen. Recent advances identifying the protein FT/Hd3a as the molecular nature responsible for florigen activity have focused current research on florigen genes as the important output of this complex signaling network. Rice is a model system for short-day plants and recent progress in elucidating the flowering network from rice and Arabidopsis, a long-day plant, provides an evolutionarily comparative view of the photoperiodic flowering pathway. This review summarizes photoperiodic flowering control in rice, including the interaction of complex layers of gene networks contributed from evolutionarily unique factors and the regulatory adaptation of conserved factors.

  20. Censusing natural Microgametophyte populations:variable spatial mosaics and extreme fine-graininess in winter-flowering Helleborus foetidus (Ranunculaceae)

    OpenAIRE

    Carlos M Herrera

    2002-01-01

    Little is known about patterns and correlates of variation in microgametophyte populations for naturally pollinated plants, yet this information is critical for evaluating the prevalence and potential evolutionary significance of gametophyte competition in the wild. This paper analyzes spatial and temporal variation in microgametophyte populations (= number of pollen tubes per style) for the winter-flowering, perennial herb Helleborus foetidus (Ranunculaceae), based on data from 29 populatio...

  1. Idaho National Laboratory Materials and Fuels Complex Natural Phenomena Hazards Flood Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Gerald Sehlke; Paul Wichlacz

    2010-12-01

    This report presents the results of flood hazards analyses performed for the Materials and Fuels Complex (MFC) and the adjacent Transient Reactor Experiment and Test Facility (TREAT) located at Idaho National Laboratory. The requirements of these analyses are provided in the U.S. Department of Energy Order 420.1B and supporting Department of Energy (DOE) Natural Phenomenon Hazard standards. The flood hazards analyses were performed by Battelle Energy Alliance and Pacific Northwest National Laboratory. The analyses addressed the following: • Determination of the design basis flood (DBFL) • Evaluation of the DBFL versus the Critical Flood Elevations (CFEs) for critical existing structures, systems, and components (SSCs).

  2. ISO investigates the nature of extremely-red hard X-ray sources responsible for the X-ray background

    CERN Document Server

    Franceschini, A; Césarsky, C J; Elbaz, D; Flores, H; Granato, G L; Franceschini, Alberto; Fadda, Dario; Cesarsky, Catherine; Elbaz, David; Flores, Hector; Granato, Gian Luigi

    2001-01-01

    We analyse very deep X-ray and mid-IR surveys in common areas of the Lockman Hole and the HDF North to study the sources of the X-ray background (XRB) and to test the standard obscured accretion paradigm. We detect with ISO a rich population of X-ray luminous sources with red optical colours, including a fraction identified with Extremely Red Objects (R-K > 5) and galaxies with SEDs typical of normal massive ellipticals or spirals at z ~ 1. The high 0.5-10 keV X-ray luminosities of these objects (1E43-1E45 erg/s) indicate that the ultimate energy source is gravitational accretion, while the X-ray to IR flux ratios and the X-ray spectral hardness show evidence of photoelectric absorption at low X-ray energies. An important hint on the physics comes from the mid-IR data at 6.7 and 15 um, well reproduced by model spectra of completely obscured quasars under standard assumptions and l.o.s. optical depths tau ~ 30-40. Other predictions of the standard XRB picture, like the distributions of intrinsic bolometric lum...

  3. The Nature of Extreme Emission Line Galaxies at z=1-2: Kinematics and Metallicities from Near-Infrared Spectroscopy

    CERN Document Server

    Maseda, Michael V; Rix, Hans-Walter; da Cunha, Elisabete; Pacifici, Camilla; Momcheva, Ivelina; Brammer, Gabriel B; Meidt, Sharon E; Franx, Marijn; van Dokkum, Pieter; Fumagalli, Mattia; Bell, Eric F; Ferguson, Henry C; Förster-Schreiber, Natascha M; Koekemoer, Anton M; Koo, David C; Lundgren, Britt F; Marchesini, Danilo; Nelson, Erica J; Patel, Shannon G; Skelton, Rosalind E; Straughn, Amber N; Trump, Jonathan R; Whitaker, Katherine E

    2014-01-01

    We present near-infrared spectroscopy of a sample of 22 Extreme Emission Line Galaxies at redshifts 1.3 5) and [N II]/H{\\alpha} is always significantly below unity, which suggests a low gas-phase metallicity. We are able to determine gas-phase metallicities for 7 of our objects using various strong-line methods, with values in the range 0.05-0.30 Z_sun and with a median of 0.15 Z_sun; for 3 of these objects we detect [O III]{\\lambda}4363 which allows for a direct constraint on the metallicity. The velocity dispersion, as measured from the nebular emission lines, is typically ~50 km/s. Combined with the observed star-forming activity, the Jeans and Toomre stability criteria imply that the gas fraction must be large (> 2/3), consistent with the difference between our dynamical and stellar mass estimates. The implied gas depletion time scale (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 galaxi...

  4. Learning, adaptation, and the complexity of human and natural interactions in the ocean

    Directory of Open Access Journals (Sweden)

    James Wilson

    2017-06-01

    Full Text Available Here, I explore the system-level consequences of learning and adaptation among fish and fishers. The fundamental idea is that the cost of acquiring the knowledge needed to resolve uncertainty is the principal driver of social and spatial organization. This cost limits agents' actions and leads them to prefer relatively persistent associations with familiar agents and places. When all agents act in this way, the regularity and self-reinforcing nature of familiarity leads to the emergence of a self-organized system. Systems like this are characterized by diverse, place-based, and relatively durable groups, groups of groups, and rough hierarchical structure. This occurs in both the natural and human parts of the system. The costs of resolving uncertainty also determine the interactions of fish and fishers. The uncertainty of search leads fishers preferentially to target older fish and aggregations of fish. These are the repositories and mechanisms for the replication of the knowledge needed for self-organization. The loss of this information selectively, but unintentionally, disrupts the behavioral regularity that organizes the natural system, leading eventually to its disorganization. From this theoretical perspective, sustainable fishing requires conservation of the knowledge in DNA and memory because this is the fundamental basis for the self-organization of the natural system. Collective action is also subject to the costs of resolving uncertainty. In complex systems, these costs are minimized at the local level in the system, where the most direct, but not the only, feedback occurs. This implies the need for multiscale governance with an emphasis on collective learning through localized science and user participation. Finally, the complexity of ecosystem interactions argues for qualitative harvesting rules governing how, when, and where fishing takes place. These rules are most likely to generate a persistent signal and rapid learning, but

  5. Natural infection of cortelezzii complex (Diptera: Psychodidae: Phlebotominae) with Leishmania braziliensis in Chaco, Argentina.

    Science.gov (United States)

    Rosa, Juan; Pereira, Daniela Pita; Brazil, Reginaldo Peçanha; Filho, José Dilermando Andrade; Salomón, Oscar; Szelag, Enrique

    2012-08-01

    In Argentina, American Cutaneous Leishmaniasis (ACL) extends up to 29°S in the phytogeographic regions of the Yungas (west), Chaco (center) and Paranaense (east). Since the Phlebotominae vectors of this disease in the western Chaco (dry Chaco) are unknown, in the present work, we studied the natural infection in Phlebotominae by PCR-ERFLP and Dot blot in order to incriminate these organisms as potential vectors. Captures with CDC-type traps were performed monthly in the domicile, the peridomicile and the forest in the Municipio Misión Nueva Pompeya, Chaco, Argentina, in two sites with human cases of ACL: Los Pozos (24°54'S, 61°22'W) and Fortín Arenales (24°58'S, 61°21'W), from November 2006 to December 2007. A total of 1702 Phlebotominae were captured: Mygonemyia migonei (83.8%), cortelezzii complex (11.1%), Mycropigomyia peresi (3.3%), Mycropygomy quinquefer (1.2%), Pintomyia torresi (0.2%) and Nyssomyia neivai (0.2%). Although no significant differences were found in species diversity, there were significant differences in abundance between both sites studied. A total of 80 phlebotomine females were analyzed: 50 of the cortelezzii complex and 30 My. migonei. No intestinal flagellates were observed by light microscopy. Two pools of 10 individuals of the cortelezzii complex of the peridomicile and forest of Fortín Arenales were reactive by PCR and Dot blot for Leishmania (Viannia) braziliensis. In Argentina, Evandromyia cortelezzii has been incriminated as a likely vector of ACL because of its abundance in areas of sporadic outbreaks. In the present work, Ev. cortelezzii females were found naturally infected, thus reinforcing the hypothesis that the members of the cortelezzii complex act as vectors of the disease.

  6. Metal Complexes Containing Natural and and Artificial Radioactive Elements and Their Applications

    Directory of Open Access Journals (Sweden)

    Oxana V. Kharissova

    2014-07-01

    Full Text Available Recent advances (during the 2007–2014 period in the coordination and organometallic chemistry of compounds containing natural and artificially prepared radionuclides (actinides and technetium, are reviewed. Radioactive isotopes of naturally stable elements are not included for discussion in this work. Actinide and technetium complexes with O-, N-, N,O, N,S-, P-containing ligands, as well π-organometallics are discussed from the view point of their synthesis, properties, and main applications. On the basis of their properties, several mono-, bi-, tri-, tetra- or polydentate ligands have been designed for specific recognition of some particular radionuclides, and can be used in the processes of nuclear waste remediation, i.e., recycling of nuclear fuel and the separation of actinides and fission products from waste solutions or for analytical determination of actinides in solutions; actinide metal complexes are also usefulas catalysts forcoupling gaseous carbon monoxide,as well as antimicrobial and anti-fungi agents due to their biological activity. Radioactive labeling based on the short-lived metastable nuclide technetium-99m (99mTc for biomedical use as heart, lung, kidney, bone, brain, liver or cancer imaging agents is also discussed. Finally, the promising applications of technetium labeling of nanomaterials, with potential applications as drug transport and delivery vehicles, radiotherapeutic agents or radiotracers for monitoring metabolic pathways, are also described.

  7. Iron Complexation to Oxygen Rich Marine Natural Products: A Computational Study

    Directory of Open Access Journals (Sweden)

    Teresa Gorman

    2010-01-01

    Full Text Available The natural products kahalalide F, halichondrin B, and discodermolide are relatively large structures that were originally harvested from marine organisms. They are oxygen rich structures that, to varying degrees, should have the ability to bind iron (II or III by Fe-O and/or Fe-N bonds. In this semi empirical study, the binding of these natural products to iron (II is studied and the aqueous stability factor (ASF is used to determine which bonding configuration is most stable. The energy, the complex charge (+1, the average Fe-O (or Fe-N bond distances and the dipole moments are used to calculate the ASF. The ASF provides insight to which complex will be the most stable and water soluble, important for a medicinal application. The ability of a molecule with a more than six oxygen and/or nitrogen atoms to bind iron (hexavalent, octahedral by shifting which six atoms (O/N are bound to the iron qualifies it as a polarity adaptive molecule.

  8. Shift in community structure in an early-successional Mediterranean shrubland driven by long-term experimental warming and drought and natural extreme droughts.

    Science.gov (United States)

    Liu, Daijun; Estiarte, Marc; Ogaya, Romà; Yang, Xiaohong; Peñuelas, Josep

    2017-10-01

    Global warming and recurring drought are expected to accelerate water limitation for plant communities in semiarid Mediterranean ecosystems and produce directional shifts in structure and composition that are not easily detected, and supporting evidence is scarce. We conducted a long-term (17 years) nocturnal-warming (+0.6°C) and drought (-40% rainfall) experiments in an early-successional Mediterranean shrubland to study the changes in community structure and composition, contrasting functional groups and dominant species, and the superimposed effects of natural extreme drought. Species richness decreased in both the warming and drought treatments. Responses to the moderate warming were associated with decreases in herb abundance, and responses to the drought were associated with decreases in both herb and shrub abundances. The drought also significantly decreased community diversity and evenness. Changes in abundance differed between herbs (decreases) and shrubs (increases or no changes). Both warming and drought, especially drought, increased the relative species richness and abundance of shrubs, favoring the establishment of shrubs. Both warming and drought produced significant shifts in plant community composition. Experimental warming shifted the community composition from Erica multiflora toward Rosmarinus officinalis, and drought consistently shifted the composition toward Globularia alypum. The responses in biodiversity (e.g., community biodiversity, changes of functional groups and compositional shifts) were also strongly correlated with atmospheric drought (SPEI) in winter-spring and/or summer, indicating sensitivity to water limitation in this early-successional Mediterranean ecosystem, especially to natural extreme droughts. Our results suggest that the shifts in species assembles and community diversity and composition are accelerated by the long-term nocturnal-warming and drought, combined with natural severe droughts, and that the magnitude of the

  9. Extremely bulky amido first row transition metal(II) halide complexes: potential precursors to low coordinate metal-metal bonded systems.

    Science.gov (United States)

    Hicks, Jamie; Jones, Cameron

    2013-04-01

    Reactions of the extremely bulky potassium amide complexes, [KL'(η(6)-toluene)] or [KL"] (L'/L" = N(Ar*)(SiR3), Ar* = C6H2{C(H)Ph2}2Me-2,6,4; R = Me (L') or Ph (L")), with a series of first row transition metal(II) halides have yielded 10 rare examples of monodentate amido first row transition metal(II) halide complexes, all of which were crystallographically characterized. They encompass the dimeric, square-planar chromium complexes, [{CrL'(THF)(μ-Cl)}2] and [{CrL"(μ-Cl)}2], the latter of which displays intramolecular η(2)-Ph···Cr interactions; the dimeric tetrahedral complexes, [{ML'(THF)(μ-Br)}2] (M = Mn or Fe), [{ML"(THF)(μ-X)}2] (M = Mn, Fe or Co; X = Cl or Br) and [{CoL"(μ-Cl)}2] (which displays intramolecular η(2)-Ph···Co interactions); and the monomeric zinc amides, [L'ZnBr(THF)] (three-coordinate) and [L"ZnBr] (two-coordinate). Solution state magnetic moment determinations on all but one of the paramagnetic compounds show them to be high-spin systems. Throughout, comparisons are made with related bulky terphenyl transition metal(II) halide complexes, and the potential for the use of the prepared complexes as precursors to low-valent transition metal systems is discussed.

  10. [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.

  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. Determination of humic substances in natural waters by cathodic stripping voltammetry of their complexes with iron.

    Science.gov (United States)

    Laglera, Luis M; Battaglia, Gianluca; van den Berg, Constant M G

    2007-09-05

    A new voltammetric method is presented for the measurement of humic substances (HS) in natural waters. The method is based on catalytic cathodic stripping voltammetry (CSV) and makes use of adsorptive properties of iron-HS complexes on the mercury drop electrode at natural pH. A fulvic acid standard (IHSS) was used to confirm the voltammetric response (peak potential and sensitivity) for the HS for natural water samples. Optimized conditions included the linear-sweep mode, deposition at -0.1 V, pH buffered at 8 and a scan rate of 50 mV s(-1). At a deposition time of 240 s in the presence of 10 nM iron and 30 mM bromate, the detection limit was 5 microg L(-1) HS in seawater, which could be lowered further by an increase in the bromate concentration, or in the adsorption time. The method was used to determine HS in the Irish Sea which were found to occur at levels between 60 and 600 microg L(-1). The new method is sufficiently sensitive to detect the low HS content in oceanic samples and has implications to the study of iron speciation.

  13. 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.

  14. Potential environmental conflicts in the area of the energy component of natural resource complex

    Directory of Open Access Journals (Sweden)

    Ie.V. Khlobystov

    2016-03-01

    Full Text Available The aim of the article. The purpose of the article is to identify potential and probable factors of environmental conflicts (EC larger amount of energy component of natural resource complex (NRC. Development of natural resource complex occurs in several ways to use them, in particular, with the position of the energy component of these methods were not considered in modern ecological and economic studies. The use of NRC for the purpose of increasing energy efficiency may determine through the essence of the principles and approaches to identifing of the potential of EC that can be implemented by defining the opportunities for renewable energy, usage of recreational, balneological and assimilation functions of natural resource complex and expensive analysis of these features, given the potential conflict of territorial development. The results of the analysis. Natural resource conflicts are the result of conflicts caused by limited quantity and quality of natural resources as between entities within the territorial social and economic systems and between different territorial systems. Energy potential of NRC can be defined as a set of certain characteristics, situation and processes that form the state energy supply a certain area at the projected use of resources. Energy potential of NRC includes such elements as natural resources and environmental sustainability, capacities for production, processing and transportation of energy. At the same time this potential has the dualistic nature, being the component part of both natural recourses and productive potential of the region. It is necessary to analyze quantitatively and qualitatively potential minerals. Quantitative characteristic provides identification of stocks of raw materials or fuel in the field of NRC, which can be used. They are divided on two type’s balance and off-balance sheet. To balance belong reserves, production and processing of which are economically viable in the achieved

  15. Using pattern recognition as a method for predicting extreme events in natural and socio-economic systems

    Science.gov (United States)

    Intriligator, M.

    2011-12-01

    Vladimir (Volodya) Keilis-Borok has pioneered the use of pattern recognition as a technique for analyzing and forecasting developments in natural as well as socio-economic systems. Keilis-Borok's work on predicting earthquakes and landslides using this technique as a leading geophysicist has been recognized around the world. Keilis-Borok has also been a world leader in the application of pattern recognition techniques to the analysis and prediction of socio-economic systems. He worked with Allan Lichtman of American University in using such techniques to predict presidential elections in the U.S. Keilis-Borok and I have worked together with others on the use of pattern recognition techniques to analyze and to predict socio-economic systems. We have used this technique to study the pattern of macroeconomic indicators that would predict the end of an economic recession in the U.S. We have also worked with officers in the Los Angeles Police Department to use this technique to predict surges of homicides in Los Angeles.

  16. Spatial distribution and frequency of precipitation during an extreme event: July 2006 mesoscale convective complexes and floods in southeastern Arizona

    Science.gov (United States)

    Griffiths, P.G.; Magirl, C.S.; Webb, R.H.; Pytlak, E.; Troch, Peter A.; Lyon, S.W.

    2009-01-01

    An extreme, multiday rainfall event over southeastern Arizona during 27-31 July 2006 caused record flooding and a historically unprecedented number of slope failures and debris flows in the Santa Catalina Mountains north of Tucson. An unusual synoptic weather pattern induced repeated nocturnal mesoscale convective systems over southeastern Arizona for five continuous days, generating multiday rainfall totals up to 360 mm. Analysis of point rainfall and weather radar data yielded storm totals for the southern Santa Catalina Mountains at 754 grid cells approximately 1 km ?? 1 km in size. Precipitation intensity for the 31 July storms was not unusual for typical monsoonal precipitation in this region (recurrence interval (RI) 50 years and individual grid cells had RI exceeding 1000 years. The 31 July storms caused the watersheds to be essentially saturated following 4 days of rainfall. Copyright 2009 by the American Geophysical Union.

  17. 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

  18. Integrating seasonal optical and thermal infrared spectra to characterize urban impervious surfaces with extreme spectral complexity: a Shanghai case study

    Science.gov (United States)

    Wang, Wei; Yao, Xinfeng; Ji, Minhe

    2016-01-01

    Despite recent rapid advancement in remote sensing technology, accurate mapping of the urban landscape in China still faces a great challenge due to unusually high spectral complexity in many big cities. Much of this complication comes from severe spectral confusion of impervious surfaces with polluted water bodies and bright bare soils. This paper proposes a two-step land cover decomposition method, which combines optical and thermal spectra from different seasons to cope with the issue of urban spectral complexity. First, a linear spectral mixture analysis was employed to generate fraction images for three preliminary endmembers (high albedo, low albedo, and vegetation). Seasonal change analysis on land surface temperature induced from thermal infrared spectra and coarse component fractions obtained from the first step was then used to reduce the confusion between impervious surfaces and nonimpervious materials. This method was tested with two-date Landsat multispectral data in Shanghai, one of China's megacities. The results showed that the method was capable of consistently estimating impervious surfaces in highly complex urban environments with an accuracy of R2 greater than 0.70 and both root mean square error and mean average error less than 0.20 for all test sites. This strategy seemed very promising for landscape mapping of complex urban areas.

  19. 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

    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...... 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...

  20. Safety and coping strategy for high dam under complex natural conditions

    Institute of Scientific and Technical Information of China (English)

    Niu Xinqiang

    2012-01-01

    In respect to current situation and new challenges for high dam construction in China, safety problems are an- alyzed for high dam construction under complex natural conditions such as high elevation, cold area, high seismic inten- sity, large-seale landslide and high dam and huge reservoirs with dam types such as concrete surface rock-fill, asphalt concrete core, roller compacted concrete (RCC) arch dam and so on. From several aspects, including risk response measures for high dam, strengthening safety awareness for high dam design and construction, improving high dam con- struetion technique, intelligent dam safety management system based on IT, developing dam rehabilitation and mainte- nance technologies, useful dam safety and coping strategy is proposed.

  1. Serious science games, social selves and complex nature of possible selves

    Science.gov (United States)

    Khan, Mubina Schroeder

    2012-12-01

    Margaret Beier, Leslie Miller, and Shu Wang's paper, Science games and the development of possible selves examines the effects of game-playing in a serious scientific game on science possible selves identity creation, utilizing a possible selves identification instrument they created. This paper continues the discussion that Beier and colleagues start in the paper by calling into question both the idea that a predictive model of science career choice can be attained by serious science game-playing and the nature of the instrument created and used by Beier and her colleagues to identify participants' creation of science possible selves. Recommendations include incorporating the idea of possible selves as being complex, dynamic and intertwined with self-concept in interpreting their findings and casting a wider net to capture the phenomena of their participants' identities and experiences by potentially making use of possible selves identification methodologies from the career training arena.

  2. 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.

  3. On the Nondimensionalization Process in Complex Problems: Application to Natural Convection in Anisotropic Porous Media

    Directory of Open Access Journals (Sweden)

    I. Alhama

    2014-01-01

    Full Text Available The nondimensionalization of the equations governing a given problem is a direct, relatively easy, and low-cost way to provide interesting information, the dimensionless groups that rule the problem and define its final patterns of solution. In complex problems, however, this technique frequently does not provide the precise and complete set of monomials we are looking for. The use of discrimination in the process of nondimensionalization, the detailed application of which is explained in this paper, always leads to a minimum set of parameters, which, separately, determine the solution of the problems. In addition, the physical meaning and order of magnitude of these discriminated monomials are also provided by the discrimination. The technique is applied to the coupled problem of natural convection between horizontal plates heated from below, containing an anisotropic porous medium.

  4. Fine-grained permutation entropy as a measure of natural complexity for time series

    Institute of Scientific and Technical Information of China (English)

    Liu Xiao-Feng; Wang Yue

    2009-01-01

    In a recent paper [2002 Phys. Rev. Lett. 88 174102], Bandt and Pompe propose permutation entropy (PE)as a natural complexity measure for arbitrary time series which may be stationary or nonstationary, deterministic or stochastic. Their method is based on a comparison of neighbouring values. This paper further develops PE, and proposes the concept of fine-grained PE (FGPE) defined by the order pattern and magnitude of the difference between neighbouring values. This measure excludes the case where vectors with a distinct appearance are mistakenly mapped onto the same permutation type, and consequently FGPE becomes more sensitive to the dynamical change of time series than does PE, according to our simulation and experimental results.

  5. 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

    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...

  6. 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.

  7. 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.

  8. 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.

  9. Synergistic Microbial Consortium for Bioenergy Generation from Complex Natural Energy Sources

    Directory of Open Access Journals (Sweden)

    Victor Bochuan Wang

    2014-01-01

    Full Text Available 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.

  10. Understanding the complex nature of salinity and drought-stress response in cereals using proteomics technologies.

    Science.gov (United States)

    Ngara, Rudo; Ndimba, Bongani K

    2014-03-01

    Worldwide, crop productivity is drastically reduced by drought and salinity stresses. In order to develop food crops with increased productivity in marginal areas, it is important to first understand the nature of plant stress response mechanisms. In the past decade, proteomics tools have been extensively used in the study of plants' proteome responses under experimental conditions mimicking drought and salinity stresses. A lot of proteomic data have been generated using different experimental designs. However, the precise roles of these proteins in stress tolerance are yet to be elucidated. This review summarises the applications of proteomics in understanding the complex nature of drought and salinity stress effects on plants, particularly cereals and also highlights the usefulness of sorghum as the next logical model crop for use in understanding drought and salinity tolerance in cereals. With the vast amount of proteomic data that have been generated to date, a call for integrated efforts across the agricultural, biotechnology, and molecular biology sectors is also highlighted in an effort to translate proteomics data into increased food productivity for the world's growing population.

  11. Complexes assembled from TMV-derived spherical particles and entire virions of heterogeneous nature.

    Science.gov (United States)

    Trifonova, Ekaterina; Nikitin, Nikolai; Gmyl, Anatoly; Lazareva, Ekaterina; Karpova, Olga; Atabekov, Joseph

    2014-01-01

    Previously, we described some structural features of spherical particles (SPs) generated by thermal remodelling of the tobacco mosaic virus. The SPs represent a universal platform that could bind various proteins. Here, we report that entire isometric virions of heterogeneous nature bind non-specifically to the SPs. Formaldehyde (FA) was used for covalent binding of a virus to the SPs surface for stabilizing the SP-virus complexes. Transmission and high resolution scanning electron microscopy showed that the SPs surface was covered with virus particles. The architecture of SP-virion complexes was examined by immunologic methods. Mean diameters of SPs and SP-human enterovirus C and SP-cauliflower mosaic virus (CaMV) compositions were determined by nanoparticle tracking analysis (NTA) in liquid. Significantly, neither free SPs nor individual virions were detected by NTA in either FA-crosslinked or FA-untreated compositions. Entirely, all virions were bound to the SPs surface and the SP sites within the SP-CaMV complexes were inaccessible for anti-SP antibodies. Likewise, the SPs immunogenicity within the FA-treated SPs-CaMV compositions was negligible. Apparently, the SP antigenic sites were hidden and masked by virions within the compositions. Previously, we reported that the SPs exhibited adjuvant activity when foreign proteins/epitopes were mixed with or crosslinked to SPs. We found that immunogenicity of entire CaMV crosslinked to SP was rather low which could be due to the above-mentioned masking of the SPs booster. Contrastingly, immunogenicity of the FA-untreated compositions increased significantly, presumably, due to partial release of virions and unmasking of some SPs-buster sites after animals immunization.

  12. Complex carbohydrates of red wine: characterization of the extreme diversity of neutral oligosaccharides by ESI-MS.

    Science.gov (United States)

    Doco, Thierry; Williams, Pascale; Meudec, Emmanuelle; Cheynier, Véronique; Sommerer, Nicolas

    2015-01-21

    The major neutral oligosaccharides of a Carignan red wine have been characterized for the first time. The oligosaccharides were prepared after removal of phenolic compounds by polyamide chromatography and of polysaccharides by alcohol precipitation and then were fractionated by anion exchange and size-exclusion chromatography. In a second step, the glycosyl composition and linkages of wine oligosaccharides were determined. Oligosaccharide fractions were analyzed by mass spectrometry (MS) with an electrospray ionization (ESI) source and an ion trap mass analyzer after separation by hydrophilic interaction liquid chromatography on a Nucleodur HILIC column (zwitterionic sulfoalkyl betaine stationary phase). Glycosyl residue composition analysis showed the predominant presence of arabinose, with galactose, rhamnose, and mannose in lower proportion. Neutral oligosaccharides were present at a concentration of 185 mg/L in this wine. The MS spectra in the negative ion mode of the oligosaccharide fractions showed a series of oligosaccharidic structures corresponding to oligo-arabinans often linked to the basic unit α-l-Rhap-(1 → 4)-α-d-GalpA. The wine oligosaccharides identified correspond to arabino-oligosaccharides, rhamno-arabino-oligosaccharides, and different rhamnogalacturonan-arabino-oligosaccharides with DP ranging from 5 to 49, resulting from the degradation of grape cell wall pectins. Oligosaccharides have an extreme diversity, with more than 100 peaks detected in HPLC-ESI-MS spectra corresponding each to at least one oligosaccharidic structure.

  13. A rare form of extremely wide QRS complex due to reversed homologous electrical ventricular separation of acute heart failure.

    Science.gov (United States)

    Yan, Sujuan; Yu, Jianhua; Xia, Zhen; Zhu, Bo; Hu, Jinzhu; Li, Juxiang

    2017-06-29

    Electrical ventricular separation, as a special complete intraventricular block, denotes that ventricles be electrically separated into two or more parts caused by severe and wide damage of myocardium and conduction. Electrical ventricular separation can be divided into homologous and heterologous, homologous electrical ventricular separation is a rare phenomenon, literally the excitement of whole ventricle originate from supraventricle, on ECG, there are two different QRS waves which connect with an isoelectric line, one ST segment and T wave. We report a valve heart disease presented with complicated electrophysiological characteristics, which has reversed complex homologous electrical ventricular separation with second degree intraventricular block. © 2017 Wiley Periodicals, Inc.

  14. Organic complexation of rare earth elements in natural waters: Evaluating model calculations from ultrafiltration data

    Science.gov (United States)

    Pourret, Olivier; Davranche, Mélanie; Gruau, Gérard; Dia, Aline

    2007-06-01

    The Stockholm Humic Model (SHM) and Humic Ion-Binding Models V and VI were compared for their ability to predict the role of dissolved organic matter (DOM) in the speciation of rare earth elements (REE) in natural waters. Unlike Models V and VI, SHM is part of a speciation code that also allows us to consider dissolution/precipitation, sorption/desorption and oxidation/reduction reactions. In this context, it is particularly interesting to test the performance of SHM. The REE specific equilibrium constants required by the speciation models were estimated using linear free-energy relationships (LFER) between the first hydrolysis constants and the stability constants for REE complexation with lactic and acetic acid. Three datasets were used for the purpose of comparison: (i) World Average River Water (Dissolved Organic Carbon (DOC) = 5 mg L -1), previously investigated using Model V, was reinvestigated using SHM and Model VI; (ii) two natural organic-rich waters (DOC = 18-24 mg L -1), whose REE speciation has already been determined with both Model V and ultrafiltration studies, were also reinvestigated using SHM and Model VI; finally, (iii) new ultrafiltration experiments were carried out on samples of circumneutral-pH (pH 6.2-7.1), organic-rich (DOC = 7-20 mg L -1) groundwaters from the Kervidy-Naizin and Petit-Hermitage catchments, western France. The results were then compared with speciation predictions provided by Model VI and SHM, successively. When applied to World Average River Water, both Model VI and SHM yield comparable results, confirming the earlier finding that a large fraction of the dissolved REE in rivers occurs as organic complexes This implies that the two models are equally valid for calculating REE speciation in low-DOC waters at circumneutral-pH. The two models also successfully reproduced ultrafiltration results obtained for DOC-rich acidic groundwaters and river waters. By contrast, the two models yielded different results when compared to

  15. Neural and response correlations to natural complex sounds in the auditory midbrain

    Directory of Open Access Journals (Sweden)

    Dominika Lyzwa

    2016-11-01

    Full Text Available How natural communication sounds are spatially represented across the inferior colliculus, the main center of convergence for auditory information in the midbrain, is not known. The neural representation of the acoustic stimuli results from the interplay of locally differing input and the organization of spectral and temporal neural preferences that change gradually across the nucleus. This raises the question how similar the neural representation of the communication sounds is across these gradients of neural preferences, and whether it also changes gradually. Analyzed neural recordings were multi-unit cluster spike trains from guinea pigs presented with a spectrotemporally rich set of eleven species-specific communication sounds. Using cross-correlation, we analyzed the response similarity of spiking activity across a broad frequency range for neurons of similar and different frequency tuning. Furthermore, we separated the contribution of the stimulus to the correlations to investigate whether similarity is only attributable to the stimulus, or, whether interactions exist between the multi-unit clusters that lead to neural correlations and whether these follow the same representation as the response correlations. We found that similarity of responses is dependent on the neurons' spatial distance for similarly and differently frequency-tuned neurons, and that similarity decreases gradually with spatial distance. Significant neural correlations exist, and contribute to the total response similarity. Our findings suggest that for multi-unit clusters in the mammalian inferior colliculus, the gradual response similarity with spatial distance to natural complex sounds is shaped by neural interactions and the gradual organization of neural preferences.

  16. 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.

  17. Dolphin social intelligence: complex alliance relationships in bottlenose dolphins and a consideration of selective environments for extreme brain size evolution in mammals.

    Science.gov (United States)

    Connor, Richard C

    2007-04-29

    Bottlenose dolphins in Shark Bay, Australia, live in a large, unbounded society with a fission-fusion grouping pattern. Potential cognitive demands include the need to develop social strategies involving the recognition of a large number of individuals and their relationships with others. Patterns of alliance affiliation among males may be more complex than are currently known for any non-human, with individuals participating in 2-3 levels of shifting alliances. Males mediate alliance relationships with gentle contact behaviours such as petting, but synchrony also plays an important role in affiliative interactions. In general, selection for social intelligence in the context of shifting alliances will depend on the extent to which there are strategic options and risk. Extreme brain size evolution may have occurred more than once in the toothed whales, reaching peaks in the dolphin family and the sperm whale. All three 'peaks' of large brain size evolution in mammals (odontocetes, humans and elephants) shared a common selective environment: extreme mutual dependence based on external threats from predators or conspecific groups. In this context, social competition, and consequently selection for greater cognitive abilities and large brain size, was intense.

  18. Upper Extremity Muscle Activation during Bodyblade Exercises Following Six Weeks of Intervention Focusing on the Lumbopelvic-Hip Complex

    Directory of Open Access Journals (Sweden)

    Gretchen D. Oliver

    2015-08-01

    Full Text Available The current study examined the effects of a six-week lumbopelvic-hip complex (LPHC strengthening program on muscle activation when performing the shoulder dump exercise. The shoulder dump is a total body exercise that includes overhead arm movements. A pre-post test with a control group was implemented. Twenty-seven graduate students (23.5 ± 1.34 yr; 174.4 ± 11.0 cm; 76.6 ± 16.9 kg participated. Participants were randomly assigned to a control or intervention group where the intervention group performed LPHC exercises. Two-way analysis of variance (ANOVA revealed a significant increase in muscle activation of the serratus anterior from pre- and post-LPHC intervention, (t = 6.5, p < 0.001. As presented by these data, incorporation of LPHC exercises may assist in facilitating greater activation in some of the scapula-stabilizing musculature that has traditionally been rehabilitated in prone or side-lying positions. It is, therefore, suggested that LPHC exercises be incorporated in a regular shoulder rehabilitation program.

  19. 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)

  20. The nature of the low energy band of the Fenna-Matthews-Olson complex: vibronic signatures.

    Science.gov (United States)

    Caycedo-Soler, Felipe; Chin, Alex W; Almeida, Javier; Huelga, Susana F; Plenio, Martin B

    2012-04-21

    Based entirely upon actual experimental observations on electron-phonon coupling, we develop a theoretical framework to show that the lowest energy band of the Fenna-Matthews-Olson complex exhibits observable features due to the quantum nature of the vibrational manifolds present in its chromophores. The study of linear spectra provides us with the basis to understand the dynamical features arising from the vibronic structure in nonlinear spectra in a progressive fashion, starting from a microscopic model to finally performing an inhomogeneous average. We show that the discreteness of the vibronic structure can be witnessed by probing the diagonal peaks of the nonlinear spectra by means of a relative phase shift in the waiting time resolved signal. Moreover, we demonstrate that the photon-echo and non-rephasing paths are sensitive to different harmonics in the vibrational manifold when static disorder is taken into account. Supported by analytical and numerical calculations, we show that non-diagonal resonances in the 2D spectra in the waiting time, further capture the discreteness of vibrations through a modulation of the amplitude without any effect in the signal intrinsic frequency. This fact generates a signal that is highly sensitive to correlations in the static disorder of the excitonic energy albeit protected against dephasing due to inhomogeneities of the vibrational ensemble.

  1. Natural Enemies of the Frankliniella Complex Species (Thysanoptera: Thripidae) in Ataulfo Mango Agroecosystems.

    Science.gov (United States)

    Rocha, Franklin H; Infante, Francisco; Castillo, Alfredo; Ibarra-Nuñez, Guillermo; Goldarazena, Arturo; Funderburk, Joe E

    2015-01-01

    A field survey was conducted in Ataulfo mango (Mangifera indica L.) orchards in Chiapas, Mexico, with the objective of determining the natural enemies of the Frankliniella complex species (Thysanoptera: Thripidae). Seven species of this genus feed and reproduce in large numbers during the mango flowering. Two representative orchards were selected: the orchard "Tres A" characterized by an intensive use of agrochemicals directed against thrips, and the orchard "La Escondida" that did not spray insecticides. During mango flowering, five inflorescences were randomly collected every 5 d in both orchards, for a total of 18 sampling dates. Results revealed the presence of 18 species of arthropods that were found predating on Frankliniella. There were 11 species in the families Aeolothripidae, Phlaeothripidae, Formicidae, Anthocoridae and Chrysopidae; and seven species of spiders in the families Araneidae, Tetragnathidae, and Uloboridae. Over 88% of predators were anthocorids, including, Paratriphleps sp. (Champion), Orius insidiosus (Say), Orius tristicolor (White), and O. perpunctatus (Reuter). The orchard that did not spray insecticides had a significantly higher number of predators suggesting a negative effect of the insecticides on the abundance of these organisms.

  2. 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.

  3. Effect of fat nature and aroma compound hydrophobicity on flavor release from complex food emulsions.

    Science.gov (United States)

    Relkin, Perla; Fabre, Marjorie; Guichard, Elisabeth

    2004-10-06

    Complex food emulsions containing either hydrogenated palm kernel oil (vegetable fat) or anhydrous milk fat (animal fat) were flavored by using different aroma compounds. The fats differed by their fatty acid and triacylglycerol compositions and by their melting behavior, while the aroma compounds (ethyl butanoate, ethyl hexanoate, methyl hexanoate, mesifurane, linalool, diacetyl, cis-3-hexen-1-ol, and gamma-octalactone) differed by their hydrophobicity. Application of differential scanning calorimetry to fat samples in bulk and emulsified forms indicated differences in the ratio of solid-to-liquid between temperatures ranging from 10 to 35 degrees C. Solid-phase microextraction coupled with GC-MS analysis indicated that flavor release from food emulsions containing animal or vegetable fat differed depending on both the fat nature and flavor compound hydrophobicity. The release of diacetyl was higher for emulsions containing animal fat, whereas the release of esters was higher for emulsions containing vegetable fat. The release of cis-3-hexenol, linalool, gamma-octalactone, and mesifurane (2,5-dimethyl-4-methoxy-(2H)-furan-3-one) was very similar for the two fatty systems. The above results were discussed not only in terms of aroma compound hydrophobicity, but also in terms of structural properties of the emulsions as affected by the lipid source.

  4. Extreme Heat

    Science.gov (United States)

    ... Landslides & Debris Flow Nuclear Blast Nuclear Power Plants Power Outages Pandemic Radiological Dispersion Device Severe Weather Snowstorms & Extreme ... Landslides & Debris Flow Nuclear Blast Nuclear Power Plants Power Outages Pandemic Radiological Dispersion Device Severe Weather Snowstorms & Extreme ...

  5. 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

  6. Extreme light rare earth element mobilization by diagenetic fluids in the geological environment of the Oklo natural reactor zones, Franceville basin, Gabon

    Science.gov (United States)

    Cuney, Michel; Mathieu, Régis

    2000-08-01

    The anomalously high Th/La ratio (˜1.14) of the Early Proterozoic silicified sandstones of the Franceville basin (Gabon), compared to Archean and Proterozoic metasedimentary rocks (Th/La ˜0.27), results from extreme light rare earth element (REE) migration during diagenesis. Monazite, which represents the main light REE-bearing phase in the sandstones, was altered by diagenetic brines at 140 °C and 1 kbar. The alteration phase is a microcrystalline Th-silicate phase, indicating low Th solubility at these conditions. Light REEs are simultaneously leached out together with P and U. The increase in Th/La from detrital monazite to residual Th-silicate phase indicates that about 76% of the light REEs were leached out, corresponding to a global amount of 2.01 × 109 metric tons at the scale of the FA Formation in the Franceville basin. Uranium was also leached during monazite alteration and may have contributed significantly to the genesis of the high-grade uranium deposits of the Franceville basin that host the natural nuclear reaction zones.

  7. 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.

  8. [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.

  9. Persistence time series analyses, complexity applied to natural hazards and the Quaternary lake history of the Lerma Valley, NW Argentina

    Science.gov (United States)

    Malamud, Bruce D.

    This dissertation explores the Quaternary history of a NW Argentina valley, persistence in synthetic self-affine time series, and complexity applied to natural hazards. Chapter one is an introduction. Chapter two examines the Lerma Valley in NW Argentina, today an externally drained basin which in the past was partially closed and contained a large fresh-water lake. Using geologic fieldwork laboratory work, and historical data analysis, we find that the lake was extant 1-50 ky during the period 0.78-0.1 Ma, had a surface area of 800-1300 kmsp2 and sedimentation rates of 1-10 m/ky. Modern denudation rates could supply enough sediment from the drainage to account for these rates, and the modern hydrologic regime could fill the lake with water in less than 500 years. Chapter three provides a framework to examine persistence techniques in self-affine time series. By using the Fourier spectral method, a white noise is appropriately filtered so that its power spectral density (S) depends upon frequency (f) according to S˜ fsp{-beta}. We examine fractional noises and walks with {-}3≤beta≤ 5 and Gaussian and log-normal distributions. The persistence analyses compared include autocorrelation, semivariogram, rescaled-range, Fourier power spectrum, extreme-value, and wavelet power spectrum. The last two are applied for the first time. In chapter four, self-organized critical (SOC) models are compared with actual events. The models have power-law noncumulative frequency-size distributions with exponent about 1.0, and the actual data have exponents 1.3-1.5 (forest-fires) and 2.3-3.3 (landslides). Actual forest fires are compared here for the first time with the forest-fire model; their robustness in one indicator of SOC behavior. Chapter five examines recurrence intervals of floods using power-law statistics applied to partial-duration series and the federally adopted log-Pearson type 3 (LP3) distribution applied to annual series. The great Mississippi River flood of 1993

  10. Complex oligomeric structure of a truncated form of DdrA: A protein required for the extreme radio-tolerance of Deinococcus

    Energy Technology Data Exchange (ETDEWEB)

    Gutsche, I. [CNRS-EMBL-Univ Grenoble 1, Unit Virus Host Cell Interact UMR5233, F-38042 Grenoble (France); Vujicic-Zagar, A.; Serre, L. [CEA-CNRS-Univ Grenoble 1, Inst Biol Struct, UMR5075, Lab Prot Membranaires, F-38027 Grenoble 01 (France); Siebert, X. [CEA-CNRS-Univ Grenoble 1, Inst Biol Struct UMR5075, Lab Microscopie Elect et struct, F-38027 Grenoble 01 (France); Servant, P.; Vannier, F.; Sommer, S. [Univ Paris 11, CNRS UMR 8621, CEA LRC42V, Inst Genet et Microbiol, F-91405 Orsay (France); Castaing, B. [CNRS, UMR4301, Ctr Biophys Mol, F-45071 Orleans 02 (France); Gallet, B. [CEA-CNRS-Univ Grenoble 1, Inst Biol Struct UMR 5075, ROBIOMOL, Lab Ingn Macrom, F-38027 Grenoble 01 (France); Heulin, T.; De Groot, A. [CEA, DSV, IBEB, SBVME, Lab Ecol Microbienne Rhizosphere et Environm Extre, UMR 6191, F-13108 St Paul Les Durance (France)

    2008-07-01

    In order to preserve their genome integrity, organisms have developed elaborate tactics for genome protection and repair. The Deinococcus radiodurans bacteria famous for their extraordinary tolerance toward high doses of radiations or long period of desiccation, possess some specific genes with unknown function which are related to their survival in such extreme conditions. Among them, ddrA is an orphan gene specific of Deinococcus genomes. DdrA, the product of this gene was suggested to be a component of the DNA end protection system. Here we provide a three-dimensional reconstruction of the Deinococcus deserti DdrA(1-160) by electron microscopy. Although not functional in vivo, this truncated protein keeps its DNA binding ability at the wild-type level. DdrA(1-160) has a complex three-dimensional structure based on a hepta-meric ring that can self-associate to form a larger molecular weight assembly. We suggest that the complex architecture of DdrA plays a role in the substrate specificity and favors an efficient DNA repair. (authors)

  11. 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.

  12. The contribution of natural killer complex loci to the development of experimental cerebral malaria.

    Directory of Open Access Journals (Sweden)

    Diana S Hansen

    Full Text Available The Natural Killer Complex (NKC is a genetic region of highly linked genes encoding several receptors involved in the control of NK cell function. The NKC is highly polymorphic and allelic variability of various NKC loci has been demonstrated in inbred mice, providing evidence for NKC haplotypes. Using BALB.B6-Cmv1r congenic mice, in which NKC genes from C57BL/6 mice were introduced into the BALB/c background, we have previously shown that the NKC is a genetic determinant of malarial pathogenesis. C57BL/6 alleles are associated with increased disease-susceptibility as BALB.B6-Cmv1r congenic mice had increased cerebral pathology and death rates during P. berghei ANKA infection than cerebral malaria-resistant BALB/c controls.To investigate which regions of the NKC are involved in susceptibility to experimental cerebral malaria (ECM, intra-NKC congenic mice generated by backcrossing recombinant F2 progeny from a (BALB/c x BALB.B6-Cmv1r F1 intercross to BALB/c mice were infected with P. berghei ANKA.Our results revealed that C57BL/6 alleles at two locations in the NKC contribute to the development of ECM. The increased severity to severe disease in intra-NKC congenic mice was not associated with higher parasite burdens but correlated with a significantly enhanced systemic IFN-γ response to infection and an increased recruitment of CD8+ T cells to the brain of infected animals.Polymorphisms within the NKC modulate malarial pathogenesis and acquired immune responses to infection.

  13. Nature of the bonding in metal-silane sigma-complexes.

    Science.gov (United States)

    McGrady, G Sean; Sirsch, Peter; Chatterton, Nicholas P; Ostermann, Andreas; Gatti, Carlo; Altmannshofer, Sandra; Herz, Verena; Eickerling, Georg; Scherer, Wolfgang

    2009-02-16

    The nature of metal silane sigma-bond interaction has been investigated in several key systems by a range of experimental and computational techniques. The structure of [Cp'Mn(CO)(2)(eta(2)-HSiHPh(2))] 1 has been determined by single crystal neutron diffraction, and the geometry at the Si atom is shown to approximate a trigonal bipyramid; salient bond distances and angles are Mn-H(1) 1.575(14), Si-H(1) 1.806(14), Si-H(2) 1.501(13) A, and H(1)-Si-H(2) 148.5(8) degrees. This complex is similar to [Cp'Mn(CO)(2)(eta(2)-HSiFPh(2))] 2, whose structure and bonding characteristics have recently been determined by charge density studies based on high-resolution X-ray and neutron diffraction data. The geometry at the Si atom in these sigma-bond complexes is compared with that in other systems containing hypercoordinate silicon. The Mn-H distances for 1 and 2 in solution have been estimated using NMR T(1) relaxation measurements, giving a value of 1.56(3) A in each case, in excellent agreement with the distances deduced from neutron diffraction. Density functional theory calculations have been employed to explore the bonding in the Mn-H-Si unit in 1 and 2 and in the related system [Cp'Mn(CO)(2)(eta(2)-HSiCl(3))] 3. These studies support the idea that the oxidative addition of a silane ligand to a transition metal center may be described as an asymmetric process in which the Mn-H bond is formed at an early stage, while both the establishment of the Mn-Si bond and also the activation of the eta(2)-coordinated Si-H moiety are controlled by the extent of Mn --> sigma*(X-Si-H) back-donation, which increases with increasing electron-withdrawing character of the X substituent trans to the metal-coordinated Si-H bond. This delocalized molecular orbital (MO) approach is complemented and supported by combined experimental and theoretical charge density studies: the source function S(r,Omega), which provides a measure of the relative importance of each atom's contribution to the density

  14. A single-molecule view of DNA replication : the dynamic nature of multi-protein complexes revealed

    NARCIS (Netherlands)

    Geertsema, Hylkje J.; van Oijen, Antoine M.; Chiu, Wah; Wagner, Gerhard

    2013-01-01

    Recent advances in the development of single-molecule approaches have made it possible to study the dynamics of biomolecular systems in great detail. More recently, such tools have been applied to study the dynamic nature of large multiprotein complexes that support multiple enzymatic activities. In

  15. Natural status of the forest biogeocenosis ecosystems in the Carpathians and its bioindication on the base of nematode complexes

    Directory of Open Access Journals (Sweden)

    Микола Павлович Козловський

    2015-09-01

    Full Text Available There are soil Nematoda complexes forming in primeval ecosystems. They have the same regularities in energy consumption by the community independently of the territorial location. Additional characteristics of species diversity and structural organization of Nematoda communities exist within the realms of biogeocenosis type. It allows determining the natural status of the forest ecosystems

  16. 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

  17. 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

  18. 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 are 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 testbed. 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 towards 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.

  19. 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.

  20. 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., Jr.; Peters-Lidard, Christa D.; Kumar, Sujay V.; Dong, Xiquan; Kennedy, Aaron D.

    2011-01-01

    Land-atmosphere interactions play a critical role in determining the. diurnal evolution of both planetary boundary layer (PBL) and land surface temperature and moisture states. The degree of coupling between the land surface and PBL in numerical weather prediction and climate models remains largely unexplored and undiagnosed due to the complex interactions and feedbacks present across a range of scales. Further, uncoupled systems or experiments (e.g., the Project for Intercomparison of Land Parameterization Schemes, PILPS) may lead to inaccurate water and energy cycle process understanding by neglecting feedback processes such as PBL-top entrainment. In this study, a framework for diagnosing local land-atmosphere coupling (LoCo) is presented using a coupled mesoscale model with a suite of PBL and land surface model (LSM) options along with observations during the summers of 200617 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 extremes of this region, along with the sensitivity of PBL-LSM coupling to perturbations in soil moisture. As such, this methodology provides a potential pathway to study factors controlling local land-atmosphere coupling (LoCo) using the LIS-WRF system, which is serving as a testbed for LoCo experiments to evaluate coupling diagnostics within the community.

  1. Determination of complexation capacity of trace metal-organic in natural water

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The complexation capacity for heavy metals (Cu, Cd, Pb) were determined by anodic stripping voltammetry in South China Sea, Hulun Lake and Wuliang Suhai. The conditional stability constants and complexation capacity index were calculated. The data showed that the complexation capacity of the Hulun Lake was greater than that of seawater and Wuliang Suhai. The sequence of complexation capacity is C (CuL) > C (CdL) > C (PbL), the values are in concord with results of analysis on dissolved organic carbon. The conditional stability constants were in an opposite sequence: K (CuL) < K(CdL) < K (PbL). When logK are similar, the greater the complexation capacity, the greater the complexation capacity index.

  2. 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

  3. Naturally occurring heavy radioactive elements in the geothermal microcosm of the Los Azufres (Mexico) volcanic complex.

    Science.gov (United States)

    Abuhani, W A; Dasgupta-Schubert, N; Villaseñor, L M; García Avila, D; Suárez, L; Johnston, C; Borjas, S E; Alexander, S A; Landsberger, S; Suárez, M C

    2015-01-01

    The Los Azufres geothermal complex of central Mexico is characterized by fumaroles and boiling hot-springs. The fumaroles form habitats for extremophilic mosses and ferns. Physico-chemical measurements of two relatively pristine fumarolic microcosms point to their resemblance with the paleo-environment of earth during the Ordovician and Devonian periods. These geothermal habitats were analysed for the distribution of elemental mass fractions in the rhizospheric soil (RS), the native volcanic substrate (VS) and the sediments (S), using the new high-sensitivity technique of polarized x-ray energy dispersive fluorescence spectrometry (PEDXRF) as well as instrumental neutron activation analysis (INAA) for selected elements. This work presents the results for the naturally occurring heavy radioactive elements (NOHRE) Bi, Th and U but principally the latter two. For the RS, the density was found to be the least and the total organic matter content the most. Bi was found to be negligibly present in all substrate types. The average Th and U mass fractions in the RS were higher than in the VS and about equal to their average mass fractions in the S. The VS mass fraction of Th was higher, and of U lower, than the mass fractions in the earth's crust. In fact for the fumaroles of one site, the average RS mass fractions of these elements were higher than the averaged values for S (without considering the statistical dispersion). The immobilization of the NOHRE in the RS is brought about by the bio-geochemical processes specific to these extremophiles. Its effectiveness is such that despite the small masses of these plants, it compares with, or may sometimes exceed, the immobilization of the NOHRE in the S by the abiotic and aggressive chemical action of the hot-springs. These results indicate that the fumarolic plants are able to transform the volcanic substrate to soil and to affect the NOHRE mass fractions even though these elements are not plant nutrients. Mirrored back to

  4. Landscape complexity and farmland biodiversity: Evaluating the CAPtarget on natural elements

    NARCIS (Netherlands)

    Cormont, A.; Siepel, H.; Clement, J.; Melman, Th.C.P.; Wallis de Vries, M.F.

    2016-01-01

    richnessa b s t r a c tIncreasing pressures on natural areas and limited conservation budgets require, particularly in rural land-scapes in the Western world, an immediate answer to the question how much natural area is requiredto provide a sustainable future for wild plant and animal species on far

  5. Superoxide dismutase activity of the naturally occurring human serum albumin-copper complex without hydroxyl radical formation.

    Science.gov (United States)

    Kato, Ryunosuke; Akiyama, Matofusa; Kawakami, Hiroyoshi; Komatsu, Teruyuki

    2014-01-01

    The superoxide radical anion (O2(.-)) is biologically toxic and contributes to the pathogenesis of various diseases. Here we describe the superoxide dismutase (SOD) activity of human serum albumin (HSA) complexed with a single Cu(II) ion at the N-terminal end (HSA-Cu complex). The structure of this naturally occurring copper-coordinated blood serum protein has been characterized by several physicochemical measurements. The O2(.-) dismutation ability of the HSA-Cu (1:1) complex is almost the same as that of the well-known SOD mimics, such as Mn(III) -tetrakis(N-methylpyridinium)porphyrin. Interestingly, the HSA-Cu complex does not induce a subsequent Fenton reaction to produce the hydroxyl radical (OH(.)), which is one of the most harmful reactive oxygen species.

  6. 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.

  7. Assessing and modeling sediment mobility in estuarine and coastal settings due to extreme climate events from natural short-lived isotope distribution

    Science.gov (United States)

    Ghaleb, Bassam; Hillaire-Marcel, Claude; Ruiz Fernandez, Ana-Carolina; Sanchez Cabeza, Joan-Albert

    2016-04-01

    Climatic events (e.g. floods, storminess) and management activities (e.g. dredging) may result in the burial or removal and re-suspension of sediments in estuaries and coastal areas. When such sediments are contaminated, such processes may either help restoring better chemical environments or lead to their long-term contamination. Geochemical signatures in surface sediments may help identifying such sedimentological events. However, short-lived isotope data are generally required to set time-constraints on their occurrence. Whereas 210Pb and radioactive fallout isotope contents can help setting time constraints at ~50 to ~100 yr-time scales, natural disequilibria in the 232Th-228Ra-228Th sequence do provide information on processes which occurred within the last 30 yrs, as illustrated in the present study. Box-cored sediments from the Saguenay Fjord and lower estuary of the St. Lawrence (Canada) as well as from estuaries and lagoons from the Sinaloa Coast (Mexico) are used to document the behavior of these isotopes either under relatively steady conditions (St. Lawrence estuary) or under high-frequency extreme climate events (storms and floods; Saguenay Fjord, Coastal Sinaloa). 228Th/232Th activity ratios were determined by chemical extraction of Th and alpha counting of unspiked samples, rapidly after sampling (228Th/232Th). The activity of the intermediate isotope 228Ra was then estimated based on replicate measurements on aliquot samples made a few years later. Under steady conditions, core-top sediment shows an excess in 228Th vs 232Th (AR ~ 1.6), whereas the intermediate 228Ra depicts a deficit vs its parent 232Th (AR ~0.6). Downcore, radioactive decay carries rapidly 228Th-activities to those of the parent 228Ra within about 10 yrs (i.e., ~ 5 half-lives of 228Th), then both move during the next ~20 yrs (~ i.e., ~ 5 half-lives of 228Ra, when added to the 10 yrs of 228Th-excess) towards secular equilibrium with the parent long-lived 232Th. A few algorithms

  8. Non coding extremities of the seven influenza virus type C vRNA segments: effect on transcription and replication by the type C and type A polymerase complexes

    Directory of Open Access Journals (Sweden)

    van der Werf Sylvie

    2008-10-01

    Full Text Available Abstract Background The transcription/replication of the influenza viruses implicate the terminal nucleotide sequences of viral RNA, which comprise sequences at the extremities conserved among the genomic segments as well as variable 3' and 5' non-coding (NC regions. The plasmid-based system for the in vivo reconstitution of functional ribonucleoproteins, upon expression of viral-like RNAs together with the nucleoprotein and polymerase proteins has been widely used to analyze transcription/replication of influenza viruses. It was thus shown that the type A polymerase could transcribe and replicate type A, B, or C vRNA templates whereas neither type B nor type C polymerases were able to transcribe and replicate type A templates efficiently. Here we studied the importance of the NC regions from the seven segments of type C influenza virus for efficient transcription/replication by the type A and C polymerases. Results The NC sequences of the seven genomic segments of the type C influenza virus C/Johannesburg/1/66 strain were found to be more variable in length than those of the type A and B viruses. The levels of transcription/replication of viral-like vRNAs harboring the NC sequences of the respective type C virus segments flanking the CAT reporter gene were comparable in the presence of either type C or type A polymerase complexes except for the NS and PB2-like vRNAs. For the NS-like vRNA, the transcription/replication level was higher after introduction of a U residue at position 6 in the 5' NC region as for all other segments. For the PB2-like vRNA the CAT expression level was particularly reduced with the type C polymerase. Analysis of mutants of the 5' NC sequence in the PB2-like vRNA, the shortest 5' NC sequence among the seven segments, showed that additional sequences within the PB2 ORF were essential for the efficiency of transcription but not replication by the type C polymerase complex. Conclusion In the context of a PB2-like reporter

  9. New polyelectrolyte complex particles as colloidal dispersions based on weak synthetic and/or natural polyelectrolytes

    Directory of Open Access Journals (Sweden)

    2011-06-01

    Full Text Available This study aims to evidence the formation of stable polyelectrolyte complex particles as colloidal dispersions using some weak polyelectrolytes: chitosan and poly(allylamine hydrochloride as polycations and poly(acrylic acid (PAA and poly(2-acrylamido-2-methylpropanesulfonic acid – co – acrylic acid (PAMPSAA as polyanions. Polyelectrolyte complex particles as colloidal dispersion were prepared by controlled mixing of the oppositely charged polymers, with a constant addition rate. The influences of the polyelectrolytes structure and the molar ratio between ionic charges on the morphology, size, and colloidal stability of the complex particles have been deeply investigated by turbidimetry, dynamic light scattering and atomic force microscopy. A strong influence of polyanion structure on the values of molar ratio n–/n+ when neutral complex particles were obtained has been noticed, which shifts from the theoretical value of 1.0, observed when PAA was used, to 0.7 for PAMPSAA based complexes. The polyions chain characteristics influenced the size and shape of the complexes, larger particles being obtained when chitosan was used, for the same polyanion, and when PAMPSAA was used, for the same polycation.

  10. Effects of various extremely low frequency magnetic fields on the free radical processes, natural antioxidant system and respiratory burst system activities in the heart and liver tissues.

    Science.gov (United States)

    Canseven, Ayse Gulnihal; Coskun, Sule; Seyhan, Nesrin

    2008-10-01

    Magnetic fields (MFs) can affect biological systems by increasing the release of free radicals that are able to alter cell defense systems and breakdown tissue homeostasis. In the present study, the effects of extremely low frequency (ELF) electromagnetic fields (EMF) were investigated on free radical levels, natural antioxidant systems and respiratory burst system activities in heart and liver tissues of guinea pigs exposed to 50 Hz MFs of 1, 2 and 3 mT for 4 h/day and 8 h/day for 5 days by measuring malondialdehyde (MDA), nitric oxide (NO), glutathione (GSH) levels and myeloperoxidase (MPO) activity. A total of sixty-two male guinea pigs, 10-12 weeks old were studied in seven groups as control and exposure groups: Group I (control), II (1 mT, 4 h/day), III (1 mT, 8 h/day), IV (2 mT, 4 h/day), V (2 mT, 8 h/day), VI (3 mT, 4 h/day), and VII (3 mT, 8 h/day). Controls were kept under the same conditions without any exposure to MF. MDA levels increased in liver in groups II and IV, but decreased in group VII for both liver and heart tissues. NOx levels declined in heart in groups II and III and in liver in groups III, V, and VI, but increased in liver in group VII. GSH levels increased in heart in groups II, IV, V, and in liver in groups V and VI and VI, but decreased in groups II and IV in liver. MPO activity decreased in liver in groups III, IV, VI and VII with respect to controls and in heart tissues in groups II, III and IV; however, there was a significant increase MPO activity in heart in group VII. From the results, it can be concluded that the intensity and exposure duration of MFs are among the effective conditions on the formation of free radicals and behaviour of antioxidant enzymes.

  11. Explicit solution format for complex-valued natural frequency of beam with R-shunted piezoelectric laminate transducer

    DEFF Research Database (Denmark)

    Høgsberg, Jan Becker; Cöent, Adrien Le

    2014-01-01

    Analysis and design of resistive shunt circuits for piezoelectric damping of beam structures is often based on a representation in terms of the single target vibration mode of the beam, neglecting spill-over effects from the out-of-bandwidth or residual vibration modes. In this article, a solution...... format is derived for the complex-valued natural frequency of the beam with a shunted piezoelectric laminate transducer, where the influence from the residual modes is taken into account by a quasi-static representation. This explicit solution format contains system parameters that directly represent....... The accuracy of the explicit frequency solution format is verified by comparison with numerical results. It is found that the complex-valued natural frequency of the first vibration mode of a beam with a piezoelectric laminate transducer shunted to a resistance is estimated with sufficient accuracy...

  12. 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

  13. Does variability matter? Major histocompatibility complex (MHC) variation and its associations to parasitism in natural small mammal populations

    OpenAIRE

    Meyer-Lucht, Yvonne

    2009-01-01

    The adaptive evolutionary potential of a species or population to cope with omnipresent environmental challenges is based on its genetic variation. Variability at immune genes, such as the major histocompatibility complex (MHC) genes, is assumed to be a very powerful and effective tool to keep pace with diverse and rapidly evolving pathogens. In my thesis, I studied natural levels of variation at the MHC genes, which have a key role in immune defence, and parasite burden in different small ma...

  14. Geometric aspect and buoyancy effects on nature convection flow in the complex annuli filled with micropolar fluids

    Science.gov (United States)

    Chen, Wen Ruey

    2016-10-01

    This paper studies the steady laminar natural convection of micropolar fluids in the complex annuli between the inner sphere and outer vertical cylinder to present a numerical analysis of the flow and heat transfer characteristics with buoyancy effects. Computations were carried out systematically by the several different parameters of geometric ratio, micropolar material parameter and Rayleigh number to determine the average Nusselt number and the skin friction coefficient on the flow and the thermal fields.

  15. 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

  16. Change ΔS of the entropy in natural time under time reversal: Complexity measures upon change of scale

    Science.gov (United States)

    Sarlis, N. V.; Christopoulos, S.-R. G.; Bemplidaki, M. M.

    2015-01-01

    The entropy S in natural time as well as the entropy in natural time under time reversal S- have already found useful applications in the physics of complex systems, e.g., in the analysis of electrocardiograms (ECGs). Here, we focus on the complexity measures Λl which result upon considering how the statistics of the time series Δ S≤ft[\\equiv S- S-\\right] changes upon varying the scale l. These scale-specific measures are ratios of the standard deviations σ(Δ S_l) and hence independent of the mean value and the standard deviation of the data. They focus on the different dynamics that appear on different scales. For this reason, they can be considered complementary to other standard measures of heart rate variability in ECG, like SDNN, as well as other complexity measures already defined in natural time. An application to the analysis of ECG —when solely using NN intervals— is presented: We show how Λl can be used to separate ECG of healthy individuals from those suffering from congestive heart failure and sudden cardiac death.

  17. Propolis: A Complex Natural Product with a Plethora of Biological Activities That Can Be Explored for Drug Development

    Directory of Open Access Journals (Sweden)

    Ricardo Silva-Carvalho

    2015-01-01

    Full Text Available The health industry has always used natural products as a rich, promising, and alternative source of drugs that are used in the health system. Propolis, a natural resinous product known for centuries, is a complex product obtained by honey bees from substances collected from parts of different plants, buds, and exudates in different geographic areas. Propolis has been attracting scientific attention since it has many biological and pharmacological properties, which are related to its chemical composition. Several in vitro and in vivo studies have been performed to characterize and understand the diverse bioactivities of propolis and its isolated compounds, as well as to evaluate and validate its potential. Yet, there is a lack of information concerning clinical effectiveness. The goal of this review is to discuss the potential of propolis for the development of new drugs by presenting published data concerning the chemical composition and the biological properties of this natural compound from different geographic origins.

  18. Propolis: A Complex Natural Product with a Plethora of Biological Activities That Can Be Explored for Drug Development.

    Science.gov (United States)

    Silva-Carvalho, Ricardo; Baltazar, Fátima; Almeida-Aguiar, Cristina

    2015-01-01

    The health industry has always used natural products as a rich, promising, and alternative source of drugs that are used in the health system. Propolis, a natural resinous product known for centuries, is a complex product obtained by honey bees from substances collected from parts of different plants, buds, and exudates in different geographic areas. Propolis has been attracting scientific attention since it has many biological and pharmacological properties, which are related to its chemical composition. Several in vitro and in vivo studies have been performed to characterize and understand the diverse bioactivities of propolis and its isolated compounds, as well as to evaluate and validate its potential. Yet, there is a lack of information concerning clinical effectiveness. The goal of this review is to discuss the potential of propolis for the development of new drugs by presenting published data concerning the chemical composition and the biological properties of this natural compound from different geographic origins.

  19. Propolis: A Complex Natural Product with a Plethora of Biological Activities That Can Be Explored for Drug Development

    Science.gov (United States)

    Silva-Carvalho, Ricardo; Baltazar, Fátima; Almeida-Aguiar, Cristina

    2015-01-01

    The health industry has always used natural products as a rich, promising, and alternative source of drugs that are used in the health system. Propolis, a natural resinous product known for centuries, is a complex product obtained by honey bees from substances collected from parts of different plants, buds, and exudates in different geographic areas. Propolis has been attracting scientific attention since it has many biological and pharmacological properties, which are related to its chemical composition. Several in vitro and in vivo studies have been performed to characterize and understand the diverse bioactivities of propolis and its isolated compounds, as well as to evaluate and validate its potential. Yet, there is a lack of information concerning clinical effectiveness. The goal of this review is to discuss the potential of propolis for the development of new drugs by presenting published data concerning the chemical composition and the biological properties of this natural compound from different geographic origins. PMID:26106433

  20. Complex self-assembly of reverse poly(butylene oxide)-poly(ethylene oxide)-poly(butylene oxide) triblock copolymers with long hydrophobic and extremely lengthy hydrophilic blocks.

    Science.gov (United States)

    Cambón, Adriana; Figueroa-Ochoa, Edgar; Juárez, Josué; Villar-Álvarez, Eva; Pardo, Alberto; Barbosa, Silvia; Soltero, J F Armando; Taboada, Pablo; Mosquera, Víctor

    2014-05-15

    Amphiphilic block copolymers have emerged during last years as a fascinating substrate material to develop micellar nanocontainers able to solubilize, protect, transport, and release under external or internal stimuli different classes of cargos to diseased cells or tissues. However, this class of materials can also induce biologically relevant actions, which complement the therapeutic activity of their cargo molecules through their mutual interactions with biologically relevant entities (cellular membranes, proteins, organelles...); these interactions at the same time, are regulated by the nature, conformation, and state of the copolymeric chains. For these reasons, in this paper we investigated the self-assembly process and physico-chemcial properties of two reverse triblock poly(butylene oxide)-poly(ethylene oxide)-poly(butylene oxide) block copolymers, BO14EO378BO14 and BO21EO385BO21, which have been recently found to be very useful as drug delivery nanovehicles and biological response modifiers under certain conditions (A. Cambón et al. Int. J. Pharm. 2013, 445, 47-57) in order to obtain a clear picture of the solution behavior of this class or block copolymers and to understand their biological activity. These block copolymers are characterized by possessing long BO blocks and extremely lengthy central EO ones, which provide them with a rich rheological behavior characterized by the formation of flowerlike micelles with sizes ranging from 20 to 40 nm in aqueous solution and the presence of intermicellar bridging even at low copolymers concentrations as denoted by atomic force microscopy. Bridging is also clearly observed by analyzing the rheological response of these block copolymers both storage and loss moduli upon changes on time, temperature, and or concentration. Strikingly, the relatively wide Poisson distribution of the polymeric chains make the present copolymers behave rather distinctly to conventional associative thickeners. The observed rich

  1. In situ investigation on rapid microstructure evolution in extreme complex environment by developing a new AFBP-TVM sparse tomography algorithm from original CS-XPCMT

    Science.gov (United States)

    Xu, Feng; Dong, Bo; Hu, Xiaofang; Xiao, Yu; Wang, Yang

    2017-09-01

    A new sparse tomography method for observing the rapid internal microstructure evolution of material, called the Algebraic Filtered-Back-Projection and Total Variation Minimization (AFBP-TVM) iteration sparse reconstruction algorithm, was proposed in this paper. The new algorithm was developed by combining the two techniques of the Algebraic Reconstruction Technique (ART) and the Filtered-Back-Projection (FBP) on the basis of analysis in linear space. A series of numerical reconstruction experiments were conducted to validate the new algorithm. The results indicated the new algorithm can obtain satisfactory reconstruction images from 1/6 of the projections that were used in traditional algorithms. So the time spent on projection acquisition process can be reduced to 1/6 of that in traditional tomography method. The quality of images reconstructed by new algorithm was better than other algorithms, which was evaluated by three quantitative parameters. The normalized average absolute distance criterion and the normalized mean square criterion, which were used to evaluate the relative error of the reconstruction results (smaller value means better quality of reconstruction), decreased from 0.3758 to 0.1272 and from 0.1832 to 0.0894 respectively. The standardized covariance criterion, which was used to evaluate the similarity level (greater value means higher accuracy of reconstruction), increased from 92.72% to 99.30%. Finally, the new algorithm was validated under actual experimental conditions. The results indicated that the AFBP-TVM algorithm obtained better reconstruction quality than other algorithms. It meant that the AFBP-TVM algorithm may be a suitable method for in situ investigation on material's rapid internal microstructure evolution in extreme complex environment.

  2. A Student Whisperer's Challenge: Complex Learner Dispositions and the Relational Nature of Teaching

    Science.gov (United States)

    McDonald, Denise

    2013-01-01

    One of the challenges of teacher educators is instructing students who possess complex dispositions or experience troubling times while under our auspices. Research supports common knowledge that student dispositions interplay with social identity formation and learning (specifically, situated cognition). This study examined learner dispositions…

  3. Chemodynamics of metal complexation by natural soft colloids: Cu(II) binding by humic acid

    NARCIS (Netherlands)

    Town, R.M.; Duval, J.F.L.; Buffle, J.; Leeuwen, van H.P.

    2012-01-01

    The chemodynamics of Cu(II) complexation by humic acid is interpreted in terms of recently developed theory for permeable charged nanoparticles. Two opposing electric effects are operational with respect to the overall rate of association, namely, (i) the conductive enhancement of the diffusion of

  4. Understanding Complex Natural Systems by Articulating Structure-Behavior-Function Models

    Science.gov (United States)

    Vattam, Swaroop S.; Goel, Ashok K.; Rugaber, Spencer; Hmelo-Silver, Cindy E.; Jordan, Rebecca; Gray, Steven; Sinha, Suparna

    2011-01-01

    Artificial intelligence research on creative design has led to Structure-Behavior-Function (SBF) models that emphasize functions as abstractions for organizing understanding of physical systems. Empirical studies on understanding complex systems suggest that novice understanding is shallow, typically focusing on their visible structures and…

  5. Adaptation of the simple or complex nature of V1 receptive fields to visual statistics.

    Science.gov (United States)

    Fournier, Julien; Monier, Cyril; Pananceau, Marc; Frégnac, Yves

    2011-07-17

    Receptive fields in primary visual cortex (V1) are categorized as simple or complex, depending on their spatial selectivity to stimulus contrast polarity. We studied the dependence of this classification on visual context by comparing, in the same cell, the synaptic responses to three classical receptive field mapping protocols: sparse noise, ternary dense noise and flashed Gabor noise. Intracellular recordings revealed that the relative weights of simple-like and complex-like receptive field components were scaled so as to make the same receptive field more simple-like with dense noise stimulation and more complex-like with sparse or Gabor noise stimulations. However, once these context-dependent receptive fields were convolved with the corresponding stimulus, the balance between simple-like and complex-like contributions to the synaptic responses appeared to be invariant across input statistics. This normalization of the linear/nonlinear input ratio suggests a previously unknown form of homeostatic control of V1 functional properties, optimizing the network nonlinearities to the statistical structure of the visual input.

  6. The complex of looped diagrams and natural operations on Hochschild homology

    DEFF Research Database (Denmark)

    Klamt, Angela

    operations for commutative algebras (as computed in the rst part of the thesis) and a shifted BV structure which has been investigated by Abbaspour earlier. We prove that this BV structure comes from a suspended Cacti operad sitting inside the complex of looped diagrams. Last, we eneralize the setup...

  7. Application of surface complexation models to anion adsorption by natural materials

    Science.gov (United States)

    Various chemical models of ion adsorption will be presented and discussed. Chemical models, such as surface complexation models, provide a molecular description of anion adsorption reactions using an equilibrium approach. Two such models, the constant capacitance model and the triple layer model w...

  8. From problem solving to problem definition: scrutinizing the complex nature of clinical practice.

    Science.gov (United States)

    Cristancho, Sayra; Lingard, Lorelei; Regehr, Glenn

    2017-02-01

    In medical education, we have tended to present problems as being singular, stable, and solvable. Problem solving has, therefore, drawn much of medical education researchers' attention. This focus has been important but it is limited in terms of preparing clinicians to deal with the complexity of the 21st century healthcare system in which they will provide team-based care for patients with complex medical illness. In this paper, we use the Soft Systems Engineering principles to introduce the idea that in complex, team-based situations, problems usually involve divergent views and evolve with multiple solution iterations. As such we need to shift the conversation from (1) problem solving to problem definition, and (2) from a problem definition derived exclusively at the level of the individual to a definition derived at the level of the situation in which the problem is manifested. Embracing such a focus on problem definition will enable us to advocate for novel educational practices that will equip trainees to effectively manage the problems they will encounter in complex, team-based healthcare.

  9. On the Nature of Sandwiched Chromium Complexes in Exchanged alpha-Zirconium Phosphate

    Directory of Open Access Journals (Sweden)

    Claudia Maria de Oliveira Rapôso

    2002-10-01

    Full Text Available Layered alpha-zirconium hydrogenphosphate monohydrate was prepared by direct precipitation, exchanged with n-propylamine and then by chromium aquacomplexes. The solids were characterized by X-ray diffraction, mass spectrometry, infrared and UV-Visible spectroscopy. The results suggest that monomer complexes form extended, hydrogen bonded, sandwiched monolayers in the interlayer space.

  10. Hydrogen-peroxide epoxidation of natural olefins catalyzed by a dinuclear manganese complex

    NARCIS (Netherlands)

    Mandelli, D; Voitiski, KB; Schuchardt, U; Shul'pin, GB

    2002-01-01

    The complex of Mn(IV) with the macrocyclic N-containing ligand 1,4,7-trimethyl-1,4,7-triazacyclononane (L) [L2Mn2O3](PF6)(2) catalyzes epoxidation of (+)-limonene in CH3CN solution at room temperature. Adding CH3COOH accelerates the reaction. The products are isomers of limonene epoxide with

  11. Hydrogen-peroxide epoxidation of natural olefins catalyzed by a dinuclear manganese complex

    NARCIS (Netherlands)

    Mandelli, D; Voitiski, KB; Schuchardt, U; Shul'pin, GB

    2002-01-01

    The complex of Mn(IV) with the macrocyclic N-containing ligand 1,4,7-trimethyl-1,4,7-triazacyclononane (L) [L2Mn2O3](PF6)(2) catalyzes epoxidation of (+)-limonene in CH3CN solution at room temperature. Adding CH3COOH accelerates the reaction. The products are isomers of limonene epoxide with predomi

  12. Age and nature of Triassic magmatism in the Netoni Intrusive Complex, West Papua, Indonesia

    Science.gov (United States)

    Webb, Max; White, Lloyd T.

    2016-12-01

    We report field observations together with petrological, geochemical and geochronological data from granitoids of the Netoni Intrusive Complex of West Papua. Until now, our knowledge of the timing of granitic magmatism in this region has been limited to a wide range of ages (241-6.7 Ma) obtained from K-Ar measurements of hornblende, biotite and plagioclase, primarily from samples of river detritus. We collected in situ samples along several traverses into the intrusive complex to: (1) develop a better understanding of the lithologies within the intrusive complex; and (2) determine the timing of magmatism using U-Pb dating of zircon. We also dated zircons from two river sand samples to identify other potential pulses of magmatism that may have been missed due to a sampling bias. The zircons extracted from the river sands yield age spectra similar to those obtained from the in situ samples. The combined data demonstrate that magmatism in the Netoni Intrusive Complex occurred between 248 Ma and 213 Ma. The petrological and geochemical data indicate that the granitoids were most likely emplaced in an ocean-continent (Andean style) subduction setting. This builds on previous work which suggests that a magmatic belt extended along eastern Gondwana (now New Guinea and eastern Australia) throughout much of the Paleozoic. The volcanic ejecta that were produced along this arc and the subsequent erosion of the mountain chain are a potential source of detritus for Triassic and younger sedimentary rocks in New Guinea, eastern Indonesia and north/northwestern Australia.

  13. Extreme environments and exobiology.

    Science.gov (United States)

    Friedmann, E I

    1993-01-01

    Ecological research on extreme environments can be applied to exobiological problems such as the question of life on Mars. If life forms (fossil or extant) are found on Mars, their study will help to solve fundamental questions about the nature of life on Earth. Extreme environments that are beyond the range of adaptability of their inhabitants are defined as "absolute extreme". Such environments can serve as terrestrial models for the last stages of life in the history of Mars, when the surface cooled down and atmosphere and water disappeared. The cryptoendolithic microbial community in porous rocks of the Ross Desert in Antarctica and the microbial mats at the bottom of frozen Antarctic lakes are such examples. The microbial communities of Siberian permafrost show that, in frozen but stable communities, long-term survival is possible. In the context of terraforming Mars, selected microorganisms isolated from absolute extreme environments are considered for use in creation of a biological carbon cycle.

  14. Characterization of Fe-leonardite complexes as novel natural iron fertilizers.

    Science.gov (United States)

    Kovács, Krisztina; Czech, Viktória; Fodor, Ferenc; Solti, Adam; Lucena, Juan J; Santos-Rosell, Sheila; Hernández-Apaolaza, Lourdes

    2013-12-18

    Water-soluble humic substances (denoted by LN) extracted at alkaline pH from leonardite are proposed to be used as complexing agents to overcome micronutrient deficiencies in plants such as iron chlorosis. LN presents oxidized functional groups that can bind Fe(2+) and Fe(3+). The knowledge of the environment of Fe in the Fe-LN complexes is a key point in the studies on their efficacy as Fe fertilizers. The aim of this work was to study the Fe(2+)/Fe(3+) species formed in Fe-LN complexes with (57)Fe Mössbauer spectroscopy under different experimental conditions in relation to the Fe-complexing capacities, chemical characteristics, and efficiency to provide iron in hydroponics. A high oxidation rate of Fe(2+) to Fe(3+) was found when samples were prepared with Fe(2+), although no well-crystalline magnetically ordered ferric oxide formation could be observed in slightly acidic or neutral media. It seems to be the case that the formation of Fe(3+)-LN compounds is favored over Fe(2+)-LN compounds, although at acidic pH no complex formation between Fe(3+) and LN occurred. The Fe(2+)/Fe(3+) speciation provided by the Mössbauer data showed that Fe(2+)-LN could be efficient in hydroponics while Fe(3+)-LN is suggested to be used more effectively under calcareous soil conditions. However, according to the biological assay, Fe(3+)-LN proved to be effective as a chlorosis corrector applied to iron-deficient cucumber in nutrient solution.

  15. Novel reduction of Cr(VI) from wastewater using a naturally derived microcapsule loaded with rutin-Cr(III) complex.

    Science.gov (United States)

    Qi, Yun; Jiang, Meng; Cui, Yuan-Lu; Zhao, Lin; Liu, Shejiang

    2015-03-21

    The harmfulness of carcinogenic hexavalent chromium (Cr(VI)) is dramatically decreased when Cr(VI) is reduced to trivalent chromium (Cr(III)). Rutin, a natural flavonoid, exhibits excellent antioxidant activity by coordinating metal ions. In this study, a complex containing rutin and Cr(III) (rutin-Cr(III)) was synthesized and characterized. The rutin-Cr(III) complex was much easier to reduce than rutin. The reduction of the rutin-Cr(III) complex was highly pH-dependent, with 90% of the Cr(VI) being reduced to Cr(III) in 2h under optimal conditions. A biodegradable, sustained-release system encapsulating the rutin-Cr(III) complex in a alginate-chitosan microcapsule (rutin-Cr(III) ACMS) was also evaluated, and the reduction of Cr(VI) was assessed. This study also demonstrated that low-pH solutions increased the reduction rate of Cr(VI). The environmentally friendly microcapsules can reduce Cr(VI) for prolonged periods of time and can easily biodegrade after releasing the rutin-Cr(III) complex. Given the excellent performance of rutin-Cr(III) ACMS, the microcapsule system represents an effective system for the remediation of Cr(VI) pollution.

  16. Natural head position: key position for radiographic and photographic analysis and research of craniofacial complex

    Science.gov (United States)

    Verma, Sanjeev Kumar; Maheshwari, Sandhya; Gautam, Sanjay N; Prabhat, KC; Kumar, Shailendra

    2012-01-01

    The Frankfort horizontal is a useful compromise for studying skulls but not for orienting the natural head position (NHP) in the living because it is normally distributed around a true extracranial horizontal. Nonetheless, orthodontists dealing with living subjects, rather than inert crania, have used this Frankfort horizontal faithfully in cephalometry. Because the cant or inclination of all intracranial reference lines is subjected to biologic variation, they are unsuitable for meaningful cephalometric analysis. Registration of head posture in its natural position has the advantage that an extracranial vertical or a horizontal perpendicular to that vertical can be used as reference line for cephalometric analysis. Purpose of this paper is to provide an updated review of various methods to reproduce and record the NHP. PMID:25756032

  17. 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…

  18. Inventory Management of Cholera Vaccinations in the Event of Complex Natural Disasters

    Science.gov (United States)

    2015-12-01

    prepositioning supplies becomes the challenge (Apte, 2009, p. 14). Disasters that are localized but strike without warning pose different challenges as...WHO, 2012). The WHO recommended that the OCV stockpile be used preemptively vice reactively due to the short duration of many cholera outbreaks...with preemptive strategic campaigns due to displaced populations to refugee camps post natural or manmade disasters. The country of Vietnam is the

  19. 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

  20. Pyrosequencing reveals the complex polymicrobial nature of invasive pyogenic infections: microbial constituents of empyema, liver abscess, and intracerebral abscess.

    Science.gov (United States)

    Sibley, C D; Church, D L; Surette, M G; Dowd, S E; Parkins, M D

    2012-10-01

    The polymicrobial nature of invasive pyogenic infections may be underestimated by routine culture practices, due to the fastidious nature of many organisms and the loss of viability during transport or from prior antibacterials. Pyrosequencing was performed on brain and liver abscesses and pleural fluid and compared to routine culture data. Forty-seven invasive pyogenic infection samples from 44 patients [6 intracerebral abscess (ICA), 21 pyogenic liver abscess (PLA), and 18 pleural fluid (PF) samples] were assayed. Pyrosequencing identified an etiologic microorganism in 100 % of samples versus 45 % by culture, p <0.01. Pyrosequencing was also more likely than traditional cultures to classify infections as polymicrobial, 91 % versus 17 %, p <0.001. The median number of genera identified by pyrosequencing compared to culture was 1 [interquartile range (IQR) 1-3] versus 0 (IQR 0-1) for ICA, 7 (IQR 1-15) versus 1 (IQR 0-1) for PLA, and 15 (IQR 9-19) versus 0 (IQR 0-1) for PF. Where organisms were cultured, they typically represented the numerically dominant species identified by pyrosequencing. Complex microbial communities are involved in invasive pyogenic infection of the lung, liver, and brain. Defining the polymicrobial nature of invasive pyogenic infections is the first step towards appreciating the clinical and diagnostic implications of these complex communities.

  1. 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

  2. Complexity

    CERN Document Server

    Gershenson, Carlos

    2011-01-01

    The term complexity derives etymologically from the Latin plexus, which means interwoven. Intuitively, this implies that something complex is composed by elements that are difficult to separate. This difficulty arises from the relevant interactions that take place between components. This lack of separability is at odds with the classical scientific method - which has been used since the times of Galileo, Newton, Descartes, and Laplace - and has also influenced philosophy and engineering. In recent decades, the scientific study of complexity and complex systems has proposed a paradigm shift in science and philosophy, proposing novel methods that take into account relevant interactions.

  3. Impact of natural organic matter on arsenic removal by modified granular natural siderite: Evidence of ternary complex formation by HPSEC-UV-ICP-MS.

    Science.gov (United States)

    Li, Fulan; Guo, Huaming; Zhou, Xiaoqian; Zhao, Kai; Shen, Jiaxing; Liu, Fei; Wei, Chao

    2017-02-01

    High arsenic (As) groundwater usually has high concentrations of natural organic matter (NOM). Effects of NOM on arsenic adsorption were investigated to evaluate the efficiency of modified granular natural siderite (MGNS) as an adsorbent for groundwater arsenic remediation. Humic and fulvic acids (HA/FA) were selected as model NOM compounds. In batch tests, HA or FA was either first adsorbed onto the MGNS, or applied together with dissolved arsenic to investigate effects of both adsorbed and dissolved NOM on arsenic removal. The kinetic data showed no significant effects of both adsorbed and dissolved HA/FA on As(III) adsorption. However, As(V) removal was inhibited, whereby the adsorbed NOM compounds had greater inhibitory effect. The inhibitory effect on As(V) removal increased with increasing NOM concentrations. FA exhibited higher inhibitory effect than HA at the same concentration. Steric Exclusion Chromatography-HPLC (SEC-HPLC), and High-Performance Size Exclusion Chromatography-UV-Inductively Coupled Plasma Mass Spectrometry (HPSEC-UV-ICP-MS) revealed that As(V) removal was mostly achieved by the oxyanion adsorption and adversely affected by dissolved FA via competitive adsorption for surface sites. In addition to oxyanion adsorption, removal of As(V) was related to scavenging of ternary HA-As-Fe complexes, which led to the less inhibitory effect of dissolved HA on As(V) removal than dissolved FA via competitive adsorption.

  4. Environmental Perceptions of Rural South African Residents: The Complex Nature of Environmental Concern

    Science.gov (United States)

    Hunter, Lori M.; Strife, Susie; Twine, Wayne

    2009-01-01

    The state of the local environment shapes the well-being of millions of rural residents in developing nations. Still, we know little of these individuals’ environmental perceptions. This study analyzes survey data collected in an impoverished, rural region in northeast South Africa, to understand the factors that shape concern with local environmental issues. We use the “post-materialist thesis” to explore the different explanations for environmental concern in less developed regions of the world, with results revealing the importance of both cultural and physical context. In particular, gendered interaction with natural resources shapes perceptions, as does the local setting. Both theoretical and policy implications are discussed. PMID:20514147

  5. A prototype natural language interface to a large complex knowledge base, the Foundational Model of Anatomy.

    Science.gov (United States)

    Distelhorst, Gregory; Srivastava, Vishrut; Rosse, Cornelius; Brinkley, James F

    2003-01-01

    We describe a constrained natural language interface to a large knowledge base, the Foundational Model of Anatomy (FMA). The interface, called GAPP, handles simple or nested questions that can be parsed to the form, subject-relation-object, where subject or object is unknown. With the aid of domain-specific dictionaries the parsed sentence is converted to queries in the StruQL graph-searching query language, then sent to a server we developed, called OQAFMA, that queries the FMA and returns output as XML. Preliminary evaluation shows that GAPP has the potential to be used in the evaluation of the FMA by domain experts in anatomy.

  6. Synthesis of Complex Natural Products as a Vehicle for Student-Centered, Problem-Based Learning

    Science.gov (United States)

    Cannon, Kevin J.; Krow, Grant R.

    1998-10-01

    Management strategies for upper-level undergraduate and graduate courses in organic synthesis at Temple University are described, and both student and faculty responsibilities are discussed. Using natural product synthesis as a vehicle, students choose a synthetic problem from the literature, identify the knowledge needed to solve the problem, explore resources for attaining that knowledge, identify the goals and criteria for a successful synthetic plan, and create and do assessments of their work. The method is an example of teacher-guided, student-directed, interdependent, small-group, problem-based learning.

  7. Natural Resources and Local Development: The Argentinian Oilseed Complex and Biofuel Production

    Directory of Open Access Journals (Sweden)

    Eliana Scialabba

    2014-01-01

    Full Text Available Argentina is very rich in natural resources, particularly those linked to the oilseed production. Global demand and improved means of production, have resulted in a mature and developed production infrastructure geared toward export. This generates not just revenue, but also has other positive effects, such as the creation of jobs and sustainable development. In this context, biofuel production adds multidimensional value to the vegetable oil industry and generations many spin-off industries.

  8. 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

    . Earlier correlative evidence indicated that, in the ant Pachycondyla inversa, the hydrocarbon 3,11-dimethylheptacosane (3,11-diMeC27) is more abundant on the surface of queen-laid eggs. Methodology We first tested the hypothesis that 3,11-diMeC27 functions as a queen egg-marking pheromone using laboratory...... 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...

  9. Environmental Perceptions of Rural South African Residents: The Complex Nature of Environmental Concern.

    Science.gov (United States)

    Hunter, Lori M; Strife, Susie; Twine, Wayne

    2010-06-01

    The state of the local environment shapes the well-being of millions of rural residents in developing nations. Still, we know little of these individuals' environmental perceptions. This study analyzes survey data collected in an impoverished, rural region in northeast South Africa, to understand the factors that shape concern with local environmental issues. We use the "post-materialist thesis" to explore the different explanations for environmental concern in less developed regions of the world, with results revealing the importance of both cultural and physical context. In particular, gendered interaction with natural resources shapes perceptions, as does the local setting. Both theoretical and policy implications are discussed.

  10. 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.

  11. 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.

  12. Natural aging of multilayer films containing hydrophobically modified poly(acrylate)s or their complexes with surfactants

    Science.gov (United States)

    Gîfu, Ioana Cătălina; Maxim, Monica Elisabeta; Iovescu, Alina; Aricov, Ludmila; Simion, Elena Livia; Leontieş, Anca Ruxandra; Anastasescu, Mihai; Munteanu, Cornel; Anghel, Dan-Florin

    2017-08-01

    The paper reports the natural aging of polyelectrolyte multilayers containing sodium hydrophobically modified poly(acrylates) (PACnNa, n = 10 and 18) or complexes of PACnNa with alkyltrimethylammonium bromides (CxTAB, x = 10, 12, 14, 18) and poly(diallyldimethylammonium chloride) (PDADMAC). Wettability, thickness and surface morphology of aged multilayers are compared with those of freshly made. Contact angle (CA) increases with the alkyl chain length of the PACnNa and of the CxTAB in the complex with PACnNa. Wettability measurements unveil that only five bilayers of alternatively deposited PAC18Na-C18TAB and PDADMAC reach in 12 months the same CA as sixty freshly prepared bilayers. The PDADMAC outer layer gives higher CA and root mean square roughness than the negatively terminated multilayers. The results are significant for gaining new insight into the underlying mechanism of multilayers aging, saving materials, and improving the surface coatings for long term preservation.

  13. 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

    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......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...... 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...

  14. The nature of the giant diffuse non-thermal source in the A3411-A3412 complex

    CERN Document Server

    Giovannini, G; Girardi, M; Feretti, L; Govoni, F; Murgia, M

    2013-01-01

    VLA deep radio images at 1.4 GHz in total intensity and polarization reveal a diffuse non-thermal source in the interacting clusters A3411 - A3412. Moreover a small-size low power radio halo at the center of the merging cluster A3411 is found. We present here new optical and X-ray data and discuss the nature and properties of the diffuse non-thermal source. We suggest that the giant diffuse radio source is related to the presence of a large scale filamentary structure and to multiple mergers in the A3411-A3412 complex.

  15. Treatment of simple and complex endometrial non-atypical hyperplasia with natural progesterone: response rate to different doses.

    Science.gov (United States)

    Marra, Chiara; Penati, Cristina; Ferrari, Luisa; Cantù, Maria Grazia; Bargossi, Lorena; Fruscio, Robert

    2014-01-01

    The aim of this study is to evaluate the response rate to natural progesterone in non-atypical endometrial hyperplasia and to identify the lowest effective dose. A total of 197 patients of childbearing age with simple or complex hyperplasia were retrospectively identified. The women were treated with a cyclic administration of progesterone at different dosages (100 versus 200 versus 300 mg daily). Endometrial biopsies were performed at 6, 12, 18 months. In comparing progesterone to a regimen of no therapy, a significantly higher remission rate was observed in the progesterone group than in the latter (95 versus 75%, p = 0.05 for simple hyperplasia; 89 versus 35%, p hyperplasia). Out of 60 women with simple hyperplasia, remission was observed in 9/11 (81.8%), 40/41 (97.5%) and 8/8 (100%) patients treated, respectively, with progesterone 100, 200 and 300 mg daily. Out of 72 women with complex hyperplasia, remission was observed in 3/5 (60%), 49/53 (92.4%) and 12/14 (85.7%) patients treated with progesterone 100, 200 and 300 mg daily, respectively. There was no statistically significant difference in the response rate in the two groups, neither with simple nor with complex hyperplasia. In conclusion, progesterone increased the regression rate of both simple and complex hyperplasia.

  16. Processing of Uav Based Range Imaging Data to Generate Detailed Elevation Models of Complex Natural Structures

    Science.gov (United States)

    Kohoutek, T. K.; Eisenbeiss, H.

    2012-07-01

    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 level. The RIM

  17. Simple models for complex natural surfaces - A strategy for the hyperspectral era of remote sensing

    Science.gov (United States)

    Adams, John B.; Smith, Milton O.; Gillespie, Alan R.

    1989-01-01

    A two-step strategy for analyzing multispectral images is described. In the first step, the analyst decomposes the signal from each pixel (as expressed by the radiance or reflectance values in each channel) into components that are contributed by spectrally distinct materials on the ground, and those that are due to atmospheric effects, instrumental effects, and other factors, such as illumination. In the second step, the isolated signals from the materials on the ground are selectively edited, and recombined to form various unit maps that are interpretable within the framework of field units. The approach has been tested on multispectral images of a variety of natural land surfaces ranging from hyperarid deserts to tropical rain forests. Data were analyzed from Landsat MSS (multispectral scanner) and TM (Thematic Mapper), the airborne NS001 TM simulator, Viking Lander and Orbiter, AIS, and AVRIS (Airborne Visible and Infrared Imaging Spectrometer).

  18. Hypnosis, human nature, and complexity: integrating neuroscience approaches into hypnosis research.

    Science.gov (United States)

    Barnier, Amanda J; McConkey, Kevin M

    2003-07-01

    Hypnosis research has contributed much to the understanding of human behavior and experience, both normal and abnormal. This paper considers ways in which neuroscience approaches may be integrated into hypnosis research to continue and enhance that contribution, as well as further reveal the nature of hypnosis itself. The authors review the influences on and advances in hypnosis research over the last century; illustrate the investigative value of hypnosis to selected phenomena across the areas of doing, feeling, believing, and remembering; and specify elements for the successful integration of neuroscience approaches into hypnosis research. The authors believe that hypnosis research offers powerful techniques to isolate psychological processes in ways that allow their neural bases to be mapped. Successful integration will be achieved when researchers add levels of explanation, rather than shift the emphasis from one level or feature to another.

  19. 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 ...

  20. de Sitter Extremal Surfaces

    CERN Document Server

    Narayan, K

    2015-01-01

    We study extremal surfaces in de Sitter space in the Poincare slicing in the upper patch, anchored on spatial subregions at the future boundary ${\\cal I}^+$, restricted to constant boundary Euclidean time slices (focussing on strip subregions). We find real extremal surfaces of minimal area as the boundaries of past lightcone wedges of the subregions in question: these are null surfaces with vanishing area. We find also complex extremal surfaces as complex extrema of the area functional, and the area is not always real-valued. In $dS_4$ the area is real and has some structural resemblance with entanglement entropy in a dual $CFT_3$. There are parallels with analytic continuation from the Ryu-Takayanagi expressions for holographic entanglement entropy in $AdS$. We also discuss extremal surfaces in the $dS$ black brane and the de Sitter "bluewall" studied previously. The $dS_4$ black brane complex surfaces exhibit a real finite cutoff-independent extensive piece. In the bluewall geometry, there are real surface...

  1. Grassland responses to precipitation extremes

    Science.gov (United States)

    Grassland ecosystems are naturally subjected to periods of prolonged drought and sequences of wet years. Climate change is expected to enhance the magnitude and frequency of extreme events at the intraannual and multiyear scales. Are grassland responses to extreme precipitation simply a response to ...

  2. Complex

    African Journals Online (AJOL)

    CLEMENT O BEWAJI

    Schiff bases and their complex compounds have been studied for their .... establishing coordination of the N–(2 – hydroxybenzyl) - L - α - valine Schiff base ..... (1967); “Spectrophotometric Identification of Organic Compounds”, Willey, New.

  3. Gender, Education, Extremism and Security

    Science.gov (United States)

    Davies, Lynn

    2008-01-01

    This paper examines the complex relationships between gender, education, extremism and security. After defining extremism and fundamentalism, it looks first at the relationship of gender to violence generally, before looking specifically at how this plays out in more extremist violence and terrorism. Religious fundamentalism is also shown to have…

  4. 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.

  5. Reactions of hexadehydro-Diels-Alder benzynes with structurally complex multifunctional natural products

    Science.gov (United States)

    Ross, Sean P.; Hoye, Thomas R.

    2017-06-01

    An important question in organic chemistry concerns the extent to which benzynes—one of the classical reactive intermediates in organic chemistry—can react in discriminating fashion with trapping reagents. In particular, whether these species can react selectively with substrates containing multiple functional groups and possible sites of reactivity has remained unanswered. Natural products comprise a palette of multifunctional compounds with which to address this question. Here, we show that benzynes produced by the hexadehydro-Diels-Alder (HDDA) reaction react with many secondary metabolites with a preference for one among several pathways. Examples demonstrating such selectivity include reactions with: phenolics, through dearomatizing ortho-substitution; alkaloids, through Hofmann-type elimination; tropolone and furan, through cycloaddition; and alkaloids, through three-component fragmentation-coupling reactions. We also demonstrate that the cinchona alkaloids quinidine and quinine give rise to products (some in as few as three steps) that enable subsequent and rapid access to structurally diverse polyheterocyclic compounds. The results show that benzynes are quite discriminating in their reactivity—a trait perhaps not broadly enough appreciated.

  6. Perceptual processing of natural scenes at rapid rates: effects of complexity, content, and emotional arousal.

    Science.gov (United States)

    Löw, Andreas; Bradley, Margaret M; Lang, Peter J

    2013-12-01

    During rapid serial visual presentation (RSVP), the perceptual system is confronted with a rapidly changing array of sensory information demanding resolution. At rapid rates of presentation, previous studies have found an early (e.g., 150-280 ms) negativity over occipital sensors that is enhanced when emotional, as compared with neutral, pictures are viewed, suggesting facilitated perception. In the present study, we explored how picture composition and the presence of people in the image affect perceptual processing of pictures of natural scenes. Using RSVP, pictures that differed in perceptual composition (figure-ground or scenes), content (presence of people or not), and emotional content (emotionally arousing or neutral) were presented in a continuous stream for 330 ms each with no intertrial interval. In both subject and picture analyses, all three variables affected the amplitude of occipital negativity, with the greatest enhancement for figure-ground compositions (as compared with scenes), irrespective of content and emotional arousal, supporting an interpretation that ease of perceptual processing is associated with enhanced occipital negativity. Viewing emotional pictures prompted enhanced negativity only for pictures that depicted people, suggesting that specific features of emotionally arousing images are associated with facilitated perceptual processing, rather than all emotional content.

  7. Double-pole nature of Λ(1405) studied with coupled-channel complex scaling method using complex-range Gaussian basis

    Energy Technology Data Exchange (ETDEWEB)

    Doté, A., E-mail: dote@post.kek.jp [KEK Theory Center, Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); J-PARC Branch, KEK Theory Center, IPNS, KEK, 203-1 Shirakata, Tokai, Ibaraki 319-1106 (Japan); Myo, T. [General Education, Faculty of Engineering, Osaka Institute of Technology, Osaka 535-8585 (Japan); Research Center for Nuclear Physics (RCNP), Osaka University, Ibaraki 567-0047 (Japan)

    2014-10-15

    The excited hyperon Λ(1405) is the important building block for kaonic nuclei which are a nuclear many-body system with anti-kaons. We have been investigating the Λ(1405) resonance with the coupled-channel Complex Scaling Method (ccCSM) in which the Λ(1405) is treated as a hadron-molecular state of a K{sup ¯}N–πΣ coupled system. We use a K{sup ¯}N(–πY) potential based on the chiral SU(3) theory. In this article, we report the double-pole nature of the Λ(1405), which is a characteristic property predicted by many studies with chiral SU(3)-based models. With the help of the complex-range Gaussian basis in ccCSM, we have found successfully another pole besides a pole near the K{sup ¯}N threshold (called higher pole) which was found in our previous work with the real-range Gaussian basis. The new pole (called lower pole) is found far below K{sup ¯}N threshold: (M,−Γ/2)=(1395,−138) MeV when f{sub π}=110 MeV. In spite of so broad width of the lower-pole state, the state is clearly identified with good separation from continuum states, since the oscillatory behavior of the continuum states is improved owing to the complex-range Gaussian basis. Analyzing the ccCSM wave function of the lower pole, we have revealed explicitly that the lower-pole state is dominated by the πΣ component rather than the K{sup ¯}N component. We have confirmed that the ccCSM wave function is correctly connected to the asymptotic form of the resonance wave function. Estimating the meson–baryon mean distance for the lower-pole state which involves a large decay width, the obtained value has a large imaginary part comparable to a real part. Therefore, the mean-distance of the lower-pole state is difficult to be interpreted intuitively. Such a nature of the lower pole is different from that of the higher pole. In addition, we have investigated the origin of the appearance of the lower pole. The lower pole is confirmed to be generated by the energy dependence attributed to the

  8. Outcome measures for hand function naturally reveal three distinct domains in older adults: strength, coordinated upper extremity function, and sensorimotor processing

    Directory of Open Access Journals (Sweden)

    Emily L Lawrence

    2015-06-01

    Full Text Available Understanding the mapping between individual outcome measures and the latent functional domains of interest is critical to a quantitative evaluation and rehabilitation of hand function. We examined whether and how the associations among six hand-specific outcome measures reveal latent functional domains in elderly individuals. We asked 66 healthy older adult participants (38F, 28M, 66.1±11.6yrs, range: 45-88yrs and 33 older adults (65.8±9.7yrs, 44-81yrs, 51 hands diagnosed with osteoarthritis (OA of the carpometacarpal (CMC joint, to complete six functional assessments: hand strength (Grip, Key and Precision Pinch, Box and Block, Nine Hole Pegboard, and Strength-Dexterity tests. The first three principal components suffice to explain 86% of variance among the six outcome measures in healthy older adults, and 84% of variance in older adults with CMC OA. The composition of these dominant associations revealed three distinct latent functional domains: strength, coordinated upper extremity function, and sensorimotor processing. Furthermore, in participants with thumb CMC OA we found a blurring of the associations between the latent functional domains of strength and coordinated upper extremity function. This motivates future work to understand how the physiological effects of thumb CMC OA lead upper extremity coordination to become strongly associated with strength, while dynamic sensorimotor ability remains an independent functional domain.Thus, when assessing the level of hand function in our growing older adult populations, it is particularly important to acknowledge its multidimensional nature—and explicitly consider how each outcome measure maps to these three latent and fundamental domains of function. Moreover, this ability to distinguish among latent functional domains may facilitate the design of treatment modalities to target the rehabilitation of each of them.

  9. 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

  10. Natural selection of the major histocompatibility complex (Mhc) in Hawaiian honeycreepers (Drepanidinae)

    Science.gov (United States)

    Jarvi, S.I.; Tarr, C.L.; Mcintosh, C.E.; Atkinson, C.T.; Fleischer, R.C.

    2004-01-01

    The native Hawaiian honeycreepers represent a classic example of adaptive radiation and speciation, but currently face one the highest extinction rates in the world. Although multiple factors have likely influenced the fate of Hawaiian birds, the relatively recent introduction of avian malaria is thought to be a major factor limiting honeycreeper distribution and abundance. We have initiated genetic analyses of class II ?? chain Mhc genes in four species of honeycreepers using methods that eliminate the possibility of sequencing mosaic variants formed by cloning heteroduplexed polymerase chain reaction products. Phylogenetic analyses group the honeycreeper Mhc sequences into two distinct clusters. Variation within one cluster is high, with dN > d S and levels of diversity similar to other studies of Mhc (B system) genes in birds. The second cluster is nearly invariant and includes sequences from honeycreepers (Fringillidae), a sparrow (Emberizidae) and a blackbird (Emberizidae). This highly conserved cluster appears reminiscent of the independently segregating Rfp-Y system of genes defined in chickens. The notion that balancing selection operates at the Mhc in the honeycreepers is supported by transpecies polymorphism and strikingly high dN/dS ratios at codons putatively involved in peptide interaction. Mitochondrial DNA control region sequences were invariant in the i'iwi, but were highly variable in the 'amakihi. By contrast, levels of variability of class II ?? chain Mhc sequence codons that are hypothesized to be directly involved in peptide interactions appear comparable between i'iwi and 'amakihi. In the i'iwi, natural selection may have maintained variation within the Mhc, even in the face of what appears to a genetic bottleneck.

  11. A surface complexation and ion exchange model of Pb and Cd competitive sorption on natural soils

    Science.gov (United States)

    Serrano, Susana; O'Day, Peggy A.; Vlassopoulos, Dimitri; García-González, Maria Teresa; Garrido, Fernando

    2009-02-01

    The bioavailability and fate of heavy metals in the environment are often controlled by sorption reactions on the reactive surfaces of soil minerals. We have developed a non-electrostatic equilibrium model (NEM) with both surface complexation and ion exchange reactions to describe the sorption of Pb and Cd in single- and binary-metal systems over a range of pH and metal concentration. Mineralogical and exchange properties of three different acidic soils were used to constrain surface reactions in the model and to estimate surface densities for sorption sites, rather than treating them as adjustable parameters. Soil heterogeneity was modeled with >FeOH and >SOH functional groups, representing Fe- and Al-oxyhydroxide minerals and phyllosilicate clay mineral edge sites, and two ion exchange sites (X - and Y -), representing clay mineral exchange. An optimization process was carried out using the entire experimental sorption data set to determine the binding constants for Pb and Cd surface complexation and ion exchange reactions. Modeling results showed that the adsorption of Pb and Cd was distributed between ion exchange sites at low pH values and specific adsorption sites at higher pH values, mainly associated with >FeOH sites. Modeling results confirmed the greater tendency of Cd to be retained on exchange sites compared to Pb, which had a higher affinity than Cd for specific adsorption on >FeOH sites. Lead retention on >FeOH occurred at lower pH than for Cd, suggesting that Pb sorbs to surface hydroxyl groups at pH values at which Cd interacts only with exchange sites. The results from the binary system (both Pb and Cd present) showed that Cd retained in >FeOH sites decreased significantly in the presence of Pb, while the occupancy of Pb in these sites did not change in the presence of Cd. As a consequence of this competition, Cd was shifted to ion exchange sites, where it competes with Pb and possibly Ca (from the background electrolyte). Sorption on >SOH

  12. On the nature of the plateau in two-step dinuclear spin-crossover complexes.

    Science.gov (United States)

    Ksenofontov, Vadim; Gaspar, Ana B; Niel, Virginie; Reiman, Sergey; Real, José A; Gütlich, Philipp

    2004-03-05

    A remarkable feature of the spin-crossover process in several dinuclear iron(II) compounds is a plateau in the two-step transition curve. Up to now, it has not been possible to analyse the spin state of dinuclear pairs that constitute such a plateau, due to the relative high temperatures at which the transition takes place in complexes investigated so far. We solved this problem by experimentally studying a novel dinuclear spin-crossover compound [[Fe(phdia)(NCS)(2)](2)(phdia)] (phdia: 4,7-phenanthroline-5,6-diamine). We report here on the synthesis and characterisation of this system, which exhibits a two-step spin transition at T(c1)=108 K and T(c2)=80 K, displaying 2 K and 7 K wide thermal hysteresis loops in the upper and the lower steps, respectively. A plateau of approximately 20 K width centred at about 90 K, which corresponds to the 50 % of the spin conversion, separates the two transitions. The composition of the plateau was identified in metastable state after quenching to 4.2 K by means of Mössbauer spectroscopy in an external magnetic field. Such experiments revealed that the plateau consists mainly of [HS-LS] pairs (HS=high spin, LS=low spin) and confirmed the hypothesis that the spin conversion in dinuclear entities proceeds through [LS-LS][HS-LS][HS-HS] pairs. The results are discussed in terms of a thermodynamic model based on the regular solution theory adapted for dinuclear spin-crossover compounds.

  13. 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

  14. Theory and application for retrieval and fusion of spatial and temporal quantitative information from complex natural environment

    Institute of Scientific and Technical Information of China (English)

    JIN Yaqiu

    2007-01-01

    This paper briefly presents the research progress of the State Major Basic Research Project 2001CB309400,"Theory and Application for Retrieval and Fusion of Spatial and Temporal Quantitative Information from Complex Natural Environment". Based on the rapid advancement of synthetic aperture radar (SAR) imagery technology, informa-tion theory of fully polarimetric scattering and applications in polarimetric SAR remote sensing are developed. To promote the modeling of passive microwave remote sensing, thevector (polarized) radiative transfer theory (VRT) of complex natural media such as inhomogeneous, multi-layered and 3-dimensional VRT is developed. With these theoretical progresses, data validation and retrieval algorithms for some typical events and characteristic parameters of earth terrain surfaces, atmosphere, and oceans from operational and experimental remote sensing satellites are studied. Employ-ing remote sensing, radiative transfer simulation, geographic information systems (GIS), land hydrological process, and data assimilation, the Chinese land data assimilation system (CLDAS) is established. Towards the future development of China's microwave meteorological satellites, employing remote sensing data of currently available SSM/I (special sensor microwave/imager), AMSU (advanced microwave sounding unit), MTI (microwave temperature imager),etc., with ground-based measurements, several operation alalgorithms and databases for atmospheric precipitation, water vapor and liquid water in clouds, and other hydrological/hydrological applications are developed. To advance China's SAR and InSAR (interferometric SAR) technologies, the image processing and analysis of ERS (European remote sensing), Radarsat SAR, and Chinese SAR, etc., the software platforms are accomplished. Based on the researches of multi-information fusion, some simulations, identification,and information extractions of the targets from complex background clutter scenes are studied. Some

  15. Spatio-temporal complexity of chimpanzee food: How cognitive adaptations can counteract the ephemeral nature of ripe fruit.

    Science.gov (United States)

    Janmaat, Karline R L; Boesch, Christophe; Byrne, Richard; Chapman, Colin A; Goné Bi, Zoro B; Head, Josephine S; Robbins, Martha M; Wrangham, Richard W; Polansky, Leo

    2016-06-01

    Ecological complexity has been proposed to play a crucial role in primate brain-size evolution. However, detailed quantification of ecological complexity is still limited. Here we assess the spatio-temporal distribution of tropical fruits and young leaves, two primary chimpanzee (Pan troglodytes) foods, focusing on the predictability of their availability in individual trees. Using up to 20 years of information on monthly availability of young leaf, unripe and ripe fruit in plant species consumed by chimpanzees from tropical forests in East, Central, and West Africa, we estimated: (1) the forest-wide frequency of occurrence of each food type and (2) the predictability of finding ripe fruit-bearing trees, focusing on the timing, frequency, and amount of ripe fruit present. In all three forests, at least half of all encountered trees belonged to species that chimpanzees were known to feed on. However, the proportion of these trees bearing young leaves and fruit fluctuated widely between months. Ripe fruit was the most ephemeral food source, and trees that had more than half of their crown filled were at least nine times scarcer than other trees. In old growth forests only one large ripe fruit crop was on average encountered per 10 km. High levels of inter-individual variation in the number of months that fruit was present existed, and in some extreme cases individuals bore ripe fruit more than seven times as often as conspecifics. Some species showed substantially less variation in such ripe fruit production frequencies and fruit quantity than others. We hypothesize that chimpanzees employ a suite of cognitive mechanisms, including abilities to: (1) generalize or classify food trees; (2) remember the relative metrics of quantity and frequency of fruit production across years; and (3) flexibly plan return times to feeding trees to optimize high-energy food consumption in individual trees, and efficient travel between them. Am. J. Primatol. 78:626-645, 2016. © 2016

  16. Contrasted effects of natural complex mixtures of PAHs and metals on oxygen cycle in a microbial mat.

    Science.gov (United States)

    Pringault, Olivier; Aube, Johanne; Bouchez, Olivier; Klopp, Christophe; Mariette, Jérome; Escudie, Frédéric; Senin, Pavel; Goni-Urriza, Marisol

    2015-09-01

    The contamination of polluted environments is often due to a complex mixture of pollutants sometimes at trace levels which nevertheless may have significant effects on the diversity and functioning of organisms. The aim of this study was to assess the functional responses of a microbial mat exposed to a natural complex mixture of PAHs and metals as a function of the maturation stage of the biofilm. Microbial mats sampled in a slightly polluted environment were exposed to contaminated water of a retention basin of an oil refinery. The responses of the microbial mats differed according to season. In spring 2012, strong inhibition of both oxygen production and respiration was observed relative to the control, with rates representing less than 5% of the control after 72 h of incubation. A decrease of microbial activities was followed by a decrease of the coupling between autotrophs and heterotrophs. In contrast, in autumn 2012, no significant changes for oxygen production and respiration were observed and the coupling between autotrophs and heterotrophs was not altered. The differences observed between the spring and autumn mats might be explained by the maturity of the microbial mat with dominance of heterotrophic bacteria in spring, and diatoms and cyanobacteria in autumn, as well as by the differences in the chemical composition of the complex mixture of PAHs and metals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Diversification of both KIR and NKG2 natural killer cell receptor genes in macaques - implications for highly complex MHC-dependent regulation of natural killer cells.

    Science.gov (United States)

    Walter, Lutz; Petersen, Beatrix

    2017-02-01

    The killer immunoglobulin-like receptors (KIR) as well as their MHC class I ligands display enormous genetic diversity and polymorphism in macaque species. Signals resulting from interaction between KIR or CD94/NKG2 receptors and their cognate MHC class I proteins essentially regulate the activity of natural killer (NK) cells. Macaque and human KIR share many features, such as clonal expression patterns, gene copy number variations, specificity for particular MHC class I allotypes, or epistasis between KIR and MHC class I genes that influence susceptibility and resistance to immunodeficiency virus infection. In this review article we also annotated publicly available rhesus macaque BAC clone sequences and provide the first description of the CD94-NKG2 genomic region. Besides the presence of genes that are orthologous to human NKG2A and NKG2F, this region contains three NKG2C paralogues. Hence, the genome of rhesus macaques contains moderately expanded and diversified NKG2 genes in addition to highly diversified KIR genes. The presence of two diversified NK cell receptor families in one species has not been described before and is expected to require a complex MHC-dependent regulation of NK cells. © 2016 John Wiley & Sons Ltd.

  18. Extreme heterogeneity of land surface in spring inducing highly complex micrometeorological flow features and heat exchange processes over partly snow covered areas

    Science.gov (United States)

    Mott, Rebecca; Schlögl, Sebastian; Dirks, Lisa; Lehning, Michael

    2017-04-01

    The melting mountain snow cover in spring typically changes from a continuous snow cover to a mosaic of patches of snow and bare ground inducing an extreme heterogeneity of the land surface. Energy balance models typically assume a continuous snow cover, neglecting the complex interaction between the atmospheric boundary layer and the strongly variable surface. We experimentally investigated the small-scale boundary layer dynamics over snow patches and their effect on the energy balance at the snow surface. A comprehensive measurement campaign, the Dischma Experiment, was conducted during three entire ablation periods in spring 2014, 2015 and 2016. The aim of this project is to investigate the boundary layer development and the energy exchange over a melting snow cover with a gradually decreasing snow cover fraction. For this purpose, two measurement towers equipped with five to six ultrasonic anemometers were installed over a long-lasting snow patch. Furthermore, temporally and spatially high resolution ablation rates and snow surface temperatures were determined with a terrestrial laser scanner and an Infrared camera. This data set allows us to relate the spatial patterns of ablation rates and snow surface temperatures to boundary layer dynamics and the changing snow cover fraction. Experimental data reveal that wind conditions, snow cover distribution, local wind fetch distance and topographical curvature control the near-surface boundary layer characteristics and heat exchange processes over snow. The strong heterogeneity of land surface induced by the patchy snow cover caused a high spatial and temporal variability of snow surface temperature and snow melt patterns. Small scale flow features, such as katabatic flows or wind sheltering can be shown to strongly affect the temporal evolution of snow surface patterns. Furthermore, turbulence data reveal a strong correlation of turbulent heat exchange over melting snow with the occurrence of internal thermal

  19. Effect of loading on the nature of the REE–humate complexes as determined by Yb3+ and Sm3+ LIII-edge EXAFS analysis

    OpenAIRE

    Marsac, Remi; Davranche, Mélanie; Briant, Nicolas; Morin, Guillaume; Takahashi, Yoshio; Gruau, Gérard; Dia, Aline

    2015-01-01

    International audience; Humic substances are major natural complexing agents that strongly influence the cycling of metal cations in the environment. The metal to humic acid (HA) concentration ratio (metal loading) can significantly impact the overall HA complexation properties in natural soils and waters. At low metal loading, cations bind to strong multi-carboxylate or -phenolate sites of HA. In addition, these strong sites might contain soft Lewis bases such as N or S, the contribution of ...

  20. Assessing operative natural and anthropogenic forcing factors from long-term climate time series of Uttarakhand (India) in the backdrop of recurring extreme rainfall events over northwest Himalaya

    Science.gov (United States)

    Agnihotri, Rajesh; Dimri, A. P.; Joshi, H. M.; Verma, N. K.; Sharma, C.; Singh, J.; Sundriyal, Y. P.

    2017-05-01

    The entire Indo-Himalayan region from northwest (Kashmir) to northeast (Assam) is facing prevalence of floods and landslides in recent years causing massive loss of property, human and animal lives, infrastructure, and eventually threatening tourist activities substantially. Extremely intense rainfall event of 2013 C.E. (between 15 and 17 June) kicked off mammoth flash floods in the Kedarnath area of Uttarakhand state, resulting in huge socioeconomic losses to the state and country. Uttarakhand is an important hilly region attracting thousands of tourists every year owing to numerous shrines and forested mountainous tourist spots. Though recent studies indicate a plausible weakening of Indian summer monsoon rainfall overall, recurrent anomalous high rainfall events over northwest Himalaya (e.g. -2010, 2013, and 2016) point out the need for a thorough reassessment of long-term time series data of regional rainfall and ambient temperatures in order to trace signatures of a shifting pattern in regional meteorology, if any. Accordingly, here we investigate 100-year-long monthly rainfall and air temperature time series data for a selected grid (28.5°N, 31.25°N; 78.75°E, 81.25°E) covering most parts of Uttarakhand state. We also examined temporal variance in interrelationships among regional meteorological data (temperature and precipitation) and key global climate variability indices using advance statistical methods. Major findings are (i) significant increase in pre-monsoon air temperature over Uttarakhand after 1997, (ii) increasing upward trend in June-July rainfall and its relationship with regional May temperatures (iii) monsoonal rainfall (June, July, August, and September; JJAS) showing covariance with interannual variability in Eurasian snow cover (ESC) extent during the month of March, and (iv) enhancing tendency of anomalous high rainfall events during negative phases of Arctic Oscillation. Obtained results indicate that under warming scenario, JJ

  1. The evolution of the natural killer complex; a comparison between mammals using new high-quality genome assemblies and targeted annotation.

    Science.gov (United States)

    Schwartz, John C; Gibson, Mark S; Heimeier, Dorothea; Koren, Sergey; Phillippy, Adam M; Bickhart, Derek M; Smith, Timothy P L; Medrano, Juan F; Hammond, John A

    2017-04-01

    Natural killer (NK) cells are a diverse population of lymphocytes with a range of biological roles including essential immune functions. NK cell diversity is in part created by the differential expression of cell surface receptors which modulate activation and function, including multiple subfamilies of C-type lectin receptors encoded within the NK complex (NKC). Little is known about the gene content of the NKC beyond rodent and primate lineages, other than it appears to be extremely variable between mammalian groups. We compared the NKC structure between mammalian species using new high-quality draft genome assemblies for cattle and goat; re-annotated sheep, pig, and horse genome assemblies; and the published human, rat, and mouse lemur NKC. The major NKC genes are largely in the equivalent positions in all eight species, with significant independent expansions and deletions between species, allowing us to propose a model for NKC evolution during mammalian radiation. The ruminant species, cattle and goats, have independently evolved a second KLRC locus flanked by KLRA and KLRJ, and a novel KLRH-like gene has acquired an activating tail. This novel gene has duplicated several times within cattle, while other activating receptor genes have been selectively disrupted. Targeted genome enrichment in cattle identified varying levels of allelic polymorphism between the NKC genes concentrated in the predicted extracellular ligand-binding domains. This novel recombination and allelic polymorphism is consistent with NKC evolution under balancing selection, suggesting that this diversity influences individual immune responses and may impact on differential outcomes of pathogen infection and vaccination.

  2. 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.

  3. 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...

  4. 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

    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......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...... from isolates in the IBT Culture Collection held at BioCentrum-DTU, Technical University of Denmark. The receiver operating characteristics statistic is used to evaluate the performance of the compound predictor, and it was found that compounds could be identified with high confidence (AUC approximate...

  5. Stability of engineered nanomaterials in complex aqueous matrices: Settling behaviour of CeO2 nanoparticles in natural surface waters.

    Science.gov (United States)

    Van Koetsem, Frederik; Verstraete, Simon; Van der Meeren, Paul; Du Laing, Gijs

    2015-10-01

    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 CeO2 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 CeO2 ENPs could potentially serve as model for other nanoparticles that possess similar characteristics. The present study examined the stability and settling of CeO2 ENPs (7.3±1.4 nm) as well as Ce(3+) ions in 10 distinct natural surface waters during 7d, 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 CeO2 ENPs was observed just below the liquid surface of the water samples after 7d. In all cases, the reduction was considerably higher for CeO2 ENPs than for Ce(3+) ions (CeO2 ENPs (R(2)≥0.998) and Ce(3+) ions (R(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 CeO2 ENPs as well as Ce(3+) ions in natural surface waters. Correlation results also suggest potential association and co-precipitation of CeO2 ENPs with aluminium- and iron-containing natural colloidal material. The CeO2 ENPs remained stable in dispersion in surface water characterized by a low pH, ionic strength (IS), and TSS content, indicating the eventual stability and settling behaviour of the nanoparticles was likely determined by a combination of physicochemical parameters. Finally, ionic

  6. THE IMPACT OF EXTREME RISK EVENTS ON THE ECONOMY

    Directory of Open Access Journals (Sweden)

    Ionela-Daniela GĂITAN

    2016-02-01

    Full Text Available In this paper I wanted to highlight the impact of extreme risk events on the economy. The issue that I will approach in this paper is one of great importance, taking into account that extreme risk events that occur are  different  and are becoming more frequent  and harder to  control.  The quickly  development  of  these eventsrequires the implementation of a suitable risk management system. The complexity of this issue involves different approaches that can be interrelated in: computer science, mathematics, risk management, crisis management, andmodeling and simulation of extreme risk events. Natural disasters are rare events, but when they occur are causing a huge damage and an adequate management is necessary to return to a state of normality in a short time. To achieve our goal, in the first part of the paper, we presented the problems that an extreme risk event causes in a country when they occur. In the last part of the paper I presented analytical, statistical and econometric methods used in analysis of the impact on the economy of extreme risk events. Natural  disasters,  which  are  extreme  risk  events,  rarely  produce,  but  when  they  occur  causing  hugedamage and an adequate management is necessary to return to a state of normality in a short time.

  7. 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.

    2015-01-01

    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.

  8. Quantum Matching Theory (with new complexity-theoretic, combinatorial and topical insights on the nature of the quantum entanglement)

    Energy Technology Data Exchange (ETDEWEB)

    Gurvits, L. (Leonid)

    2002-01-01

    Classical matching theory can be defined in terms of matrices with nonnegative entries. The notion of Positive operator, central in Quantum Theory, is a natural generalization of matrices with non-negative entries. Based on this point of view, we introduce a definition of perfect Quantum (operator) matching. We show that the new notion inherits many 'classical' properties, but not all of them. This new notion goes somewhere beyound matroids. For separable bipartite quantum states this new notion coinsides with the full rank property of the intersection of two corresponding geometric matroids. In the classical situation, permanents are naturally associated with perfects matchings. We introduce an analog of permanents for positive operators, called Quantum Permanent and show how this generalization of the permanent is related to the Quantum Entanglement. Besides many other things, Quantum Permanents provide new rational inequalities necessary for the separability of bipartite quantum states. Using Quantum Permanents, we give deterministic poly-time algorithm to solve Hidden Matroids Intersection Problem and indicate some 'classical' complexity difficulties associated with the Quantum Entanglement. Finally, we prove that the weak membership problem for the convex set of separable bipartite density matrices is NP-HARD.

  9. Assessing the efficiency and the criticality of the elements belonging to a complex territorial system subject to natural hazards

    Directory of Open Access Journals (Sweden)

    R. Minciardi

    2006-01-01

    Full Text Available The effects of natural hazards can be mitigated by the use of proper 'pre-event' interventions on 'key' elements of the territory, that is on elements that are mostly vulnerable to a given catastrophic scenario and whose loss of functionality can cause damages on people, property and environment. In this respect, methodologies and tools should be studied to support decision makers in the analysis of a territory, in order to point out such elements. In this work, vulnerability is taken into account under two aspects: 'physical vulnerability', which measures the propensity of a territorial element to suffer damage when subject to an external stress corresponding to the occurrence of a natural phenomenon; 'functional vulnerability', which measures the propensity of a territorial element to suffer loss in functionality, even when that is caused by the loss of functionality of other territorial elements. In the proposed modeling approach, vulnerability is represented through the use of a graph-based formalization. A territorial system is represented as a complex set of elements or sub-systems. Such elements have differentiated and dedicated functions, and they may be functionally interconnected among them. In addition, vulnerability is defined through the use of two different variables, namely the criticality and the efficiency. Focusing the attention on the temporal phases corresponding to the occurrence of a calamitous event, the first one measures the service demand of an element, whereas the efficiency is a measure of the service that can be offered by such an element. The approach presented is largely independent from the natural risk considered. Besides, the tools introduced for the vulnerability analysis of the territorial system can also be used to formalize decision problems relevant to the location of the available resources for emergency management. A specific case study pertaining to the hydrological risk in the Val di Vara area (Italy is

  10. Assessing the efficiency and the criticality of the elements belonging to a complex territorial system subject to natural hazards

    Science.gov (United States)

    Minciardi, R.; Sacile, R.; Trasforini, E.

    2006-01-01

    The effects of natural hazards can be mitigated by the use of proper "pre-event" interventions on "key" elements of the territory, that is on elements that are mostly vulnerable to a given catastrophic scenario and whose loss of functionality can cause damages on people, property and environment. In this respect, methodologies and tools should be studied to support decision makers in the analysis of a territory, in order to point out such elements. In this work, vulnerability is taken into account under two aspects: "physical vulnerability", which measures the propensity of a territorial element to suffer damage when subject to an external stress corresponding to the occurrence of a natural phenomenon; "functional vulnerability", which measures the propensity of a territorial element to suffer loss in functionality, even when that is caused by the loss of functionality of other territorial elements. In the proposed modeling approach, vulnerability is represented through the use of a graph-based formalization. A territorial system is represented as a complex set of elements or sub-systems. Such elements have differentiated and dedicated functions, and they may be functionally interconnected among them. In addition, vulnerability is defined through the use of two different variables, namely the criticality and the efficiency. Focusing the attention on the temporal phases corresponding to the occurrence of a calamitous event, the first one measures the service demand of an element, whereas the efficiency is a measure of the service that can be offered by such an element. The approach presented is largely independent from the natural risk considered. Besides, the tools introduced for the vulnerability analysis of the territorial system can also be used to formalize decision problems relevant to the location of the available resources for emergency management. A specific case study pertaining to the hydrological risk in the Val di Vara area (Italy) is presented.

  11. Expression profiling of major histocompatibility and natural killer complex genes reveals candidates for controlling risk of graft versus host disease.

    Directory of Open Access Journals (Sweden)

    Peter Novota

    Full Text Available BACKGROUND: The major histocompatibility complex (MHC is the most important genomic region that contributes to the risk of graft versus host disease (GVHD after haematopoietic stem cell transplantation. Matching of MHC class I and II genes is essential for the success of transplantation. However, the MHC contains additional genes that also contribute to the risk of developing acute GVHD. It is difficult to identify these genes by genetic association studies alone due to linkage disequilibrium in this region. Therefore, we aimed to identify MHC genes and other genes involved in the pathophysiology of GVHD by mRNA expression profiling. METHODOLOGY/PRINCIPAL FINDINGS: To reduce the complexity of the task, we used genetically well-defined rat inbred strains and a rat skin explant assay, an in-vitro-model of the graft versus host reaction (GVHR, to analyze the expression of MHC, natural killer complex (NKC, and other genes in cutaneous GVHR. We observed a statistically significant and strong up or down regulation of 11 MHC, 6 NKC, and 168 genes encoded in other genomic regions, i.e. 4.9%, 14.0%, and 2.6% of the tested genes respectively. The regulation of 7 selected MHC and 3 NKC genes was confirmed by quantitative real-time PCR and in independent skin explant assays. In addition, similar regulations of most of the selected genes were observed in GVHD-affected skin lesions of transplanted rats and in human skin explant assays. CONCLUSIONS/SIGNIFICANCE: We identified rat and human MHC and NKC genes that are regulated during GVHR in skin explant assays and could therefore serve as biomarkers for GVHD. Several of the respective human genes, including HLA-DMB, C2, AIF1, SPR1, UBD, and OLR1, are polymorphic. These candidates may therefore contribute to the genetic risk of GVHD in patients.

  12. Expression profiling of major histocompatibility and natural killer complex genes reveals candidates for controlling risk of graft versus host disease.

    Science.gov (United States)

    Novota, Peter; Zinöcker, Severin; Norden, Jean; Wang, Xiao Nong; Sviland, Lisbet; Opitz, Lennart; Salinas-Riester, Gabriela; Rolstad, Bent; Dickinson, Anne M; Walter, Lutz; Dressel, Ralf

    2011-01-28

    The major histocompatibility complex (MHC) is the most important genomic region that contributes to the risk of graft versus host disease (GVHD) after haematopoietic stem cell transplantation. Matching of MHC class I and II genes is essential for the success of transplantation. However, the MHC contains additional genes that also contribute to the risk of developing acute GVHD. It is difficult to identify these genes by genetic association studies alone due to linkage disequilibrium in this region. Therefore, we aimed to identify MHC genes and other genes involved in the pathophysiology of GVHD by mRNA expression profiling. To reduce the complexity of the task, we used genetically well-defined rat inbred strains and a rat skin explant assay, an in-vitro-model of the graft versus host reaction (GVHR), to analyze the expression of MHC, natural killer complex (NKC), and other genes in cutaneous GVHR. We observed a statistically significant and strong up or down regulation of 11 MHC, 6 NKC, and 168 genes encoded in other genomic regions, i.e. 4.9%, 14.0%, and 2.6% of the tested genes respectively. The regulation of 7 selected MHC and 3 NKC genes was confirmed by quantitative real-time PCR and in independent skin explant assays. In addition, similar regulations of most of the selected genes were observed in GVHD-affected skin lesions of transplanted rats and in human skin explant assays. We identified rat and human MHC and NKC genes that are regulated during GVHR in skin explant assays and could therefore serve as biomarkers for GVHD. Several of the respective human genes, including HLA-DMB, C2, AIF1, SPR1, UBD, and OLR1, are polymorphic. These candidates may therefore contribute to the genetic risk of GVHD in patients.

  13. Pyrosequencing-Based Assessment of the Microbial Community Structure of Pastoruri Glacier Area (Huascarán National Park, Perú), a Natural Extreme Acidic Environment.

    Science.gov (United States)

    González-Toril, Elena; Santofimia, Esther; Blanco, Yolanda; López-Pamo, Enrique; Gómez, Manuel J; Bobadilla, Miguel; Cruz, Rolando; Palomino, Edwin Julio; Aguilera, Ángeles

    2015-11-01

    The exposure of fresh sulfide-rich lithologies by the retracement of the Nevado Pastoruri glacier (Central Andes, Perú) is increasing the presence of heavy metals in the water as well as decreasing the pH, producing an acid rock drainage (ARD) process in the area. We describe the microbial communities of an extreme ARD site in Huascarán National Park as well as their correlation with the water physicochemistry. Microbial biodiversity was analyzed by FLX 454 sequencing of the 16S rRNA gene. The suggested geomicrobiological model of the area distinguishes three different zones. The proglacial zone is located in the upper part of the valley, where the ARD process is not evident yet. Most of the OTUs detected in this area were related to sequences associated with cold environments (i.e., psychrotolerant species of Cyanobacteria or Bacteroidetes). After the proglacial area, an ARD-influenced zone appeared, characterized by the presence of phylotypes related to acidophiles (Acidiphilium) as well as other species related to acidic and cold environments (i.e., acidophilic species of Chloroflexi, Clostridium and Verrumicrobia). Sulfur- and iron-oxidizing acidophilic bacteria (Acidithiobacillus) were also identified. The post-ARD area was characterized by the presence of OTUs related to microorganisms detected in soils, permafrost, high mountain environments, and deglaciation areas (Sphingomonadales, Caulobacter or Comamonadaceae).

  14. 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

  15. Metabolic rates in five animal populations after prolonged exposure to weak extremely low frequency electromagnetic fields in nature. [Lambricus terrestris, L. rubellus, Arion sp. , Oniscus asellus, Plettrodon cinereus

    Energy Technology Data Exchange (ETDEWEB)

    Greenberg, B.; Ash, N.

    1976-08-01

    Five species of soil-dwelling animals were collected under or some distance from the Navy's Project Sanguine extremely low frequency experimental antenna in September 1974 and in summer 1975, and their oxygen consumption and respiratory quotient (RQ) were tested and compared. The species were: earthworms, Lumbricus terrestris L. and Lumbricus rubellus Hoffmeister; slug, Arion sp.; wood louse, Oniscus asellus L.; and redbacked salamander, Plethodon cinereus cinereus (Green). Controls were collected on the same or next day, 6 to 13 miles from the nearest antenna. Test and control animals were tested simultaneously. In September 1974 there were no significant differences in O/sub 2/ consumption and RQ, except for a marginal difference (0.05 greater than P greater than 0.025) in O/sub 2/ consumption of L. rubellus; in 1975, there were no significant differences. Comparisons of metabolic rates between exposed and control groups in fall 1974 and between fall and summer (1973 and 1975) populations show no seasonally linked change in sensitivity to the electromagnetic fields. Controls showed an autumnal increase in metabolic rate of wood lice and salamanders. Oxygen consumption of wood lice is significantly (P less than 0.05) affected by method of shipment but there is no evidence that exposed and control animals react differently from each other to shipment by air or by car. Short-term (1 week) exposure of earthworms to the electromagnetic fields did not alter metabolic rate; however, confinement in nylon bags and translocation did, thereby limiting meaningful conclusions. No abnormalities in behavior, habitat selection, or external features and pigmentation have been observed in any of the exposed populations during 4 yr of collecting and observation.

  16. Design of Complex Systems to Achieve Passive Safety: Natural Circulation Cooling of Liquid Salt Pebble Bed Reactors

    Science.gov (United States)

    Scarlat, Raluca Olga

    This dissertation treats system design, modeling of transient system response, and characterization of individual phenomena and demonstrates a framework for integration of these three activities early in the design process of a complex engineered system. A system analysis framework for prioritization of experiments, modeling, and development of detailed design is proposed. Two fundamental topics in thermal-hydraulics are discussed, which illustrate the integration of modeling and experimentation with nuclear reactor design and safety analysis: thermal-hydraulic modeling of heat generating pebble bed cores, and scaled experiments for natural circulation heat removal with Boussinesq liquids. The case studies used in this dissertation are derived from the design and safety analysis of a pebble bed fluoride salt cooled high temperature nuclear reactor (PB-FHR), currently under development in the United States at the university and national laboratories level. In the context of the phenomena identification and ranking table (PIRT) methodology, new tools and approaches are proposed and demonstrated here, which are specifically relevant to technology in the early stages of development, and to analysis of passive safety features. A system decomposition approach is proposed. Definition of system functional requirements complements identification and compilation of the current knowledge base for the behavior of the system. Two new graphical tools are developed for ranking of phenomena importance: a phenomena ranking map, and a phenomena identification and ranking matrix (PIRM). The functional requirements established through this methodology were used for the design and optimization of the reactor core, and for the transient analysis and design of the passive natural circulation driven decay heat removal system for the PB-FHR. A numerical modeling approach for heat-generating porous media, with multi-dimensional fluid flow is presented. The application of this modeling

  17. Using Isomap to differentiate between anthropogenic and natural effects on groundwater dynamics in a complex geological setting

    Science.gov (United States)

    Boettcher, Steven; Merz, Christoph; Lischeid, Gunnar

    2015-04-01

    The water budget of many catchments has vastly changed throughout the last decades. Intensified land use and increased water withdrawal for drinking water production and irrigation are likely to intensify pressure on water resources. According to model predictions, changing rainfall intensity, duration and spatial distribution in conjunction with increasing temperatures will worsen the situation in the future. The current water resources management has to adapt to these negative developments and to account for competing demands and threats. Essential for successful management applications is the identification and the quantification of the cause-and-effect chains driving the hydrological behavior of a catchment on the scale of management. It needs to check direction and magnitude of intended effects of measures taken as well as to identify unintended side effects that interact with natural effects in heterogeneous environments (Wood et al., 1988; Bloschl and Sivapalan, 1995). Therefore, these tools have to be able to distinguish between natural and anthropogenic driven impacts, even in complex geological settings like the Pleistocene landscape of North-East Germany. This study presents an approach that utilizes monitoring data to detect and quantitatively describe the predominant processes or factors of an observed hydrological system. The multivariate data analysis involves a non-linear dimension reduction method called Isometric Feature Mapping (Isomap, Tenenbaum et al., 2000) to extract information about the causes for the observed dynamics. Ordination methods like Isomap are used to derive a meaningful low-dimensional representation of a complex, high-dimensional data set. The approach is based on the hypothesis, that the number of processes which explain the variance of the data is relative low although the intensity of the processes varies in time and space. Therefore, the results can be interpreted in reference to the effective hydrological processes which

  18. 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

  19. Natural Crossbreeding between Sympatric Species of the Phyllosoma Complex (Insecta: Hemiptera: Reduviidae) Indicate the Existence of Only One Species with Morphologic and Genetic Variations

    Science.gov (United States)

    Martínez-Hernandez, Fernando; Martínez-Ibarra, Jose A.; Catalá, Silvia; Villalobos, Guiehdani; de la Torre, Patricia; Laclette, Juan P.; Alejandre-Aguilar, Ricardo; Espinoza, Bertha

    2010-01-01

    The nucleotide sequences of the cytochrome B gene and the antennal phenotypes were analyzed for the following triatomine species: Triatoma longipennis, Triatoma pallidipennis, and Triatoma picturata, which belong to the Phyllosoma complex. These species inhabit sympatric areas from Talpa de Allende, Autlan de Navarro, and Teocuitatlan de Corona in Jalisco, Mexico. Molecular marker analysis showed that the sympatric individuals are the natural crossbred descendents of different individuals living in close proximity in these natural areas that resulted in mixed populations. The antennal phenotype results are coincident with these genetic findings, which point to the high similitude between all Phyllosoma complex populations analyzed. These data support the hypothesis that these species are morphotypes with chromatic and genetic varieties, which preserves the possibility of natural breeding with fertile descent. In conclusion, our results strongly support the hypothesis that T. pallidipennis, T. longipennis, and T. picturata are subspecies of the Phyllosoma complex. PMID:20064999

  20. Osmoregulatory strategies in natural populations of the black-chinned tilapia Sarotherodon melanotheron exposed to extreme salinities in West African estuaries.

    Science.gov (United States)

    Lorin-Nebel, Catherine; Avarre, Jean-Christophe; Faivre, Nicolas; Wallon, Sophie; Charmantier, Guy; Durand, Jean-Dominique

    2012-08-01

    The effect of salinity was studied in natural populations of the black-chinned tilapia (Sarotherodon melanotheron) from West Africa. This euryhaline species colonizes nearly all coastal environments from bays to lagoons characterized by salinities ranging from fresh water to hypersaline water over 100 ‰. Individuals were sampled during the dry season at several locations characterized by different levels of salinity (3-102 ‰). Their osmotic status and their gills were analyzed. The branchial mitochondria-rich cells (MRC), localized at the basis of the filaments and along the lamellae in fish taken from the saline stations, showed a wide plasticity with significant differences in their number and size. The most striking results were a significant larger area (≈3x) and a higher number (≈55x) of MRC at high salinity (102 ‰) compared to low salinity (3 ‰). The major ion transporters and channels were localized by immunocytochemistry and different expression patterns have been recorded between stations. Despite an increased Na⁺/K⁺-ATPase (NKA) α-subunit expression and NKA activity, pointing to an increased monovalent ion excretion, a severe osmotic imbalance was recorded in animals living in hypersaline environments.

  1. The complex nature of superconductivity in MgB2 as revealed by the reduced total isotope effect.

    Science.gov (United States)

    Hinks, D G; Claus, H; Jorgensen, J D

    2001-05-24

    Magnesium diboride, MgB2, was recently observed to become superconducting at 39 K, which is the highest known transition temperature for a non-copper-oxide bulk material. Isotope-effect measurements, in which atoms are substituted by isotopes of different mass to systematically change the phonon frequencies, are one of the fundamental tests of the nature of the superconducting mechanism in a material. In a conventional Bardeen-Cooper-Schrieffer (BCS) superconductor, where the mechanism is mediated by electron-phonon coupling, the total isotope-effect coefficient (in this case, the sum of both the Mg and B coefficients) should be about 0.5. The boron isotope effect was previously shown to be large and that was sufficient to establish that MgB2 is a conventional superconductor, but the Mg effect has not hitherto been measured. Here we report the determination of the Mg isotope effect, which is small but measurable. The total reduced isotope-effect coefficient is 0.32, which is much lower than the value expected for a typical BCS superconductor. The low value could be due to complex materials properties, and would seem to require both a large electron-phonon coupling constant and a value of mu* (the repulsive electron-electron interaction) larger than found for most simple metals.

  2. Application of an Immersed Boundary Treatment in Simulation of Natural Convection Problems with Complex Geometry via the Lattice Boltzmann Method

    Directory of Open Access Journals (Sweden)

    Reza Khazaeli

    2015-01-01

    Full Text Available In this study, a version of thermal immersed boundary-Lattice Boltzmann method (TIB-LBM is used to simulate thermal flow problems within complex geometries. The present approach is a combination of the immersed boundary method (IBM and the thermal lattice Boltzmann method (TLBM under the double population approach. The method combines two different grid systems, an Eulerian grid for the flow domain and a Lagrangian grid for the boundary points immersed in the flow. In the present method, an unknown velocity correction is considered on the boundary points to impose the no-slip boundary condition. As a similar approach, an unknown internal energy correction on the boundary points is applied to satisfy the constant temperature boundary condition. The advantages of this approach are its second-order accuracy and straightforward calculation of the Nusselt number. The natural convection in an annulus with various outer cylinder shapes for different Rayleigh numbers have been simulated to demonstrate the capability and the accuracy of present approach. In terms of accuracy, the predicted results show an excellent agreement with those predicted by other experimental and numerical approaches.

  3. Structure of daidzin, a naturally occurring anti-alcohol-addiction agent, in complex with human mitochondrial aldehyde dehydrogenase.

    Science.gov (United States)

    Lowe, Edward D; Gao, Guang-Yao; Johnson, Louise N; Keung, Wing Ming

    2008-08-14

    The ALDH2*2 gene encoding the inactive variant form of mitochondrial aldehyde dehydrogenase (ALDH2) protects nearly all carriers of this gene from alcoholism. Inhibition of ALDH2 has hence become a possible strategy to treat alcoholism. The natural product 7-O-glucosyl-4'-hydroxyisoflavone (daidzin), isolated from the kudzu vine ( Peruraria lobata), is a specific inhibitor of ALDH2 and suppresses ethanol consumption. Daidzin is the active principle in a herbal remedy for "alcohol addiction" and provides a lead for the design of improved ALDH2. The structure of daidzin/ALDH2 in complex at 2.4 A resolution shows the isoflavone moiety of daidzin binding close to the aldehyde substrate-binding site in a hydrophobic cleft and the glucosyl function binding to a hydrophobic patch immediately outside the isoflavone-binding pocket. These observations provide an explanation for both the specificity and affinity of daidzin (IC50 =80 nM) and the affinity of analogues with different substituents at the glucosyl position.

  4. The role of macrocyclic ligands in the peroxo/superoxo nature of Ni-O2 biomimetic complexes.

    Science.gov (United States)

    Zapata-Rivera, Jhon; Caballol, Rosa; Calzado, Carmen J

    2012-06-15

    The impact of the macrocyclic ligand on the electronic structure of two LNi-O2 biomimetic adducts, [Ni(12-TMC)O2](+) (12-TMC = 1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane) and [Ni(14-TMC)O2](+) (14-TMC = 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane), has been inspected by means of difference-dedicated configuration interaction calculations and a valence bond reading of the wavefunction. The system containing the 12-membered macrocyclic ligand has been experimentally described as a side-on nickel(III)-peroxo complex, whereas the 14-membered one has been characterized as an end-on nickel(II)-superoxide. Our results put in evidence the relationship between the steric effect of the macrocyclic ligand, the O2 coordination mode and the charge transfer extent between the Ni center and the O2 molecule. The 12-membered macrocyclic ligand favors a side-on coordination, a most efficient overlap between Ni 3d and O2 π* orbitals and, consequently, a larger charge transfer from LNi fragment to O2 molecule. The analysis of the ground-state electronic structure shows an enhancement of the peroxide nature of the Ni-O2 interaction for [Ni(12-TMC)O2](+), although a dominant superoxide character is found for both systems.

  5. Network pharmacology of cancer: From understanding of complex interactomes to the design of multi-target specific therapeutics from nature.

    Science.gov (United States)

    Poornima, Paramasivan; Kumar, Jothi Dinesh; Zhao, Qiaoli; Blunder, Martina; Efferth, Thomas

    2016-09-01

    Despite massive investments in drug research and development, the significant decline in the number of new drugs approved or translated to clinical use raises the question, whether single targeted drug discovery is the right approach. To combat complex systemic diseases that harbour robust biological networks such as cancer, single target intervention is proved to be ineffective. In such cases, network pharmacology approaches are highly useful, because they differ from conventional drug discovery by addressing the ability of drugs to target numerous proteins or networks involved in a disease. Pleiotropic natural products are one of the promising strategies due to their multi-targeting and due to lower side effects. In this review, we discuss the application of network pharmacology for cancer drug discovery. We provide an overview of the current state of knowledge on network pharmacology, focus on different technical approaches and implications for cancer therapy (e.g. polypharmacology and synthetic lethality), and illustrate the therapeutic potential with selected examples green tea polyphenolics, Eleutherococcus senticosus, Rhodiola rosea, and Schisandra chinensis). Finally, we present future perspectives on their plausible applications for diagnosis and therapy of cancer.

  6. Deformations of extremal toric manifolds

    CERN Document Server

    Rollin, Yann

    2012-01-01

    Let $X$ be a compact toric extremal K\\"ahler manifold. Using the work of Sz\\'ekelyhidi, we provide a simple criterion on the fan describing $X$ to ensure the existence of complex deformations of $X$ that carry extremal metrics. As an example, we find new CSC metrics on 4-points blow-ups of $\\C\\P^1\\times\\C\\P^1$.

  7. Genetic diversity and geographic structure in Aglaia elaeagnoidea (Meliaceae, Sapindales), a morphologically complex tree species, near the two extremes of its distribution

    NARCIS (Netherlands)

    Muellner, A.N.; Greger, H.; Pannell, C.M.

    2009-01-01

    Aglaia elaeagnoidea is the most widespread and one of the more morphologically diverse complex species in the largest genus of the mahogany family (Meliaceae, Sapindales). We performed maximum parsimony, maximum likelihood and Bayesian analyses (nuclear ITS rDNA) to estimate genetic relations among

  8. A computational study of structural and magnetic properties of bi- and trinuclear Cu(II) complexes with extremely long Cu-Cu distances

    Science.gov (United States)

    Baryshnikov, Gleb V.; Minaev, Boris F.; Baryshnikova, Alina T.; Ågren, Hans

    2017-07-01

    Three recently synthesized copper(II) complexes with aroylhydrazones of trifluoroacetic and benzenecarboxylic acids (Dalton Trans., 2013, 42, 16878) have been computationally investigated by density functional theory within the broken symmetry approximation accounting for empirical dispersion corrections. A topological analysis of electron density distributions has been carried out using Bader's ;quantum theory of atoms in molecules; formalism. The calculated values of spin-spin exchange for the studied dinuclear complexes indicate a very weak ferromagnetic coupling of the unpaired electrons in good agreement with experimental data. At the same time, the trinuclear copper(II) complex possesses a low-spin doublet ground state with one ferromagnetic and two antiferromagnetic spin projections between the triangular-positioned Cu2+ ions. The estimated values of the coupling constants for the spin-spin exchange in this trinuclear complex are in a good agreement with experimental observations. The calculations support a mechanism of exchange coupling through the aromatic links in these strongly spin-separated systems.

  9. Family violence, war, and natural disasters: a study of the effect of extreme stress on children's mental health in Sri Lanka.

    Science.gov (United States)

    Catani, Claudia; Jacob, Nadja; Schauer, Elisabeth; Kohila, Mahendran; Neuner, Frank

    2008-05-02

    The consequences of war violence and natural disasters on the mental health of children as well as on family dynamics remain poorly understood. Aim of the present investigation was to establish the prevalence and predictors of traumatic stress related to war, family violence and the recent Tsunami experience in children living in a region affected by a long-lasting violent conflict. In addition, the study looked at whether higher levels of war violence would be related to higher levels of violence within the family and whether this would result in higher rates of psychological problems in the affected children. 296 Tamil school children in Sri Lanka's North-Eastern provinces were randomly selected for the survey. Diagnostic interviews were carried out by extensively trained local Master level counselors. PTSD symptoms were established by means of a validated Tamil version of the UCLA PTSD Index. Additionally, participants completed a detailed checklist of event types related to organized and family violence. 82.4% of the children had experienced at least one war-related event. 95.6% reported at least one aversive experience out of the family violence spectrum. The consequences are reflected in a 30.4% PTSD and a 19.6% Major Depression prevalence. Linear regression analyses showed that fathers' alcohol intake and previous exposure to war were significantly linked to the amount of maltreatment reported by the child. A clear dose-effect relationship between exposure to various stressful experiences and PTSD was found in the examined children. Data argue for a relationship between war violence and violent behavior inflicted on children in their families. Both of these factors, together with the experience of the recent Tsunami, resulted as significant predictors of PTSD in children, thus highlighting the detrimental effect that the experience of cumulative stress can have on children's mental health.

  10. Family violence, war, and natural disasters: A study of the effect of extreme stress on children's mental health in Sri Lanka

    Directory of Open Access Journals (Sweden)

    Schauer Elisabeth

    2008-05-01

    Full Text Available Abstract Background The consequences of war violence and natural disasters on the mental health of children as well as on family dynamics remain poorly understood. Aim of the present investigation was to establish the prevalence and predictors of traumatic stress related to war, family violence and the recent Tsunami experience in children living in a region affected by a long-lasting violent conflict. In addition, the study looked at whether higher levels of war violence would be related to higher levels of violence within the family and whether this would result in higher rates of psychological problems in the affected children. Methods 296 Tamil school children in Sri Lanka's North-Eastern provinces were randomly selected for the survey. Diagnostic interviews were carried out by extensively trained local Master level counselors. PTSD symptoms were established by means of a validated Tamil version of the UCLA PTSD Index. Additionally, participants completed a detailed checklist of event types related to organized and family violence. Results 82.4% of the children had experienced at least one war-related event. 95.6% reported at least one aversive experience out of the family violence spectrum. The consequences are reflected in a 30.4% PTSD and a 19.6% Major Depression prevalence. Linear regression analyses showed that fathers' alcohol intake and previous exposure to war were significantly linked to the amount of maltreatment reported by the child. A clear dose-effect relationship between exposure to various stressful experiences and PTSD was found in the examined children. Conclusion Data argue for a relationship between war violence and violent behavior inflicted on children in their families. Both of these factors, together with the experience of the recent Tsunami, resulted as significant predictors of PTSD in children, thus highlighting the detrimental effect that the experience of cumulative stress can have on children's mental health.

  11. Comparing the peroxo/superoxo nature of the interaction between molecular O2 and β-diketiminato-copper and nickel complexes.

    Science.gov (United States)

    Zapata-Rivera, Jhon; Caballol, Rosa; Calzado, Carmen J

    2011-12-01

    Adducts resulting from the interaction between molecular oxygen and β-diketiminato-copper and nickel complexes have been recently described in the literature as peroxo and superoxo complexes, respectively. The nature of the interaction is analyzed by means of DDCI calculations and an orthogonal valence bond reading of the ground state wavefunction for each system. Our results reveal that there is not any substantial difference between these systems, both presenting a marked leading superoxo nature, which is in line with the fact that LCu-O(2) and LNi-O(2) adducts present similar O-O distances and quite close O-O stretching vibration modes.

  12. 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

  13. Genetic diversity and geographic structure in Aglaia elaeagnoidea (Meliaceae, Sapindales), a morphologically complex tree species, near the two extremes of its distribution

    OpenAIRE

    2009-01-01

    Aglaia elaeagnoidea is the most widespread and one of the more morphologically diverse complex species in the largest genus of the mahogany family (Meliaceae, Sapindales). We performed maximum parsimony, maximum likelihood and Bayesian analyses (nuclear ITS rDNA) to estimate genetic relations among samples of Aglaia elaeagnoidea, and their phylogenetic position within Aglaia (more than 120 species in Indomalesia, Australasia, and the Pacific islands). Based on 90 accessions of Melioideae (ing...

  14. 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

    Energy Technology Data Exchange (ETDEWEB)

    Kubas, G.J.; Eckert, J.; Luo, X.L. [and others

    1997-07-01

    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{sub 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{sub 2}, silanes, and halocarbons. The first metal-SiH{sub 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.

  15. Metagenomics of extreme environments.

    Science.gov (United States)

    Cowan, D A; Ramond, J-B; Makhalanyane, T P; De Maayer, P

    2015-06-01

    Whether they are exposed to extremes of heat or cold, or buried deep beneath the Earth's surface, microorganisms have an uncanny ability to survive under these conditions. This ability to survive has fascinated scientists for nearly a century, but the recent development of metagenomics and 'omics' tools has allowed us to make huge leaps in understanding the remarkable complexity and versatility of extremophile communities. Here, in the context of the recently developed metagenomic tools, we discuss recent research on the community composition, adaptive strategies and biological functions of extremophiles.

  16. Interfacing a haptic robotic system with complex virtual environments to treat impaired upper extremity motor function in children with cerebral palsy

    Science.gov (United States)

    FLUET, GERARD G.; QIU, QINYIN; KELLY, DONNA; PARIKH, HETA D.; RAMIREZ, DIEGO; SALEH, SOHA; ADAMOVICH, SERGEI V.

    2011-01-01

    Objective To investigate the ability of the New Jersey Institute of Technology Robot Assisted Virtual Rehabilitation (NJIT-RAVR) system training to elicit changes in upper extremity (UE) function in children with hemiplegia secondary to cerebral palsy. Methods Nine children (mean age 9 years, three males) participated in three pilots. Subjects trained 1 hour, 3 days a week for 3 weeks. Two groups performed this protocol as their only intervention. The third group also performed 5–6 hours of constraint-induced movement therapy. Results All subjects participated in a short programme of nine, 60-minute training sessions without adverse effects. As a group, subjects demonstrated statistically significant improvements in Melbourne Assessment of Unilateral Upper Limb Function Test, a composite of three timed UE tasks and several measurements of reaching kinematics. Several subjects demonstrated clinically significant improvements in active shoulder abduction and flexion as well as forearm supination. Conclusion Three small pilots of NJIT-RAVR training demonstrated measurable benefit with no complications, warranting further examination. PMID:20828330

  17. Evolution of the C2RCC Neural Network for Sentinel 2 and 3 for the Retrieval of Ocean Colour Products in Normal and Extreme Optically Complex Waters

    Science.gov (United States)

    Brockmann, Carsten; Doerffer, Roland; Peters, Marco; Kerstin, Stelzer; Embacher, Sabine; Ruescas, Ana

    2016-08-01

    Retrieval of water constituents, or its optical properties, requires inversion of the water leaving reflectance spectrum, measured at top of atmosphere by ocean colour satellites. The Case 2 Regional processor, originally developed by Doerffer and Schiller [6], uses a large database of radiative transfer simulations inverted by neural networks as basic technology. Through the CoastColour project major improvements were introduced. It has been amended by a set of additional neural networks performing specific tasks and special neural networks have been trained to cover extreme ranges of scattering and absorption. The processor has been renamed into C2RCC (Case 2 Regional CoastColour) and is applicable to all past and current ocean colour sensors as well as Sentinel 2. It has been validated in various studies and is available through ESA's Sentinel toolbox SNAP. It is also used in the Sentinel 3 OLCI ground segment processor of ESA for the generation of the Case 2 water products, as well as in the processor for the upcoming MERIS 4th reprocessing.

  18. 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.

  19. Novel FeII and CoII Complexes of Natural Product Tryptanthrin: Synthesis and Binding with G-Quadruplex DNA

    Science.gov (United States)

    Zhong, Yi-ning; Zhang, Yan; Gu, Yun-qiong; Wu, Shi-yun; Shen, Wen-ying

    2016-01-01

    Tryptanthrin is one of the most important members of indoloquinoline alkaloids. We obtained this alkaloid from Isatis. Two novel FeII and CoII complexes of tryptanthrin were first synthesized. Single-crystal X-ray diffraction analyses show that these complexes display distorted four-coordinated tetrahedron geometry via two heterocyclic nitrogen and oxygen atoms from tryptanthrin ligand. Binding with G-quadruplex DNA properties revealed that both complexes were found to exhibit significant interaction with G-quadruplex DNA. This study may potentially serve as the basis of future rational design of metal-based drugs from natural products that target the G-quadruplex DNA. PMID:27698647

  20. Unravelling the complex nature of the Upper Weichselian till section at Gdynia Babie Doły, northern Poland

    Science.gov (United States)

    Woźniak, Piotr Paweł; Czubla, Piotr

    2016-03-01

    The complexity of glacial sequences may increase when these formed underneath ice sheets despite subsequent changes in their extent that are accompanied by alterations in the direction of the ice flow. Our aim was to determine whether or not changes in ice sheet dynamics during the Late Weichselian are also recorded in sediments formed north of the area of its fluctuating margin (i.e., where the ice sheet prevailed independent of such fluctuations). It is shown that in these areas such a record could have occurred, as documented by results of till studies at Babie Doły. The examination was carried out using several analyses: lithofacies properties of sediments, petrographic till composition (fine gravel fraction, indicator erratics), till matrix CaCO3 content, till fabric, as well as orientation of striae on the top surfaces of large clasts. In parallel, datings of sub- and supra-till sediments using the TL method were carried out. The basal till at Babie Doły represents almost the entire Upper Weichselian, but it can be divided into subunits whose features indicate different ice flow directions and debris supply. The lower subunit developed as a result of the palaeo-ice stream along the main axis of the Baltic Sea (from the north), expanding to areas adjacent to the depression of the Gulf of Gdańsk. The upper subunit developed when the influence of the palaeo-ice stream in the study area decreased, the main role having been taken over by the ice flowing from the northwest. The till analysed also shows considerable lateral variation, indicative of the mosaic nature of subglacial sedimentation. We consider the diversity of permeability of deposits over which the ice sheet extended to be the prime factor that determined such a situation.

  1. Unravelling the complex nature of the Upper Weichselian till section at Gdynia Babie Doły, northern Poland

    Directory of Open Access Journals (Sweden)

    Woźniak Piotr Paweł

    2016-03-01

    Full Text Available The complexity of glacial sequences may increase when these formed underneath ice sheets despite subsequent changes in their extent that are accompanied by alterations in the direction of the ice flow. Our aim was to determine whether or not changes in ice sheet dynamics during the Late Weichselian are also recorded in sediments formed north of the area of its fluctuating margin (i.e., where the ice sheet prevailed independent of such fluctuations. It is shown that in these areas such a record could have occurred, as documented by results of till studies at Babie Doły. The examination was carried out using several analyses: lithofacies properties of sediments, petrographic till composition (fine gravel fraction, indicator erratics, till matrix CaCO3 content, till fabric, as well as orientation of striae on the top surfaces of large clasts. In parallel, datings of sub- and supra-till sediments using the TL method were carried out. The basal till at Babie Doły represents almost the entire Upper Weichselian, but it can be divided into subunits whose features indicate different ice flow directions and debris supply. The lower subunit developed as a result of the palaeo-ice stream along the main axis of the Baltic Sea (from the north, expanding to areas adjacent to the depression of the Gulf of Gdańsk. The upper subunit developed when the influence of the palaeo-ice stream in the study area decreased, the main role having been taken over by the ice flowing from the northwest. The till analysed also shows considerable lateral variation, indicative of the mosaic nature of subglacial sedimentation. We consider the diversity of permeability of deposits over which the ice sheet extended to be the prime factor that determined such a situation.

  2. 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.

  3. Density functional theory, natural bond orbital and quantum theory of atoms in molecule analyses on the hydrogen bonding interactions in tryptophan-water complexes

    Indian Academy of Sciences (India)

    Xiqian Niu; Zhengguo Huang; Lingling Ma; Tingting Shen; Lingfei Guo

    2013-07-01

    The tryptophan-water (Trp-H2O) complexes formed by hydrogen bonding interactions were investigated at the B97XD/6-311++G(d,p) level. Five Trp-H2O complexes possessing various types of hydrogen bonds (H-bonds) were characterized by geometries, energies, vibrational frequencies. The nature of the H-bonds were characterized by the natural bond orbital (NBO) and the quantum theory of atoms in molecule (QTAIM) analyses as well. The intramolecular H-bond formed between the amino and carboxyl oxygen atom of tryptophan was retained in most of the complexes, and the cooperativity between the intra and intermolecular H-bonds exist in some complexes. The intramolecular H-bond and some intermolecular H-bonds are strong and have partial covalent character. The H-bonds formed between carboxyl and oxygen/nitrogen atoms are stronger than other H-bonds. The H-bonds involving methylene of tryptophan as H-donor are weak H-bonds. For all complexes,ele and ex makes major contributions to the total interaction energy (MP2), while disp is the smallest component of the interaction energy. Both hydrogen bonding interaction and structural deformation play important roles in the relative stabilities of the complexes. Regardless of strong H-bonds, the stabilities of some complexes are weakened by the serious structural deformations.

  4. The complex of neural networks and probabilistic methods for mathematical modeling of the syntactic structure of a sentence of natural language

    Science.gov (United States)

    Sboev, A.; Rybka, R.; Moloshnikov, I.; Gudovskikh, D.

    2016-02-01

    The formalized model to construct the syntactic structure of sentences of a natural language is presented. On base of this model the complex algorithm with use of neural networks founded on data of Russian National language Corpus and set of parameters extracted from this data was developed. The resulted accuracy along with possible accuracy which theoretically could be received with these parameters is presented.

  5. [The effect of natural polyphenol complex of red grape wine on L-arginine/NO system in peripheral blood of rats under low doses of ionizing radiation].

    Science.gov (United States)

    Sabadashka, M V; Hnatush, A R; Datsiuk, L O; Staranko, U V; Fedorovych, A M; Herzhikova, V H; Zotov, A M; Slast'ia, É A; Sybirna, N O

    2014-01-01

    The total activity of NO-synthase and content of stable metabolitic products of nitric oxide in the peripheral blood of rats under low doses of ionizing radiation and administration of natural polyphenol complex of grape was investigated. It was found that natural polyphenol compounds of grapes have the ability to correct radioinduced changes in L-arginine/NO system. It was noted that the action of X-radiation increased activity of NO-synthase in the peripheral blood of rats. However, the consumption of natural polyphenol complex of grape led to a decrease of this index to control values. An increase in NOS activity under irradiation leads to the increase of NO stable metabolites content, which is reflected in the accumulation of nitrite- and nitrate-anions in the peripheral blood of rats. The consumption of preparation of polyphenol complex this index decreased in the early period of the experiment, and on the third day after exposure, the total content of NO stable metabolites is slightly higher compared to the indices of control animals. Thus, the ability of natural polyphenol complex to cause attenuation of oxidative-nitrative stress caused by ionizing radiation was investigated experimentally.

  6. A perspective on the advancement of natural language processing tasks via topological analysis of complex networks. Comment on "Approaching human language with complex networks" by Cong and Liu

    Science.gov (United States)

    Amancio, Diego Raphael

    2014-12-01

    Concepts and methods of complex networks have been applied to probe the properties of a myriad of real systems [1]. The finding that written texts modeled as graphs share several properties of other completely different real systems has inspired the study of language as a complex system [2]. Actually, language can be represented as a complex network in its several levels of complexity. As a consequence, morphological, syntactical and semantical properties have been employed in the construction of linguistic networks [3]. Even the character level has been useful to unfold particular patterns [4,5]. In the review by Cong and Liu [6], the authors emphasize the need to use the topological information of complex networks modeling the various spheres of the language to better understand its origins, evolution and organization. In addition, the authors cite the use of networks in applications aiming at holistic typology and stylistic variations. In this context, I will discuss some possible directions that could be followed in future research directed towards the understanding of language via topological characterization of complex linguistic networks. In addition, I will comment the use of network models for language processing applications. Additional prospects for future practical research lines will also be discussed in this comment.

  7. 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.

  8. Experimental analysis of the influence of pest management practice on the efficacy of an endemic arthropod natural enemy complex of the diamondback moth.

    Science.gov (United States)

    Furlong, Michael J; Shi, Zu-Hua; Liu, Yin-Quan; Guo, Shi-Jian; Lu, Yao-Bin; Liu, Shu-Sheng; Zalucki, Myron P

    2004-12-01

    Maximizing the contribution of endemic natural enemies to integrated pest management (IPM), programs requires a detailed knowledge of their interactions with the target pest. This experimental field study evaluated the impact of the endemic natural enemy complex of Plutella xylostella (L.) (Lepidoptera: Yponomeutidae) on pest populations in commercial cabbage crops in southeastern Queensland, Australia. Management data were used to score pest management practices at experimental sites on independent Brassica farms practicing a range of pest management strategies, and mechanical methods of natural enemy exclusion were used to assess the impact of natural enemies on introduced cohorts of P. xylostella at each site. Natural enemy impact was greatest at sites adopting IPM and least at sites practicing conventional pest management strategies. At IPM sites, the contribution of natural enemies to P. xylostella mortality permitted the cultivation of marketable crops with no yield loss but with a substantial reduction in insecticide inputs. Three species of larval parasitoids (Diadegma semiclausum Hellén [Hymenoptera: Ichneumonidae], Apanteles ippeus Nixon [Hymenoptera: Braconidae], and Oomyzus sokolowskii Kurdjumov [Hymenoptera: Eulophidae]) and one species of pupal parasitoid Diadromus collaris Gravenhorst (Hymenoptera: Ichneumonidae) attacked immature P. xylostella. The most abundant groups of predatory arthropods caught in pitfall traps were Araneae (Lycosidae) > Coleoptera (Carabidae, Coccinelidae, Staphylinidae) > Neuroptera (Chrysopidae) > Formicidae, whereas on crop foliage Araneae (Clubionidae, Oxyopidae) > Coleoptera (Coccinelidae) > Neuroptera (Chrysopidae) were most common. The abundance and diversity of natural enemies was greatest at sites that adopted IPM, correlating greater P. xylostella mortality at these sites. The efficacy of the natural enemy complex to pest mortality under different pest management regimes and appropriate strategies to optimize this

  9. Luminescence investigation on Eu–pillar[5]arene-based diglycolamide (DGA) complexes: Nature of the complex, Judd–Ofelt calculations and effect of ligand structure

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, Arijit, E-mail: arijita@barc.gov.in [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Wu, Lei; Feng, Wen; Yuan, Lihua [College of Chemistry, Key Laboratory for Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan, University, Chengdu 610064 (China); Natarajan, V. [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2015-02-15

    An attempt was made to understand the insight of complexation of Eu{sup 3+} ion with three different structurally modified pillar[5]arene-based diglycolamides (P5DGA) and a comparison was also made with their molecular identity, TODGA. {sup 7}F{sub 0}-{sup 5}D{sub 2}, {sup 5}G{sub 2,3,4}, {sup 5}L{sub 6} transitions were observed in the absorption profiles while {sup 5}D{sub 0}-{sup 7}F{sub 0,1,2,3,4} transitions for emission spectra. Number of water molecules present in the primary coordination sphere of Eu{sup 3+} and the number of species were calculated from the life time measurement of the complexes under investigation. From the splitting pattern of the luminescence spectra of Eu{sup 3+} complex the point group symmetry around Eu{sup 3+} was found to be C4v. Judd-Offelt parameters (Ω{sub λ}, λ=2,4) were calculated for the complexes and correlated with the covalency of metal ligand bonds and long range ordering, respectively. It was demonstrated that preorganization of ligating moieties on the platform of pillararenes favoured the covalency of the metal–ligand bond in diglycolamides. Different photo physical properties such as radiative and non radiative life time, magnetic and electric dipole transition probabilities, branching ratio values for different transitions, quantum efficiency were evaluated for all the Eu{sup 3+}-diglycolamide complexes. - Highlights: • The complexation of Eu{sup 3+} with pillar[5]arene-based diglycolamides (P5DGA) • Comparison with the molecular identity, TODGA. • Absorption spectra assigned as {sup 7}F{sub 0}-{sup 5}D{sub 2}, {sup 5}G{sub 2,3,4}, {sup 5}L{sub 6} transitions • Emission spectra assigned as {sup 5}D{sub 0}-{sup 7}F{sub 0,1,2,3,4} transitions • Number of inner sphere water molecules and number of species were calculated from the life time measurement • The point group symmetry around Eu{sup 3+} was found to be C4v. • Judd-Offelt parameters (Ω{sub λ}, λ=2,4) were calculated for the complexes.

  10. Groundwater Sustainability in the Michigan Lowlands - Understanding the Complex Interplay of Natural Brine Upwelling, Human Activity, and Climate Change

    Science.gov (United States)

    Curtis, Z. K.; Li, S. G.; Sampath, P. V.; Liao, H. S.

    2015-12-01

    /analysis to simulate the complex interplay of human activity, natural upwelling, and climate change. Insight from the modeling effort will be used to inform resource planners and policy makers of various groundwater management options available to vulnerable communities across the Lower Peninsula of Michigan in years to come.

  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. Extreme weather: does nature keep up?

    NARCIS (Netherlands)

    Leemans, R.; Vliet, van A.J.H.

    2004-01-01

    The IPCC indicated that above a 2°C increase in global mean surface temperature the risk of adverse impacts will rapidly increase. This study suggests this level is too high. Even with small global temperature changes, there will be disproportionately large changes in the frequency and magnitude of

  13. 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 “ ...

  14. 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.

  15. Knowledge-based remote sensing of complex objects: Recognition of spatial patterns resulting from natural hydrocarbon seepages

    NARCIS (Netherlands)

    Werff, Harald Michael Arnout van der

    2006-01-01

    This thesis outlines the development of four image processing algorithms that combine spectral and spatial information for the detection of complex objects on the Earth' surface by remote sensing. Complex objects are objects that are composed of several smaller parts. These smaller parts may not be

  16. Inclusion complexes of red bell pepper pigments with β-cyclodextrin: preparation, characterisation and application as natural colorant in yogurt.

    Science.gov (United States)

    Gomes, Lidiane Martins Mendes; Petito, Nicolly; Costa, Valéria Gonçalves; Falcão, Deborah Quintanilha; de Lima Araújo, Kátia G

    2014-04-01

    This work aimed to prepare inclusion complexes between red bell pepper pigments and β-cyclodextrin using two different procedures (i.e., magnetic stirring and ultrasonic homogenisation), to characterise the prepared inclusion complexes and to evaluate the colour stability of a selected complex added to yogurt. The mass ratio of extract to β-cyclodextrin was 1:4. The formed extract: β-cyclodextrin complexes and a physical mixture of extract and β-cyclodextrin were evaluated by differential scanning calorimetry, Fourier transform-infrared spectroscopy, proton nuclear magnetic resonance, particle size distribution and Zeta potential. The obtained data showed that ultrasonic homogenisation resulted in better yield and inclusion efficiency compared to magnetic stirring. The yogurt with the added complex produced by ultrasonic homogenisation showed slower variations for the a(∗) (redness) and b(∗) (yellowness) indices compared to yogurt with added extract, indicating a higher protection of the colour during storage.

  17. A phylogenetic assessment of the polyphyletic nature and intraspecific color polymorphism in the Bactrocera dorsalis complex (Diptera, Tephritidae).

    Science.gov (United States)

    Leblanc, Luc; San Jose, Michael; Barr, Norman; Rubinoff, Daniel

    2015-01-01

    The Bactrocera dorsalis complex (Tephritidae) comprises 85 species of fruit flies, including five highly destructive polyphagous fruit pests. Despite significant work on a few key pest species within the complex, little has been published on the majority of non-economic species in the complex, other than basic descriptions and illustrations of single specimens regarded as typical representatives. To elucidate the species relationships within the Bactrocera dorsalis complex, we used 159 sequences from one mitochondrial (COI) and two nuclear (elongation factor-1α and period) genes to construct a phylogeny containing 20 described species from within the complex, four additional species that may be new to science, and 26 other species from Bactrocera and its sister genus Dacus. The resulting concatenated phylogeny revealed that most of the species placed in the complex appear to be unrelated, emerging across numerous clades. This suggests that they were placed in the Bactrocera dorsalis complex based on the similarity of convergent characters, which does not appear to be diagnostic. Variations in scutum and abdomen color patterns within each of the non-economic species are presented and demonstrate that distantly-related, cryptic species overlap greatly in traditional morphological color patterns used to separate them in keys. Some of these species may not be distinguishable with confidence by means other than DNA data.

  18. Magnitude and nature of carbohydrate-aromatic interactions in fucose-phenol and fucose-indole complexes: CCSD(T) level interaction energy calculations.

    Science.gov (United States)

    Tsuzuki, Seiji; Uchimaru, Tadafumi; Mikami, Masuhiro

    2011-10-20

    The CH/π contact structures of the fucose-phenol and fucose-indole complexes and the stabilization energies by formation of the complexes (E(form)) were studied by ab initio molecular orbital calculations. The three types of interactions (CH/π and OH/π interactions and OH/O hydrogen bonds) were compared and evaluated in a single molecular system and at the same level of theory. The E(form) calculated for the most stable CH/π contact structure of the fucose-phenol complex at the CCSD(T) level (-4.9 kcal/mol) is close to that for the most stable CH/π contact structure of the fucose-benzene complex (-4.5 kcal/mol). On the other hand the most stable CH/π contact structure of the fucose-indole complex has substantially larger E(form) (-6.5 kcal/mol). The dispersion interaction is the major source of the attraction in the CH/π contact structures of the fucose-phenol and fucose-indole complexes as in the case of the fucose-benzene complex. The electrostatic interactions in the CH/π contact structures are small (less than 1.5 kcal/mol). The nature of the interactions between the nonpolar surface of the carbohydrate and aromatic rings is completely different from that of the conventional hydrogen bonds where the electrostatic interaction is the major source of the attraction. The distributed multipole analysis and DFT-SATP analysis show that the dispersion interactions in the CH/π contact structure of fucose-indole complex are substantially larger than those in the CH/π contact structures of fucose-benzene and fucose-phenol complexes. The large dispersion interactions are responsible for the large E(form) for the fucose-indole complex.

  19. Complex marine natural products as potential epigenetic and production regulators of antibiotics from a marine Pseudomonas aeruginosa

    Science.gov (United States)

    Marine microbes are capable of producing secondary metabolites for defense and competition. Factors exerting an impact on secondary metabolite production of microbial communities included bioactive natural products and co-culturing. These external influences may have practical applications such as ...

  20. A two-layer sparse coding model learns simple and complex cell receptive fields and topography from natural images

    National Research Council Canada - National Science Library

    Hyvärinen, Aapo; Hoyer, Patrik O

    2001-01-01

    The classical receptive fields of simple cells in the visual cortex have been shown to emerge from the statistical properties of natural images by forcing the cell responses to be maximally sparse, i.e...

  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. Local Regeneration of Dentin-Pulp Complex Using Controlled Release of FGF-2 and Naturally Derived Sponge-Like Scaffolds

    Directory of Open Access Journals (Sweden)

    Chiaki Kitamura

    2012-01-01

    Full Text Available Restorative and endodontic procedures have been recently developed in an attempt to preserve the vitality of dental pulp after exposure to external stimuli, such as caries infection or traumatic injury. When damage to dental pulp is reversible, pulp wound healing can proceed, whereas irreversible damage induces pathological changes in dental pulp, eventually requiring its removal. Nonvital teeth lose their defensive abilities and become severely damaged, resulting in extraction. Development of regeneration therapy for the dentin-pulp complex is important to overcome limitations with presently available therapies. Three strategies to regenerate the dentin-pulp complex have been proposed; regeneration of the entire tooth, local regeneration of the dentin-pulp complex from amputated dental pulp, and regeneration of dental pulp from apical dental pulp or periapical tissues. In this paper, we focus on the local regeneration of the dentin-pulp complex by application of exogenous growth factors and scaffolds to amputated dental pulp.

  3. North Cascades National Park Service Complex Natural Resource Preservation Program Amphibian Inventory Big Beaver Watershed 1996 - Progress Report

    Data.gov (United States)

    Oak Ridge National Laboratory — The 1996 amphibian inventory in North Cascades National Park Service Complex Big Beaver watershed is part of a four year program to inventory amphibians in Pacific...

  4. A parallel workload has extreme varibility

    CERN Document Server

    Henwood, R; Chapman, S C; McLay, R

    2016-01-01

    In both high-performance computing (HPC) environments and the public cloud, the duration of time to retrieve or save your results is simultaneously unpredictable and important to your over all resource budget. It is generally accepted ("Google: Taming the Long Latency Tail - When More Machines Equals Worse Results", Todd Hoff, highscalability.com 2012), but without a robust explanation, that identical parallel tasks do take different durations to complete -- a phenomena known as variability. This paper advances understanding of this topic. We carefully choose a model from which system-level complexity emerges that can be studied directly. We find that a generalized extreme value (GEV) model for variability naturally emerges. Using the public cloud, we find real-world observations have excellent agreement with our model. Since the GEV distribution is a limit distribution this suggests a universal property of parallel systems gated by the slowest communication element of some sort. Hence, this model is applicab...

  5. Planck cold clumps in the $\\lambda$ Orionis complex: I. Discovery of an extremely young Class 0 protostellar object and a proto-brown dwarf candidate in a bright rimmed clump PGCC G192.32-11.88

    CERN Document Server

    Liu, Tie; Kim, Kee-Tae; Wu, Yuefang; Lee, Chang Won; Lee, Jeong-Eun; Tatematsu, Kenichi; Choi, Minho; Juvela, Mika; Thompson, Mark; Goldsmith, Paul F; Liu, Sheng-yuan; Naomi, Hirano; Koch, Patrick; Henkel, Christian; Sanhueza, Patricio; He, JinHua; Rivera-Ingraham, Alana; Wang, Ke; Cunningham, Maria R; Tang, Ya-Wen; Lai, Shih-Ping; Yuan, Jinghua; Li, Di; Fuller, Gary; Kang, Miju; Luong, Quang Nguyen; Liu, Hauyu Baobab; Ristorcelli, Isabelle; Yang, Ji; Xu, Ye; Hirota, Tomoya; Mardones, Diego; Qin, Sheng-Li; Chen, Huei-Ru; Kwon, Woojin; Meng, FanYi; Zhang, Huawei; Kim, Mi-Ryang; Yi, Hee-Weon

    2015-01-01

    We are performing a series of observations with ground-based telescopes toward Planck Galactic cold clumps (PGCCs) in the $\\lambda$ Orionis complex in order to systematically investigate the effects of stellar feedback. In the particular case of PGCC G192.32-11.88, we discovered an extremely young Class 0 protostellar object (G192N) and a proto-brown dwarf candidate (G192S). G192N and G192S are located in a gravitationally bound bright-rimmed clump. The velocity and temperature gradients seen in line emission of CO isotopologues indicate that PGCC G192.32-11.88 is externally heated and compressed. G192N probably has the lowest bolometric luminosity ($\\sim0.8$ L$_{\\sun}$) and accretion rate (6.3$\\times10^{-7}$ M$_{\\sun}$~yr$^{-1}$) when compared with other young Class 0 sources (e.g. PACS Bright Red sources (PBRs)) in the Orion complex. It has slightly larger internal luminosity ($0.21\\pm0.01$ L$_{\\sun}$) and outflow velocity ($\\sim$14 km~s$^{-1}$) than the predictions of first hydrostatic cores (FHSCs). G192N...

  6. Complex Fluids and Hydraulic Fracturing.

    Science.gov (United States)

    Barbati, Alexander C; Desroches, Jean; Robisson, Agathe; McKinley, Gareth H

    2016-06-07

    Nearly 70 years old, hydraulic fracturing is a core technique for stimulating hydrocarbon production in a majority of oil and gas reservoirs. Complex fluids are implemented in nearly every step of the fracturing process, most significantly to generate and sustain fractures and transport and distribute proppant particles during and following fluid injection. An extremely wide range of complex fluids are used: naturally occurring polysaccharide and synthetic polymer solutions, aqueous physical and chemical gels, organic gels, micellar surfactant solutions, emulsions, and foams. These fluids are loaded over a wide range of concentrations with particles of varying sizes and aspect ratios and are subjected to extreme mechanical and environmental conditions. We describe the settings of hydraulic fracturing (framed by geology), fracturing mechanics and physics, and the critical role that non-Newtonian fluid dynamics and complex fluids play in the hydraulic fracturing process.

  7. Multidimensional extremal dependence coefficients

    OpenAIRE

    2017-01-01

    Extreme values modeling has attracting the attention of researchers in diverse areas such as the environment, engineering, or finance. Multivariate extreme value distributions are particularly suitable to model the tails of multidimensional phenomena. The analysis of the dependence among multivariate maxima is useful to evaluate risk. Here we present new multivariate extreme value models, as well as, coefficients to assess multivariate extremal dependence.

  8. The European Extreme Right and Religious Extremism

    Directory of Open Access Journals (Sweden)

    Jean-Yves Camus

    2007-12-01

    Full Text Available The ideology of the Extreme Right in Western Europe is rooted in Catholic fundamentalism and Counter-Revolutionary ideas. However, the Extreme Right, like all other political families, has had to adjust to an increasingly secular society. The old link between religion and the Extreme Right has thus been broken and in fact already was when Fascism overtook Europe: Fascism was secular, sometimes even anti-religious, in its essence. Although Catholic fundamentalists still retain strong positions within the apparatus of several Extreme Right parties (Front National, the vote for the Extreme Right is generally weak among regular churchgoers and strong among non-believers. In several countries, the vote for the Extreme Right is stronger among Protestant voters than among Catholics, since while Catholics may support Christian-Democratic parties, there are very few political parties linked to Protestant churches. Presently, it also seems that Paganism is becoming the dominant religious creed within the Extreme Right. In a multicultural Europe, non-Christian forms of religious fundamentalism such as Islamism also exist with ideological similarities to the Extreme Right, but this is not sufficient to categorize Islamism as a form of Fascism. Some Islamist groups seek alliances with the Extreme Right on the basis of their common dislike for Israel and the West, globalization and individual freedom of thought.

  9. Improved method for the analysis of organic acids and new derivatization of alcohols in complex natural aqueous matrixes: application to wine and apple vinegar.

    Science.gov (United States)

    Giumanini, A G; Verardo, G; Della Martina, D; Toniutti, N

    2001-06-01

    An improvement in the procedure for investigation of organic acids and a new derivatization method, amenable to gas chromatographic-mass spectrometric detection of alcohols, are presented. The latter is based on the formation of phenacetyl esters. The simultaneous application of the two methods also allows data to be obtained on some volatile neutrals present in complex natural aqueous fluids. Application to wine and cider vinegars allowed detection of a number of previously unreported components, among which are interesting partially esterified polycarboxylic esters.

  10. Natural Crossbreeding between Sympatric Species of the Phyllosoma Complex (Insecta: Hemiptera: Reduviidae) Indicate the Existence of Only One Species with Morphologic and Genetic Variations

    OpenAIRE

    2010-01-01

    The nucleotide sequences of the cytochrome B gene and the antennal phenotypes were analyzed for the following triatomine species: Triatoma longipennis, Triatoma pallidipennis, and Triatoma picturata, which belong to the Phyllosoma complex. These species inhabit sympatric areas from Talpa de Allende, Autlan de Navarro, and Teocuitatlan de Corona in Jalisco, Mexico. Molecular marker analysis showed that the sympatric individuals are the natural crossbred descendents of different individuals liv...

  11. β-cyclodextrin and caffeine complexes with natural polyphenols from olive and olive oils: NMR, thermodynamic, and molecular modeling studies.

    Science.gov (United States)

    Rescifina, Antonio; Chiacchio, Ugo; Iannazzo, Daniela; Piperno, Anna; Romeo, Giovanni

    2010-11-24

    Complexes of β-cyclodextrin (β-CD) and caffeine (Caf) with biophenols present in olive and olive oil (tyrosol, hydroxytyrosol, homovanillic acid, 3,4-dihydroxyphenylacetic acid, and protocatechuic acid) were investigated by NMR spectroscopy and thermodynamical-molecular dynamic studies to verify the formation of supermolecular aggregates. The obtained results indicated that the investigated biophenols form inclusion complexes with β-CD in a molar ratio of 1:1 in aqueous solution having binding constant values from 10- to 40-fold bigger than those of the corresponding complexes with Caf. Then, β-CD preferentially encloses the biophenol molecule, decreasing its bitter taste and, at the same time, preserving it against chemical and physical decomposition reactions that occur during storage.

  12. Synthesis and Characterization of Some New Complexes of Magnesium (II and Zinc (II with the Natural Flavonoid Primuletin

    Directory of Open Access Journals (Sweden)

    Ştefania Felicia Bǎrbuceanu

    2013-07-01

    Full Text Available Two new metal complexes formulated as [Mg(L2(H2O2]·H2O (1 and [Zn(L2(H2O2]·0.5H2O (2, where HL = 5-hydroxyflavone (primuletin, have been synthesized and characterized by elemental and thermal analyses, molar conductance, IR, UV-Vis, 1H- and 13C-NMR, fluorescence and mass spectra. In solid state, complexes had shown higher fluorescence intensities comparing to the free ligand, and this behavior is appreciated as a consequence of the coordination process.

  13. Clinical application of estimating hepatitis B virus quasispecies complexity by massive sequencing: correlation between natural evolution and on-treatment evolution.

    Directory of Open Access Journals (Sweden)

    Maria Homs

    Full Text Available AIM: To evaluate HBV quasispecies (QA complexity in the preCore/Core regions in relation to HBeAg status, and explore QA changes under natural evolution and nucleoside analogue (NUC treatment. METHODS: Ultra-deep pyrosequencing of HBV preCore/Core regions in 30 sequential samples (baseline [diagnosis], treatment-free, and treatment-nonresponse from 10 retrospectively selected patients grouped according to HBeAg status over time: HBeAg+ (N = 4, HBeAg- (N = 2, and fluctuating HBeAg (transient seroreversion/seroconversion pattern (N = 4. QA complexity was defined by Shannon entropy, mutation frequency, nucleotide diversity, and mutation frequency of amino acids (MfAA in preCore and Core. RESULTS: The QA was less complex in HBeAg+ than in HBeAg- or fluctuating HBeAg. High complexity in preCore was associated with decreased viral replication (preCore MfAA negatively correlated with HBV-DNA, p = 0.005. QA complexity in the treatment-free period negatively correlated with values seen during treatment. Specific variants were mainly selected in the Core region in HBeAg- and fluctuating HBeAg patients, suggesting higher immune pressure than in HBeAg+. CONCLUSIONS: The negative correlation between QA natural evolution and on-treatment evolution indicates the importance of pre-treatment QA study to predict QA changes in NUC nonresponders. Study of QA complexity could be useful for managing HBV infection.

  14. Clinical Application of Estimating Hepatitis B Virus Quasispecies Complexity by Massive Sequencing: Correlation between Natural Evolution and On-Treatment Evolution

    Science.gov (United States)

    Homs, Maria; Caballero, Andrea; Gregori, Josep; Tabernero, David; Quer, Josep; Nieto, Leonardo; Esteban, Rafael; Buti, Maria; Rodriguez-Frias, Francisco

    2014-01-01

    Aim To evaluate HBV quasispecies (QA) complexity in the preCore/Core regions in relation to HBeAg status, and explore QA changes under natural evolution and nucleoside analogue (NUC) treatment. Methods Ultra-deep pyrosequencing of HBV preCore/Core regions in 30 sequential samples (baseline [diagnosis], treatment-free, and treatment-nonresponse) from 10 retrospectively selected patients grouped according to HBeAg status over time: HBeAg+ (N = 4), HBeAg- (N = 2), and fluctuating HBeAg (transient seroreversion/seroconversion pattern) (N = 4). QA complexity was defined by Shannon entropy, mutation frequency, nucleotide diversity, and mutation frequency of amino acids (MfAA) in preCore and Core. Results The QA was less complex in HBeAg+ than in HBeAg- or fluctuating HBeAg. High complexity in preCore was associated with decreased viral replication (preCore MfAA negatively correlated with HBV-DNA, p = 0.005). QA complexity in the treatment-free period negatively correlated with values seen during treatment. Specific variants were mainly selected in the Core region in HBeAg- and fluctuating HBeAg patients, suggesting higher immune pressure than in HBeAg+. Conclusions The negative correlation between QA natural evolution and on-treatment evolution indicates the importance of pre-treatment QA study to predict QA changes in NUC nonresponders. Study of QA complexity could be useful for managing HBV infection. PMID:25393280

  15. Relevant role of dissolved humic matter in phosphorus bioavailability in natural and agronomical ecosystems through the formation of Humic-(Metal)-Phosphate complexes

    Science.gov (United States)

    Baigorri, Roberto; Urrutia, Óscar; Erro, Javier; Pazos-Pérez, Nicolás; María García-Mina, José

    2016-04-01

    Natural Organic Matter (NOM) and the NOM fraction present in soil solution (dissolved organic matter: DOM) are currently considered as fundamental actors in soil fertility and crop mineral nutrition. Indeed, decreases in crop yields as well as soil erosion are closely related to low values of NOM and, in fact, the use of organic amendments as both soil improvers and plant growth enhancers is very usual in countries with soils poor in NOM. This role of NOM (and DOM) seems to be associated with the presence of bio-transformed organic molecules (humic substances) with high cation chelating-complexing ability. In fact, bioavailable micronutrients with metallic character in soil solutions of alkaline and calcareous soils are forming stable complexes with DOM. This beneficial action of DOM also concerns other plant nutrients such as inorganic phosphate (Pi). Among the different mechanisms involved in the beneficial action of DOM on P bioavailability, the possible formation of poly-nuclear complexes including stable chemical bonds between negative binding sites in humic substances and Pi through metal bridges in soil solution might be relevant, especially in acidic soils. In fact, several studies have proven that these complexes can be obtained in the laboratory and are very efficient in prevent Pi soil fixation and improve Pi root uptake. However, clear experimental evidence about their presence in soil solutions of natural and agronomical soil ecosystems has not published yet. We present here experimental results supporting the real presence of stable Pi-metal-Humic (PMH) complexes in the soil solution of several acidic soils. The study is based on the physico-chemical characterization (31P-NMR, FTIR, TEM-EDAX, ICP-OES) of the DOM fraction isolated by ultrafiltration from the soil solution of several representative acidic soils. In average, more than 60 % of Pi was found in the soil solution humic fraction forming stable humic-metal (Fe, Al) complexes.

  16. Monitoring the natural attenuation of petroleum in ground water at the former naval complex, Operable Unit A, Adak Island, Alaska, May and June 2003

    Science.gov (United States)

    Dinicola, R.S.; Simonds, F.W.; Defawe, Rose

    2005-01-01

    During May and June 2003, the U.S. Geological Survey installed monitoring wells and collected data to characterize the effectiveness of natural attenuation processes for remediating petroleum-contaminated ground water at Operable Unit A of the former Naval complex on Adak Island, Alaska. In addition, the evidence for petroleum biodegradation in ground water was evaluated at selected petroleum sites, plans for future natural attenuation monitoring were suggested for the selected petroleum sites, and the natural attenuation monitoring strategy for the Downtown area of Adak Island was reviewed and refinements were suggested. U.S. Geological Survey personnel measured water levels and collected ground-water samples from about 100 temporary boreholes and 50 monitoring wells. Most samples were analyzed on-site for concentrations of selected petroleum compounds and natural attenuation parameters such as dissolved oxygen, ferrous iron, and carbon dioxide. The U.S. Geological Survey evaluated the data on-site, selected new monitoring well locations, and installed, developed, and sampled 10 monitoring wells. The review and suggestions for the natural attenuation monitoring strategy focused on how to better achieve monitoring objectives specified in the Record of Decision for Adak Island petroleum sites. To achieve the monitoring objective of verifying that natural attenuation is occurring, the monitoring plans for each monitored natural attenuation site need to include sampling of at least one strategically placed well at the downgradient margin of the contaminant plume margin, preferably where contaminant concentrations are detectable but less than the cleanup level. Collection of natural attenuation parameter data and sampling background wells is no longer needed to achieve the monitoring objective of demonstrating the occurrence of natural attenuation. To achieve the objective of monitoring locations where chemical concentrations exceed specified cleanup levels, at least

  17. On the nature of stabilization in weak, medium, and strong charge-transfer complexes: CCSD(T)/CBS and SAPT calculations.

    Science.gov (United States)

    Karthikeyan, S; Sedlak, Robert; Hobza, Pavel

    2011-09-01

    Weak, medium, and strong charge-transfer (CT) complexes containing various electron donors (C(2)H(4), C(2)H(2), NH(3), NMe(3), HCN, H(2)O) and acceptors (F(2), Cl(2), BH(3), SO(2)) were investigated at the CCSD(T)/complete basis set (CBS) limit. The nature of the stabilization for these CT complexes was evaluated on the basis of perturbative NBO calculations and DFT-SAPT/CBS calculations. The structure of all of the complexes was determined by the counterpoise-corrected gradient optimization performed at the MP2/cc-pVTZ level, and most of complexes possess a linear-like contact structure. The total stabilization energies lie between 1 and 55 kcal/mol and the strongest complexes contain BH(3) as an electron acceptor. When ordering the electron donors and electron acceptors on the basis of these energies, we obtain the same order as that based on the perturbative E2 charge-transfer energies, which provides evidence that the charge-transfer term is the dominant energy contribution. The CCSD(T) correction term, defined as the difference between the CCSD(T) and MP2 interaction energies, is mostly small, which allows the investigation of the CT complexes of this type at the "cheap" MP2/CBS level. In the case of weak and medium CT complexes (with stabilization energy smaller than about 15 kcal/mol), the dominant stabilization originates in the electrostatic term; the dispersion as well as induction and δ(HF) terms covering the CT energy contribution are, however, important as well. For strong CT complexes, induction energy is the second (after electrostatic) most important energy term. The role of the induction and δ(HF) terms is unique and characteristic for CT complexes. For all CT complexes, the CCSD(T)/CBS and DFT-SAPT/CBS stabilization energies are comparable, and surprisingly, it is true even for very strong CT complexes with stabilization energy close to 50 kcal/mol characteristic by substantial charge transfer (more than 0.3 e). It is thus possible to conclude

  18. 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 u

  19. A procedure for the safety evaluation of natural flavor complexes used as ingredients in food: Essential oils

    NARCIS (Netherlands)

    Smith, R.L.; Cohen, S.M.; Doull, J.; Feron, V.J.; Goodman, J.I.; Marnett, L.J.; Portoghese, P.S.; Waddell, W.J.; Wagner, B.M.; Hall, R.L.; Higley, N.A.; Lucas-Gavin, C.; Adams, T.B.

    2005-01-01

    A scientifically based guide has been developed to evaluate the safety of naturally occurring mixtures, particularly essential oils, for their intended use as flavor ingredients. The approach relies on the complete chemical characterization of the essential oil and the variability of the composition

  20. 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 u

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

    NARCIS (Netherlands)

    Choma, Christin T.; Schudde, Ebe P.; Kellogg, Richard M.; Robillard, George T.; Feringa, Ben L.

    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 activ

  2. 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...

  3. 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

    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...

  4. Understanding natural semiquinone radicals--multifrequency EPR and relativistic DFT studies of the structure of Hg(II) complexes.

    Science.gov (United States)

    Witwicki, Maciej; Jerzykiewicz, Maria; Ozarowski, Andrzej

    2015-01-01

    Multifrequency EPR spectroscopy and DFT calculations were used to investigate Hg(II) complexes with semiquinone radical ligands formed in a direct reaction between the metal ions and tannic acid (a polyphenol closely related to tannins). Because of the intricate structure of tannic acid a vast array of substituted phenolic compounds were tested to find a structural model mimicking its ability to react with Hg(II) ions. The components of the g matrix (the g tensor) determined from the high field (208 GHz) EPR spectra of the Hg(II) complexes with the radical ligands derived from tannic acid and from the model compounds were analogous, indicating a similar coordination mode in all the studied Hg(II) complexes. Since catechol (1,2-dihydroxybenzene) was the simplest compound undergoing the reaction with Hg(II) it was selected for DFT studies which were aimed at providing an insight into the structural properties of the investigated complexes. Various coordination numbers and different conformations and protonation states of the ligands were included in the theoretical analyses. g Matrices were computed for all the DFT optimized geometries. A good agreement between the theoretical and experimental values was observed only for the model with the Hg(II) ion tetracoordinated by two ligands, one of the ligands being monoprotonated with the unpaired electron mainly localized on it.

  5. Unpacking the Complex and Multifaceted Nature of Parental Influences on Southeast Asian American College Students' Educational Trajectories

    Science.gov (United States)

    Museus, Samuel D.

    2013-01-01

    This article reports on a study that examined the ways in which parents influence the educational trajectories of Southeast Asian American (SEAA) undergraduates at four-year institutions. Individual, face-to-face interviews with 34 SEAAs were conducted and analyzed. Findings illustrate the complex and multifaceted ways that parental influences…

  6. Deficiently Extremal Cohen-Macaulay Algebras

    Indian Academy of Sciences (India)

    Chanchal Kumar; Pavinder Singh

    2010-04-01

    The aim of this paper is to study homological properties of deficiently extremal Cohen–Macaulay algebras. Eagon–Reiner showed that the Stanley–Reisner ring of a simplicial complex has a linear resolution if and only if the Alexander dual of the simplicial complex is Cohen–Macaulay. An extension of a special case of Eagon–Reiner theorem is obtained for deficiently extremal Cohen–Macaulay Stanley–Reisner rings.

  7. Complex adaptive responses during antagonistic coevolution between Tribolium castaneum and its natural parasite Nosema whitei revealed by multiple fitness components

    Directory of Open Access Journals (Sweden)

    Bérénos Camillo

    2012-01-01

    Full Text Available Abstract Background Host-parasite coevolution can lead to local adaptation of either parasite or host if there is specificity (GxG interactions and asymmetric evolutionary potential between host and parasite. This has been demonstrated both experimentally and in field studies, but a substantial proportion of studies fail to detect such clear-cut patterns. One explanation for this is that adaptation can be masked by counter-adaptation by the antagonist. Additionally, genetic architecture underlying the interaction is often highly complex thus preventing specific adaptive responses. Here, we have employed a reciprocal cross-infection experiment to unravel the adaptive responses of two components of fitness affecting both parties with different complexities of the underlying genetic architecture (i.e. mortality and spore load. Furthermore, our experimental coevolution of hosts (Tribolium castaneum and parasites (Nosema whitei included paired replicates of naive hosts from identical genetic backgrounds to allow separation between host- and parasite-specific responses. Results In hosts, coevolution led to higher resistance and altered resistance profiles compared to paired control lines. Host genotype × parasite genotype interactions (GH × GP were observed for spore load (the trait of lower genetic complexity, but not for mortality. Overall parasite performance correlated with resistance of its matching host coevolution background reflecting a directional and unspecific response to strength of selection during coevolution. Despite high selective pressures exerted by the obligatory killing parasite, and host- and parasite-specific mortality profiles, no general pattern of local adaptation was observed, but one case of parasite maladaptation was consistently observed on both coevolved and control host populations. In addition, the use of replicate control host populations in the assay revealed one case of host maladaptation and one case of parasite

  8. Tapasin discriminates peptide-human leukocyte antigen-A*02:01 complexes formed with natural ligands

    DEFF Research Database (Denmark)

    Røder, Gustav Andreas; Geironson, Linda; Rasmussen, Michael

    2011-01-01

    A plethora of peptides are generated intracellularly, and most peptide-human leukocyte antigen (HLA)-I interactions are of a transient, unproductive nature. Without a quality control mechanism, the HLA-I system would be stressed by futile attempts to present peptides not sufficient for the stable...... according to the identity of the peptide. The facilitation was also specific for the identity of the HLA-I heavy chain, where it correlated to established tapasin dependence hierarchies. Two large sets of HLA-A*02:01 binding peptides, one extracted from natural HLA-I ligands from the SYFPEITHI database...... functionally discriminate the selected SYFPEITHI peptides from the other peptide binders with high sensitivity and specificity. We suggest that this HLA-I- and peptide-specific function, together with the functions exerted by the more C-terminal parts of tapasin, are major features of tapasin-mediated HLA...

  9. Studies on the evolution of complex natural products biosynthetic pathways on basis of Taxol biosynthesis in plants and endophytic fungi

    OpenAIRE

    Heinig, Uwe Herbert

    2012-01-01

    Focus of the present PhD thesis was the examination of the interesting and only poorly understood phenomenon of detection of identical natural products in distantly related organisms with regard to metabolite pathway evolution. Due to the impact of Taxol as one of the most important anti-cancer drugs today intensive research efforts were made with respect to improvement of production systems in order to overcome the supply problems. During the search for new production systems in the early 19...

  10. Catalytic Enantioselective Olefin Metathesis in Natural Product Synthesis. Chiral Metal-Based Complexes that Deliver High Enantioselectivity and More

    Science.gov (United States)

    Malcolmson, Steven J.; Meek, Simon J.; Zhugralin, Adil R.

    2012-01-01

    Chiral olefin metathesis catalysts enable chemists to access enantiomerically enriched small molecules with high efficiency; synthesis schemes involving such complexes can be substantially more concise than those that would involve enantiomerically pure substrates and achiral Mo alkylidenes or Ru-based carbenes. The scope of research towards design and development of chiral catalysts is not limited to discovery of complexes that are merely the chiral versions of the related achiral variants. A chiral olefin metathesis catalyst, in addition to furnishing products of high enantiomeric purity, can offer levels of efficiency, product selectivity and/or olefin stereoselectivity that are unavailable through the achiral variants. Such positive attributes of chiral catalysts (whether utilized in racemic or enantiomerically enriched form) should be considered as general, applicable to other classes of transformations. PMID:19967680

  11. Design of Complex Systems to Achieve Passive Safety: Natural Circulation Cooling of Liquid Salt Pebble Bed Reactors

    OpenAIRE

    Scarlat, Raluca Olga

    2012-01-01

    This dissertation treats system design, modeling of transient system response, and characterization of individual phenomena and demonstrates a framework for integration of these three activities early in the design process of a complex engineered system. A system analysis framework for prioritization of experiments, modeling, and development of detailed design is proposed. Two fundamental topics in thermal-hydraulics are discussed, which illustrate the integration of modeling and experimentat...

  12. 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.

  13. Monte-Carlo Simulation of Response Functions for Natural Gamma-Rays in LaBr3 Detector System with Complex Borehole Configurations

    Institute of Scientific and Technical Information of China (English)

    吴永鹏; 汤彬

    2012-01-01

    Usually, there are several methods, e.g. experiment, interpolation experiment-based, analytic function, and Monte-Carlo simulation, to calculate the response functions in LaBr3(Ce) detectors. In logging applications, the experiment-based methods cannot be adopted because of their limitations. Analytic function has the advantage of fast calculating speed, but it is very difficult to take into account many effects that occur in practical applications. On the contrary, Monte-Carlo simulation can deal with physical and geometric configurations very tactfully. It has a distinct advantage for calculating the functions with complex configurations in borehole. A new application of LaBr3(Ce) detector is in natural gamma-rays borehole spectrometer for uranium well logging. Calculation of response functions must consider a series of physical and geometric factors under complex logging conditions, including earth formations and its relevant parameters, different energies, material and thickness of the casings, the fluid between the two tubes, and relative position of the LaBr3(Ce) crystal to steel ingot at the front of logging tube. The present work establishes Monte-Carlo simulation models for the above-mentioned situations, and then performs calculations for main gamma-rays from natural radio-elements series. The response functions can offer experimental directions for the design of borehole detection system, and provide technique basis and basic data for spectral analysis of natural gamma-rays, and for sonrceless calibration in uranium quantitative interpretation.

  14. Legacy to the extreme

    NARCIS (Netherlands)

    A. van Deursen (Arie); T. Kuipers (Tobias); L.M.F. Moonen (Leon)

    2000-01-01

    textabstractWe explore the differences between developing a system using extreme programming techniques, and maintaining a legacy system. We investigate whether applying extreme programming techniques to legacy maintenance is useful and feasible.

  15. Legacy to the extreme

    NARCIS (Netherlands)

    Deursen, A. van; Kuipers, T.; Moonen, L.M.F.

    2000-01-01

    We explore the differences between developing a system using extreme programming techniques, and maintaining a legacy system. We investigate whether applying extreme programming techniques to legacy maintenance is useful and feasible.

  16. An Assessment of Extreme Programming Based Requirement Engineering Process

    Directory of Open Access Journals (Sweden)

    Muhammad Khalid

    2013-02-01

    Full Text Available Comprehensive requirement engineering (RE process acts as a backbone of any successful project. RE processes are very complex because most of the requirement engineering documentation is written in natural languages, which are less formal and often distract the designers and developers of the system. To streamline different phases of the software lifecycle, first we need to model the requirement document so that we can analyze and integrate the software artifacts. Designers can ensure completeness and consistency of the system by generating models using the requirement documents. In this paper, we have made an attempt to analyze extreme programming based RE approach to understand its utility in the requirement elicitation phase. In this study, different RE process models are evaluated and a comparison of the extreme programming technique is drawn to highlight the merits of the latter technique over the conventional RE techniques.

  17. 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

  18. Upper Extremity Injuries in Gymnasts.

    Science.gov (United States)

    Wolf, Megan R; Avery, Daniel; Wolf, Jennifer Moriatis

    2017-02-01

    Gymnastics is a unique sport, which loads the wrist and arms as weight-bearing extremities. Because of the load demands on the wrist in particular, stress fractures, physeal injury, and overuse syndromes may be observed. This spectrum of injury has been termed "gymnast's wrist," and incorporates such disorders as wrist capsulitis, ligamentous tears, triangular fibrocartilage complex tears, chondromalacia of the carpus, stress fractures, distal radius physeal arrest, and grip lock injury.

  19. Electro-Thermal and Semiconductivity Behaviour of Natural Sintered Complex Carbonate Ore for Thermo-Technological Applications

    OpenAIRE

    Loutfy H. Madkour

    2014-01-01

    The polymetal (Zn, Pb, Fe, Ca, Mg, Cd, Ba, Ni, Ti, and SiO2) complex Umm-Gheig carbonate ore is subjected to sintering treatment at 573, 773, 973 and 1273 K respectively for four hours. Chemical, spectral, X-ray and differential thermal analyses are applied for the native ore as well as for the samples preheated and sintered. The current versus applied DC voltage (I–V) characteristics, bulk density (Db), percent shrinkage (%S), activation energy (Ea) and energy gap (Eg) are established for th...

  20. Deficiently Extremal Gorenstein Algebras

    Indian Academy of Sciences (India)

    Pavinder Singh

    2011-08-01

    The aim of this article is to study the homological properties of deficiently extremal Gorenstein algebras. We prove that if / is an odd deficiently extremal Gorenstein algebra with pure minimal free resolution, then the codimension of / must be odd. As an application, the structure of pure minimal free resolution of a nearly extremal Gorenstein algebra is obtained.

  1. 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.

  2. Social and ethical dimension of the natural sciences, complex problems of the age, interdisciplinarity, and the contribution of education

    Science.gov (United States)

    Develaki, Maria

    2008-09-01

    In view of the complex problems of this age, the question of the socio-ethical dimension of science acquires particular importance. We approach this matter from a philosophical and sociological standpoint, looking at such focal concerns as the motivation, purposes and methods of scientific activity, the ambivalence of scientific research and the concomitant risks, and the conflict between research freedom and external socio-political intervention. We then point out the impediments to the effectiveness of cross-disciplinary or broader meetings for addressing these complex problems and managing the associated risks, given the difficulty in communication between experts in different fields and non-experts, difficulties that education is challenged to help resolve. We find that the social necessity of informed decision-making on the basis of cross-disciplinary collaboration is reflected in the newer curricula, such as that of Greece, in aims like the acquisition of cross-subject knowledge and skills, and the ability to make decisions on controversial issues involving value conflicts. The interest and the reflections of the science education community in these matters increase its—traditionally limited—contribution to the theoretical debate on education and, by extension, the value of science education in the education system.

  3. The separation and synthesis of lipidic 1,2- and 1,3-diols from natural phenolic lipids for the complexation and recovery of boron.

    Science.gov (United States)

    Tyman, John H P; Mehet, Satinderjit K

    2003-12-01

    A study has been made of the semi-synthesis of 1,3-diols (anacardic alcohols) from natural phenolic lipid resources from Anacardium occidentale and Anacardium giganteum which have given C15 and C11 derivatives, respectively. An isomeric 1,3-diol (isoanacardic alcohol) has been obtained from cardanol separated from technical cashew nut-shell liquid. Homologous 1,3-diols have been synthesised from a range of synthetic 2-alkyl-, 3-alkyl- and 4-alkylphenols and from 6-alkylsalicylic acids. The natural 1,2-diol, urushiol, from Rhus vernicifera has been purified. All these lipidic compounds have been studied for their complexation and the potential recovery of boron as boric acid.

  4. 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.

  5. Abdominal Skin Flaps in the Repair of 108 Patients with Complex Defects of Upper Extremity%腹部皮瓣修复上肢复杂损伤108例

    Institute of Scientific and Technical Information of China (English)

    王恒; 胡洪良; 沈卫军; 王战磊; 闫纪涛; 龚俊武

    2016-01-01

    目的:探讨应用腹部皮瓣修复上肢复杂损伤的临床疗效及安全性。方法:回顾性分析2011年8月-2014年8月在本院接受腹部皮瓣修复上肢复杂损伤的108例患者的临床资料。术后随访6~12个月,观察修复效果。结果:108例患者皮瓣均成活,其中101例获得随访,随访率为93.5%。随访101例患者皮瓣血运良好,皮瓣质地柔软,厚度适中,触之弹性较好,皮瓣恢复保护性感觉,两点分辨觉15 mm左右。供区愈合良好,无明显瘢痕,仅有少量增生,上肢功能基本得到恢复。1例患者因皮瓣下血肿压迫出现皮瓣供血障碍,经拆除部分缝线后血运恢复;2例多指脱套损伤患者在修复后对外观不甚满意,经二期整形修复后满意出院;2例手部掌背两侧复合脱套伤患者修复后精细活动功能受到轻微的影响。101例随访患者中96例评价满意,满意率为95.0%。结论:腹部皮瓣适用于修复各类上肢复杂性损伤,安全可靠。不过,临床需要加强修复过程的护理,以切实减少后遗症,提高患者生存质量。%Objective:To investigate the clinical efficacy and safety of the application of abdominal skin flaps in the repair of complex defects of upper extremity.Method:The clinical data of 108 patients with complex defects of upper extremity who accepted abdominal skin flaps admitted to our hospital from August 2011 to August 2014 were retrospectively analyzed.The postoperative followed-up was taken for 6 to 12 months,the repair effects were observed.Result:All flaps of the 108 cases survived,and 101 cases got followed-up service,so the follow-up rate was 93.5%.The flaps of the followed-up 101 cases were soft with good blood circulation,the thickness of the skin was moderate,the elasticity of the skin was good with touching,the sense of protection of the skin flaps restored,the two-point-discrimination of the digits was 15 mm.The donor sites healed

  6. 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.

  7. Can Retention Harvest Maintain Natural Structural Complexity? A Comparison of Post-Harvest and Post-Fire Residual Patches in Boreal Forest

    Directory of Open Access Journals (Sweden)

    Louiza Moussaoui

    2016-10-01

    Full Text Available Variable retention harvest promotes biodiversity conservation in managed boreal forests by ensuring forest continuity and structural complexity. However, do post-harvest and post-fire patches maintain the same structural complexity? This study compares post-harvest and post-fire residual patches and proposes retention modalities that can maintain the same structural complexity as in natural forests, here considering both continuous forest stands and post-fire residual patches. In boreal black spruce forests, 41 post-fire residual patches, and 45 post-harvest retention patches of varying size and ages (exposure time to disturbed matrix and 37 continuous forest stands were classified into six diameter structure types. Types 1 (inverted-J and 2 (trunked-unimodal characterized stands dominated by small trees. The abundance of small trees decreased and the abundance of large trees increased from Type 1 to Type 6. Type 6 had the most irregular structure with a wide range of diameters. This study indicates that: (1 old post-harvest residual retentions maintained the range of structural complexity found in natural stands; (2 Types 1 and 2 were generally associated with young post-fire patches and post-harvest retention clumps; (3 the structure of residual patches containing only small trees was usually younger (in terms of the age of the original forest from which residual patches were formed than those with larger trees. To avoid the risk of simplifying the structure, retention patches should be intentionally oriented towards Types 3–6, dominated by intermediate and large trees.

  8. 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.

  9. Extreme precipitation patterns reduced terrestrial ecosystem production across biomes

    Science.gov (United States)

    Zhang, Y.; Moran, S. M.; Nearing, M.; Ponce Campos, G. E.; Huete, A. R.; Buda, A. R.; Bosch, D. D.; Gunter, S. A.; Kitchen, S. G.; McNab, W.; Morgan, J. A.; McClaran, M. P.; Montoya, D. S.; Peters, D. P.; Starks, P. J.

    2012-12-01

    Precipitation regimes are predicted to shift to more extreme patterns that are characterized by more intense rainfall events and longer dry intervals, yet their ecological impacts on vegetation production remain uncertain across biomes in natural climatic conditions. This in situ study investigated the effects of novel climatic conditions on aboveground net primary production (ANPP) by combining a greenness index from satellite measurements and climatic records during 2000 to 2009 from 11 long-term experimental sites in multiple biomes and climates. Results showed that extreme precipitation patterns decreased the sensitivity of ANPP to total annual precipitation (PT), at the regional and decadal scales, leading to a mean 20% decrease in rain-use efficiency across biomes. Relative decreases in ANPP were greatest for arid grassland (16%) and Mediterranean forest (20%), and less for mesic grassland and temperate forest (3%). The co-occurrence of more heavy rainfall events and longer dry intervals caused greater water stress that resulted in reduced vegetation production. A new generalized model was developed to improve predictions of the ANPP response to changes in extreme precipitation patterns by using a function of both PT and an index of precipitation extremes. These findings suggest that extreme precipitation patterns have more substantial and complex effects on vegetation production across biomes, and are as important as total annual precipitation in understanding vegetation processes. With predictions of more extreme weather events, forecasts of ecosystem production should consider these non-linear responses to altered precipitation patterns associated with climate change. Figure. Relation of production across precipitation gradients for 11 sites for two groups (Low: R95p% definitions. The relations were significantly different for the two groups (F2, 106 = 18.51, P < 0.0001).

  10. Complex marine natural products as potential epigenetic and production regulators of antibiotics from a marine Pseudomonas aeruginosa.

    Science.gov (United States)

    Wang, Bin; Waters, Amanda L; Sims, James W; Fullmer, Alexis; Ellison, Serena; Hamann, Mark T

    2013-05-01

    Marine microbes are capable of producing secondary metabolites for defense and competition. Factors exerting an impact on secondary metabolite production of microbial communities included bioactive natural products and co-culturing. These external influences may have practical applications such as increased yields or the generation of new metabolites from otherwise silent genes in addition to reducing or limiting the production of undesirable metabolites. In this paper, we discuss the metabolic profiles of a marine Pseudomonas aeruginosa in the presence of a number of potential chemical epigenetic regulators, adjusting carbon sources and co-culturing with other microbes to induce a competitive response. As a result of these stressors certain groups of antibiotics or antimalarial agents were increased most notably when treating P. aeruginosa with sceptrin and co-culturing with another Pseudomonas sp. An interesting cross-talking event between these two Pseudomonas species when cultured together and exposed to sceptrin was observed.

  11. Investigation on rainfall extremes events trough a geoadditive model

    Science.gov (United States)

    Bocci, C.; Caporali, E.; Petrucci, A.; Rossi, G.

    2012-04-01

    Rainfall can be considered a very important variable, and rainfall extreme events analysis of great concern for the enormous impacts that they may have on everyday life particularly when related to intense rainfalls and floods, and hydraulic risk management. On the catchment area of Arno River in Tuscany, Central Italy, a geoadditive mixed model of rainfall extremes is developed. Most of the territory of Arno River has suffered in the past of many severe hydro-geological events, with high levels of risk due to the vulnerability of a unique artistic and cultural heritage. The area has a complex topography that greatly influences the precipitation regime. The dataset is composed by the time series of the annual maxima of daily rainfall recorded in about 400 rain gauges, spatially distributed over the catchment area of about 8.800 km2. The record period covers mainly the second half of 20th century. The rainfall observations are assumed to follow generalized extreme value distributions whose locations are spatially dependent and where the dependence is captured using a geoadditive model. In particular, since rainfall has a natural spatial domain and a significant spatial variability, a spatial hierarchical model for extremes is used. The spatial hierarchical models, in fact, take into account data from all locations, borrowing strength from neighbouring locations when they estimate parameters and are of great interest when small set of data is available, as in the case of rainfall extreme values. Together with rain gauges location variables further physiographic variables are investigated as explanation variables. The implemented geoadditive mixed model of spatially referenced time series of rainfall extreme values, is able to capture the spatial dynamics of the rainfall extreme phenomenon. Since the model shows evidence of a spatial trend in the rainfall extreme dynamic, the temporal dynamic and the time influence can be also taken into account. The implemented

  12. Natural field infections of wheat and triticale by fungi from the complex of fungi Stagonospora nodorum/Septoria tritici under climatic conditions of Poland.

    Science.gov (United States)

    Gilon, M; Arseniuk, E

    2014-01-01

    Stagonospora nodorum and Septoria tritici are classified as necrotrophic fungi that cause glume and leaf blotch and speckled leaf blotch of cereals and grasses worldwide. Stagonospora nodorum blotch (SNB) and Septoria tritici blotch (STB) occur quite often in complexes and are classified among the most destructive diseases to their hosts, what also was found in the present study. The intensity of diseases caused on wheat and triticale in Poland is associated with weather and environmental conditions. Moderate temperatures in the range of 20 - 23 degrees C and high relative humidity are conducive for the occurrence and development of both, SNB and STB. Results of presently reported experiments confirm that species of Stagonospora nodorum and S. tritici complex on wheat and triticale occur naturally throughout the country. In addition, statistical tests proved that the natural infections of triticale and wheat varieties in field nurseries are statistically different between locations and within each location. Plants were subjected to phenotypic evaluation, taking into account the degree of infection of leaves and glumes (Poznań et al., 2011). The reported data are generally in coincidence with our previous findings, however, they need to be confirmed on multi annual basis.

  13. Crystal structure of a mirror-image L-RNA aptamer (Spiegelmer) in complex with the natural L-protein target CCL2

    Science.gov (United States)

    Oberthür, Dominik; Achenbach, John; Gabdulkhakov, Azat; Buchner, Klaus; Maasch, Christian; Falke, Sven; Rehders, Dirk; Klussmann, Sven; Betzel, Christian

    2015-04-01

    We report the crystal structure of a 40mer mirror-image RNA oligonucleotide completely built from nucleotides of the non-natural L-chirality in complex with the pro-inflammatory chemokine L-CLL2 (monocyte chemoattractant protein-1), a natural protein composed of regular L-amino acids. The L-oligonucleotide is an L-aptamer (a Spiegelmer) identified to bind L-CCL2 with high affinity, thereby neutralizing the chemokine's activity. CCL2 plays a key role in attracting and positioning monocytes; its overexpression in several inflammatory diseases makes CCL2 an interesting pharmacological target. The PEGylated form of the L-aptamer, NOX-E36 (emapticap pegol), already showed promising efficacy in clinical Phase II studies conducted in diabetic nephropathy patients. The structure of the L-oligonucleotide.L-protein complex was solved and refined to 2.05 Å. It unveils the L-aptamer's intramolecular contacts and permits a detailed analysis of its structure-function relationship. Furthermore, the analysis of the intermolecular drug-target interactions reveals insight into the selectivity of the L-aptamer for certain related chemokines.

  14. A possible evolutionary origin for the Mn4 cluster of the photosynthetic water oxidation complex from natural MnO2 precipitates in the early ocean

    Energy Technology Data Exchange (ETDEWEB)

    Sauer, Kenneth; Yachandra, Vittal K.

    2002-04-30

    The photosynthetic water oxidation complex consists of a cluster of 4 Mn atoms bridged by O atoms, associated with Ca2+ and Cl- and incorporated into protein. The structure is similar in higher plants and algae, as well as in cyanobacteria of more ancient lineage, dating back more than 2.5 Ga on Earth. It has been proposed that the proto-enzyme derived from a component of a natural early marine manganese precipitate that contained a CaMn4O9 cluster. A variety of MnO2 minerals is found in nature. Three major classes are spinels, sheet-like layered structures and 3-dimensional networks that contain parallel tunnels. These relatively open structures readily incorporate cations (Na+, Li+, Mg2+, Ca2+, Ba2+, H+ and even Mn2+) and water. The minerals have different ratios of Mn(III) and Mn(IV) octahedrally coordinated to oxygens. Using X-ray spectroscopy we compare the chemical structures of Mn in the minerals with what is known about the arrangement in the water-oxidation complex to define the parameters of a structural model for the photosynthetic catalytic site. This comparison provides for the structural model a set of candidate Mn4 clusters -- some previously proposed and considered and others entirely novel.

  15. 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.

  16. 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.

  17. Studying complex decision making in natural settings: using a head-mounted video camera to study competitive orienteering.

    Science.gov (United States)

    Omodei, M M; McLennan, J

    1994-12-01

    Head-mounted video recording is described as a potentially powerful method for studying decision making in natural settings. Most alternative data-collection procedures are intrusive and disruptive of the decision-making processes involved while conventional video-recording procedures are either impractical or impossible. As a severe test of the robustness of the methodology we studied the decision making of 6 experienced orienteers who carried a head-mounted light-weight video camera as they navigated, running as fast as possible, around a set of control points in a forest. Use of the Wilcoxon matched-pairs signed-ranks test indicated that compared with free recall, video-assisted recall evoked (a) significantly greater experiential immersion in the recall, (b) significantly more specific recollections of navigation-related thoughts and feelings, (c) significantly more realizations of map and terrain features and aspects of running speed which were not noticed at the time of actual competition, and (d) significantly greater insight into specific navigational errors and the intrusion of distracting thoughts into the decision-making process. Potential applications of the technique in (a) the environments of emergency services, (b) therapeutic contexts, (c) education and training, and (d) sports psychology are discussed.

  18. Stacked Extreme Learning Machines.

    Science.gov (United States)

    Zhou, Hongming; Huang, Guang-Bin; Lin, Zhiping; Wang, Han; Soh, Yeng Chai

    2015-09-01

    Extreme learning machine (ELM) has recently attracted many researchers' interest due to its very fast learning speed, good generalization ability, and ease of implementation. It provides a unified solution that can be used directly to solve regression, binary, and multiclass classification problems. In this paper, we propose a stacked ELMs (S-ELMs) that is specially designed for solving large and complex data problems. The S-ELMs divides a single large ELM network into multiple stacked small ELMs which are serially connected. The S-ELMs can approximate a very large ELM network with small memory requirement. To further improve the testing accuracy on big data problems, the ELM autoencoder can be implemented during each iteration of the S-ELMs algorithm. The simulation results show that the S-ELMs even with random hidden nodes can achieve similar testing accuracy to support vector machine (SVM) while having low memory requirements. With the help of ELM autoencoder, the S-ELMs can achieve much better testing accuracy than SVM and slightly better accuracy than deep belief network (DBN) with much faster training speed.

  19. Surface enhanced Raman scattering, natural bond orbitals and Mulliken atomic charge distribution in the normal modes of diethyldithiocarbamate cadmium (II) complex, [Cd(DDTC)2

    Science.gov (United States)

    Téllez Soto, C. A.; Costa, A. C.; Versiane, O.; Lemma, T.; Machado, N. C. F.; Mondragón, M. A.; Martin, A. A.

    2015-07-01

    Theoretical and experimental bands have been assigned to the Fourier Transform Infrared (FT-IR) and FT-Raman spectra of the bis(diethyldithiocarbamate)Cd(II) complex, abbreviated as ([Cd(DDTC)2]). The calculations and spectral interpretation have been based on the DFT/B3LYP method, infrared and Raman second derivative spectra, and band deconvolution analysis to assist in the assignment of observed fundamentals. This study validated the unusual pseudo tetrahedral molecular structure formed around the Cd(II) cation. Surface-enhanced Raman scattering (SERS) was used to determine the interactions of the normal-modes of the diethyldithiocarbamate cadmium (II) complex on nano-structured silver surfaces. Natural bond orbital (NBO) analysis was also carried out to study the Cd(II) hybridization causing the pseudo tetrahedral geometry of the framework of the [Cd(DDTC)2] complex, and to confirm the charge transfer mechanisms through second order perturbation theory analysis of the Fox Matrix. In order to find out the electronic dispersion of the Mulliken atomic charges (MAC) in the normal modes, we calculated the MAC for each normal mode and correlated these values with the SERS effect. Experimental UV-Vis spectra were obtained and charge transfer bands were assigned. Good agreement between the calculated and experimental values for the vibrational and UV-Vis spectra was obtained.

  20. Surface enhanced Raman scattering, electronic spectrum, natural bond orbital, and Mulliken charge distribution in the normal modes of diethyldithiocarbamate copper (II) complex, [Cu(DDTC)2].

    Science.gov (United States)

    Téllez Soto, C A; Costa, A C; Ramos, J M; Vieira, L S; Rost, N C V; Versiane, O; Rangel, J L; Mondragón, M A; Raniero, L; Martin, A A

    2013-12-01

    Surface-enhanced Raman scattering (SERS) was used to study the interactions of the normal modes of the diethyldithiocarbamate copper (II) complex, [Cu(DDTC)2] on nano-structured mixture silver-gold surfaces and on silver surfaces. The electronic spectrum of this complex was measured and the charge transfer bands were assigned through the TD-PBE1PBE procedure. Natural bond orbital (NBO) were also carried out to study the Cu(II) hybridation leading to the square planar geometry of the framework of the [Cu(DDTC)2] complex, and to study which are the donor NBO and the acceptor NBO in meaningful charge transfer through the Second Order Perturbation Theory Analysis of the Fox Matrix in NBO basis. To see the electronic dispersion, the Mulliken electronic charges (MAC) were calculated for each normal mode and correlated with the SERS effect. Full assignment of the SERS spectra was also supported by carefully analysis of the distorted geometries generated by the normal modes.

  1. Magnetic storms and solar flares: can be analysed within similar mathematical framework with other extreme events?

    Science.gov (United States)

    Balasis, Georgios; Potirakis, Stelios M.; Papadimitriou, Constantinos; Zitis, Pavlos I.; Eftaxias, Konstantinos

    2015-04-01

    The field of study of complex systems considers that the dynamics of complex systems are founded on universal principles that may be used to describe a great variety of scientific and technological approaches of different types of natural, artificial, and social systems. We apply concepts of the nonextensive statistical physics, on time-series data of observable manifestations of the underlying complex processes ending up to different extreme events, in order to support the suggestion that a dynamical analogy characterizes the generation of a single magnetic storm, solar flare, earthquake (in terms of pre-seismic electromagnetic signals) , epileptic seizure, and economic crisis. The analysis reveals that all the above mentioned different extreme events can be analyzed within similar mathematical framework. More precisely, we show that the populations of magnitudes of fluctuations included in all the above mentioned pulse-like-type time series follow the traditional Gutenberg-Richter law as well as a nonextensive model for earthquake dynamics, with similar nonextensive q-parameter values. Moreover, based on a multidisciplinary statistical analysis we show that the extreme events are characterized by crucial common symptoms, namely: (i) high organization, high compressibility, low complexity, high information content; (ii) strong persistency; and (iii) existence of clear preferred direction of emerged activities. These symptoms clearly discriminate the appearance of the extreme events under study from the corresponding background noise.

  2. Modern analytics for naturally derived complex drug substances: NMR and MS tests for protamine sulfate from chum salmon.

    Science.gov (United States)

    Gucinski, Ashley C; Boyne, Michael T; Keire, David A

    2015-01-01

    This work describes orthogonal NMR and MS tests for the structure and composition of the drug protamine sulfate derived from chum salmon. The spectral response pattern obtained by 1D-(1)H-NMR and MS methods from salmon protamine, a mixture of four predominant peptide chains, is dependent on the amino acid sequence and abundance of each peptide. Thus, an assay was developed based on the ratios of alanine, glycine and arginine amino acid residue NMR peaks (relative to the arginine CδH proton signal) in this mixture that are unique to the salmon source. In addition, MS analysis provided sensitive sequence determination and impurity analysis based on shifts from exact masses. Spectra from protamine sulfate active pharmaceutical ingredient (API) suppliers and from a formulated drug product purchased from the US market were examined. Based on these marketplace survey data, NMR acceptance criteria for chum salmon derived protamine sulfate could be based on the absence of aromatic amino acid signals and on ratios of Ala βH/Arg δH, Gly αH/Arg δH and Arg αH/Arg δH integrated areas of 2.4 ± 1%, 9.4 ± 3% and 50 ± 5%, respectively. For MS, acceptance criteria based on the presence of specific mass to charge (m/z) ratio peaks (m/z = +8 of 530.455, 540.841, 532.208 and 508.950) could be used for the four major peptides present in the mixture with relative abundances of 17 ± 1%, 31 ± 2%, 27 ± 1% and 25 ± 3%, respectively. The specificity of the combined NMR and MS assay was tested by comparison to data obtained from herring protamine which contains a different mixture of peptides with related amino acid sequences. Both assays were able to clearly distinguish protamine derived from these different natural sources.

  3. Extreme Velocity Wind Sensor

    Science.gov (United States)

    Perotti, Jose; Voska, Ned (Technical Monitor)

    2002-01-01

    This presentation provides an overview of the development of new hurricane wind sensor (Extreme Velocity Wind Sensor) for the Kennedy Space Center (KSC) which is designed to withstand winds of up to three hundred miles an hour. The proposed Extreme Velocity Wind Sensor contains no moveable components that would be exposed to extreme wind conditions. Topics covered include: need for new hurricane wind sensor, conceptual design, software applications, computational fluid dynamic simulations of design concept, preliminary performance tests, and project status.

  4. Women in extreme poverty.

    Science.gov (United States)

    1994-01-01

    Population is estimated to increase from 5.5 billion in 1990 to 10 billion by 2050; the poverty level is expected to increase from 1 billion to 2-3 billion people. Women in development has been promoted throughout the UN and development system, but women in poverty who perform work in the informal sector are still uncounted, and solutions are elusive. The issue of extreme poverty can not be approached as just another natural disaster with immediate emergency relief. Many people live in precarious economic circumstances throughout their lives. Recent research reveals a greater understanding of the underlying causes and the need for inclusion of poor women in sustainable development. Sanitation, water, housing, health facilities need to be improved. Women must have access to education, opportunities for trading, and loans on reasonable terms. UNESCO makes available a book on survival strategies for poor women in the informal sector. The profile shows common problems of illiteracy, broken marriages, and full time involvement in provision of subsistence level existence. Existence is a fragile balance. Jeanne Vickers' "Women and the World" offers simple, low cost interventions for aiding extremely poor women. The 1992 Commission on the Status of Women was held in Vienna. Excerpts from several speeches are provided. The emphasis is on some global responses and an analysis of solutions. The recommendation is for attention to the gender dimension of poverty. Women's dual role contributes to greater disadvantages. Women are affected differently by macroeconomic factors, and that there is intergenerational transfer of poverty. Social services should be viewed as investments and directed to easing the burdens on time and energy. Public programs must be equipped to deal with poverty and to bring about social and economic change. Programs must be aware of the different distribution of resources within households. Women must be recognized as principal economic providers within

  5. 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.

  6. On causality of extreme events

    CERN Document Server

    Zanin, Massimiliano

    2016-01-01

    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 both linear and 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.

  7. 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.

  8. On causality of extreme events

    Science.gov (United States)

    2016-01-01

    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. PMID:27330866

  9. Test fields cannot destroy extremal black holes

    Science.gov (United States)

    Natário, José; Queimada, Leonel; Vicente, Rodrigo

    2016-09-01

    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.

  10. 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.

  11. [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.

  12. 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

  13. 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...

  14. Molecular structure, natural bond analysis, vibrational and electronic spectra, surface enhanced Raman scattering and Mulliken atomic charges of the normal modes of [Mn(DDTC)2] complex

    Science.gov (United States)

    Téllez S., Claudio A.; Costa, Anilton C.; Mondragón, M. A.; Ferreira, Glaucio B.; Versiane, O.; Rangel, J. L.; Lima, G. Müller; Martin, A. A.

    2016-12-01

    Theoretical and experimental bands have been assigned for the Fourier Transform Infrared and Raman spectra of the bis(diethyldithiocarbamate)Mn(II) complex, [Mn(DDTC)2]. The calculations have been based on the DFT/B3LYP method, second derivative spectra and band deconvolution analysis. The UV-vis experimental spectra were measured in acetonitrile solution, and the calculated electronic spectrum was obtained using the TD/B3LYP method with 6-311G(d, p) basis set for all atoms. Charge transfer bands and those d-d spin forbidden were assigned in the UV-vis spectrum. The natural bond orbital analysis was carried out using the DFT/B3LYP method and the Mn(II) hybridization leading to the planar geometry of the framework was discussed. Surface enhanced Raman scattering (SERS) was also performed. Mulliken charges of the normal modes were obtained and related to the SERS enhanced bands.

  15. Upper-extremity deep venous thrombosis: a review.

    Science.gov (United States)

    Mai, Cuc; Hunt, Daniel

    2011-05-01

    Upper-extremity deep venous thrombosis is less common than lower-extremity deep venous thrombosis. However, upper-extremity deep venous thrombosis is associated with similar adverse consequences and is becoming more common in patients with complex medical conditions requiring central venous catheters or wires. Although guidelines suggest that this disorder be managed using approaches similar to those for lower-extremity deep venous thrombosis, studies are refining the prognosis and management of upper-extremity deep venous thrombosis. Physicians should be familiar with the diagnostic and treatment considerations for this disease. This review will differentiate between primary and secondary upper-extremity deep venous thromboses; assess the risk factors and clinical sequelae associated with upper-extremity deep venous thrombosis, comparing these with lower-extremity deep venous thrombosis; and describe an approach to treatment and prevention of secondary upper-extremity deep venous thrombosis based on clinical evidence.

  16. 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

  17. Complex Convexity of Orlicz Modular Sequence Spaces

    Directory of Open Access Journals (Sweden)

    Lili Chen

    2016-01-01

    Full Text Available The concepts of complex extreme points, complex strongly extreme points, complex strict convexity, and complex midpoint locally uniform convexity in general modular spaces are introduced. Then we prove that, for any Orlicz modular sequence space lΦ,ρ, lΦ,ρ is complex midpoint locally uniformly convex. As a corollary, lΦ,ρ is also complex strictly convex.

  18. Distribution of Natural (U-238, Th-232, Ra-226) and Technogenic (Sr-90, Cs-137) Radionuclides in Soil-Plants Complex Near Issyk-Kul Lake, Kyrgyzstan

    Science.gov (United States)

    Jovanovic, L.; Kaldybaev, B.; Djenbaev, B.; Tilenbaev, A.

    2012-04-01

    Researches on radionuclides distribution in the soil-plants complex provide essential information in understanding human exposure to natural and technogenic sources of radiation. It is necessary in establishing regulation relating to radiation protection. The aim of this study was the radiochemical analysis of the content natural radionuclides 238U, 232Th,226Ra and technogenic radionuclides content (90Sr, 137Cs) in soils near Issyk-Kul lake (Kyrgyzstan). Results of radiochemical analyses have shown, that the concentrations of thorium-232 are fluctuating in the limits (11.7-84.1)-10-4% in the soils. The greatest concentration of thorium-232 has been found in the light chestnut soils. The content of uranium-238 in the soils near Issyk-Kul lake is fluctuating from 2.8 up to 12.7-10-4%. Radium-226 has more migration ability in comparison with other heavy natural radionuclides. According to our research the concentrations of radium-226 are fluctuating in the limits (9.4-43.0)-10-11%. The greatest concentration of radium-226 (43,0±2,8)-10-11% has been determined in the light chestnut soil. In connection with global migration of contaminating substances, including radioactive, the special attention is given long-lived radionuclides strontium-90 and caesium-137 in food-chains, and agroecosystems. Results of radiochemical analyses have shown, that specific activity of strontium-90 is fluctuating in the range of 2.9 up to 11.1 Bq/kg, and caesium-137 from 3.7 up to 14,3 Bq/kg in the soil of agroecosystems in the region of Issyk-Kul. In soil samples down to 1 meter we have observed vertical migration of these radionuclides, they were found to accumulate on the surface of soil horizon (0-5 cm) and their specific activity sharply decreases with depth. In addition in high-mountain pastures characterized by horizontal migration of cattle in profiles of soil, it was discovered that specific activity of radionuclides are lower on the slope than at the foot of the mountain. The

  19. The frequency and heterogeneous nature of complex clauses in the literary texts Seta and La luna e i falò

    Directory of Open Access Journals (Sweden)

    Darja Mertelj

    2010-12-01

    Full Text Available yntactically complex clauses are often a vital part of literary language. The aim of this paper is to present the syntactically heterogeneous nature of two longer Italian literary texts selected as being suitable for reading at high school, and to highlight potential difficulties Slovenian learners may have when dealing with them. The analysis focuses on subordinate clauses introduced by the conjunctions se, anche se and come se which can introduce various subordinate clauses most of which are notorious for Slovenian and other Slavic learners of Italian due to interferences in the area of the appropriate use of verbal forms in subordinates. It was found that all the subordinates dealt with constantly appear in the Italian novels Seta and La luna e i falò, but they cannot all be defined as very frequent. Due to their relatively sporadic appearance but highly heterogeneous nature they can not represent a stable input for learners: successful unconscious acquisition is not very likely. Instead, conscious learning appears to be necessary due to the different principles governing the choice of tenses in the two languages. Accordingly, the most frequent and prototypical syntactic patterns (subordinates should be included in conscious learning/teaching of Italian as a foreign language.

  20. Speciation analysis of aluminium(III) in natural waters and biological fluids by complexing with various catechols followed by differential pulse voltammetry detection.

    Science.gov (United States)

    Liu, Jian; Bi, Shuping; Yang, Li; Gu, Xiaodong; Ma, Pengju; Gan, Ning; Wang, Xianlong; Long, Xiufeng; Zhang, Fuping

    2002-12-01

    The biological effects of aluminium have received much attention in recent years. Speciation of Al is of basic relevance as it concerns its reactivity and bioavailability. A differential pulse voltammetry (DPV) procedure is proposed for speciation analysis of Al(III) in natural waters and biological fluids using six catechols (L-dopa, dopamine, epinephrine, norepinephrine, caffeic acid and o-benzenediol) as electroactive ligands. The decrease of the DPV anodic peak current for each catechol ligand is linear with the increase of Al concentration. This speciation analysis idea is based on the measurement of the complexation capacity, namely, different affinities of Al(III) for catechols and organic ligands under two pH conditions. The labile monomeric Al fraction (mainly inorganic aluminium) is determined at pH 4.6, while the total monomeric Al fraction is determined at pH 8.5. The principle for Al(III) speciation analysis by an electrochemical method is discussed. This sensitive and simple fractionation method is successfully applied to the speciation analysis of Al in natural waters and the results agree well with those of Driscoll's method. The speciation analysis of Al in biological fluids is also explored and the results are compared with those obtained by ultrafiltration and dialysis. Compared with other speciation protocols the electrochemical method possesses some remarkable advantages: rapidity, high sensitivity, cheap instrumentation and a simple operation procedure.

  1. Complexity: The bigger picture

    CERN Document Server

    Vicsek, Tamás

    2010-01-01

    If a concept is not well defined, there are grounds for its abuse. This is particularly true of complexity, an inherently interdisciplinary concept that has penetrated very different fields of intellectual activity from physics to linguistics, but with no underlying, unified theory. Complexity has become a popular buzzword used in the hope of gaining attention or funding -- institutes and research networks associated with complex systems grow like mushrooms. Why and how did it happen that this vague notion has become a central motif in modern science? Is it only a fashion, a kind of sociological phenomenon, or is it a sign of a changing paradigm of our perception of the laws of nature and of the approaches required to understand them? Because virtually every real system is inherently extremely complicated, to say that a system is complex is almost an empty statement - couldn't an Institute of Complex Systems just as well be called an Institute for Almost Everything? Despite these valid concerns, the world is ...

  2. Effect of the shell-forming polymer ratio on the encapsulation of tea tree oil by complex coacervation as a natural biocide.

    Science.gov (United States)

    Pérez-Limiñana, María Ángeles; Payá-Nohales, Federico J; Arán-Ais, Francisca; Orgilés-Barceló, César

    2014-01-01

    The aim of this study was to develop footwear materials with antimicrobial properties using microencapsulated Tea Tree oil (TTO) as a natural biocide. For that purpose, gelatine-carboxymethylcellulose based microcapsules containing TTO were synthesised by a complex coacervation process. Furthermore, the influence of the gelatine (G)/sodium carboxymethylmethyl cellulose (CMC) ratio (G/C) on the microcapsule properties, as well as in the microencapsulation oil efficiency, was evaluated. The microcapsules were characterised by different experimental techniques and applied to footwear materials (leather and textile) to evaluate their performance. The microcapsule durability under different conditions, such as rubbing and ironing, was analysed in order to simulate shoe manufacturing and shoe wearing. The properties of the microcapsules obtained by complex coacervation, using gelatine and sodium carboxymethylcellulose as shell-forming polymers, are determined by the ratio between those two polymers (G/C). The results obtained showed a notable effect of G/C ratio on the formation of the coacervate during the synthesis process and also on the encapsulation efficiency of the antimicrobial oil, with the optimal value for the G/C ratio being around 10.

  3. Hydrothermal circulation along oceanic detachment fault: Constraints on the nature and conditions of syntectonic silicification at the 13°20'N oceanic core complex (Mid-Atlantic ridge)

    Science.gov (United States)

    Bonnemains, D.; Verlaguet, A.; Escartin, J.; Mevel, C.; Andreani, M.

    2016-12-01

    To understand the link between extreme strain localization and fluid flow at long-lived oceanic detachment faults, we present results of geological investigations at the active 13°20'N detachment fault along the Mid-Atlantic ridge (ODEMAR cruise, Nov-Dec13) onboard NO Pourquoi pas? using the ROV Victor6000. During this cruise, we identified and sampled 7 fault outcrops on the flanks of detachment microbathymetric corrugations. These fault surfaces, extending up to 100m laterally, with extension-parallel subhorizontal striations. Sampled fault rocks are breccias containing mainly diabase clasts (often altered) and rare ultramafic clasts. Samples also show striated surfaces indicating strain localization at outcrop to sample scales. These fault rocks, which show pervasive syntectonic silicification during fault exhumation, are not documented along other detachments. To constrain the nature and origin of the silicifying fluids and the conditions of fluid-rock interactions, we combined whole-rock and mineral analyses with a study of fluid inclusions in quartz. Highly silicified samples record high homogenization temperatures (250-350°C), while moderate silicification temperatures are lower (150-250°C). In all cases salinities are generally higher than seawater (4-10 wt% eq. NaCl). These high salinity fluids likely record phase separation at high temperature (>400°C), and Raman spectroscopy shows that they contain H2±CH4±CO2. These results suggest an interaction of these fluids with ultramafic rocks undergoing serpentinization reactions (H2 release) in the footwall of the detachment and the presence of a high temperature zone at depth. This is supported by trace element patterns of mafic breccias, which shift towards ultramafic compositions with increasing silicification degree. The detachment fault zone thus channels and records a tectonic mixing between hydrothermal serpentinite fluids, and shallower seawater-like fluids potentially from the mafic hanging wall.

  4. Moving in extreme environments

    DEFF Research Database (Denmark)

    Lucas, Samuel J E; Helge, Jørn W; Schütz, Uwe H W;

    2016-01-01

    This review addresses human capacity for movement in the context of extreme loading and with it the combined effects of metabolic, biomechanical and gravitational stress on the human body. This topic encompasses extreme duration, as occurs in ultra-endurance competitions (e.g. adventure racing...... and transcontinental races) and expeditions (e.g. polar crossings), to the more gravitationally limited load carriage (e.g. in the military context). Juxtaposed to these circumstances is the extreme metabolic and mechanical unloading associated with space travel, prolonged bedrest and sedentary lifestyle, which may...

  5. Extremal surface barriers

    Energy Technology Data Exchange (ETDEWEB)

    Engelhardt, Netta; Wall, Aron C. [Department of Physics, University of California,Santa Barbara, CA 93106 (United States)

    2014-03-13

    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.

  6. 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.

  7. Extremal limits and Ba\\~nados-Silk-West effect

    CERN Document Server

    Pradhan, Parthapratim

    2016-01-01

    A fascinating property of extremal Kerr black hole (BH) is that it could be act as a particle accelerator with infinite high center-of-mass (CM) energy \\cite{bsw}. In this note, we would like to discuss about such fascinating result and to point out that this infinite energy at the event horizon comes solely due \\emph{to the singular nature of the extremal limit}. We also show that a non-extremal Kerr BH can \\emph{not} transform into extremal Kerr BH by the Ba\\~{n}ados-Silk-West mechanism. Moreover, we discuss about three possible geometries (near extremal, purely extremal and near horizon of extremal Kerr) of this mechanism. We further prove that near extremal geometry and near horizon geometry, precisely extremal geometry of extremal Kerr BHs are qualitatively different. Near extremal geometry and near horizon geometry gives the CM energy is finite, whereas precisely extremal geometry gives the diverging energy. Thus, we can argue that extremal Kerr BH and non-extremal Kerr BH are quite distinct objects. Fi...

  8. 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...

  9. Venous Ultrasound (Extremities)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound - Venous (Extremities) Venous ultrasound uses sound waves to ... limitations of Venous Ultrasound Imaging? What is Venous Ultrasound Imaging? Ultrasound is safe and painless, and produces ...

  10. Statistics of extremes

    CERN Document Server

    Gumbel, E J

    2012-01-01

    This classic text covers order statistics and their exceedances; exact distribution of extremes; the 1st asymptotic distribution; uses of the 1st, 2nd, and 3rd asymptotes; more. 1958 edition. Includes 44 tables and 97 graphs.

  11. Critical analysis of the data on complexation of lanthanides and actinides by natural organic matter: particular case of humic substances; Analyse critique des donnees de complexation des lanthanides et actinides par la matiere organique naturelle: cas des substances humiques

    Energy Technology Data Exchange (ETDEWEB)

    Reiller, P.

    2010-07-01

    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{sup 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

  12. Scaling Behavior and Phase Change in Complex Network

    Directory of Open Access Journals (Sweden)

    Wei Cheng

    2013-11-01

    Full Text Available Scaling behavior is a extremely typical phenomenon in complex system research, as well as it can act that many Macro indicators in system or distribution function of some variables meet exactly power-law behavior, which possesses different kinds of Exponents. In this article, according to Phase Change concept in Physics, it is researched that the nature in critical state of complex network with Seepage model, and it is totally stated that the basic reason of Self-similar behavior, Fractal behavior, and so on, and also Phase Change in complex network in critical state of complex network in accord with power-law distribution.    

  13. 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

  14. An integrated profile of natural fractures in gas-bearing shale complex (Pomerania, Poland): based on structural profiling of oriented core and borehole logging data.

    Science.gov (United States)

    Bobek, Kinga; Jarosiński, Marek; Stadtmuller, Marek; Pachytel, Radomir; Lis-Śledziona, Anita

    2016-04-01

    Natural fractures in gas-bearing shales has significant impact on reservoir stimulation and increase of exploitation. Density of natural fractures and their orientation in respect to the maximum horizontal stress are crucial for propagation of technological hydraulic fractures. Having access to continuous borehole core profile and modern geophysical logging from several wells in the Pomeranian part of the Early Paleozoic Baltic Basin (Poland) we were able to compare the consistency of structural interpretation of several data sets. Although, final aim of our research is to optimize the method of fracture network reconstruction on a reservoir scale, at a recent stage we were focused on quantitative characterization of tectonic structures in a direct vicinity of boreholes. The data we have, cover several hundred meters long profiles of boreholes from the Ordovician and Silurian shale complexes. Combining different sets of data we broaden the scale of observation from borehole core (5 cm radius), through XRMI scan of a borehole wall (10 cm radius), up to penetration of a signal of an acoustic dipole logging (several tens of cm range). At the borehole core we examined the natural tectonic structures and mechanically significant features, like: mineral veins, fractured veins, bare fractures, slickensides, fault zones, stylolites, bedding plane and mechanically contrasting layers. We have also noticed drilling-induced features like centerline fractures and core disking, controlled by a recent tectonic stress. We have measured the orientation of fractures, their size, aperture and spacing and also describe the character of veins and tried to determine the stress regime responsible for fault slippage and fracture propagation. Wide range of analyzed features allowed us to discriminate fracture sets and reconstruct tectonic evolution of the complex. The most typical for analyzed shale complexes are steep and vertical strata-bound fractures that create an orthogonal joint

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. Complex narratives

    NARCIS (Netherlands)

    Simons, J.

    2008-01-01

    This paper brings together narratology, game theory, and complexity theory to untangle the intricate nature of complex narratives in contemporary cinema. It interrogates the different terms - forking-path narratives, mind-game films, modular narratives, multiple-draft films, database narratives, puz

  1. 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,...

  2. Calabi Energies of Extremal Toric Surfaces

    CERN Document Server

    LeBrun, Claude

    2011-01-01

    We derive a formula for the L^2 norm of the scalar curvature of any extremal Kaehler metric on a compact complex toric surface, stated purely in terms of the geometry of the corresponding moment polygon. We then describe some applications of this formula to the construction of 4-manifolds with vanishing Bach tensor.

  3. Increased Survivorship and Altered Cytokine Profile from Treatment of Influenza A H1N1-Infected Mice with Ekybion: A Drug Complex of Natural Extracts and Inorganic Compounds

    Directory of Open Access Journals (Sweden)

    Christopher Lupfer

    2011-01-01

    Full Text Available Ekybion is a drug complex of 16 natural extracts and inorganic compounds designed to treat a variety of respiratory pathogens of bacterial and viral origin. It is licensed throughout Europe for the treatment of respiratory tract infections from equine parainfluenza type 3 and equine herpes virus type 1 in equine stables. The purpose of this paper was to test the efficacy of Ekybion on a well-developed animal model of influenza A infection and determine a mode of action. Experiments were performed with Balb/c mice infected with a lethal dose of influenza A/PR/8/34 H1N1 virus and treated with nebulized Ekybion every 8 h in a time-dependant or dose-dependant fashion. These experiments showed that mice treated prior to infection with Ekybion had a higher survival rates (~46% compared with untreated animals (~0%. Paradoxically, these mice showed no significant difference in lung virus titer or weight loss. There was, however, a decrease in the level of GM-CSF, IL-6, and G-CSF cytokines in the lungs of Ekybion-treated, infected mice. It is possible that decreases in proinflammatory cytokines may have contributed to increased survivorship in Ekybion-treated influenza-infected mice.

  4. Sensitive Determination of Uranium in Natural Waters Using UV-Vis Spectrometry After Preconcentration by Ion-Imprinted Polymer-Ternary Complexes.

    Science.gov (United States)

    Bicim, Tulin; Yaman, Mehmet

    2016-07-01

    The main purpose of this study was to achieve a substantial increase in the sensitivity of the uranium determination using UV-Vis spectrometry. To achieve this goal, ion-imprinted polymers were prepared for the uranyl (imprint) ion by the formation of a ternary (salicylaldoxime and 4-vinylpyridine) complex in 2-methoxy ethanol (porogen) following copolymerization with methacrylic acid. The synthesized polymers were characterized by FTIR analysis and thermogravimetric analysis. In the preconcentration step, the optimal pH was determined to be between values of 3.5 and 6.5. The adsorbed UO2(2+) was completely eluted by 10 mL of 3.0 mol L(-1) HClO4. The developed method was applied to uranium (VI) determination in natural water samples. By using the initial volume of 500 mL and final volume of 5 mL, a concentration of 1 μg L(-1) can be determined by applying the developed method in this study.

  5. Observations on sporozoite detection in naturally infected sibling species of the Anopheles culicifacies complex and variant of Anopheles stephensi in India

    Indian Academy of Sciences (India)

    Susanta Kumar Ghosh; Satyanarayan Tiwari; Kamaraju Raghavendra; Tiruchinapalli Sundaraj; Aditya Prasad Dash

    2008-09-01

    Sporozoites were detected in naturally infected sibling species of the primary rural vector Anopheles culicifacies complex in two primary health centres (PHCs) and a variant of the urban vector Anopheles stephensi in Mangalore city, Karnataka, south India while carrying out malaria outbreak investigations from 1998–2006. Sibling species of An. culicifacies were identified based on the banding patterns on ovarian polytene chromosomes, and variants of An. stephensi were identified based on the number of ridges on the egg floats. Sporozoites were detected in the salivary glands by the dissection method. Of the total 334 salivary glands of An. culicifacies dissected, 17 (5.08%) were found to be positive for sporozoites. Of the 17 positive samples, 11 were suitable for sibling species analysis; 10 were species A (an efficient vector) and 1 was species B (a poor vector). Out of 46 An. stephensi dissected, one was sporozoite positive and belonged to the type form (an efficient vector). In malaria epidemiology this observation is useful for planning an effective vector control programme, because each sibling species/variant differs in host specificity, susceptibility to malarial parasites, breeding habitats and response to insecticides.

  6. The effect of precipitation on the transmission of Japanese encephalitis (JE) virus in nature: a complex effect on antibody-positive rate to JE virus in sentinel pigs.

    Science.gov (United States)

    Kurane, Ichiro; Shibasaki, Ken-ichi; Kotaki, Akira; Hijioka, Yasuaki; Takasaki, Tomohiko

    2013-05-03

    Japanese encephalitis (JE) is one of the most important mosquito-borne viral diseases in Asia. Pigs are a natural host and the amplifier of JE virus. The sero-conversion rate to JE virus in sentinel pigs reflects the activity of JE virus in the region. We analyzed whether precipitation has any effect on the sero-conversion rate to JE virus in sentinel pigs. Linear regression analysis was performed to determine the correlations between the levels of precipitation and sero-conversion rates to JE virus, in the entire year and during summertime over the period of 32 years from 1969 to 2000. The levels of the annual and summertime precipitation demonstrated statistically significant positive correlations with sero-conversion rates for the whole of the country and for some regions in Japan. The levels of the summertime precipitation, on the other hand, demonstrated statistically significant inverse correlations with the sero-conversion rates in other regions. Further, the levels of precipitation during preceding 10-day periods from days 1-40 before blood collection showed inverse correlation with antibody-positive rates in some regions. The results indicate that the relationship between the annual and summertime precipitation, and the sero-conversion rate to JE virus is complex; both positive and inverse effects are demonstrated depending on the regions.

  7. A new human natural killer leukemia cell line, IMC-1. A complex chromosomal rearrangement defined by spectral karyotyping: functional and cytogenetic characterization.

    Science.gov (United States)

    Chen, I-Ming; Whalen, Margaret; Bankhurst, Arthur; Sever, Cordelia E; Doshi, Rashmi; Hardekopf, David; Montgomery, Karen; Willman, Cheryl L

    2004-03-01

    A new human IL-2 dependent leukemic cell line with a natural killer (NK) cell phenotype, IMC-1, was established from an adult patient with aggressive NK cell leukemia. The IMC-1 cell line expresses the CD56, CD2, CD11a, CD38 and HLA-DR cell surface antigens, whereas the CD16 and CD8 antigens expressed on the primary leukemic blasts from which the cell line was derived were lost after 7 and 28 weeks of culture, respectively. The IMC-1 cell line displays functional NK cytotoxicity and lyses target cells in a non-MHC restricted, antibody-independent manner with equal or superior efficiency to freshly isolated NK cells. Cytogenetic analysis at presentation and after 55 weeks in culture revealed complex structural and numerical abnormalities, defined by classic G-banding and by spectral karyotyping (SKY). Three apparently intact copies of chromosome 8 occurred in the diagnostic bone marrow specimen; the cell line also contains three copies of chromosome 8 but each was structurally altered. The development and detailed characterization of this new NK leukemic cell line will facilitate biologic and functional studies of NK cells and chromosomal aberrations potentially important in leukemic transformation.

  8. Design and Synthesis of Chiral Zn2+ Complexes Mimicking Natural Aldolases for Catalytic C–C Bond Forming Reactions in Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Susumu Itoh

    2014-01-01

    Full Text Available Extending carbon frameworks via a series of C–C bond forming reactions is essential for the synthesis of natural products, pharmaceutically active compounds, active agrochemical ingredients, and a variety of functional materials. The application of stereoselective C–C bond forming reactions to the one-pot synthesis of biorelevant compounds is now emerging as a challenging and powerful strategy for improving the efficiency of a chemical reaction, in which some of the reactants are subjected to successive chemical reactions in just one reactor. However, organic reactions are generally conducted in organic solvents, as many organic molecules, reagents, and intermediates are not stable or soluble in water. In contrast, enzymatic reactions in living systems proceed in aqueous solvents, as most of enzymes generally function only within a narrow range of temperature and pH and are not so stable in less polar organic environments, which makes it difficult to conduct chemoenzymatic reactions in organic solvents. In this review, we describe the design and synthesis of chiral metal complexes with Zn2+ ions as a catalytic factor that mimic aldolases in stereoselective C–C bond forming reactions, especially for enantioselective aldol reactions. Their application to chemoenzymatic reactions in aqueous solution is also presented.

  9. 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.

  10. 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 ...

  11. Precursors of extreme increments

    CERN Document Server

    Hallerberg, S; Holstein, D; Kantz, H; Hallerberg, Sarah; Altmann, Eduardo G.; Holstein, Detlef; Kantz, Holger

    2006-01-01

    We investigate precursors and predictability of extreme events in time series, which consist in large increments within successive time steps. In order to understand the predictability of this class of extreme events, we study analytically the prediction of extreme increments in AR(1)-processes. The resulting strategies are then applied to predict sudden increases in wind speed recordings. In both cases we evaluate the success of predictions via creating receiver operator characteristics (ROC-plots). Surprisingly, we obtain better ROC-plots for completely uncorrelated Gaussian random numbers than for AR(1)-correlated data. Furthermore, we observe an increase of predictability with increasing event size. Both effects can be understood by using the likelihood ratio as a summary index for smooth ROC-curves.

  12. Climatic changes of extreme precipitation in Denmark from 1874 to 2100

    Science.gov (United States)

    Arnbjerg-Nielsen, Karsten; Bülow Gregersen, Ida; Sunyer, Maria; Madsen, Henrik; Rosbjerg, Dan

    2014-05-01

    During the past 30 years rather dramatic changes in extreme precipitation have been observed in Denmark. These changes are mainly in the frequency of extreme events, but there is also a tendency towards more severe events. Both are considered effects of anthropogenic climate change. The increase in precipitation extremes has led to inundations in most of the larger cities during the last 10 years. The flood in Copenhagen in 2011 implied the second highest damage costs measured in Denmark during the last 100 years. To establish cities that are resilient to pluvial floods robust projections of the frequency and intensity of extreme precipitation events in a changing climate are needed. Additionally, it is equally important to understand the natural variation on which the anthropogenic changes are imposed. This study presents the results of a coordinated effort to estimate the changes and uncertainties in Danish design rainfall. Trends and oscillations are identified in five daily precipitation records from 1874 to present, 83 records from high-resolution rain-gauges from 1979 to present and 18 state-of-the-art climate model simulations. It is shown that the frequency of extreme events in the past has oscillated with a cycle of 25-35 years, a behavior that can in part be explained by sea level pressure differences over the Atlantic. Projections based on the historical observations suggest that precipitation extremes in the Eastern part of Denmark should have been ascending in the last two decades. However, the increase has continued longer than expected and with larger amplitude in the most recent years. This indicates a likely influence from anthropogenic greenhouse gas emissions. With the complex combination of general increase and natural variation several additional years of observation are needed before this hypothesis can be evaluated by statistical means. Extensive analysis of 18 different regional climate model (RCM) simulations shows that anthropogenic

  13. Weather and Climate Extremes.

    Science.gov (United States)

    1997-09-01

    Antarctica’s highest (New Zealand Antarctic Society, 1974). This extreme exceeded the record of 58°F (14.4°C) that occurred on 20 October 1956 at Esperanza ... Esperanza (also known as Bahia Esperanza , Hope Bay) was in operation from 1945 through the early 1960s. Meteorological/Climatological Factors: This extreme...cm) Location: Grand Ilet, La R’eunion Island [21°00’S, 55°30’E] Date: 26 January 1980 WORLD’S GREATEST 24-HOUR RAINFALL 72 in (182.5 cm

  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.

  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. 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 ext

  18. Hydrological extremes and security

    Science.gov (United States)

    Kundzewicz, Z. W.; Matczak, P.

    2015-04-01

    Economic losses caused by hydrological extremes - floods and droughts - have been on the rise. Hydrological extremes jeopardize human security and impact on societal livelihood and welfare. Security can be generally understood as freedom from threat and the ability of societies to maintain their independent identity and their functional integrity against forces of change. Several dimensions of security are reviewed in the context of hydrological extremes. The traditional interpretation of security, focused on the state military capabilities, has been replaced by a wider understanding, including economic, societal and environmental aspects that get increasing attention. Floods and droughts pose a burden and serious challenges to the state that is responsible for sustaining economic development, and societal and environmental security. The latter can be regarded as the maintenance of ecosystem services, on which a society depends. An important part of it is water security, which can be defined as the availability of an adequate quantity and quality of water for health, livelihoods, ecosystems and production, coupled with an acceptable level of water-related risks to people, environments and economies. Security concerns arise because, over large areas, hydrological extremes - floods and droughts - are becoming more frequent and more severe. In terms of dealing with water-related risks, climate change can increase uncertainties, which makes the state's task to deliver security more difficult and more expensive. However, changes in population size and development, and level of protection, drive exposure to hydrological hazards.

  19. Acute lower extremity ischaemia

    African Journals Online (AJOL)

    tend to impact at arterial bifurcations, the commonest site being the ... Other ominous signs of advanced ischaemia include bluish ... Recommended standards for lower extremity ischaemia*. Doppler signals ... of the embolectomy procedure. An ... in a cath-lab or angio-suite under local ... We serially measure the aPTT and.

  20. 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