Cascade phenomenon against subsequent failures in complex networks

NASA Astrophysics Data System (ADS)

Jiang, Zhong-Yuan; Liu, Zhi-Quan; He, Xuan; Ma, Jian-Feng

2018-06-01

Cascade phenomenon may lead to catastrophic disasters which extremely imperil the network safety or security in various complex systems such as communication networks, power grids, social networks and so on. In some flow-based networks, the load of failed nodes can be redistributed locally to their neighboring nodes to maximally preserve the traffic oscillations or large-scale cascading failures. However, in such local flow redistribution model, a small set of key nodes attacked subsequently can result in network collapse. Then it is a critical problem to effectively find the set of key nodes in the network. To our best knowledge, this work is the first to study this problem comprehensively. We first introduce the extra capacity for every node to put up with flow fluctuations from neighbors, and two extra capacity distributions including degree based distribution and average distribution are employed. Four heuristic key nodes discovering methods including High-Degree-First (HDF), Low-Degree-First (LDF), Random and Greedy Algorithms (GA) are presented. Extensive simulations are realized in both scale-free networks and random networks. The results show that the greedy algorithm can efficiently find the set of key nodes in both scale-free and random networks. Our work studies network robustness against cascading failures from a very novel perspective, and methods and results are very useful for network robustness evaluations and protections.

Fires, Floods, and Hurricanes: Is ENSO to Blame?

ERIC Educational Resources Information Center

Mjelde, James W.; Litzenberg, Kerry K.; Hoyle, Julie E.; Holochwost, Sharon R.; Funkhouser, Sarah

2007-01-01

Scientists have associated the El Nino/Southern Oscillation (ENSO) phenomenon with extreme climate events such as flooding in California, droughts in Australia, fires in Indonesia, and increased hurricane activity in the Atlantic Ocean. The popular media is constantly attributing individual storms to the ENSO phenomenon. The reality is that a…

Molecular data reveal complex hybridization and a cryptic species of neotropical wild cat.

PubMed

Trigo, Tatiane C; Schneider, Alexsandra; de Oliveira, Tadeu G; Lehugeur, Livia M; Silveira, Leandro; Freitas, Thales R O; Eizirik, Eduardo

2013-12-16

Hybridization among animal species has recently become more recognized as an important phenomenon, especially in the context of recent radiations. Here we show that complex hybridization has led to contrasting patterns of genomic composition among closely related species of the Neotropical cat genus Leopardus. We show strong evidence of ancient hybridization and introgression between the pampas cat (L. colocolo) and northeastern populations of tigrina (L. tigrinus), leading to remarkable cytonuclear discordance in the latter. In contrast, southern tigrina populations show recent and continuing hybridization with Geoffroy's cat (L. geoffroyi), leading to extreme levels of interspecific admixture at their contact zone. Finally, we demonstrate that two seemingly continuous Brazilian tigrina populations show no evidence of ongoing gene flow between them, leading us to support their formal recognition as distinct species, namely L. tigrinus in the northeast and L. guttulus in the south. Copyright © 2013 Elsevier Ltd. All rights reserved.

Work-Related Upper Limb Disorders: A Case Report

PubMed Central

Stoyneva, Zlatka Borisova; Dermendjiev, Svetlan; Dermendjiev, Tihomir; Dobrev, Hristo

2015-01-01

In this study the complex interrelationship between physical factors, job stress, lifestyle and genetic factors on symptoms of work-related musculoskeletal disorders of the upper limbs is demonstrated by a case report and discussion of the literature. A 58 year old woman with long lasting complaints of the upper limbs with increasing intensity and duration, generalisation, combined with skin thickness, Raynaud’s phenomenon, joint disorders, arterial and pulmonary hypertension, metabolic lipid dysfunctions is presented. Occupational history proves continuous duration of service at a job with occupational physical static load with numerous repetitive monotonous systematic motions of fingers and hands as a weaver of Persian rugs followed by work at an automated loom and variable labour activities. Though the complaints dated since the time she was a manual weaver, the manifestations of generalized joint degenerative changes, system sclerosis with Raynaud’s phenomenon with similar upper extremities signs and symptoms discount upper limbs musculoskeletal disorder as caused only or mainly by occupational risk factors. The main principles and criteria for occupational diagnosis of musculoskeletal upper limb disorders and legislative requirements for their reglamentation are discussed. PMID:27275213

State-of-the-art Nanofabrication in Catalysis.

PubMed

Karim, Waiz; Tschupp, Simon A; Herranz, Juan; Schmidt, Thomas J; Ekinci, Yasin; van Bokhovenac, Jeroen A

2017-04-26

We present recent developments in top-down nanofabrication that have found application in catalysis research. To unravel the complexity of catalytic systems, the design and use of models with control of size, morphology, shape and inter-particle distances is a necessity. The study of well-defined and ordered nanoparticles on a support contributes to the understanding of complex phenomena that govern reactions in heterogeneous and electro-catalysis. We review the strengths and limitations of different nanolithography methods such as electron beam lithography (EBL), photolithography, extreme ultraviolet (EUV) lithography and colloidal lithography for the creation of such highly tunable catalytic model systems and their applications in catalysis. Innovative strategies have enabled particle sizes reaching dimensions below 10 nm. It is now possible to create pairs of particles with distance controlled with an extremely high precision in the order of one nanometer. We discuss our approach to study these model systems at the single-particle level using X-ray absorption spectroscopy and show new ways to fabricate arrays of single nanoparticles or nanoparticles in pairs over a large area using EBL and EUV-achromatic Talbot lithography. These advancements have provided new insights into the active sites in metal catalysts and enhanced the understanding of the role of inter-particle interactions and catalyst supports, such as in the phenomenon of hydrogen spillover. We present a perspective on future directions for employing top-down nanofabrication in heterogeneous and electrocatalysis. The rapid development in nanofabrication and characterization methods will continue to have an impact on understanding of complex catalytic processes.

Simulation and visualization of fundamental optics phenomenon by LabVIEW

NASA Astrophysics Data System (ADS)

Lyu, Bohan

2017-08-01

Most instructors teach complex phenomenon by equation and static illustration without interactive multimedia. Students usually memorize phenomenon by taking note. However, only note or complex formula can not make user visualize the phenomenon of the photonics system. LabVIEW is a good tool for in automatic measurement. However, the simplicity of coding in LabVIEW makes it not only suit for automatic measurement, but also suitable for simulation and visualization of fundamental optics phenomenon. In this paper, five simple optics phenomenon will be discuss and simulation with LabVIEW. They are Snell's Law, Hermite-Gaussian beam transverse mode, square and circular aperture diffraction, polarization wave and Poincare sphere, and finally Fabry-Perrot etalon in spectrum domain.

Gravitational Instabilities, Chondrule Formation, and the FU Orionis Phenomenon

NASA Astrophysics Data System (ADS)

Boley, Aaron C.; Durisen, Richard H.

2008-10-01

Using analytic arguments and numerical simulations, we examine whether chondrule formation and the FU Orionis phenomenon can be caused by the burstlike onset of gravitational instabilities (GIs) in dead zones. At least two scenarios for bursting dead zones can work, in principle. If the disk is on the verge of fragmentation, GI activation near r ~ 4-5 AU can produce chondrule-forming shocks, at least under extreme conditions. Mass fluxes are also high enough during the onset of GIs to suggest that the outburst is related to an FU Orionis phenomenon. This situation is demonstrated by numerical simulations. In contrast, as supported by analytic arguments, if the burst takes place close to r ~ 1 AU, then even low pitch angle spiral waves can create chondrule-producing shocks and outbursts. We also study the stability of the massive disks in our simulations against fragmentation and find that although disk evolution is sensitive to changes in opacity, the disks we study do not fragment, even at high resolution and even for extreme assumptions.

Statistical similarities of pre-earthquake electromagnetic emissions to biological and economic extreme events

NASA Astrophysics Data System (ADS)

Potirakis, Stelios M.; Contoyiannis, Yiannis; Kopanas, John; Kalimeris, Anastasios; Antonopoulos, George; Peratzakis, Athanasios; Eftaxias, Konstantinos; Nomicos, Costantinos

2014-05-01

When one considers a phenomenon that is "complex" refers to a system whose phenomenological laws that describe the global behavior of the system, are not necessarily directly related to the "microscopic" laws that regulate the evolution of its elementary parts. 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 disparate problems ranging from particle physics to economies of societies. Several authors have suggested that earthquake (EQ) dynamics can be analyzed within similar mathematical frameworks with economy dynamics, and neurodynamics. A central property of the EQ preparation process is the occurrence of coherent large-scale collective behavior with a very rich structure, resulting from repeated nonlinear interactions among the constituents of the system. As a result, nonextensive statistics is an appropriate, physically meaningful, tool for the study of EQ dynamics. Since the fracture induced electromagnetic (EM) precursors are observable manifestations of the underlying EQ preparation process, the analysis of a fracture induced EM precursor observed prior to the occurrence of a large EQ can also be conducted within the nonextensive statistics framework. Within the frame of the investigation for universal principles that may hold for different dynamical systems that are related to the genesis of extreme events, we present here statistical similarities of the pre-earthquake EM emissions related to an EQ, with the pre-ictal electrical brain activity related to an epileptic seizure, and with the pre-crisis economic observables related to the collapse of a share. It is demonstrated the all three dynamical systems' observables can be analyzed in the frame of nonextensive statistical mechanics, while the frequency-size relations of appropriately defined "events" that precede the extreme event related to each one of these different systems present striking quantitative similarities. It is also demonstrated that, for the considered systems, the nonextensive parameter q increases as the extreme event approaches, which indicates that the strength of the long-memory / long-range interactions between the constituents of the system increases characterizing the dynamics of the system.

Statistical significance of the rich-club phenomenon in complex networks

NASA Astrophysics Data System (ADS)

Jiang, Zhi-Qiang; Zhou, Wei-Xing

2008-04-01

We propose that the rich-club phenomenon in complex networks should be defined in the spirit of bootstrapping, in which a null model is adopted to assess the statistical significance of the rich-club detected. Our method can serve as a definition of the rich-club phenomenon and is applied to analyze three real networks and three model networks. The results show significant improvement compared with previously reported results. We report a dilemma with an exceptional example, showing that there does not exist an omnipotent definition for the rich-club phenomenon.

Planes, Trains, Automobiles--and Tea Sets: Extremely Intense Interests in Very Young Children

ERIC Educational Resources Information Center

DeLoache, Judy S.; Simcock, Gabrielle; Macari, Suzanne

2007-01-01

Some normally developing young children show an intense, passionate interest in a particular category of objects or activities. The present article documents the existence of extremely intense interests that emerge very early in life and establishes some of the basic parameters of the phenomenon. Surveys and interviews with 177 parents revealed…

``Hiss, clicks and pops'' - The enigmatic sounds of meteors

NASA Astrophysics Data System (ADS)

Finnegan, J. A.

2015-04-01

The improbability of sounds heard simultaneously with meteors allows the phenomenon to remain on the margins of scientific interest and research. This is unjustified, since these audibly perceived electric field effects indicate complex, inconsistent and still unresolved electric-magnetic coupling and charge dynamics; interacting between the meteor; the ionosphere and mesosphere; stratosphere; troposphere and the surface of the earth. This paper reviews meteor acoustic effects, presents illustrating reports and hypotheses and includes a summary of similar and additional phenomena observed during the 2013 February 15 asteroid fragment disintegration above the Russian district of Chelyabinsk. An augmenting theory involving near ground, non uniform electric field production of Ozone, as a stimulated geo-physical phenomenon to explain some hissing `meteor sounds' is suggested in section 2.2. Unlike previous theories, electric-magnetic field fluctuation rates are not required to occur in the audio frequency range for this process to acoustically emit hissing and intermittent impulsive sounds; removing the requirements of direct conversion, passive human transduction or excited, localised acoustic `emitters'. Links to the Armagh Observatory All-sky meteor cameras, electrophonic meteor research and full construction plans for an extremely low frequency (ELF) receiver are also included.

Impact of Electrostatics on Processing and Product Performance of Pharmaceutical Solids.

PubMed

Desai, Parind Mahendrakumar; Tan, Bernice Mei Jin; Liew, Celine Valeria; Chan, Lai Wah; Heng, Paul Wan Sia

2015-01-01

Manufacturing of pharmaceutical solids involves different unit operations and processing steps such as powder blending, fluidization, sieving, powder coating, pneumatic conveying and spray drying. During these operations, particles come in contact with other particles, different metallic, glass or polymer surfaces and can become electrically charged. Electrostatic charging often gives a negative connotation as it creates sticking, jamming, segregation or other issues during tablet manufacturing, capsule filling, film packaging and other pharmaceutical operations. A thorough and fundamental appreciation of the current knowledge of mechanisms and the potential outcomes is essential in order to minimize potential risks resulting from this phenomenon. The intent of this review is to discuss the electrostatic properties of pharmaceutical powders, equipment surfaces and devices affecting pharmaceutical processing and product performance. Furthermore, the underlying mechanisms responsible for the electrostatic charging are described and factors affecting electrostatic charging have been reviewed in detail. Feasibility of different methods used in the laboratory and pharmaceutical industry to measure charge propensity and decay has been summarized. Different computational and experimental methods studied have proven that the particle charging is a very complex phenomenon and control of particle charging is extremely important to achieve reliable manufacturing and reproducible product performance.

The clinicide phenomenon: an exploration of medical murder.

PubMed

Kaplan, Robert

2007-08-01

The aim of this paper is to explore the phenomenon of clinicide. The study of medical killers is barely in its infancy. Clinicide is the unnatural death of multiple patients in the course of treatment by a doctor. Serial medical killing is a relatively new phenomenon. The role model is Dr Marcel Petiot, the worst serial killer in French history. More recently, Dr Harold Shipman was Britain's worst serial killer and in the United States and Zimbabwe, Dr Michael Swango killed 60 patients. A number of doctors have such high patient death rates that it cannot be ignored. At some level, these doctors have an awareness of what they are doing, countered by an overweening refusal to acknowledge the implications or desist from further treatment. Treatment killer offences usually occur on the basis of serial mental illness, but may include the contentious area of euthanasia killing. Doctors have frequently been accomplices in state repression, brutality and genocide in direct contravention to their sanctioned role to relieve suffering and save life. They have become mass murderers on an exponential scale, making any comparison with a doctor killing his own patients almost risible. Many clinicidal doctors have extreme narcissistic personalities, a grandiose view of their own capability and inability to accept that they could be criticized or need assistance from other doctors. Such doctors develop a God-complex, getting a vicarious thrill out of ending suffering and by determining when a person dies.

Choice Shift in Opinion Network Dynamics

NASA Astrophysics Data System (ADS)

Gabbay, Michael

Choice shift is a phenomenon associated with small group dynamics whereby group discussion causes group members to shift their opinions in a more extreme direction so that the mean post-discussion opinion exceeds the mean pre-discussion opinion. Also known as group polarization, choice shift is a robust experimental phenomenon and has been well-studied within social psychology. In opinion network models, shifts toward extremism are typically produced by the presence of stubborn agents at the extremes of the opinion axis, whose opinions are much more resistant to change than moderate agents. However, we present a model in which choice shift can arise without the assumption of stubborn agents; the model evolves member opinions and uncertainties using coupled nonlinear differential equations. In addition, we briefly describe the results of a recent experiment conducted involving online group discussion concerning the outcome of National Football League games are described. The model predictions concerning the effects of network structure, disagreement level, and team choice (favorite or underdog) are in accord with the experimental results. This research was funded by the Office of Naval Research and the Defense Threat Reduction Agency.

Forecasting seasonal hydrologic response in major river basins

NASA Astrophysics Data System (ADS)

Bhuiyan, A. M.

2014-05-01

Seasonal precipitation variation due to natural climate variation influences stream flow and the apparent frequency and severity of extreme hydrological conditions such as flood and drought. To study hydrologic response and understand the occurrence of extreme hydrological events, the relevant forcing variables must be identified. This study attempts to assess and quantify the historical occurrence and context of extreme hydrologic flow events and quantify the relation between relevant climate variables. Once identified, the flow data and climate variables are evaluated to identify the primary relationship indicators of hydrologic extreme event occurrence. Existing studies focus on developing basin-scale forecasting techniques based on climate anomalies in El Nino/La Nina episodes linked to global climate. Building on earlier work, the goal of this research is to quantify variations in historical river flows at seasonal temporal-scale, and regional to continental spatial-scale. The work identifies and quantifies runoff variability of major river basins and correlates flow with environmental forcing variables such as El Nino, La Nina, sunspot cycle. These variables are expected to be the primary external natural indicators of inter-annual and inter-seasonal patterns of regional precipitation and river flow. Relations between continental-scale hydrologic flows and external climate variables are evaluated through direct correlations in a seasonal context with environmental phenomenon such as sun spot numbers (SSN), Southern Oscillation Index (SOI), and Pacific Decadal Oscillation (PDO). Methods including stochastic time series analysis and artificial neural networks are developed to represent the seasonal variability evident in the historical records of river flows. River flows are categorized into low, average and high flow levels to evaluate and simulate flow variations under associated climate variable variations. Results demonstrated not any particular method is suited to represent scenarios leading to extreme flow conditions. For selected flow scenarios, the persistence model performance may be comparable to more complex multivariate approaches, and complex methods did not always improve flow estimation. Overall model performance indicates inclusion of river flows and forcing variables on average improve model extreme event forecasting skills. As a means to further refine the flow estimation, an ensemble forecast method is implemented to provide a likelihood-based indication of expected river flow magnitude and variability. Results indicate seasonal flow variations are well-captured in the ensemble range, therefore the ensemble approach can often prove efficient in estimating extreme river flow conditions. The discriminant prediction approach, a probabilistic measure to forecast streamflow, is also adopted to derive model performance. Results show the efficiency of the method in terms of representing uncertainties in the forecasts.

Universal dynamical properties preclude standard clustering in a large class of biochemical data.

PubMed

Gomez, Florian; Stoop, Ralph L; Stoop, Ruedi

2014-09-01

Clustering of chemical and biochemical data based on observed features is a central cognitive step in the analysis of chemical substances, in particular in combinatorial chemistry, or of complex biochemical reaction networks. Often, for reasons unknown to the researcher, this step produces disappointing results. Once the sources of the problem are known, improved clustering methods might revitalize the statistical approach of compound and reaction search and analysis. Here, we present a generic mechanism that may be at the origin of many clustering difficulties. The variety of dynamical behaviors that can be exhibited by complex biochemical reactions on variation of the system parameters are fundamental system fingerprints. In parameter space, shrimp-like or swallow-tail structures separate parameter sets that lead to stable periodic dynamical behavior from those leading to irregular behavior. We work out the genericity of this phenomenon and demonstrate novel examples for their occurrence in realistic models of biophysics. Although we elucidate the phenomenon by considering the emergence of periodicity in dependence on system parameters in a low-dimensional parameter space, the conclusions from our simple setting are shown to continue to be valid for features in a higher-dimensional feature space, as long as the feature-generating mechanism is not too extreme and the dimension of this space is not too high compared with the amount of available data. For online versions of super-paramagnetic clustering see http://stoop.ini.uzh.ch/research/clustering. Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Drought assessment in the Duero basin (Central Spain) by means of multivariate extreme value statistics

NASA Astrophysics Data System (ADS)

Kallache, M.

2012-04-01

Droughts cause important losses. On the Iberian Peninsula, for example, non-irrigated agriculture and the tourism sector are affected in regular intervals. The goal of this study is the description of droughts and their dependence in the Duero basin in Central Spain. To do so, daily or monthly precipitation data is used. Here cumulative precipitation deficits below a threshold define meteorological droughts. This drought indicator is similar to the commonly used standard precipitation index. However, here the focus lies on the modeling of severe droughts, which is done by applying multivariate extreme value theory (MEVT) to model extreme drought events. Data from several stations are assessed jointly, thus the uncertainty of the results is reduced. Droughts are a complex phenomenon, their severity, spatial extension and duration has to be taken into account. Our approach captures severity and spatial extension. In general we find a high correlation between deficit volumes and drought duration, thus the duration is not explicitely modeled. We apply a MEVT model with asymmetric logistic dependence function, which is capable to model asymptotic dependence and independence (cf. Ramos and Ledford, 2009). To summarize the information on the dependence in the joint tail of the extreme drought events, we utilise the fragility index (Geluk et al., 2007). Results show that droughts also occur frequently in winter. Moreover, it is very common for one site to suffer dry conditions, whilst neighboring areas experience normal or even humid conditions. Interpolation is thus difficult. Bivariate extremal dependence is present in the data. However, most stations are at least asymptotically independent. The according fragility indices are important information for risk calculations. The emerging spatial patterns for bivariate dependence are mostly influenced by topography. When looking at the dependence between more than two stations, it shows that joint extremes can occur more often than randomly for up to 6 stations, this depends on the distance between the stations.

Simulation of laser generated ultrasound with application to defect detection

NASA Astrophysics Data System (ADS)

Pantano, A.; Cerniglia, D.

2008-06-01

Laser generated ultrasound holds substantial promise for use as a tool for defect detection in remote inspection thanks to its ability to produce frequencies in the MHz range, enabling fine spatial resolution of defects. Despite the potential impact of laser generated ultrasound in many areas of science and industry, robust tools for studying the phenomenon are lacking and thus limit the design and optimization of non-destructive testing and evaluation techniques. The laser generated ultrasound propagation in complex structures is an intricate phenomenon and is extremely hard to analyze. Only simple geometries can be studied analytically. Numerical techniques found in the literature have proved to be limited in their applicability, by the frequencies in the MHz range and very short wavelengths. The objective of this research is to prove that by using an explicit integration rule together with diagonal element mass matrices, instead of the almost universally adopted implicit integration rule to integrate the equations of motion in a dynamic analysis, it is possible to efficiently and accurately solve ultrasound wave propagation problems with frequencies in the MHz range travelling in relatively large bodies. Presented results on NDE testing of rails demonstrate that the proposed FE technique can provide a valuable tool for studying the laser generated ultrasound propagation.

A delay differential model of ENSO variability: Extreme values and stability analysis

NASA Astrophysics Data System (ADS)

Zaliapin, I.; Ghil, M.

2009-04-01

We consider a delay differential equation (DDE) model for El-Niño Southern Oscillation (ENSO) variability [Ghil et al. (2008), Nonlin. Proc. Geophys., 15, 417-433.] The model combines two key mechanisms that participate in ENSO dynamics: delayed negative feedback and seasonal forcing. Toy models of this type were shown to capture major features of the ENSO phenomenon [Jin et al., Science (1994); Tziperman et al., Science (1994)]; they provide a convenient paradigm for explaining interannual ENSO variability and shed new light on its dynamical properties. So far, though, DDE model studies of ENSO have been limited to linear stability analysis of steady-state solutions, which are not typical in forced systems, case studies of particular trajectories, or one-dimensional scenarios of transition to chaos, varying a single parameter while the others are kept fixed. In this work we take several steps toward a comprehensive analysis of DDE models relevant for ENSO phenomenology and illustrate the complexity of phase-parameter space structure for even such a simple model of climate dynamics. We formulate an initial value problem for our model and prove the existence, uniqueness, and continuous dependence theorem. We then use this theoretical result to perform detailed numerical stability analyses of the model in the three-dimensional space of its physically relevant parameters: strength of seasonal forcing b, atmosphere-ocean coupling ΰ, and propagation period ? of oceanic waves across the Tropical Pacific. Two regimes of variability, stable and unstable, are reported; they are separated by a sharp neutral curve in the (b,?) plane at constant ΰ. The detailed structure of the neutral curve becomes very irregular and possibly fractal, while individual trajectories within the unstable region become highly complex and possibly chaotic, as the atmosphere-ocean coupling ΰ increases. In the unstable regime, spontaneous transitions occur in the mean temperature (i.e., thermocline depth), period, and extreme annual values, for purely periodic, seasonal forcing. The model reproduces the Devils bleachers characterizing other ENSO models, such as nonlinear, coupled systems of partial differential equations; some of the features of this behavior have been documented in general circulation models, as well as in observations. We analyze the values of annual extremes and their location within an annual cycle and report the phase-locking phenomenon, which is connected to the occurrence of El-Niño events during the boreal (Northern Hemisphere) winter. We report existence of multiple solutions and study their basins of attraction in a space of initial conditions. We also present a model-based justification for the observed quasi-biennial oscillation in Tropical Pacific SSTs. We expect similar behavior in much more detailed and realistic models, where it is harder to describe its causes as completely. The basic mechanisms used in our model (delayed feedback and forcing) may be relevant to other natural systems in which internal instabilities interact with external forcing and give rise to extreme events.

To the fringe and back: Violent extremism and the psychology of deviance.

PubMed

Kruglanski, Arie W; Jasko, Katarzyna; Chernikova, Marina; Dugas, Michelle; Webber, David

2017-04-01

We outline a general psychological theory of extremism and apply it to the special case of violent extremism (VE). Extremism is defined as motivated deviance from general behavioral norms and is assumed to stem from a shift from a balanced satisfaction of basic human needs afforded by moderation to a motivational imbalance wherein a given need dominates the others. Because motivational imbalance is difficult to sustain, only few individuals do, rendering extreme behavior relatively rare, hence deviant. Thus, individual dynamics translate into social patterns wherein majorities of individuals practice moderation, whereas extremism is the province of the few. Both extremism and moderation require the ability to successfully carry out the activities that these demand. Ability is partially determined by the activities' difficulty, controllable in part by external agents who promote or oppose extremism. Application of this general framework to VE identifies the specific need that animates it and offers broad guidelines for addressing this pernicious phenomenon. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Tobacco Withdrawal Components and Their Relations with Cessation Success

PubMed Central

Piper, Megan E.; Schlam, Tanya R.; Cook, Jessica W.; Sheffer, Megan A.; Smith, Stevens S.; Loh, Wei-Yin; Bolt, Daniel M.; Kim, Su-Young; Kaye, Jesse T.; Hefner, Kathryn R.; Baker, Timothy B.

2011-01-01

Rationale Tobacco withdrawal is a key factor in smoking relapse, but important questions about the withdrawal phenomenon remain. Objectives This research was intended to provide information about two core components of withdrawal (negative affect and craving): 1) how various withdrawal symptom profile dimensions (e.g., mean level, volatility, extreme values) differ between negative affect and craving; and 2) how these dimensions relate to cessation outcome. Methods Adult smokers (N=1504) in a double-blind randomized placebo-controlled smoking cessation trial provided real-time withdrawal symptom data four times per day for 4 weeks (2 weeks pre-quit and 2 weeks post-quit) via palmtop computers. Cessation outcome was biochemically confirmed 8-week point-prevalence abstinence. Results Examination of craving and negative affect dimensions following a cessation attempt revealed that craving symptoms differed from negative affect symptoms, with higher means, greater variability, and a greater incidence of extreme peaks. Regression analyses revealed that abstinence was associated with lower mean levels of both craving and negative affect and fewer incidences of extreme craving peaks. In a multivariate model, the increase in mean craving and negative affect scores each uniquely predicted relapse. Conclusions Real-time reports revealed different patterns of abstinence-related negative affect and craving and that dimensions of both predict cessation outcome, suggesting that negative affect and craving dimensions each has motivational significance. This underscores the complexity of withdrawal as a determinant of relapse and the need to measure its distinct components and dimensions. PMID:21416234

Planes, trains, automobiles--and tea sets: extremely intense interests in very young children.

PubMed

DeLoache, Judy S; Simcock, Gabrielle; Macari, Suzanne

2007-11-01

Some normally developing young children show an intense, passionate interest in a particular category of objects or activities. The present article documents the existence of extremely intense interests that emerge very early in life and establishes some of the basic parameters of the phenomenon. Surveys and interviews with 177 parents revealed that nearly one third of young children have extremely intense interests. The nature of these intense interests is described, with particular focus on their emergence, commonalities in the content of the interests, and the reactions of other people to them. One of the most striking findings is a large gender difference: Extremely intense interests are much more common for young boys than for girls. (c) 2007 APA.

Overcoming Barriers in Unhealthy Settings

PubMed Central

Lemke, Michael K.; Meissen, Gregory J.; Apostolopoulos, Yorghos

2016-01-01

We investigated the phenomenon of sustained health-supportive behaviors among long-haul commercial truck drivers, who belong to an occupational segment with extreme health disparities. With a focus on setting-level factors, this study sought to discover ways in which individuals exhibit resiliency while immersed in endemically obesogenic environments, as well as understand setting-level barriers to engaging in health-supportive behaviors. Using a transcendental phenomenological research design, 12 long-haul truck drivers who met screening criteria were selected using purposeful maximum sampling. Seven broad themes were identified: access to health resources, barriers to health behaviors, recommended alternative settings, constituents of health behavior, motivation for health behaviors, attitude toward health behaviors, and trucking culture. We suggest applying ecological theories of health behavior and settings approaches to improve driver health. We also propose the Integrative and Dynamic Healthy Commercial Driving (IDHCD) paradigm, grounded in complexity science, as a new theoretical framework for improving driver health outcomes. PMID:28462332

Ritualistic child sexual abuse in post-conflict Eastern DRC: Factors associated with the phenomenon and implications for social work.

PubMed

Kasherwa, Amani Clovis; Twikirize, Janestic Mwende

2018-04-30

Ritualistic child sexual abuse (RCSA) is a critical and under-recognised form of child maltreatment prevailing in developing countries. In the Democratic Republic of Congo (DRC), children from specific communities suffer complex forms of RCSA perpetrated with extreme brutality by various individuals and groups of conspirators. Although the DRC has achieved significant milestones towards combatting war-related sexual abuse of women and children, disturbing forms of RCSA, notably child kidnapping, rape, child defilement for fetish and superstitious beliefs, child sexual exploitation, and cult-based child marriage persist and affect many victims. This study examines the factors associated with the resurgence of RCSA in post-conflict eastern DRC. The article also discusses the implications of such forms of abuse for social work practice and education in a post-war context. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effect of extreme data loss on heart rate signals quantified by entropy analysis

NASA Astrophysics Data System (ADS)

Li, Yu; Wang, Jun; Li, Jin; Liu, Dazhao

2015-02-01

The phenomenon of data loss always occurs in the analysis of large databases. Maintaining the stability of analysis results in the event of data loss is very important. In this paper, we used a segmentation approach to generate a synthetic signal that is randomly wiped from data according to the Gaussian distribution and the exponential distribution of the original signal. Then, the logistic map is used as verification. Finally, two methods of measuring entropy-base-scale entropy and approximate entropy-are comparatively analyzed. Our results show the following: (1) Two key parameters-the percentage and the average length of removed data segments-can change the sequence complexity according to logistic map testing. (2) The calculation results have preferable stability for base-scale entropy analysis, which is not sensitive to data loss. (3) The loss percentage of HRV signals should be controlled below the range (p = 30 %), which can provide useful information in clinical applications.

Geographic patterns of networks derived from extreme precipitation over the Indian subcontinent

NASA Astrophysics Data System (ADS)

Stolbova, Veronika; Bookhagen, Bodo; Marwan, Norbert; Kurths, Juergen

2014-05-01

Complex networks (CN) and event synchronization (ES) methods have been applied to study a number of climate phenomena such as Indian Summer Monsoon (ISM), South-American Monsoon, and African Monsoon. These methods proved to be powerful tools to infer interdependencies in climate dynamics between geographical sites, spatial structures, and key regions of the considered climate phenomenon. Here, we use these methods to study the spatial temporal variability of the extreme rainfall over the Indian subcontinent, in order to filter the data by coarse-graining the network, and to identify geographic patterns that are signature features (spatial signatures) of the ISM. We find four main geographic patterns of networks derived from extreme precipitation over the Indian subcontinent using up-to-date satellite-derived, and high temporal and spatial resolution rain-gauge interpolated daily rainfall datasets. In order to prove that our results are also relevant for other climatic variables like pressure and temperature, we use re-analysis data provided by the National Center for Environmental Prediction and National Center for Atmospheric Research (NCEP/NCAR). We find that two of the patterns revealed from the CN extreme rainfall analysis coincide with those obtained for the pressure and temperature fields, and all four above mentioned patterns can be explained by topography, winds, and monsoon circulation. CN and ES enable to select the most informative regions for the ISM, providing realistic description of the ISM dynamics with fewer data, and also help to infer geographic pattern that are spatial signatures of the ISM. These patterns deserve a special attention for the meteorologists and can be used as markers of the ISM variability.

Molecular mechanisms of phenotypic plasticity in social insects

USDA-ARS?s Scientific Manuscript database

Polyphenism in insects, whereby a single genome expresses different phenotypes in response to environmental cues, is a fascinating biological phenomenon. Social insects are especially intriguing examples of phenotypic plasticity because division of labor results in the development of extreme morphol...

[Spinal cord stimulation (SCS) as a treatment for the spread phenomenon related to complex regional pain syndrome type- I (CRPS-I )].

PubMed

Goto, Shinichi; Taira, Takaomi; Hori, Tomokatsu

2009-09-01

The authors describe an experience of spinal cord stimulation (SCS) in a 30-year-old woman who developed complex regional pain syndrome type-I (CRPS-I) with spread phenomenon. She had received lumbar SCS under a diagnosis of CRPS-I in her left leg for 8 years. She had refractory pain in her right arm for the recent two years. There was no new lesion explaining her refractory pain on physical or radiological examination. Thus, the pain in her right upper arm was considered as spread phenomenon of CRPS-I. Test stimulation with cervical epidural spinal electrode showed good results and the pulse generator was implanted. It is suggested that the symptom of CRPS-I involving spread phenomenon was possibly due to a cortical reorganization. But a certain effect of SCS may be contributing to the favorable results of test stimulation for the treatment of CRPS-I with spread phenomenon in this case.

Diurnal and nocturnal skin temperature regulation in chronic complex regional pain syndrome.

PubMed

Schilder, Johanna C M; Niehof, Sjoerd P; Marinus, Johan; van Hilten, Jacobus J

2015-03-01

Skin temperature changes due to vasomotor disturbances are important features of complex regional pain syndrome (CRPS). Because this phenomenon has only been studied under controlled conditions, information on daily circadian variability is lacking. Also, studies in chronic CRPS patients with abnormal posturing, in which coldness of the affected extremity is more common, do not exist. We examined the response to external heating as well as circadian temperature changes over several days in the affected legs of 14 chronic CRPS patients with abnormal posturing and 17 controls. Skin temperatures were recorded hourly for 14 days using wireless sensors. Although the patients' affected extremities were significantly colder before external heating, the vasodilatory response was similar in the 2 groups. Additionally, median skin temperature differences between both legs and their variability was larger in patients than in controls during the day, but not during the night. These findings indicate that the mechanisms underlying impaired skin circulation in CRPS during daytime are reversible under certain circumstances. The large variation in skin temperature differences during the day questions the validity of using a single measurement in the diagnosis of CRPS, and our results indicate that only temperature differences >1.0 °C should be considered to reflect vasomotor disturbances. This article shows that chronic CRPS patients have a normal vasodilatory response to external heating and that skin temperature differences between the affected and unaffected lower limbs, which were highly variable during daytime, disappeared during sleep. This indicates that part of the vasomotor regulation in these patients is still functional. Copyright © 2015 American Pain Society. Published by Elsevier Inc. All rights reserved.

Critical exponents of extremal Kerr perturbations

NASA Astrophysics Data System (ADS)

Gralla, Samuel E.; Zimmerman, Peter

2018-05-01

We show that scalar, electromagnetic, and gravitational perturbations of extremal Kerr black holes are asymptotically self-similar under the near-horizon, late-time scaling symmetry of the background metric. This accounts for the Aretakis instability (growth of transverse derivatives) as a critical phenomenon associated with the emergent symmetry. We compute the critical exponent of each mode, which is equivalent to its decay rate. It follows from symmetry arguments that, despite the growth of transverse derivatives, all generally covariant scalar quantities decay to zero.

Child and Adolescent Use of Mobile Phones: An Unparalleled Complex Developmental Phenomenon.

PubMed

Yan, Zheng

2018-01-01

This article addresses why children's use of mobile phones is an unparalleled complex developmental phenomenon in hopes of providing a broad context for this special section. It first outlines mobile phones as a sophisticated personalized and multifunction technology. Then it presents mobile phone use by children as an unparalleled complex developmental phenomenon on the basis of its four behavioral elements, two mobile cultures, and two developmental processes. It further illustrates the existing knowledge about children's mobile phones use that has been accumulated over the past 23 years and highlights 12 most studied topics, especially distracted driving and radiation exposure. It concludes with three types of scientific contributions made by the 12 articles in the special section. © 2017 The Author. Child Development © 2017 Society for Research in Child Development, Inc.

Parallels in Communication and Navigation Technology and Natural Phenomenon

NASA Technical Reports Server (NTRS)

Romanofsky, Robert

2017-01-01

The premise is more than art imitates life, or technology imitates nature it is a nascent step to see how we might be unwittingly inspired and influenced. An example that might immediately come to mind is a starling murmuration (a phenomenon called scale-free correlation) and Intels recent Coachella music festival drone performance. Superconductivity is a macroscopic manifestation of a quantum phenomenon - choreographed electrons (i.e. an electron murmuration) that enable astonishing devices. There is indeed an intimate connectedness between biology and electromagnetism. Our brains are complex neural circuits generating magnetic fields with a magnitude around 100 femtoTesla (roughly one billion times weaker than a typical magnet used to tack notes to a refrigerator door). Migratory birds navigate by orienteering with respect to the Earth's magnetic field. Electromagnetic field therapy is used in orthopedics to aid in bone repair. The electric eel generates a large electric field for self-defense. Sharks apparently detect extremely weak electric fields for finding prey. And so on. There are similarities between the way a field of wheat responds to a breeze and the natural restoring forces of a semiconductor crystal. And waves in a slowly moving river can lap backwards against a peninsular shoreline mimicking a diffraction effect. Getting back to the introductory sentence and mysterious links over cosmic distances, in August 2016, China launched the Quantum Experiments at Space Scale (QUESS) satellite. The technology is based on a non-linear crystal that produces pairs of entangled photons whose attributes apparently remain entwined regardless of how far apart they are separated. This paper will, no doubt superficially, attempt to enumerate and examine these types of connections and parallelisms.

Extremism without extremists: Deffuant model with emotions

NASA Astrophysics Data System (ADS)

Sobkowicz, Pawel

2015-03-01

The frequent occurrence of extremist views in many social contexts, often growing from small minorities to almost total majority, poses a significant challenge for democratic societies. The phenomenon can be described within the sociophysical paradigm. We present a modified version of the continuous bounded confidence opinion model, including a simple description of the influence of emotions on tolerances, and eventually on the evolution of opinions. Allowing for psychologically based correlation between the extreme opinions, high emotions and low tolerance for other people's views leads to quick dominance of the extreme views within the studied model, without introducing a special class of agents, as has been done in previous works. This dominance occurs even if the initial numbers of people with extreme opinions is very small. Possible suggestions related to mitigation of the process are briefly discussed.

Social Cooperation and Disharmony in Communities Mediated through Common Pool Resource Exploitation

NASA Astrophysics Data System (ADS)

Sugiarto, H. S.; Lansing, J. S.; Chung, N. N.; Lai, C. H.; Cheong, S. A.; Chew, L. Y.

2017-05-01

It was theorized that when a society exploits a shared resource, the system can undergo extreme phase transition from full cooperation in abiding by a social agreement, to full defection from it. This was shown to happen in an integrated society with complex social relationships. However, real-world agents tend to segregate into communities whose interactions contain features of the associated community structure. We found that such social segregation softens the abrupt extreme transition through the emergence of multiple intermediate phases composed of communities of cooperators and defectors. Phase transitions thus now occur through these intermediate phases which avert the instantaneous collapse of social cooperation within a society. While this is beneficial to society, it nonetheless costs society in two ways. First, the return to full cooperation from full defection at the phase transition is no longer immediate. Community linkages have rendered greater societal inertia such that the switch back is now typically stepwise rather than a single change. Second, there is a drastic increase in social disharmony within the society due to the greater tension in the relationship between segregated communities of defectors and cooperators. Intriguingly, these results on multiple phases with its associated phenomenon of social disharmony are found to characterize the level of cooperation within a society of Balinese farmers who exploit water for rice production.

Temporal-spatial evolution of the hydrologic drought characteristics of the karst drainage basins in South China

NASA Astrophysics Data System (ADS)

He, Zhonghua; Liang, Hong; Yang, Chaohui; Huang, Fasu; Zeng, Xinbo

2018-02-01

Hydrologic drought, as a typical natural phenomenon in the context of global climate change, is the extension and development of meteorological and agricultural droughts, and it is an eventual and extreme drought. This study selects 55 hydrological control basins in Southern China as research areas. The study analyzes features, such as intensity and occurrence frequency of hydrologic droughts, and explores the spatial-temporal evolution patterns in the karst drainage basins in Southern China by virtue of Streamflow Drought Index. Results show that (1) the general hydrologic droughts from 1970s to 2010s exhibited ;an upward trend after having experienced a previous decline; in the karst drainage basins in Southern China; the trend was mainly represented by the gradual alleviation of hydrologic droughts from 1970s to 1990s and the gradual aggravation from 2000s to 2010s. (2) The spatial-temporal evolution pattern of occurrence frequency in the karst drainage basins in Southern China was consistent with the intensity of hydrologic droughts. The periods of 1970s and 2010s exhibited the highest occurrence frequency. (3) The karst drainage basins in Southern China experienced extremely complex variability of hydrologic droughts from 1970s to 2010s. Drought intensity and occurrence frequency significantly vary for different types of hydrology.

The Induction of Mental and Contact Contamination

ERIC Educational Resources Information Center

Lee, Michelle; Shafran, Roz; Burgess, Charlotte; Carpenter, Jodi; Millard, Emma; Thorpe, Susan

2013-01-01

Background: Extreme fear of contamination within obsessive compulsive disorder (OCD) is traditionally conceptualised as a physical phenomenon. More recent research has supported the notion of "mental" contamination (MC) in which people feel contaminated in the absence of physical contact. The current research sought to determine whether…

Extreme temperatures in Southeast Asia caused by El Niño and worsened by global warming

NASA Astrophysics Data System (ADS)

Thirumalai, Kaustubh; Dinezio, Pedro N.; Okumura, Yuko; Deser, Clara

2017-06-01

In April 2016, southeast Asia experienced surface air temperatures (SATs) that surpassed national records, exacerbated energy consumption, disrupted agriculture and caused severe human discomfort. Here we show using observations and an ensemble of global warming simulations the combined impact of the El Niño/Southern Oscillation (ENSO) phenomenon and long-term warming on regional SAT extremes. We find a robust relationship between ENSO and southeast Asian SATs wherein virtually all April extremes occur during El Niño years. We then quantify the relative contributions of long-term warming and the 2015-16 El Niño to the extreme April 2016 SATs. The results indicate that global warming increases the likelihood of record-breaking April extremes where we estimate that 29% of the 2016 anomaly was caused by warming and 49% by El Niño. These post-Niño Aprils can potentially be anticipated a few months in advance, and thus, help societies prepare for the projected continued increases in extremes.

Extreme temperatures in Southeast Asia caused by El Niño and worsened by global warming.

PubMed

Thirumalai, Kaustubh; DiNezio, Pedro N; Okumura, Yuko; Deser, Clara

2017-06-06

In April 2016, southeast Asia experienced surface air temperatures (SATs) that surpassed national records, exacerbated energy consumption, disrupted agriculture and caused severe human discomfort. Here we show using observations and an ensemble of global warming simulations the combined impact of the El Niño/Southern Oscillation (ENSO) phenomenon and long-term warming on regional SAT extremes. We find a robust relationship between ENSO and southeast Asian SATs wherein virtually all April extremes occur during El Niño years. We then quantify the relative contributions of long-term warming and the 2015-16 El Niño to the extreme April 2016 SATs. The results indicate that global warming increases the likelihood of record-breaking April extremes where we estimate that 29% of the 2016 anomaly was caused by warming and 49% by El Niño. These post-Niño Aprils can potentially be anticipated a few months in advance, and thus, help societies prepare for the projected continued increases in extremes.

Academic Procrastination in Non-Traditional College Students

ERIC Educational Resources Information Center

Garzón-Umerenkova, Angélica; Gil-Flores, Javier

2017-01-01

Introduction: Procrastination is the act of delaying necessary tasks to the extreme of experiencing discomfort and negative consequences for the individuals. The presence of nontraditional students at universities is a phenomenon which has increased remarkably over the last decades. This type of university students finds some difficulties during…

Herpes simplex virus following stab phlebectomy.

PubMed

Hicks, Caitlin W; Lum, Ying Wei; Heller, Jennifer A

2017-03-01

Herpes simplex virus infection following surgery is an unusual postoperative phenomenon. Many mechanisms have been suggested, with the most likely explanation related to latent virus reactivation due to a proinflammatory response in the setting of local trauma. Here, we present a case of herpes simplex virus reactivation in an immunocompetent female following a conventional right lower extremity stab phlebectomy. Salient clinical and physical examination findings are described, and management strategies for herpes simplex virus reactivation are outlined. This is the first known case report of herpes simplex virus reactivation following lower extremity phlebectomy.

Overshoot in biological systems modelled by Markov chains: a non-equilibrium dynamic phenomenon.

PubMed

Jia, Chen; Qian, Minping; Jiang, Daquan

2014-08-01

A number of biological systems can be modelled by Markov chains. Recently, there has been an increasing concern about when biological systems modelled by Markov chains will perform a dynamic phenomenon called overshoot. In this study, the authors found that the steady-state behaviour of the system will have a great effect on the occurrence of overshoot. They showed that overshoot in general cannot occur in systems that will finally approach an equilibrium steady state. They further classified overshoot into two types, named as simple overshoot and oscillating overshoot. They showed that except for extreme cases, oscillating overshoot will occur if the system is far from equilibrium. All these results clearly show that overshoot is a non-equilibrium dynamic phenomenon with energy consumption. In addition, the main result in this study is validated with real experimental data.

25. Ischemic pain in the extremities and Raynaud's phenomenon.

PubMed

Devulder, Jacques; van Suijlekom, Hans; van Dongen, Robert; Diwan, Sudhir; Mekhail, Nagy; van Kleef, Maarten; Huygen, Frank

2011-01-01

Two important groups of disorders result from an insufficient blood supply to the extremities: critical vascular disease and the Raynaud's phenomenon. The latter can be subdivided into a primary and a secondary type. Critical ischemic disease is often caused by arteriosclerosis due to hypertension or diabetes. Primary Raynaud's is idiopathic and will be diagnosed as such if underlying systemic pathology has been excluded. Secondary Raynaud's is often a manifestation of a systemic disease. It is essential to try to establish a diagnosis as soon as possible in order to influence the evolution of the disease. A sympathetic nerve block can be considered in patients with critical ischemic vascular disease after extensive conservative treatment, preferably in the context of a study (2B±). If this has insufficient effect, spinal cord stimulation can be considered in a selected patient group (2B±). In view of the degree of invasiveness and the costs involved, this treatment should preferably be applied in the context of a study and with the use of transcutaneous pO(2) measurements. In case of primary Raynaud's, life style changes are the first step. Sympathectomy can be considered as a treatment of Raynaud's phenomenon (2C+), but only after multidisciplinary evaluation of the patient and in close consultation with the patient's rheumatologist, vascular surgeon or internist. © 2011 The Authors. Pain Practice © 2011 World Institute of Pain.

A Practical Measure for the Complexity of Evolving Seismicity Patterns

NASA Astrophysics Data System (ADS)

Goltz, C.

2005-12-01

Earthquakes are a "complex" phenomenon. There is, however, no clear definition of what complexity actually is. Yet, it is important to distinguish between what is merely complicated and what is complex in the sense that simple rules can give rise to very rich behaviour. Seismicity is certainly a complicated phenomenon (difficult to understand) but simple models such as cellular automata indicate that earthquakes are truly complex. From the observational point of view, there exists the problem of quantification of complexity in real world seismicity patterns. Such a measurement is desirable, not only for fundamental understanding but also for monitoring and possibly for forecasting. Maybe the most workable definitions of complexity exist in informatics, summarised under the topic of algorithmic complexity. Here, after introducing the concepts, I apply such a measure of complexity to temporally evolving real-world seismicity patterns. Finally, I discuss the usefulness of the approach and regard the results in view of the occurrence of large earthquakes.

Decreasing Math Anxiety in College Students

ERIC Educational Resources Information Center

Perry, Andrew B.

2004-01-01

This paper examines the phenomenon of mathematics anxiety in contemporary college and university students. Forms of math anxiety range from moderate test anxiety to extreme anxiety including physiological symptoms such as nausea. For each of several types of math anxiety, one or more case studies is analyzed. Selected strategies for coping with…

Global climate anomalies and potential infectious disease risks: 2014-2015

USDA-ARS?s Scientific Manuscript database

Background: The El Niño/Southern Oscillation (ENSO) is a global climate phenomenon that impacts human infectious disease risk worldwide through droughts, floods, and other climate extremes. Throughout summer and fall 2014, El Niño Watch, issued by the US National Oceanic and Atmospheric Administrat...

Pore-water pressures associated with clogging of soil pipes: Numerical analysis of laboratory experiments

USDA-ARS?s Scientific Manuscript database

Clogging of soil pipes due to excessive internal erosion has been hypothesized to cause extreme erosion events such as landslides, debris flows, and gullies, but confirmation of this phenomenon has been lacking. Laboratory and field measurements have failed to measure pore water pressures within pip...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Portone, Teresa; Niederhaus, John Henry; Sanchez, Jason James

This report introduces the concepts of Bayesian model selection, which provides a systematic means of calibrating and selecting an optimal model to represent a phenomenon. This has many potential applications, including for comparing constitutive models. The ideas described herein are applied to a model selection problem between different yield models for hardened steel under extreme loading conditions.

Eclogitization on the way up: Lu-Hf garnet chronology of metasomatic ultrahigh-pressure rocks from the Western Gneiss Complex, Norway

NASA Astrophysics Data System (ADS)

Cutts, J.; Smit, M. A.; Vrijmoed, J. C.

2016-12-01

The Western Gneiss Complex (WGC) is a fragment of continental crust that was subjected to high- and ultrahigh pressure (HP; UHP) conditions as a result of Caledonian continental collision (420-400 Ma). Most eclogite lenses and related high-pressure rocks have yielded petrological and chronological results that are consistent with a generalized model of Caledonian continental subduction. A distinct suite of eclogitic rocks - metasomatized (`Caledonized') Fe-Ti meta-peridotites - indicate extreme pressure conditions that do not fit the regional field gradient. The timing of these excursions is critical to their interpretation; however, so far limited age constraints exist for these rocks. In this study, we subject one such rock - the Magerøy orthopyroxene eclogite on the island of Otrøy - to Lu-Hf garnet chronology; a method that provides precise and robust data for garnet even at extreme temperatures. Conventional barometry indicates equilibration of the main garnet-bearing assemblage at c. 4.3 GPa and garnet geochronology yielded a date of c. 390 Ma. This result overlaps with Sm-Nd garnet and U-Pb zircon ages from the nearby diamond-bearing Svartberget peridotite body and leucosomes in its host gneiss. However, the age is ≥ 10 Ma younger than age data for most other eclogite lenses in WGC and corresponds to a time when the terrane was already exhumed to 30-35 km depth. The discrepancy in P-T-t evolution between the bulk of the WGC, and the (ultra-) mafic rocks at Magerøy and Svartberget indicates that the latter rocks reflect localized fluid-induced re-equilibration at pressures higher than lithostatic. The new data provide new support for the occurrence of this phenomenon in subducted continental crust undergoing exhumation and partial melting.

Application of EEM fluorescence spectroscopy in understanding of the "LIGA" phenomenon in the Bay of Biscay (France)

NASA Astrophysics Data System (ADS)

Parot, Jérémie; Susperregui, Nicolas; Rouaud, Vanessa; Dubois, Laurent; Anglade, Nathalie; Parlanti, Edith

2014-05-01

Marine mucilage is present in all oceans over the world, and in particular in the Mediterranean Sea and in the Pacific Ocean. Surface water warming and hydrodynamic processes can favor the coalescence of marine mucilage, large marine aggregates representing an ephemeral and extreme habitat for biota. DOM is a heterogeneous, complex mixture of compounds, including extracellular polymeric substances (EPS), with wide ranging chemical properties and it is well known to interact with pollutants and to affect their transport and their fate in aquatic environment. The LIGA French research program focuses on tracing colloidal dissolved organic matter (DOM) sources and cycling in the Bay of Biscay (South Western French coast). This ephemeral phenomenon (called "LIGA" in the South West of France) has been observed more than 750 times since 2010. It presents a great ecological impact on marine ecosystems and has been shown to be concomitant with the development of pathogen organisms. A one-year intensive survey of fluorescent DOM was undertaken. From April 2013 until May 2014, water samples were monthly collected from the Adour River (main fresh water inputs) and from 2 sites in the Bay of Biscay at 3 depths of the water column (surface water, at the maximum of chlorophyll-a, and deep water). Moreover, intensified samplings took place from the appearance of the phenomenon twice a week during 4 weeks. UV/visible absorbance and excitation emission matrix (EEM) fluorescence spectroscopy combined with PARAFAC and PCA analyses have been used to characterize colloidal DOM in the Bay of Biscay in order to estimate DOM sources as well as spatial and temporal variability of DOM properties. The preliminary results, obtained for about 70 samples of this survey, have already highlighted spatial and temporal variations of DOM optical properties and a peculiar fluorescent component (exc300nm/em338nm) was detected while the LIGA phenomenon arises. The appearance of this specific fluorescence signal seems to be correlated with high freshwater and terrestrial DOM inputs combined with physical forcing (flows, swell) as well as a rise in temperature and sunshine. This work already allowed us to identify different sources of colloidal DOM in the Bay of Biscay and highlighted a specific fingerprint of the LIGA phenomenon. The combination of EEM fluorescence spectroscopy with PARAFAC and PCA analyses appears thus to be a very powerful tool for the long term monitoring of such a phenomenon and would be very useful for a better understanding of the biogeochemical processes in marine environments and of the marine colloidal DOM ecodynamics.

Concept "Medical Museum" as a Sociocultural Phenomenon

ERIC Educational Resources Information Center

Chizh, Nina V.; Slyshkin, Gennady G.; Zheltukhina, Marina R.; Privalova, Irina V.; Kravchenko, Olga A.

2016-01-01

The article examines the concept "medical museum" as a sociocultural phenomenon. The register of medical museums in Russia makes the material of research. The complex methods of analysis of the concept "medical museum" are used. The philosophical, historical, cultural, structural, communicative and semantic analysis is carried…

Beyond the Accusation of Plagiarism

ERIC Educational Resources Information Center

Gu, Qing; Brooks, Jane

2008-01-01

The paper explores the complexity of the notion of plagiarism from sociocultural and psychological perspectives. Plagiarism is a dynamic and multi-layered phenomenon [Russikoff, K., Fucaloro, L., Salkauskiene, D., 2003. "Plagiarism as a cross-cultural phenomenon." "The CAL Poly Pomona Journal of Interdisciplinary Studies" 16, 109-120.…

Hydrogen environment embrittlement of metals

NASA Technical Reports Server (NTRS)

Jewett, R. P.; Walter, R. J.; Chandler, W. T.; Frohmberg, R. P.

1973-01-01

Hydrogen environment embrittlement refers to metals stressed while exposed to a hydrogen atmosphere. Tested in air, even after exposure to hydrogen under pressure, this effect is not observed on similar specimens. Much high purity hydrogen is prepared by evaporation of liquid hydrogen, and thus has low levels for potential impurities which could otherwise inhibit or poison the absorbent reactions that are involved. High strength steels and nickel-base allows are rated as showing extreme embrittlement; aluminum alloys and the austenitic stainless steels, as well as copper, have negligible susceptibility to this phenomenon. The cracking that occurs appears to be a surface phenomenon, is unlike that of internal hydrogen embrittlement.

Extreme values and fat tails of multifractal fluctuations

NASA Astrophysics Data System (ADS)

Muzy, J. F.; Bacry, E.; Kozhemyak, A.

2006-06-01

In this paper we discuss the problem of the estimation of extreme event occurrence probability for data drawn from some multifractal process. We also study the heavy (power-law) tail behavior of probability density function associated with such data. We show that because of strong correlations, the standard extreme value approach is not valid and classical tail exponent estimators should be interpreted cautiously. Extreme statistics associated with multifractal random processes turn out to be characterized by non-self-averaging properties. Our considerations rely upon some analogy between random multiplicative cascades and the physics of disordered systems and also on recent mathematical results about the so-called multifractal formalism. Applied to financial time series, our findings allow us to propose an unified framework that accounts for the observed multiscaling properties of return fluctuations, the volatility clustering phenomenon and the observed “inverse cubic law” of the return pdf tails.

Extreme value laws for fractal intensity functions in dynamical systems: Minkowski analysis

NASA Astrophysics Data System (ADS)

Mantica, Giorgio; Perotti, Luca

2016-09-01

Typically, in the dynamical theory of extremal events, the function that gauges the intensity of a phenomenon is assumed to be convex and maximal, or singular, at a single, or at most a finite collection of points in phase-space. In this paper we generalize this situation to fractal landscapes, i.e. intensity functions characterized by an uncountable set of singularities, located on a Cantor set. This reveals the dynamical rôle of classical quantities like the Minkowski dimension and content, whose definition we extend to account for singular continuous invariant measures. We also introduce the concept of extremely rare event, quantified by non-standard Minkowski constants and we study its consequences to extreme value statistics. Limit laws are derived from formal calculations and are verified by numerical experiments. Dedicated to the memory of Joseph Ford, on the twentieth anniversary of his departure.

Extreme temperatures in Southeast Asia caused by El Niño and worsened by global warming

PubMed Central

Thirumalai, Kaustubh; DiNezio, Pedro N.; Okumura, Yuko; Deser, Clara

2017-01-01

In April 2016, southeast Asia experienced surface air temperatures (SATs) that surpassed national records, exacerbated energy consumption, disrupted agriculture and caused severe human discomfort. Here we show using observations and an ensemble of global warming simulations the combined impact of the El Niño/Southern Oscillation (ENSO) phenomenon and long-term warming on regional SAT extremes. We find a robust relationship between ENSO and southeast Asian SATs wherein virtually all April extremes occur during El Niño years. We then quantify the relative contributions of long-term warming and the 2015–16 El Niño to the extreme April 2016 SATs. The results indicate that global warming increases the likelihood of record-breaking April extremes where we estimate that 29% of the 2016 anomaly was caused by warming and 49% by El Niño. These post-Niño Aprils can potentially be anticipated a few months in advance, and thus, help societies prepare for the projected continued increases in extremes. PMID:28585927

Narcissists’ social pain seen only in the brain

PubMed Central

Konrath, Sara H.; Falk, Emily B.

2015-01-01

Narcissism is a complex phenomenon, involving a level of defensive self-enhancement. Narcissists have avoidant attachment styles, maintain distance in relationships and claim not to need others. However, they are especially sensitive to others’ evaluations, needing positive reflected appraisals to maintain their inflated self-views, and showing extreme responses (e.g. aggression) when rejected. The current study tested the hypothesis that narcissists also show hypersensitivity in brain systems associated with distress during exclusion. We measured individual differences in narcissism (Narcissistic Personality Inventory) and monitored neural responses to social exclusion (Cyberball). Narcissism was significantly associated with activity in an a priori anatomically defined social pain network (anterior insula, dorsal anterior cingulate cortex and subgenual anterior cingulate cortex) during social exclusion. Results suggest hypersensitivity to exclusion in narcissists may be a function of hypersensitivity in brain systems associated with distress, and suggests a potential pathway that connects narcissism to negative consequences for longer-term physical and mental health—findings not apparent with self-report alone. PMID:24860084

Extreme fluctuations in stochastic network coordination with time delays

NASA Astrophysics Data System (ADS)

Hunt, D.; Molnár, F.; Szymanski, B. K.; Korniss, G.

2015-12-01

We study the effects of uniform time delays on the extreme fluctuations in stochastic synchronization and coordination problems with linear couplings in complex networks. We obtain the average size of the fluctuations at the nodes from the behavior of the underlying modes of the network. We then obtain the scaling behavior of the extreme fluctuations with system size, as well as the distribution of the extremes on complex networks, and compare them to those on regular one-dimensional lattices. For large complex networks, when the delay is not too close to the critical one, fluctuations at the nodes effectively decouple, and the limit distributions converge to the Fisher-Tippett-Gumbel density. In contrast, fluctuations in low-dimensional spatial graphs are strongly correlated, and the limit distribution of the extremes is the Airy density. Finally, we also explore the effects of nonlinear couplings on the stability and on the extremes of the synchronization landscapes.

Analysis of the Effects of ENSO and Atmospheric Rivers on Precipitation in Los Angeles County

NASA Astrophysics Data System (ADS)

Santacruz, A.; Lamb, K.

2017-12-01

The Winter 2016-2017 season in California was marked by substantial amounts of precipitation; this resulted in critically-low reservoirs filling up and the removal of most of California from drought status. The year prior was characterized by one of the strongest El Nino-Southern Oscillation (ENSO) events, though it did not produce nearly enough precipitation as the 2016-2017 season. The major contributors to the increased rainfall during the 2016-2017 season were climactic phenomenon known as atmospheric rivers (ARs), which transport water vapor through the atmosphere in narrow bands, and are known to produce extreme rain events. Determining the exact timing, landfall areas, and total precipitation amounts of ARs is currently of great interest; a recent study showed that extreme weather events are likely to increase in California in the coming years, which motivates research into how phenomenon such as ENSO and ARs play a role. Using long-term daily rain gauge data provided by the Los Angeles County Department of Public Works, we compute the precipitation volume and storm count for various locations in Los Angeles County and identify anomalies. These data will then be compared with the occurrence and intensity of AR and ENSO events by using NOAA's NOI and ESRL AR data. The results can be used to provide a better grasp of extreme climactic patterns and their effects on the amount of precipitation in the region.

Variations of trends of indicators describing complex systems: Change of scaling precursory to extreme events

NASA Astrophysics Data System (ADS)

Keilis-Borok, V. I.; Soloviev, A. A.

2010-09-01

Socioeconomic and natural complex systems persistently generate extreme events also known as disasters, crises, or critical transitions. Here we analyze patterns of background activity preceding extreme events in four complex systems: economic recessions, surges in homicides in a megacity, magnetic storms, and strong earthquakes. We use as a starting point the indicators describing the system's behavior and identify changes in an indicator's trend. Those changes constitute our background events (BEs). We demonstrate a premonitory pattern common to all four systems considered: relatively large magnitude BEs become more frequent before extreme event. A premonitory change of scaling has been found in various models and observations. Here we demonstrate this change in scaling of uniformly defined BEs in four real complex systems, their enormous differences notwithstanding.

An Interesting Case of Basal Cell Carcinoma with Raynaud's Phenomenon Following Chronic Arsenic Exposure.

PubMed

Gulshan, S; Rahman, M J; Sarkar, R; Ghosh, S; Hazra, R

2016-01-01

Arsenic is commonly known to be associated with squamous cell carcinoma. Among the lesser known associations is basal cell carcinoma and even rarer is its effect on blood vessels causing peripheral vascular disease. Here we present a case of a 55 yr old man with ulceroproliferative lesions on scalp and forehead along with several hyperpigmented patches on trunk and extremities. He had symptoms suggestive of Raynaud's phenomenon that eventually led to digital gangrene. FNAC was done which was suggestive of basal cell carcinoma. On further enquiry, he was found to reside in an arsenic endemic zone and was investigated for blood arsenic level which was elevated. Punch biopsy from different lesions from body confirmed nodular basal cell carcinoma. Presently the patient has stopped drinking water from the local tubewell. On follow-up he shows improvement of Raynaud's phenomenon and skin lesions.

Is there a Greater Role for Prime Numbers in our Schools?

ERIC Educational Resources Information Center

Cairns, Grant

2005-01-01

Prime numbers play an extremely important role in modern mathematics. Apart from still being the object of intense research activity, their applications in banking and security underline a key phenomenon: in the modern world, useful applications of mathematics often come from very "pure" abstract theories. Curiously, despite their undeniable…

(Self) Evaluation of Knowledge in Students' Population in Higher Education in Macedonia

ERIC Educational Resources Information Center

Kevereski, Ljupco

2017-01-01

Students' assessment, in general, observed through a socio-historical prism, has always been treated as an extremely sensitive, current, significant, indicative and continuously present phenomenon. In that respect, what is especially relevant is that for a very long time docimological procedures and their effects have been focused on following…

INDICATORS OF UV EXPOSURE IN CORAL AND THEIR RELEVANCE TO GLOBAL CLIMATE CHANGE AND CORAL BLEACHING

EPA Science Inventory

A compelling aspect of the deterioration of coral reefs is the phenomenon of coral bleaching. Bleaching can destroy large areas of a reef with limited recovery or recruitment, and it may be induced by a variety of stressors ranging from exposure to temperature and salinity extrem...

Interplay between Insulin Signaling, Juvenile Hormone and Vitellogenin Regulates Maternal Effects on Polyphenism in Ants

USDA-ARS?s Scientific Manuscript database

Polyphenism is the phenomenon where alternative phenotypes are produced by a single genotype in response to environmental cues. An extreme case is found in social insects, where reproductive queens and sterile workers that greatly differ in morphology and behavior can arise from a single genotype. T...

On the Need for the Comparative Study of Communication: Some Conceptual and Methodological Considerations.

ERIC Educational Resources Information Center

Goetzinger, Charles; Rummel, Lynda

A comparative approach to the study of communication can be seen as extremely valuable for a thorough understanding of human communication. In its broadest sense, communication is a biological phenomenon, defined as the interchange of information between an organism and its environment. Communication systems of living organisms differ…

Seeing Like PISA: A Cautionary Tale about the Performativity of International Assessments

ERIC Educational Resources Information Center

Gorur, Radhika

2016-01-01

PISA is an extremely influential large-scale assessment, and its "policy lessons" are being incorporated in a range of nations all over the world. In this paper I argue that not only is PISA influencing policies and practices, but also that "seeing like PISA" is becoming a widespread phenomenon. Globally, education…

Workshop on Viability of Halophilic Bacteria in Salt Deposits

NASA Technical Reports Server (NTRS)

1997-01-01

The significance of finding viable extreme halophiles in halites associated with Permian-aged sedimentary deposits is considered. Issues related to the microbiology and geochemistry of the halite environment are addressed. Recommendations that related the significance of this phenomenon to NASA's interest in planetary exploration and the early evolution of life are provided.

Global patterns of drought recovery

Treesearch

Christopher R. Schwalm; William R. L. Anderegg; Anna M. Michalak; Joshua B. Fisher; Franco Biondi; George Koch; Marcy Litvak; Kiona Ogle; John D. Shaw; Adam Wolf; Deborah N. Huntzinger; Kevin Schaefer; Robert Cook; Yaxing Wei; Yuanyuan Fang; Daniel Hayes; Maoyi Huang; Atul Jain; Hanqin Tian

2017-01-01

Drought, a recurring phenomenon with major impacts on both human and natural systems is the most widespread climatic extreme that negatively affects the land carbon sink. Although twentieth-century trends in drought regimes are ambiguous, across many regions more frequent and severe droughts are expected in the twenty-first century. Recovery time - how long an...

Consumed Ischemia of Lower Limbs in the Newborn: A Case Report

PubMed Central

Hamid, Jiber; Rita, Hajji; Youssef, Zrihni; Abdellatif, Bouarhroum

2013-01-01

The limb ischemia is a rare phenomenon in the newborn. It is most often a postnatal ischemia secondary to arterial or venous catheterization, to neonatal infection. Maternal diabetes is most often implicated. The diagnosis implies an urgent situation which may result in extremity gangrene and ultimate loss of limb. PMID:24251263

Repression to Reform: Education in the Republic of Paraguay, 1811-1850.

ERIC Educational Resources Information Center

Cooney, Jerry W.

1983-01-01

A social question faced by Latin American countries when they gained their independence from Spain was that of education. An extreme example of the difficulties encountered can be found in Paraguay where education was affected by the events of independence and by a new phenomenon, the Spanish American dictator. (RM)

Information Technology (IT) and the Learning Society: Growth and Challenges

ERIC Educational Resources Information Center

Oguzor, Nkasiobi S.; Nosike, Austin N.; Opara, Jacinta A.

2011-01-01

There is no human culture which has never learned anything from another. Learning from other cultures is a natural phenomenon. There is nothing wrong with it. However, when foreign influence is overwhelming, beyond the control of the receiving country, psychological delicate problems emerge. This paper holds the view that the extremely rapid…

Teaching the Concept of Breakdown Point in Simple Linear Regression.

ERIC Educational Resources Information Center

Chan, Wai-Sum

2001-01-01

Most introductory textbooks on simple linear regression analysis mention the fact that extreme data points have a great influence on ordinary least-squares regression estimation; however, not many textbooks provide a rigorous mathematical explanation of this phenomenon. Suggests a way to fill this gap by teaching students the concept of breakdown…

Extreme events and natural hazards: The complexity perspective

NASA Astrophysics Data System (ADS)

Schultz, Colin

2012-10-01

Advanced societies have become quite proficient at defending against moderate-size earthquakes, hurricanes, floods, or other natural assaults. What still pose a significant threat, however, are the unknowns, the extremes, the natural phenomena encompassed by the upper tail of the probability distribution. Alongside the large or powerful events, truly extreme natural disasters are those that tie different systems together: an earthquake that causes a tsunami, which leads to flooding, which takes down a nuclear reactor. In the geophysical monograph Extreme Events and Natural Hazards: The Complexity Perspective, editors A. Surjalal Sharma, Armin Bunde, Vijay P. Dimro, and Daniel N. Baker present a lens through which such multidisciplinary phenomena can be understood. In this interview, Eos talks to Sharma about complexity science, predicting extreme events and natural hazards, and the push for "big data."

Accurate localization of organ representation areas on the feet & hands using the bi-digital O-ring test resonance phenomenon: its clinical implication in diagnosis & treatment--Part I.

PubMed

Omura, Y

1994-01-01

Accuracy of the widely used organ representation areas, currently used in different schools of foot and hand reflexology was evaluated using Bi-Digital O-Ring test resonance phenomenon. Our previous study indicated that mapping organ representation areas of the tongue using Bi-Digital O-Ring Test resonance phenomenon between 2 identical substances often provided more reliable clinical information for both diagnosis and treatment than the 2 widely used, but crude, traditional schools of Chinese tongue diagnosis. This same method was applied for the mapping of the organ representation areas on the feet and hands. We succeeded in mapping the following areas on human feet: 1) Middle (3rd) toe on the sole side represents the following starting from the tip: A) Head, B) Face with eye, ear, nose, and mouth (1st Digit) C) Neck and organs within the neck (narrow band of space between 1st crease after the 1st digit and crease at the junction of the beginning of the sole); 2) 2nd and 4th toe represent upper extremities, the beginning tip being fingers and hands. The crease at the base of these toes represents the shoulder. The 2nd toe represents right upper extremity, and the 4th toe represents left upper extremity; 3) 1st and 5th toes in both the right and left feet represent lower extremities with the tip being the toes and soles of feet. The crease at the base of these toes represents the inguinal area. The 1st toe of each foot represents right lower extremity, and 5th toe represents left lower extremity. The sole of the foot is divided into the following 3 distinctive sections. 1) Upper (1st) section represents organs in the chest cavity including 2 thymus glands, trachea, 2 lungs, with the heart between them, and with the esophagus appearing as a narrow band outside of the lung near and below the 1st and 2nd toe depending upon the individual. Chest section occupies the first 1/3 to 1/5 (on a relatively long foot) of the entire sole. The boundary between the chest and G.I. system can be approximately estimated by extending the length of the entire toe or up to 25% longer to the sole, but it can be accurately determined using a diaphragm tissue microscope slide as a reference control substance. 2) Middle (2nd) section represents Gastro-Intestinal system, including lower end of the esophagus, liver, stomach, spleen, gall bladder, pancreas, duodenum, jejunum, ileum, appendix, colon, and anus.(ABSTRACT TRUNCATED AT 400 WORDS)

Genetics of Rapid and Extreme Size Evolution in Island Mice

PubMed Central

Gray, Melissa M.; Parmenter, Michelle D.; Hogan, Caley A.; Ford, Irene; Cuthbert, Richard J.; Ryan, Peter G.; Broman, Karl W.; Payseur, Bret A.

2015-01-01

Organisms on islands provide a revealing window into the process of adaptation. Populations that colonize islands often evolve substantial differences in body size from their mainland relatives. Although the ecological drivers of this phenomenon have received considerable attention, its genetic basis remains poorly understood. We use house mice (subspecies: Mus musculus domesticus) from remote Gough Island to provide a genetic portrait of rapid and extreme size evolution. In just a few hundred generations, Gough Island mice evolved the largest body size among wild house mice from around the world. Through comparisons with a smaller-bodied wild-derived strain from the same subspecies (WSB/EiJ), we demonstrate that Gough Island mice achieve their exceptional body weight primarily by growing faster during the 6 weeks after birth. We use genetic mapping in large F2 intercrosses between Gough Island mice and WSB/EiJ to identify 19 quantitative trait loci (QTL) responsible for the evolution of 16-week weight trajectories: 8 QTL for body weight and 11 QTL for growth rate. QTL exhibit modest effects that are mostly additive. We conclude that body size evolution on islands can be genetically complex, even when substantial size changes occur rapidly. In comparisons to published studies of laboratory strains of mice that were artificially selected for divergent body sizes, we discover that the overall genetic profile of size evolution in nature and in the laboratory is similar, but many contributing loci are distinct. Our results underscore the power of genetically characterizing the entire growth trajectory in wild populations and lay the foundation necessary for identifying the mutations responsible for extreme body size evolution in nature. PMID:26199233

Genetics of Rapid and Extreme Size Evolution in Island Mice.

PubMed

Gray, Melissa M; Parmenter, Michelle D; Hogan, Caley A; Ford, Irene; Cuthbert, Richard J; Ryan, Peter G; Broman, Karl W; Payseur, Bret A

2015-09-01

Organisms on islands provide a revealing window into the process of adaptation. Populations that colonize islands often evolve substantial differences in body size from their mainland relatives. Although the ecological drivers of this phenomenon have received considerable attention, its genetic basis remains poorly understood. We use house mice (subspecies: Mus musculus domesticus) from remote Gough Island to provide a genetic portrait of rapid and extreme size evolution. In just a few hundred generations, Gough Island mice evolved the largest body size among wild house mice from around the world. Through comparisons with a smaller-bodied wild-derived strain from the same subspecies (WSB/EiJ), we demonstrate that Gough Island mice achieve their exceptional body weight primarily by growing faster during the 6 weeks after birth. We use genetic mapping in large F(2) intercrosses between Gough Island mice and WSB/EiJ to identify 19 quantitative trait loci (QTL) responsible for the evolution of 16-week weight trajectories: 8 QTL for body weight and 11 QTL for growth rate. QTL exhibit modest effects that are mostly additive. We conclude that body size evolution on islands can be genetically complex, even when substantial size changes occur rapidly. In comparisons to published studies of laboratory strains of mice that were artificially selected for divergent body sizes, we discover that the overall genetic profile of size evolution in nature and in the laboratory is similar, but many contributing loci are distinct. Our results underscore the power of genetically characterizing the entire growth trajectory in wild populations and lay the foundation necessary for identifying the mutations responsible for extreme body size evolution in nature. Copyright © 2015 by the Genetics Society of America.

A Fast SVD-Hidden-nodes based Extreme Learning Machine for Large-Scale Data Analytics.

PubMed

Deng, Wan-Yu; Bai, Zuo; Huang, Guang-Bin; Zheng, Qing-Hua

2016-05-01

Big dimensional data is a growing trend that is emerging in many real world contexts, extending from web mining, gene expression analysis, protein-protein interaction to high-frequency financial data. Nowadays, there is a growing consensus that the increasing dimensionality poses impeding effects on the performances of classifiers, which is termed as the "peaking phenomenon" in the field of machine intelligence. To address the issue, dimensionality reduction is commonly employed as a preprocessing step on the Big dimensional data before building the classifiers. In this paper, we propose an Extreme Learning Machine (ELM) approach for large-scale data analytic. In contrast to existing approaches, we embed hidden nodes that are designed using singular value decomposition (SVD) into the classical ELM. These SVD nodes in the hidden layer are shown to capture the underlying characteristics of the Big dimensional data well, exhibiting excellent generalization performances. The drawback of using SVD on the entire dataset, however, is the high computational complexity involved. To address this, a fast divide and conquer approximation scheme is introduced to maintain computational tractability on high volume data. The resultant algorithm proposed is labeled here as Fast Singular Value Decomposition-Hidden-nodes based Extreme Learning Machine or FSVD-H-ELM in short. In FSVD-H-ELM, instead of identifying the SVD hidden nodes directly from the entire dataset, SVD hidden nodes are derived from multiple random subsets of data sampled from the original dataset. Comprehensive experiments and comparisons are conducted to assess the FSVD-H-ELM against other state-of-the-art algorithms. The results obtained demonstrated the superior generalization performance and efficiency of the FSVD-H-ELM. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

NASA Astrophysics Data System (ADS)

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

2013-12-01

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

Statistical Extremes of Turbulence and a Cascade Generalisation of Euler's Gyroscope Equation

NASA Astrophysics Data System (ADS)

Tchiguirinskaia, Ioulia; Scherzer, Daniel

2016-04-01

Turbulence refers to a rather well defined hydrodynamical phenomenon uncovered by Reynolds. Nowadays, the word turbulence is used to designate the loss of order in many different geophysical fields and the related fundamental extreme variability of environmental data over a wide range of scales. Classical statistical techniques for estimating the extremes, being largely limited to statistical distributions, do not take into account the mechanisms generating such extreme variability. An alternative approaches to nonlinear variability are based on a fundamental property of the non-linear equations: scale invariance, which means that these equations are formally invariant under given scale transforms. Its specific framework is that of multifractals. In this framework extreme variability builds up scale by scale leading to non-classical statistics. Although multifractals are increasingly understood as a basic framework for handling such variability, there is still a gap between their potential and their actual use. In this presentation we discuss how to dealt with highly theoretical problems of mathematical physics together with a wide range of geophysical applications. We use Euler's gyroscope equation as a basic element in constructing a complex deterministic system that preserves not only the scale symmetry of the Navier-Stokes equations, but some more of their symmetries. Euler's equation has been not only the object of many theoretical investigations of the gyroscope device, but also generalised enough to become the basic equation of fluid mechanics. Therefore, there is no surprise that a cascade generalisation of this equation can be used to characterise the intermittency of turbulence, to better understand the links between the multifractal exponents and the structure of a simplified, but not simplistic, version of the Navier-Stokes equations. In a given way, this approach is similar to that of Lorenz, who studied how the flap of a butterfly wing could generate a cyclone with the help of a 3D ordinary differential system. Being well supported by the extensive numerical results, the cascade generalisation of Euler's gyroscope equation opens new horizons for predictability and predictions of processes having long-range dependences.

Design and Mechanical Stability Analysis of the Interaction Region for the Inverse Compton Scattering Gamma-Ray Source Using Finite Element Method

NASA Astrophysics Data System (ADS)

Khizhanok, Andrei

Development of a compact source of high-spectral brilliance and high impulse frequency gamma rays has been in scope of Fermi National Accelerator Laboratory for quite some time. Main goal of the project is to develop a setup to support gamma rays detection test and gamma ray spectroscopy. Potential applications include but not limited to nuclear astrophysics, nuclear medicine, oncology ('gamma knife'). Present work covers multiple interconnected stages of development of the interaction region to ensure high levels of structural strength and vibrational resistance. Inverse Compton scattering is a complex phenomenon, in which charged particle transfers a part of its energy to a photon. It requires extreme precision as the interaction point is estimated to be 20 microm. The slightest deflection of the mirrors will reduce effectiveness of conversion by orders of magnitude. For acceptable conversion efficiency laser cavity also must have >1000 finesse value, which requires a trade-off between size, mechanical stability, complexity, and price of the setup. This work focuses on advantages and weak points of different designs of interaction regions as well as in-depth description of analyses performed. This includes laser cavity amplification and finesse estimates, natural frequency mapping, harmonic analysis. Structural analysis is required as interaction must occur under high vacuum conditions.

Porcine colonization of the Americas: a 60k SNP story

PubMed Central

Burgos-Paz, W; Souza, C A; Megens, H J; Ramayo-Caldas, Y; Melo, M; Lemús-Flores, C; Caal, E; Soto, H W; Martínez, R; Álvarez, L A; Aguirre, L; Iñiguez, V; Revidatti, M A; Martínez-López, O R; Llambi, S; Esteve-Codina, A; Rodríguez, M C; Crooijmans, R P M A; Paiva, S R; Schook, L B; Groenen, M A M; Pérez-Enciso, M

2013-01-01

The pig, Sus scrofa, is a foreign species to the American continent. Although pigs originally introduced in the Americas should be related to those from the Iberian Peninsula and Canary islands, the phylogeny of current creole pigs that now populate the continent is likely to be very complex. Because of the extreme climates that America harbors, these populations also provide a unique example of a fast evolutionary phenomenon of adaptation. Here, we provide a genome wide study of these issues by genotyping, with a 60k SNP chip, 206 village pigs sampled across 14 countries and 183 pigs from outgroup breeds that are potential founders of the American populations, including wild boar, Iberian, international and Chinese breeds. Results show that American village pigs are primarily of European ancestry, although the observed genetic landscape is that of a complex conglomerate. There was no correlation between genetic and geographical distances, neither continent wide nor when analyzing specific areas. Most populations showed a clear admixed structure where the Iberian pig was not necessarily the main component, illustrating how international breeds, but also Chinese pigs, have contributed to extant genetic composition of American village pigs. We also observe that many genes related to the cardiovascular system show an increased differentiation between altiplano and genetically related pigs living near sea level. PMID:23250008

Causes and characteristics of the street child phenomenon: a global perspective.

PubMed

le Roux, J; Smith, C S

1998-01-01

The street child phenomenon is an alarming and escalating worldwide problem. Street children are maltreated, imprisoned and, in some countries, killed. Street children, as the offspring of complex contemporary urban environments, represent one of our most serious global challenges. This article investigates the causes of this phenomenon, as well as the characteristics of street children throughout the world. In addition, the specific circumstances of street children in Nepal, Indonesia, India, Latin America, and the Philippines are discussed.

Kinesiology and Learning: Implications for Turkish School Curriculum

ERIC Educational Resources Information Center

Ozar, Mirac

2013-01-01

Learning is a complex phenomenon and multi-faceted in nature. There are a number of parameters which influence learning cycle and the process in general. Physical exercise is thought to be one of the variants that affect the learning phenomenon. Accumulated scientific evidence can be found in the literature showing high correlations between…

Approach to the Phenomenon of M-Learning in English Teaching

ERIC Educational Resources Information Center

García, Sergio; Fombona, Javier

2015-01-01

This research analyzes the situation of mobile devices and some specific options of support for the teaching of the English language. The features of this complex and novel phenomenon of Mobile-Assisted Language Learning (MALL) are addressed with an exploratory descriptive methodology. The article is part of a more extensive research which deals…

Revisiting First Language Acquisition through Empirical and Rational Perspectives

ERIC Educational Resources Information Center

Tahriri, Abdorreza

2012-01-01

Acquisition in general and first language acquisition in particular is a very complex and a multifaceted phenomenon. The way that children acquire a language in a very limited period is astonishing. Various approaches have been proposed so far to account for this extraordinary phenomenon. These approaches are indeed based on various philosophical…

Whole Language as an Ecological Phenomenon: On Sustaining the Agonies of Innovative Language Arts Practices.

ERIC Educational Resources Information Center

Field, James C.; Jardine, David W.

In the area of language instruction, a network of ecological relationships exists among the teacher, the child, and the text--the sustaining and nurturing of these relationships is at the heart of whole language instruction. Moreover, this network of relationships falls prey to neither of the unsustainable extremities of "gericentrism"…

From Helicopter Parent to Valued Partner: Shaping the Parental Relationship for Student Success

ERIC Educational Resources Information Center

Cutright, Marc

2008-01-01

In this chapter, the author addresses one important issue of contemporary campus life: parental involvement in the lives of today's college students. There seems to be broad consensus that the institution-parent relationship is changing, and at its most extreme manifestations presents the helicopter parent phenomenon. However, it is important not…

Deep-subwavelength waveguiding via inhomogeneous second-harmonic generation.

PubMed

Roppo, Vito; Vincenti, Maria Antonietta; de Ceglia, Domenico; Scalora, Michael

2012-08-01

We theoretically investigate second-harmonic generation in extremely narrow, subwavelength semiconductor and dielectric waveguides. We discuss a guiding mechanism characterized by the inhibition of diffraction and the suppression of cutoff limits in the context of a light trapping phenomenon that sets in under conditions of general phase and group velocity mismatch between the fundamental and the generated harmonic.

Polyuria with sevoflurane administration: a case report.

PubMed

Schirle, Lori

2011-02-01

Polyuria has been reported as a side effect of sevoflurane administration, but because of its relative rarity, many practitioners are not aware of this potential phenomenon. Polyuria in its extreme form can cause undesirable hemodynamic changes. A case study, in an 18-year-old man, is presented highlighting polyuria as a probable side effect of sevoflurane administration.

The Educational Environment as a Means for Overcoming Youth Extremism

ERIC Educational Resources Information Center

Panina, G. V.

2010-01-01

During Russia's societal transition extremist behavior by young people shows signs of increasing. An extra effort is required on the part of Russian educators to try to contain this phenomenon. The increasing extremist activity on the part of young people is linked to a particular stage of the development of society. It appears that youth…

A Descriptive Study of the Behavior and Personality Characteristics of Adolescent Runaways Using the Personality Inventory for Children.

ERIC Educational Resources Information Center

Rohr, Michael E.

The phenomenon of adolescent runaway behavior is of critical concern to mental health professionals. Conceptualization, prediction, and treatment interventions are of extreme importance. This study sought to build upon prior research by using the Personality Inventory for Children (PIC). Previous research indicated that adolescent running away…

Signs of Autonomy: Facilitating Independence and Inquiry in Deaf Science Classrooms

ERIC Educational Resources Information Center

Kahn, Sami; Feldman, Allan; Cooke, Michele L.

2013-01-01

Deaf and hard of hearing (DHH) persons are underrepresented in the fields of science, technology, engineering, and mathematics (STEM). One of the major barriers to STEM careers is DHH students' extremely low college graduation rates. While social and literacy barriers play a critical role in this phenomenon, student autonomy has also been cited as…

Simple systems that exhibit self-directed replication

NASA Technical Reports Server (NTRS)

Reggia, James A.; Armentrout, Steven L.; Chou, Hui-Hsien; Peng, Yun

1993-01-01

Biological experience and intuition suggest that self-replication is an inherently complex phenomenon, and early cellular automata models support that conception. More recently, simpler computational models of self-directed replication called sheathed loops have been developed. It is shown here that 'unsheathing' these structures and altering certain assumptions about the symmetry of their components leads to a family of nontrivial self-replicating structures some substantially smaller and simpler than those previously reported. The dependence of replication time and transition function complexity on initial structure size, cell state symmetry, and neighborhood are examined. These results support the view that self-replication is not an inherently complex phenomenon but rather an emergent property arising from local interactions in systems that can be much simpler than is generally believed.

Hydroelectric power plant on a paper strip.

PubMed

Das, Sankha Shuvra; Kar, Shantimoy; Anwar, Tarique; Saha, Partha; Chakraborty, Suman

2018-05-03

We exploit the combinatorial advantage of electrokinetics and tortuosity of a cellulose-based paper network on laboratory grade filter paper for the development of a simple, inexpensive, yet extremely robust (shows constant performance for 12 days) 'paper-and-pencil'-based device for energy harvesting applications. We successfully achieve harvesting of a maximum output power of ∼640 pW in a single channel, while the same is significantly improved (by ∼100 times) with the use of a multichannel microfluidic array (maximum of up to 20 channels). Furthermore, we also provide theoretical insights into the observed phenomenon and show that the experimentally predicted trends agree well with our theoretical calculations. Thus, we envisage that such ultra-low cost devices may turn out to be extremely useful in energizing analytical microdevices in resource limited settings, for instance, in extreme point of care diagnostic applications.

Moving towards Multidimensional Evaluation of Teaching in Higher Education: A Study across Four Faculties

ERIC Educational Resources Information Center

Ghedin, Elisabetta; Aquario, Debora

2008-01-01

The article investigates the issue of teaching evaluation in higher education, providing a picture of the phenomenon into the Italian specific context within a European dimension. Starting from the premise that in Italian universities, teaching evaluation is based on general indicators which reflect a simplification of a complex phenomenon,…

Pedagogical Conditions for the Development of Students' Intellect within the Framework of the Research Culture

ERIC Educational Resources Information Center

Mizimbayeva, Almira; Ashirbayeva, Nazilya; Oralkenuly, Danabek; Sabyt, Taulanov

2016-01-01

The article presents different opinions for the concept of "research culture," gives the characteristics of this phenomenon from the point of view of the pedagogical science including the functions, components of this phenomenon; the article studies the complex of research skills as the basis of the research culture. Special attention is…

The Overshoot Phenomenon in Geodynamics Codes

NASA Astrophysics Data System (ADS)

Kommu, R. K.; Heien, E. M.; Kellogg, L. H.; Bangerth, W.; Heister, T.; Studley, E. H.

2013-12-01

The overshoot phenomenon is a common occurrence in numerical software when a continuous function on a finite dimensional discretized space is used to approximate a discontinuous jump, in temperature and material concentration, for example. The resulting solution overshoots, and undershoots, the discontinuous jump. Numerical simulations play an extremely important role in mantle convection research. This is both due to the strong temperature and stress dependence of viscosity and also due to the inaccessibility of deep earth. Under these circumstances, it is essential that mantle convection simulations be extremely accurate and reliable. CitcomS and ASPECT are two finite element based mantle convection simulations developed and maintained by the Computational Infrastructure for Geodynamics. CitcomS is a finite element based mantle convection code that is designed to run on multiple high-performance computing platforms. ASPECT, an adaptive mesh refinement (AMR) code built on the Deal.II library, is also a finite element based mantle convection code that scales well on various HPC platforms. CitcomS and ASPECT both exhibit the overshoot phenomenon. One attempt at controlling the overshoot uses the Entropy Viscosity method, which introduces an artificial diffusion term in the energy equation of mantle convection. This artificial diffusion term is small where the temperature field is smooth. We present results from CitcomS and ASPECT that quantify the effect of the Entropy Viscosity method in reducing the overshoot phenomenon. In the discontinuous Galerkin (DG) finite element method, the test functions used in the method are continuous within each element but are discontinuous across inter-element boundaries. The solution space in the DG method is discontinuous. FEniCS is a collection of free software tools that automate the solution of differential equations using finite element methods. In this work we also present results from a finite element mantle convection simulation implemented in FEniCS that investigates the effect of using DG elements in reducing the overshoot problem.

[The optimization of restoration approaches of advanced hand activity using the sensorial glove and the mCIMT method].

PubMed

Mozheiko, E Yu; Prokopenko, S V; Alekseevich, G V

To reason the choice of methods of restoration of advanced hand activity depending on severity of motor disturbance in the top extremity. Eighty-eight patients were randomized into 3 groups: 1) the mCIMT group, 2) the 'touch glove' group, 3) the control group. For assessment of physical activity of the top extremity Fugl-Meyer Assessment Upper Extremity, Nine-Hole Peg Test, Motor Assessment Scale were used. Assessment of non-use phenomenon was carried out with the Motor Activity Log scale. At a stage of severe motor dysfunction, there was a restoration of proximal departments of a hand in all groups, neither method was superior to the other. In case of moderate severity of motor deficiency of the upper extremity the most effective was the method based on the principle of biological feedback - 'a touch glove'. In the group with mild severity of motor dysfunction, the best recovery was achieved in the mCIMT group.

The rise of the mediocre forest: why chronically stressed trees may better survive extreme episodic climate variability

Treesearch

Steven G. McNulty; Johnny L. Boggs; Ge Sun

2014-01-01

Anthropogenic climate change is a relatively new phenomenon, largely occurring over the past 150 years, and much of the discussion on climate change impacts to forests has focused on long-term shifts in temperature and precipitation. However, individual trees respond to the much shorter impacts of climate variability. Historically, fast growing, fully canopied, non-...

Systemic sclerosis and sarcoidosis: a rare case of chronic intestinal pseudo-obstruction.

PubMed

Bernardo, Sónia; Gonçalves, Ana Rita; Araújo-Correia, Luís

2018-06-01

The coexistence of systemic sclerosis (SSc) and sarcoidosis is an extremely rare phenomenon; some studies question its existence. We report the case of a male with a diagnosis of sarcoidosis that was admitted due to abdominal distension and pain. After a thorough investigation, he was diagnosed with severe chronic intestinal pseudo-obstruction as a manifestation of SSc.

Impacts of urbanization on Indian summer monsoon rainfall extremes

NASA Astrophysics Data System (ADS)

Shastri, Hiteshri; Paul, Supantha; Ghosh, Subimal; Karmakar, Subhankar

2015-01-01

areas have different climatology with respect to their rural surroundings. Though urbanization is a worldwide phenomenon, it is especially prevalent in India, where urban areas have experienced an unprecedented rate of growth over the last 30 years. Here we take up an observational study to understand the influence of urbanization on the characteristics of precipitation (specifically extremes) in India. We identify 42 urban regions and compare their extreme rainfall characteristics with those of surrounding rural areas. We observe that, on an overall scale, the urban signatures on extreme rainfall are not prominently and consistently visible, but they are spatially nonuniform. Zonal analysis reveals significant impacts of urbanization on extreme rainfall in central and western regions of India. An additional examination, to understand the influences of urbanization on heavy rainfall climatology, is carried with station level data using a statistical method, quantile regression. This is performed for the most populated city of India, Mumbai, in pair with a nearby nonurban area, Alibaug; both having similar geographic location. The derived extreme rainfall regression quantiles reveal the sensitivity of extreme rainfall events to the increased urbanization. Overall the study identifies the climatological zones in India, where increased urbanization affects regional rainfall pattern and extremes, with a detailed case study of Mumbai. This also calls attention to the need of further experimental investigation, for the identification of the key climatological processes, in different regions of India, affected by increased urbanization.

How Do High School Students Solve Probability Problems? A Mixed Methods Study on Probabilistic Reasoning

ERIC Educational Resources Information Center

Heyvaert, Mieke; Deleye, Maarten; Saenen, Lore; Van Dooren, Wim; Onghena, Patrick

2018-01-01

When studying a complex research phenomenon, a mixed methods design allows to answer a broader set of research questions and to tap into different aspects of this phenomenon, compared to a monomethod design. This paper reports on how a sequential equal status design (QUAN ? QUAL) was used to examine students' reasoning processes when solving…

Beyond Self-Rated Health: The Adolescent Girl's Lived Experience of Health in Sweden

ERIC Educational Resources Information Center

Larsson, Margaretha; Sundler, Annelie Johansson; Ekebergh, Margaretha

2013-01-01

The aim of this phenomenological study was to describe the phenomenon of health as experienced by adolescent girls in Sweden. Fifteen adolescent girls were interviewed with a focus on what made them feel well in their everyday life. This study reveals that the adolescent girl's health is a complex phenomenon interwoven with their lives. Health…

Because Trucks Aren't Bicycles: Orthographic Complexity as an Important Variable in Reading Research

ERIC Educational Resources Information Center

Galletly, Susan A.; Knight, Bruce Allen

2013-01-01

Severe enduring reading- and writing-accuracy difficulties seem a phenomenon largely restricted to nations using complex orthographies, notably Anglophone nations, given English's highly complex orthography (Geva and Siegel, "Read Writ" 12:1-30, 2000; Landerl et al., "Cognition" 63:315-334, 1997; Share, "Psychol Bul"l…

The Hydraulic Jump: Finding Complexity in Turbulent Water

ERIC Educational Resources Information Center

Vondracek, Mark

2013-01-01

Students who do not progress to more advanced science disciplines in college generally do not realize that seemingly simple physical systems are--when studied in detail--more complex than one might imagine. This article presents one such phenomenon--the hydraulic jump--as a way to help students see the complexity behind the seemingly simple, and…

Ubiquitous and temperature-dependent neural plasticity in hibernators.

PubMed

von der Ohe, Christina G; Darian-Smith, Corinna; Garner, Craig C; Heller, H Craig

2006-10-11

Hibernating mammals are remarkable for surviving near-freezing brain temperatures and near cessation of neural activity for a week or more at a time. This extreme physiological state is associated with dendritic and synaptic changes in hippocampal neurons. Here, we investigate whether these changes are a ubiquitous phenomenon throughout the brain that is driven by temperature. We iontophoretically injected Lucifer yellow into several types of neurons in fixed slices from hibernating ground squirrels. We analyzed neuronal microstructure from animals at several stages of torpor at two different ambient temperatures, and during the summer. We show that neuronal cell bodies, dendrites, and spines from several cell types in hibernating ground squirrels retract on entry into torpor, change little over the course of several days, and then regrow during the 2 h return to euthermia. Similar structural changes take place in neurons from the hippocampus, cortex, and thalamus, suggesting a global phenomenon. Investigation of neural microstructure from groups of animals hibernating at different ambient temperatures revealed that there is a linear relationship between neural retraction and minimum body temperature. Despite significant temperature-dependent differences in extent of retraction during torpor, recovery reaches the same final values of cell body area, dendritic arbor complexity, and spine density. This study demonstrates large-scale and seemingly ubiquitous neural plasticity in the ground squirrel brain during torpor. It also defines a temperature-driven model of dramatic neural plasticity, which provides a unique opportunity to explore mechanisms of large-scale regrowth in adult mammals, and the effects of remodeling on learning and memory.

Extreme fog events in Poland with respect to circulation conditions

NASA Astrophysics Data System (ADS)

Ustrnul, Z.; Czekierda, D.; Wypych, A.

2010-09-01

Fog is a phenomenon which belongs to a group of so-called hydrometeorites and, according to the different dictionaries, it is a suspension of water droplets or ice crystals in the ground layer of the air that impairs visibility in the horizontal direction below 1 km. The phenomenon of fog, although much less dynamic or violent than other extreme phenomena, such as thunderstorms or hail, is equally dangerous and brings about huge social and economic complications. Land and air transportation suffer and fog may sometimes leads to a complete crippling of the whole economy in an area where fog occurs. The main objective of the study is determination of the circulation types bringing extreme fog events in Poland. The duration of fog at each meteorological station was considered as the main input data originated from 54 synoptic stations located across the country. The mentioned data series cover the period of 56 years (1951-2006). The occurrence of fog depends on meteorological conditions caused to a large extent by a given synoptic situation and local terrain conditions. In this study, according to its objectives, only circulation conditions are taken into consideration. These have been described by 5 different circulation classifications (Grosswetterlagen, Litynski, Osuchowska-Klein, Niedzwiedz and Ustrnul). Situations when this phenomenon occurred across a large part of the country were taken into detailed consideration. Special attention was paid to fog coverage during 24-hour periods. In this work, in light of certain doubts about the homogeneity of the observation material available, the intensity of fog was not included, as it requires additional and very tedious analysis. In the first step all cases of fog during the 1966-2006 study period which lasted 24 hours at more than 10 of the considered weather stations, i.e: at least 5 stations have been considered. As expected, in most cases, either a centre of a classical high pressure system or a high pressure wedge prevailed over Poland. In many cases, the dominance of baric patterns with advection from the eastern or southern sectors can be observed. Only in a few cases does a type with advection from the western sector come into play. In summary, it can be stated that intensive extreme fog of long duration occurred first of all in high pressure non-advective situations or along with weak advection, mainly from the southern or eastern direction. This statement, however, is not revolutionary. It simply confirms that the most troublesome of fog types is the radiation type, and can cover all of Poland at the same time and last up to several days. The study contains detailed meteorological-synoptic analyses of the most extreme events during the whole investigated period.

Biased assimilation, homophily, and the dynamics of polarization

PubMed Central

Dandekar, Pranav; Goel, Ashish; Lee, David T.

2013-01-01

We study the issue of polarization in society through a model of opinion formation. We say an opinion formation process is polarizing if it results in increased divergence of opinions. Empirical studies have shown that homophily, i.e., greater interaction between like-minded individuals, results in polarization. However, we show that DeGroot’s well-known model of opinion formation based on repeated averaging can never be polarizing, even if individuals are arbitrarily homophilous. We generalize DeGroot’s model to account for a phenomenon well known in social psychology as biased assimilation: When presented with mixed or inconclusive evidence on a complex issue, individuals draw undue support for their initial position, thereby arriving at a more extreme opinion. We show that in a simple model of homophilous networks, our biased opinion formation process results in polarization if individuals are sufficiently biased. In other words, homophily alone, without biased assimilation, is not sufficient to polarize society. Quite interestingly, biased assimilation also provides a framework to analyze the polarizing effect of Internet-based recommender systems that show us personalized content. PMID:23536293

[H2O ortho-para spin conversion in aqueous solutions as a quantum factor of Konovalov paradox].

PubMed

Pershin, S M

2014-01-01

Recently academician Konovalov and co-workers observed an increase in electroconductivity and biological activity simultaneously with diffusion slowing (or nanoobject diameter increasing) and extremes of other parameters (ζ-potential, surface tension, pH, optical activity) in low concentration aqueous solutions. This phenomenon completely disappeared when samples were shielded against external electromagnetic fields by a Faraday cage. A conventional theory of water and water solutions couldn't explain "Konovalov paradox" observed in numerous experiments (representative sampling about 60 samples and 7 parameters). The new approach was suggested to describe the physics of water and explain "Konovalov paradox". The proposed concept takes into account the quantum differences of ortho-para spin isomers of H2O in bulk water (rotational spin-selectivity upon hydration and spontaneous formation of ice-like structures, quantum beats and spin conversion induced in the presence of a resonant electromagnetic radiation). A size-dependent self-assembly of amorphous complexes of H2O molecules more than 275 leading to the ice Ih structure observed in the previous experiments supports this concept.

Finite element model for MOI applications using A-V formulation

NASA Astrophysics Data System (ADS)

Xuan, L.; Shanker, B.; Udpa, L.; Shih, W.; Fitzpatrick, G.

2001-04-01

Magneto-optic imaging (MOI) is a relatively new sensor application of an extension of bubble memory technology to NDT and produce easy-to-interpret, real time analog images. MOI systems use a magneto-optic (MO) sensor to produce analog images of magnetic flux leakage from surface and subsurface defects. The instrument's capability in detecting the relatively weak magnetic fields associated with subsurface defects depends on the sensitivity of the magneto-optic sensor. The availability of a theoretical model that can simulate the MOI system performance is extremely important for optimization of the MOI sensor and hardware system. A nodal finite element model based on magnetic vector potential formulation has been developed for simulating MOI phenomenon. This model has been used for predicting the magnetic fields in simple test geometry with corrosion dome defects. In the case of test samples with multiple discontinuities, a more robust model using the magnetic vector potential Ā and electrical scalar potential V is required. In this paper, a finite element model based on A-V formulation is developed to model complex circumferential crack under aluminum rivets in dimpled countersink.

Building human resilience: the role of public health preparedness and response as an adaptation to climate change.

PubMed

Keim, Mark E

2008-11-01

Global climate change will increase the probability of extreme weather events, including heatwaves, drought, wildfire, cyclones, and heavy precipitation that could cause floods and landslides. Such events create significant public health needs that can exceed local capacity to respond, resulting in excess morbidity or mortality and in the declaration of disasters. Human vulnerability to any disaster is a complex phenomenon with social, economic, health, and cultural dimensions. Vulnerability to natural disasters has two sides: the degree of exposure to dangerous hazards (susceptibility) and the capacity to cope with or recover from disaster consequences (resilience). Vulnerability reduction programs reduce susceptibility and increase resilience. Susceptibility to disasters is reduced largely by prevention and mitigation of emergencies. Emergency preparedness and response and recovery activities--including those that address climate change--increase disaster resilience. Because adaptation must occur at the community level, local public health agencies are uniquely placed to build human resilience to climate-related disasters. This article discusses the role of public health in reducing human vulnerability to climate change within the context of select examples for emergency preparedness and response.

Inverse Symmetry in Complete Genomes and Whole-Genome Inverse Duplication

PubMed Central

Kong, Sing-Guan; Fan, Wen-Lang; Chen, Hong-Da; Hsu, Zi-Ting; Zhou, Nengji; Zheng, Bo; Lee, Hoong-Chien

2009-01-01

The cause of symmetry is usually subtle, and its study often leads to a deeper understanding of the bearer of the symmetry. To gain insight into the dynamics driving the growth and evolution of genomes, we conducted a comprehensive study of textual symmetries in 786 complete chromosomes. We focused on symmetry based on our belief that, in spite of their extreme diversity, genomes must share common dynamical principles and mechanisms that drive their growth and evolution, and that the most robust footprints of such dynamics are symmetry related. We found that while complement and reverse symmetries are essentially absent in genomic sequences, inverse–complement plus reverse–symmetry is prevalent in complex patterns in most chromosomes, a vast majority of which have near maximum global inverse symmetry. We also discovered relations that can quantitatively account for the long observed but unexplained phenomenon of -mer skews in genomes. Our results suggest segmental and whole-genome inverse duplications are important mechanisms in genome growth and evolution, probably because they are efficient means by which the genome can exploit its double-stranded structure to enrich its code-inventory. PMID:19898631

Noise-induced transitions and shifts in a climate-vegetation feedback model.

PubMed

Alexandrov, Dmitri V; Bashkirtseva, Irina A; Ryashko, Lev B

2018-04-01

Motivated by the extremely important role of the Earth's vegetation dynamics in climate changes, we study the stochastic variability of a simple climate-vegetation system. In the case of deterministic dynamics, the system has one stable equilibrium and limit cycle or two stable equilibria corresponding to two opposite (cold and warm) climate-vegetation states. These states are divided by a separatrix going across a point of unstable equilibrium. Some possible stochastic scenarios caused by different externally induced natural and anthropogenic processes inherit properties of deterministic behaviour and drastically change the system dynamics. We demonstrate that the system transitions across its separatrix occur with increasing noise intensity. The climate-vegetation system therewith fluctuates, transits and localizes in the vicinity of its attractor. We show that this phenomenon occurs within some critical range of noise intensities. A noise-induced shift into the range of smaller global average temperatures corresponding to substantial oscillations of the Earth's vegetation cover is revealed. Our analysis demonstrates that the climate-vegetation interactions essentially contribute to climate dynamics and should be taken into account in more precise and complex models of climate variability.

Reward Circuitry Plasticity in Pain Perception and Modulation

PubMed Central

DosSantos, Marcos F.; Moura, Brenda de Souza; DaSilva, Alexandre F.

2017-01-01

Although pain is a widely known phenomenon and an important clinical symptom that occurs in numerous diseases, its mechanisms are still barely understood. Owing to the scarce information concerning its pathophysiology, particularly what is involved in the transition from an acute state to a chronic condition, pain treatment is frequently unsatisfactory, therefore contributing to the amplification of the chronic pain burden. In fact, pain is an extremely complex experience that demands the recruitment of an intricate set of central nervous system components. This includes cortical and subcortical areas involved in interpretation of the general characteristics of noxious stimuli. It also comprises neural circuits that process the motivational-affective dimension of pain. Hence, the reward circuitry represents a vital element for pain experience and modulation. This review article focuses on the interpretation of the extensive data available connecting the major components of the reward circuitry to pain suffering, including the nucleus accumbens, ventral tegmental area, and the medial prefrontal cortex; with especial attention dedicated to the evaluation of neuroplastic changes affecting these structures found in chronic pain syndromes, such as migraine, trigeminal neuropathic pain, chronic back pain, and fibromyalgia. PMID:29209204

Cultural definitions of elder maltreatment in Portugal.

PubMed

Mercurio, Andrea E; Nyborn, Justin

2006-01-01

A small convenience sample of 34 participants (17 males, 17 females) from the Portuguese islands of the Azores and Madeira were asked to provide examples of how extreme, moderate, and mild maltreatment towards an elder would be defined in their culture and society. Neglect, especially psychological neglect, physical maltreatment, and psychological maltreatment were the most frequently reported types of maltreatment. References to neglect and physical maltreatment appeared most often as examples of extreme maltreatment. In general, men were somewhat more likely than women to provide examples of physical aggression in their examples of maltreatment. As examples of extreme maltreatment, females provided significantly more examples of abandonment than males. Although interpretations of the findings must be cautious because of the small sample size and limited statistical power, the study illustrates a procedure for assessing constructs of elder mistreatment in a way that attends to respondents' own constructions of the phenomenon.

A statistical mechanics approach to computing rare transitions in multi-stable turbulent geophysical flows

NASA Astrophysics Data System (ADS)

Laurie, J.; Bouchet, F.

2012-04-01

Many turbulent flows undergo sporadic random transitions, after long periods of apparent statistical stationarity. For instance, paths of the Kuroshio [1], the Earth's magnetic field reversal, atmospheric flows [2], MHD experiments [3], 2D turbulence experiments [4,5], 3D flows [6] show this kind of behavior. The understanding of this phenomena is extremely difficult due to the complexity, the large number of degrees of freedom, and the non-equilibrium nature of these turbulent flows. It is however a key issue for many geophysical problems. A straightforward study of these transitions, through a direct numerical simulation of the governing equations, is nearly always impracticable. This is mainly a complexity problem, due to the large number of degrees of freedom involved for genuine turbulent flows, and the extremely long time between two transitions. In this talk, we consider two-dimensional and geostrophic turbulent models, with stochastic forces. We consider regimes where two or more attractors coexist. As an alternative to direct numerical simulation, we propose a non-equilibrium statistical mechanics approach to the computation of this phenomenon. Our strategy is based on large deviation theory [7], derived from a path integral representation of the stochastic process. Among the trajectories connecting two non-equilibrium attractors, we determine the most probable one. Moreover, we also determine the transition rates, and in which cases this most probable trajectory is a typical one. Interestingly, we prove that in the class of models we consider, a mechanism exists for diffusion over sets of connected attractors. For the type of stochastic forces that allows this diffusion, the transition between attractors is not a rare event. It is then very difficult to characterize the flow as bistable. However for another class of stochastic forces, this diffusion mechanism is prevented, and genuine bistability or multi-stability is observed. We discuss how these results are probably connected to the long debated existence of multi-stability in the atmosphere and oceans.

A Weak Solar Burst Submillimeter Only Spectral Component During a GOES M Class Flare: Implications for its Emission Mechanisms

NASA Astrophysics Data System (ADS)

Cristiani, G. D.; Giménez de Castro, C. G.; Mandrini, C. H.; et al.

2008-09-01

Since the installation of the Submillimeter Solar Radio Telescope, a new spectral burst component was discovered at frequencies above 100 GHz, creating the THz bursts category. In all the reported cases, the events were X class flares and the THz component was increasing with frequency. We report for the first time an M class flare which shows a submillimeter radio spectral component different from the one in microwave classical bursts. Two successive flares of 2 minute duration occurred in active region NOAA 10226 with 2 minutes delay. They started at around 13:15 UT and had an M 6.8 maximum intensity in soft X-rays. The submillimeter flux density from the Solar Submillimeter Telescope (SST) is used in addition to microwave total Sun patrol telescope observations. Images with H filters from the H-alpha Solar Telescope for Argentina (HASTA) and in the extreme UV from the Extreme-ultraviolet Imaging Telescope (EIT) are used to characterize the flaring region. An extensive analysis of the magnetic topology evolution is derived from Michelson Doppler Imager (MDI) magnetograms and used to constrain the space of solutions for the possible emission mechanisms. The submillimeter component is observed at 212 GHz only. We have upper limits for the emission at 89.4and 405 GHz which are smaller than the observed flux density at 212 GHz. The analysis of the magnetic topology reveals a very compact and complex system of arches that reconnects at a low height, while from the soft X-ray observations we deduce that the flaring area is compact and dense (n=1e12 cm-3). The finding of a submillimeter only burst component in a medium size flare indicates that the phenomenon is more universal than shown until now. The multiwavelength analysis reveals that neither positron synchrotron nor free-free emission could produce the submillimeter component, which is explained here by synchrotron of accelerated electrons in a rather complex and compact magnetic configuration.

First time description of dismantling phenomenon

PubMed Central

Barrer, Laurence; Gimenez, Guy

2015-01-01

Dismantling is a complex psychic phenomenon, which is not easy to define, and little interest has been shown in the subject. The authors of this paper want to demonstrate that dismantling is the main defense mechanism in autism, bringing about de-consensus of senses. The effects perceived in a child with autistic disorder are passivity and lack of thought. The authors’ purpose here is to define the dismantled state and reveal its underlying process. This paper will therefore describe for the first time in literature, the dismantling phenomenon and will submit a metapsychological approach of this defense mechanism. PMID:25999871

Teaching the abyss: living the art-science of nursing.

PubMed

Ramey, Sandra L; Bunkers, Sandra Schmidt

2006-10-01

This column addresses how nurse educators can provide the teaching-learning experiences for novice nurses to develop the leadership competence to effectively practice nursing in an extremely demanding healthcare environment. The authors delve into Mitchell and Bunkers' use of the metaphor of an abyss to explore the lived experience of risking being with others in extremely intense interpersonal situations. Using reflection, students' journal narratives affirm connections made among past experiences and the new knowledge gleaned from exploring and naming the phenomenon of the abyss. Several teaching-learning strategies are offered as ways for addressing the leadership issues related to dealing with intense relational experiences in nursing practice, including exploring nurse theorist Rosemarie Rizzo Parse's essentials of leadership.

The Renewable City: Dawn of an Urban Revolution

ERIC Educational Resources Information Center

Droege, Peter

2006-01-01

A vexing modern conundrum is to be solved. The use of oil, gas, and coal is extremely short-lived as a historical phenomenon: a mere blink of an eye at a little more than 1% of total urban history of 10,000 years to-date. Yet current urban civilization is almost entirely based on it. And the fossil-fuel economy poses not only a massive security…

Adsorption of 59Fe on glassware and its effect on data deduced

PubMed Central

Smith, Mary D.; Kernaghan, T.

1969-01-01

The attachment of 59Fe to glassware under conditions of hospital laboratory procedure forms the subject of this communication. Adsorption of this nature can be extreme and can invalidate data derived or prejudice intended dose levels. It is aggravated by sterilization by autoclave. Data indicating the severity of the phenomenon are presented and methods of controlling it are discussed. PMID:5365342

Geophysical fluid dynamics: whence, whither and why?

PubMed Central

2016-01-01

This article discusses the role of geophysical fluid dynamics (GFD) in understanding the natural environment, and in particular the dynamics of atmospheres and oceans on Earth and elsewhere. GFD, as usually understood, is a branch of the geosciences that deals with fluid dynamics and that, by tradition, seeks to extract the bare essence of a phenomenon, omitting detail where possible. The geosciences in general deal with complex interacting systems and in some ways resemble condensed matter physics or aspects of biology, where we seek explanations of phenomena at a higher level than simply directly calculating the interactions of all the constituent parts. That is, we try to develop theories or make simple models of the behaviour of the system as a whole. However, these days in many geophysical systems of interest, we can also obtain information for how the system behaves by almost direct numerical simulation from the governing equations. The numerical model itself then explicitly predicts the emergent phenomena—the Gulf Stream, for example—something that is still usually impossible in biology or condensed matter physics. Such simulations, as manifested, for example, in complicated general circulation models, have in some ways been extremely successful and one may reasonably now ask whether understanding a complex geophysical system is necessary for predicting it. In what follows we discuss such issues and the roles that GFD has played in the past and will play in the future. PMID:27616918

Network Theory of Human Decision Making

DTIC Science & Technology

2012-06-14

must share the same complexity as the brain. This explains why music can be interpreted as the mirror of the brain [3]. According to [11] a...origin and that phenomenon of neural entrainment has the same origin, with a close connection with the phenomenon of cooperation-induced...renewal critical events, Central European Journal of Physics, 7, 421-431 (2009). [3] D. Adams, P. Grigolini, “ Music , New Aesthetic and

"The Et Tu Brute Complex" Compulsive Self Betrayal

ERIC Educational Resources Information Center

Antus, Robert Lawrence

2006-01-01

In this article, the author discusses "The Et Tu Brute Complex." More specifically, this phenomenon occurs when a person, instead of supporting and befriending himself, orally condemns himself in front of other people and becomes his own worst enemy. This is a form of compulsive self-hatred. Most often, the victim of this complex is unaware of the…

OPTIMIZING THROUGH CO-EVOLUTIONARY AVALANCHES

DOE Office of Scientific and Technical Information (OSTI.GOV)

S. BOETTCHER; A. PERCUS

2000-08-01

We explore a new general-purpose heuristic for finding high-quality solutions to hard optimization problems. The method, called extremal optimization, is inspired by ''self-organized critically,'' a concept introduced to describe emergent complexity in many physical systems. In contrast to Genetic Algorithms which operate on an entire ''gene-pool'' of possible solutions, extremal optimization successively replaces extremely undesirable elements of a sub-optimal solution with new, random ones. Large fluctuations, called ''avalanches,'' ensue that efficiently explore many local optima. Drawing upon models used to simulate far-from-equilibrium dynamics, extremal optimization complements approximation methods inspired by equilibrium statistical physics, such as simulated annealing. With only onemore » adjustable parameter, its performance has proved competitive with more elaborate methods, especially near phase transitions. Those phase transitions are found in the parameter space of most optimization problems, and have recently been conjectured to be the origin of some of the hardest instances in computational complexity. We will demonstrate how extremal optimization can be implemented for a variety of combinatorial optimization problems. We believe that extremal optimization will be a useful tool in the investigation of phase transitions in combinatorial optimization problems, hence valuable in elucidating the origin of computational complexity.« less

Collective almost synchronisation in complex networks.

PubMed

Baptista, Murilo S; Ren, Hai-Peng; Swarts, Johen C M; Carareto, Rodrigo; Nijmeijer, Henk; Grebogi, Celso

2012-01-01

This work introduces the phenomenon of Collective Almost Synchronisation (CAS), which describes a universal way of how patterns can appear in complex networks for small coupling strengths. The CAS phenomenon appears due to the existence of an approximately constant local mean field and is characterised by having nodes with trajectories evolving around periodic stable orbits. Common notion based on statistical knowledge would lead one to interpret the appearance of a local constant mean field as a consequence of the fact that the behaviour of each node is not correlated to the behaviours of the others. Contrary to this common notion, we show that various well known weaker forms of synchronisation (almost, time-lag, phase synchronisation, and generalised synchronisation) appear as a result of the onset of an almost constant local mean field. If the memory is formed in a brain by minimising the coupling strength among neurons and maximising the number of possible patterns, then the CAS phenomenon is a plausible explanation for it.

Collective Almost Synchronisation in Complex Networks

PubMed Central

Baptista, Murilo S.; Ren, Hai-Peng; Swarts, Johen C. M.; Carareto, Rodrigo; Nijmeijer, Henk; Grebogi, Celso

2012-01-01

This work introduces the phenomenon of Collective Almost Synchronisation (CAS), which describes a universal way of how patterns can appear in complex networks for small coupling strengths. The CAS phenomenon appears due to the existence of an approximately constant local mean field and is characterised by having nodes with trajectories evolving around periodic stable orbits. Common notion based on statistical knowledge would lead one to interpret the appearance of a local constant mean field as a consequence of the fact that the behaviour of each node is not correlated to the behaviours of the others. Contrary to this common notion, we show that various well known weaker forms of synchronisation (almost, time-lag, phase synchronisation, and generalised synchronisation) appear as a result of the onset of an almost constant local mean field. If the memory is formed in a brain by minimising the coupling strength among neurons and maximising the number of possible patterns, then the CAS phenomenon is a plausible explanation for it. PMID:23144851

Developing a concept of social-ecological-technological systems to characterize resilience of urban areas and infrastructure to extreme events

NASA Astrophysics Data System (ADS)

Chester, M.; Grimm, N. B.; Redman, C.; Miller, T.; McPherson, T.; Munoz-Erickson, T.; Chandler, D. G.

2015-12-01

Climate change is widely considered one of the greatest challenges to global sustainability, with extreme events being the most immediate way that people experience this phenomenon. Urban areas are particularly vulnerable to these events given their location, concentration of people, and increasingly complex and interdependent infrastructure. We are developing a conceptual framework for urban social-ecological-technological systems (SETS) that will allow researchers and practitioners to assess how infrastructure can be resilient, provide ecosystem services, improve social well being, and exploit new technologies in ways that benefit urban populations. The framework integrates the three domains of social and equity issues, environmental quality and protection, and technical/engineering aspects, to form a concept of infrastructure that occurs at the intersection of the domains. Examples show how the more common socioecological systems and socially sensitive engineering approaches that fail to incorporate the third dimension may elevate vulnerability to climate-related disaster. The SETS conceptual framework bridges currently siloed social science, environmental science, and engineering approaches to significantly advance research into the structure, function, and emergent properties of SETS. Extreme events like heat waves in Phoenix; coastal and urban flooding in the wake of superstorm Sandy and following hurricanes in Miami, FL; drought in Mexico; and urban flooding in Baltimore, Portland, San Juan PR, Syracuse, and Valdivia, Chile provide examples of the impacts of and vulnerability to extreme events that demand a new approach. The infrastructure of the future must be resilient, leverage ecosystem services, improve social well being, and exploit new technologies in ways that benefit all segments of urban populations and are appropriate to the particular urban contexts. These contexts are defined not only by the biophysical environment but also by culture and institutions of each place. We apply the SETS conceptual framework to nine western hemisphere cities in diverse settings, presenting hypotheses about the relative efficacy of strategies for resilient SETS infrastructure in cities contrasting in event type, biophysical setting, and cultural and institutional contexts.

Rogue Waves and Extreme Events in Optics - Challenges and Questions

NASA Astrophysics Data System (ADS)

Dudley, John; Lacourt, Pierre-Ambroise; Genty, Goery; Dias, Frederic; Akhmediev, Nail

2010-05-01

A central challenge in understanding extreme events in physics is to develop rigorous models linking the complex generation dynamics and the associated statistical behavior. Quantitative studies of extreme phenomena, however, are often hampered in two ways: (i) the intrinsic scarcity of the events under study and (ii) the fact that such events often appear in environments where measurements are difficult. A particular case of interest concerns the infamous oceanic rogue waves that have been associated with many catastrophic maritime disasters. Studying rogue waves under controlled conditions is problematic, and the phenomenon remains a subject of intensive research. On the other hand, there are many qualitative and quantitative links between wave propagation in optics and in hydrodynamics, and it is thus natural to consider to what degree (if any) insights from studying instability phenomena in optics can be applied to other systems. In this context, significant experiments were reported by Solli et al. in late 2007 ["Optical rogue waves," Nature 450, 1054 (2007)], where a wavelength-to-time detection technique allowed the direct characterization of shot-to-shot instabilities in the extreme nonlinear optical spectral broadening process of supercontinuum generation. Specifically, although the process of supercontinuum generation is well-known to exhibit fluctuations in both the time and frequency domains, Solli et al. have shown that these fluctuations contain a small number of statistically-rare "rogue" events associated with a greatly enhanced spectral bandwidth and the generation of localized temporal solitons with greatly increased intensity. Crucially, because these experiments were performed in a regime where modulation instability (MI) plays a key role in the dynamics, an analogy was drawn with hydrodynamic rogue waves, whose origin and dynamics has also been discussed in terms of MI or, as it often referred to in hydrodynamics, the Benjamin-Feir instability. The analogy between the appearance of localized structures in optics and the rogue waves on the ocean's surface is both intriguing and attractive, as it opens up possibilities to explore the extreme value dynamics in a convenient benchtop optical environment. In addition to the proposed links with solitons suggested by Solli et al., other recent studies motivated from an optical context have experimentally demonstrated links with nonlinear breather propagation. The purpose of this paper will be to discuss these results that have been obtained in optics, and to consider possible similarities and differences with oceanic rogue wave counterparts.

[Friends of virtual Ana--the phenomenon of pro-anorexia in the Internet].

PubMed

Stochel, Martyna; Janas-Kozik, Małgorzata

2010-01-01

Anorexia nervosa is regarded as a serious mental disturbance, where denial of illness and strong resistance to treatment are symptomatic features. In many cases it leads to extreme devastation or even to death. Effective treatment of this disorder still remains a challenge for clinicians and researchers. Since the 90-ies of the previous century there has been a rise in the free access to the internet. At present over a billion people all over the world use it. What young people look for in the internet is not only information, but also friends, support or entertainment. For last a few years, a phenomenon of pro-anorexia has been present in the Internet, connecting people who claim that anorexia is a "lifestyle" rather than a deadly illness, which should be treat. They communicate with each other through the internet blogs, forums and popular social networking sites, creating a virtual community. The pro-ana community is made up of adolescent girls and young women who decide on dieting. Pro-anorexia is still a poorly known phenomenon, especially in Poland. It seems to be very important to take a note on this phenomenon in the face of an increasing prevalence of eating disorders in the last years.

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

NASA Astrophysics Data System (ADS)

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

2018-02-01

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

An AST-ELM Method for Eliminating the Influence of Charging Phenomenon on ECT.

PubMed

Wang, Xiaoxin; Hu, Hongli; Jia, Huiqin; Tang, Kaihao

2017-12-09

Electrical capacitance tomography (ECT) is a promising imaging technology of permittivity distributions in multiphase flow. To reduce the effect of charging phenomenon on ECT measurement, an improved extreme learning machine method combined with adaptive soft-thresholding (AST-ELM) is presented and studied for image reconstruction. This method can provide a nonlinear mapping model between the capacitance values and medium distributions by using machine learning but not an electromagnetic-sensitive mechanism. Both simulation and experimental tests are carried out to validate the performance of the presented method, and reconstructed images are evaluated by relative error and correlation coefficient. The results have illustrated that the image reconstruction accuracy by the proposed AST-ELM method has greatly improved than that by the conventional methods under the condition with charging object.

An AST-ELM Method for Eliminating the Influence of Charging Phenomenon on ECT

PubMed Central

Wang, Xiaoxin; Hu, Hongli; Jia, Huiqin; Tang, Kaihao

2017-01-01

Electrical capacitance tomography (ECT) is a promising imaging technology of permittivity distributions in multiphase flow. To reduce the effect of charging phenomenon on ECT measurement, an improved extreme learning machine method combined with adaptive soft-thresholding (AST-ELM) is presented and studied for image reconstruction. This method can provide a nonlinear mapping model between the capacitance values and medium distributions by using machine learning but not an electromagnetic-sensitive mechanism. Both simulation and experimental tests are carried out to validate the performance of the presented method, and reconstructed images are evaluated by relative error and correlation coefficient. The results have illustrated that the image reconstruction accuracy by the proposed AST-ELM method has greatly improved than that by the conventional methods under the condition with charging object. PMID:29232850

[A method for reproducing amnesia in mice by the complex extremal exposure].

PubMed

Iasnetsov, V V; Provornova, N A

2003-01-01

It is suggested to reproduce a retrograde amnesia in mice by means of a complex extremal action: emaciating swim in cold water with simultaneous wheel rotation. It was found that nootropes such as pyracetam, mexidol, semax, nooglutil, acephen, and noopept fully or completely prevent from the amnesia development.

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

NASA Astrophysics Data System (ADS)

Konapala, Goutam; Mishra, Ashok

2017-12-01

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

Early Reconstructions of Complex Lower Extremity Battlefield Soft Tissue Wounds

PubMed Central

Ebrahimi, Ali; Nejadsarvari, Nasrin; Ebrahimi, Azin; Rasouli, Hamid Reza

2017-01-01

BACKGROUND Severe lower extremity trauma as a devastating combat related injury is on the rise and this presents reconstructive surgeons with significant challenges to reach optimal cosmetic and functional outcomes. This study assessed early reconstructions of complex lower extremity battlefield soft tissue wounds. METHODS This was a prospective case series study of battled field injured patients which was done in the Department of Plastic Surgery, Baqiyatallah University of Medical Sciences hospitals, Tehran, Iran between 2013-2015. In this survey, 73 patients were operated for reconstruction of lower extremity soft tissue defects due to battlefield injuries RESULTS Seventy-three patients (65 men, 8 womens) ranging from 21-48 years old (mean: 35 years) were enrolled. Our study showed that early debridement and bone stabilization and later coverage of complex battlefields soft tissue wounds with suitable flaps and grafts of lower extremity were effective method for difficult wounds managements with less amputation and infections. CONCLUSION Serial debridement and bone stabilization before early soft tissue reconstruction according to reconstructive ladder were shown to be essential steps. PMID:29218283

Strategic Studies Quarterly. Volume 2, Number 2, Summer 2008

DTIC Science & Technology

2008-06-01

terrorists seek financing , recruit followers, and continue to plot against the United States and our partners and allies. The phenomenon of suicide...moderate cost in terms of lives, finances , and opportunity costs to other missions and global commitments). Once physical sustainment is possible...private Saudi financing of al-Qaeda and other terrorist groups and the Saudi monarchy’s official promotion, throughout the Muslim world, of its own extreme

Stakeholders’ perspectives towards effective climate change adaptation on the Mongolian livestock sector

NASA Astrophysics Data System (ADS)

Batbaatar, A.; Apichayakul, P.; Tantanee, S.

2018-03-01

Climate change is one of the greatest threats that world is facing today, and having significant deleterious effects on natural and human systems. Recent climate-induced extreme events and their impacts demand timely adaptation actions to the changing odds of their occurrence. The great phenomenon is already being felt in the Mongolian plateau, especially on the livestock sector. The sector provides the main income and livelihood for one-third of the population of about three million people. A high number of livestock is lost due to a unique phenomenon is known as a “dzud”. This paper examines the key stakeholders’ perspectives in the implementation of climate change adaptation and identifies its barriers, with a focus on the livestock sector. In order to meet the objectives, this research used a semi-structured interview with organizations related to the livestock sector and climate change. The extent of stakeholders’ perspectives might be depending on the way they share information, stakeholder engagement, and their experiences with extreme events, as well as their location and level in government. The research findings will indicate an understanding of climate change perspectives, adaptation, and level of capacity of organizations, which can be used as a guideline for organizations to develop climate change adaptation policies related to the livestock sector in Mongolia.

Part 1--unravelling primary health care conceptual predicaments through the lenses of complexity and political economy: a position paper for progressive transformation.

PubMed

Félix-Bortolotti, Margot

2009-10-01

To disentangle the concepts of primary health care and primary care as well as their conceptual and empirical ramifications for progressive transformation. over 400 international and interdisciplinary abstracts and papers with 96 annotated bibliography abstracts of literature across multiple dimensions relating to the knowledge base around mechanisms in PHC development were reviewed. The text is confronted with the reality, as it exists in the field and makes the case for complexity perspectives to assess this phenomenon in its context. PHC complexity is an important analytical tool to interrogate the ways in which this phenomenon is socially constructed as well as in the matrices in which it is embedded. It is also a potent analytical tool to assist in the deconstruction of prevalent linear thinking built around PHC as a whole.

Surgical Management of Complex Lower-Extremity Trauma With a Long Hindfoot Fusion Nail: A Case Report.

PubMed

Jain, Nickul S; Lopez, Gregory D; Bederman, S Samuel; Wirth, Garrett A; Scolaro, John A

2016-08-01

High-energy injuries can result in complete or partial loss of the talus. Ipsilateral fractures to the lower limb increase the complexity of surgical management, and treatment is guided by previous case reports of similar injuries. A case of complex lower-extremity trauma with extruded and missing talar body and ipsilateral type IIIB open tibia fracture is presented. Surgical limb reconstruction and salvage was performed successfully with a single orthopaedic implant in a manner not described previously in the literature. The purpose of this case report is to present the novel use of a single orthopaedic implant for treatment of a complex, open traumatic injury. Previous case reports in the literature have described the management of complete or partial talar loss. We describe the novel use of a long hindfoot fusion nail and staged bone grafting to achieve tibiocalcaneal arthrodesis for the treatment of complex lower-extremity trauma. Therapeutic, Level IV: Case study. © 2015 The Author(s).

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

ERIC Educational Resources Information Center

Hall, Darlene Kordich

1999-01-01

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

Micro-bubble emission boiling with the cavitation bubble blow pit

PubMed Central

Inada, Shigeaki; Shinagawa, Kazuaki; Illias, Suhaimi Bin; Sumiya, Hiroyuki; Jalaludin, Helmisyah A.

2016-01-01

The miniaturization boiling (micro-bubble emission boiling [MEB]) phenomenon, with a high heat removal capacity that contributes considerably to the cooling of the divertor of the nuclear fusion reactor, was discovered in the early 1980s. Extensive research on MEB has been performed since its discovery. However, the progress of the application has been delayed because the generation mechanism of MEB remains unclear. Reasons for this lack of clarity include the complexity of the phenomenon itself and the high-speed phase change phenomenon in which boiling and condensation are rapidly generated. In addition, a more advanced thermal technique is required to realize the MEB phenomenon at the laboratory scale. To the authors’ knowledge, few studies have discussed the rush mechanism of subcooled liquid to the heating surface, which is critical to elucidating the mechanism behind MEB. This study used photographic images to verify that the cavitation phenomenon spreads to the inside of the superheated liquid on the heating surface and thus clarify the mechanism of MEB. PMID:27628271

From Avicennia to Zizania: Seed Recalcitrance in Perspective

PubMed Central

Berjak, Patricia; Pammenter, N. W.

2008-01-01

Background Considered only in terms of tolerance of, or sensitivity to, desiccation (which is an oversimplification), orthodox seeds are those which tolerate dehydration and are storable in this condition, while highly recalcitrant seeds are damaged by loss of only a small proportion of water and are unstorable for practical purposes. Between these extremes, however, there may be a gradation of the responses to dehydration – and also to other factors – suggesting perhaps that seed behaviour might be best considered as constituting a continuum subtended by extreme orthodoxy and the highest degree of recalcitrance. As the characteristics of seeds of an increasing number of species are elucidated, non-orthodox seed behaviour is emerging as considerably more commonplace – and its basis far more complex – than previously suspected. Scope Whatever the post-harvest responses of seeds of individual species may be, they are the outcome of the properties of pre-shedding development, and a full understanding of the subtleties of various degrees of non-orthodox behaviour must await the identification of, and interaction among, all the factors conferring extreme orthodoxy. Appreciation of the phenomenon of recalcitrance is confounded by intra- and interseasonal variability across species, as well as within individual species. However, recent evidence suggests that provenance is a pivotal factor in determining the degree of recalcitrant behaviour exhibited by seeds of individual species. Non-orthodox – and, in particular, recalcitrant – seed behaviour is not merely a matter of desiccation sensitivity: the primary basis is that the seeds are actively metabolic when they are shed, in contrast to orthodox types which are quiescent. This affects all aspects of the handling and storage of recalcitrant seeds. In the short to medium term, recalcitrant seeds should be stored in as hydrated a condition as when they are shed, and at the lowest temperature not diminishing vigour or viability. Such hydrated storage has attendant problems of fungal proliferation which, unless minimized, will inevitably and significantly affect seed quality. The life span of seeds in hydrated storage even under the best conditions is variable among species, but is curtailed (days to months), and various approaches attempting to extend non-orthodox seed longevity are discussed. Conservation of the genetic resources by means other than seed storage is then briefly considered, with detail on the potential for, and difficulties with, cryostorage highlighted. Conclusions There appears to be little taxonomic relationship among species exhibiting the phenomenon of seed recalcitrance, suggesting that it is a derived trait, with tolerance having been lost a number of times. Although recalcitrant seededness is best represented in the mesic tropics, particularly among rainforest climax species, it does occur in cooler, drier and markedly seasonal habitats. The selective advantages of the trait are considered. PMID:17704237

Predictability of Extreme Climate Events via a Complex Network Approach

NASA Astrophysics Data System (ADS)

Muhkin, D.; Kurths, J.

2017-12-01

We analyse climate dynamics from a complex network approach. This leads to an inverse problem: Is there a backbone-like structure underlying the climate system? For this we propose a method to reconstruct and analyze a complex network from data generated by a spatio-temporal dynamical system. This approach enables us to uncover relations to global circulation patterns in oceans and atmosphere. This concept is then applied to Monsoon data; in particular, we develop a general framework to predict extreme events by combining a non-linear synchronization technique with complex networks. Applying this method, we uncover a new mechanism of extreme floods in the eastern Central Andes which could be used for operational forecasts. Moreover, we analyze the Indian Summer Monsoon (ISM) and identify two regions of high importance. By estimating an underlying critical point, this leads to an improved prediction of the onset of the ISM; this scheme was successful in 2016 and 2017.

Effects of Demand Complexity on Echolalia in Students with Autism

ERIC Educational Resources Information Center

Edelstein, Matthew Lawrence

2015-01-01

Echolalia is a linguistic phenomenon common in individuals with Autism Spectrum Disorder. This study examined the relationship between demand complexity and immediate echolalia in 4 students with an autism diagnosis in a university-based academic setting. Mastered and novel antecedent verbal demands that required an intraverbal response were…

Non destructive testing of soft body armor

NASA Astrophysics Data System (ADS)

Bhise, Karan

Pristine bullet proof vests are extremely effective at halting pre-determined projectile threats and have saved over 3000 lives. However, the effectiveness of these vests to halt a bullet is seen to decrease over time.Owing to the importance of bullet proof vests over a period of time, tests to determine their effectiveness have been carried out on every batch of vests at the time of inception and at certain time intervals by shooting a bullet through them. A few vests from every batch are picked up and shot at to check for bullet penetration during this process while these results are extrapolated onto the other vests from the batch.One of the main issues with this method is the fact that testing a few jackets among a large set of jackets does not guarantee the safety of every jacket in the entire batch.Further the jackets that are shot-at have the possibility of undergoing substantial damage during the process thus compromising its safety rendering them unsafe for future use.As the vest penetration phenomenon is extremely complex too, there arose a need for a better testing procedure that could not only help ensure more safety, but also save time and money.The new testing procedure proposed a non-destructive evaluation of the jackets that would solve the issues previous faced in testing the vests. This would lead to the building of a portable set up which could be carried to any location to test jackets in a matter of minutes thus saving time and money.

A global analysis of the asymmetric effect of ENSO on extreme precipitation

NASA Astrophysics Data System (ADS)

Sun, Xun; Renard, Benjamin; Thyer, Mark; Westra, Seth; Lang, Michel

2015-11-01

The global and regional influence of the El Niño-Southern Oscillation (ENSO) phenomenon on extreme precipitation was analyzed using a global database comprising over 7000 high quality observation sites. To better quantify possible changes in relatively rare design-relevant precipitation quantiles (e.g. the 1 in 10 year event), a Bayesian regional extreme value model was used, which employed the Southern Oscillation Index (SOI) - a measure of ENSO - as a covariate. Regions found to be influenced by ENSO include parts of North and South America, southern and eastern Asia, South Africa, Australia and Europe. The season experiencing the greatest ENSO effect varies regionally, but in most of the ENSO-affected regions the strongest effect happens in boreal winter, during which time the 10-year precipitation for |SOI| = 20 (corresponding to either a strong El Niño or La Niña episode) can be up to 50% higher or lower than for SOI = 0 (a neutral phase). Importantly, the effect of ENSO on extreme precipitation is asymmetric, with most parts of the world experiencing a significant effect only for a single ENSO phase. This finding has important implications on the current understanding of how ENSO influences extreme precipitation, and will enable a more rigorous theoretical foundation for providing quantitative extreme precipitation intensity predictions at seasonal timescales. We anticipate that incorporating asymmetric impacts of ENSO on extreme precipitation will help lead to better-informed climate-adaptive design of flood-sensitive infrastructure.

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

NASA Astrophysics Data System (ADS)

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.

Interlimb transfer of motor skill learning during walking: No evidence for asymmetric transfer.

PubMed

Krishnan, Chandramouli; Ranganathan, Rajiv; Tetarbe, Manik

2017-07-01

Several studies have shown that learning a motor skill in one limb can transfer to the opposite limb-a phenomenon called as interlimb transfer. The transfer of motor skills between limbs, however, has shown to be asymmetric, where one side benefits to a greater extent than the other. While this phenomenon has been well-documented in the upper-extremity, evidence for interlimb transfer in the lower-extremity is limited and mixed. This study investigated the extent of interlimb transfer during walking, and tested whether this transfer was asymmetric using a foot trajectory-tracking paradigm that has been specifically used for gait rehabilitation. The paradigm involved learning a new gait pattern which required greater hip and knee flexion during the swing phase of the gait while walking on a treadmill. Twenty young adults were randomized into two equal groups, where one group (right-to-left: RL) practiced the task initially with the dominant right leg and the other group (left-to-right: LR) practiced the task initially with their non-dominant left leg. After training, both groups practiced the task with their opposite leg to test the transfer effects. The changes in tracking error on each leg were computed to quantify learning and transfer effects. The results indicated that practice with one leg improved the motor performance of the other leg; however, the amount of transfer was similar across groups, indicating that there was no asymmetry in transfer. This finding is contradictory to most upper-extremity studies (where asymmetric transfer has been reported) and points out that both differences in neural processes and types of tasks may mediate interlimb transfer. Copyright © 2017 Elsevier B.V. All rights reserved.

Dragon-Kings, Black-Swans and Prediction (Invited)

NASA Astrophysics Data System (ADS)

Sornette, D.

2010-12-01

Extreme fluctuations or events are often associated with power law statistics. Indeed, it is a popular belief that "wild randomness'' is deeply associated with distributions with power law tails characterized by small exponents. In other words, power law tails are often seen as the epitome of extreme events (the "Black Swan'' story). Here, we document in very different systems that there is life beyond power law tails: power laws can be superseded by "dragon-kings'', monster events that occur beyond (or changing) the power law tail. Dragon-kings reveal hidden mechanisms that are only transiently active and that amplify the normal fluctuations (often described by the power laws of the normal regime). The goal of this lecture is to catalyze the interest of the community of geophysicists across all fields of geosciences so that the "invisible gorilla" fallacy may be avoided. Our own research illustrates that new statistics or representation of data are often necessary to identify dragon-kings, with strategies guided by the underlying mechanisms. Paradoxically, the monsters may be ignored or hidden by the use of inappropriate analysis or statistical tools that amount to cut a mamooth in small pieces, so as to lead to the incorrect belief that only mice exist. In order to stimulate further research, we will document and discuss the dragon-king phenomenon on the statistics of financial losses, economic geography, hydrodynamic turbulence, mechanical ruptures, avalanches in complex heterogeneous media, earthquakes, and epileptic seizures. The special status of dragon-kings open a new research program on their predictability, based on the fact that they belong to a different class of their own and express specific mechanisms amplifying the normal dynamics via positive feedbacks. We will present evidence of these claims for the predictions of material rupture, financial crashes and epileptic seizures. As a bonus, a few remarks will be offered at the end on how the dragon-king phenomenon allows us to understand the present World financial crisis as underpinned in two decades of successive financial and economic bubbles, inflating the mother of all bubbles with new monster dragon-kings at the horizon. The consequences in terms of a new "normal" are eye-opening. Ref: D. Sornette, Dragon-Kings, Black Swans and the Prediction of Crises, International Journal of Terraspace Science and Engineering 1(3), 1-17 (2009) (http://arXiv.org/abs/0907.4290) and (http://ssrn.com/abstract=1470006)

A climatology of extreme wave height events impacting eastern Lake Ontario shorelines

NASA Astrophysics Data System (ADS)

Grieco, Matthew B.; DeGaetano, Arthur T.

2018-05-01

Model-derived wave height data for points along the eastern Lake Ontario shoreline provide the basis for a 36-year climatology of extreme wave heights. The most extreme wave heights exceed 6 m at all locations, except for those along the extreme northeastern shoreline of the Lake. Typically extreme wave events are a regional phenomenon, affecting multiple locations along the eastern and southeastern shoreline. A pronounced seasonal cycle in wave event occurrence is characterized by peaks in autumn and spring, with an absence of 99.9th percentile wave heights during summer. Less extreme (90th percentile heights) occur in all months with a peak in winter. Extreme wave events are most often associated with a low pressure center tracking to the north of Lake Ontario from the Ohio Valley. This track produces the strong winds > 10 ms-1 and predominantly west-to-east wind fetch that characterize high wave height events. The seasonal frequency of the wave events exceeding the historical 95th percentile has shown a statistically significant increase at most locations since 1979. This has been partially offset by declines in the frequency of events with wave heights between the 90 and 95th percentile. Seasonal extreme wave height frequency is also found to be related to the occurrence of El Niño. During El Niño winters, there are significantly fewer events with wave heights exceeding 2.5 m than would be expected by chance. A corresponding relationship to La Niña occurrence is not evident.

Morphological Characteristics of Particulate Material Formed from High Velocity Impact of Depleted Uranium Projectiles with Armor Targets

DTIC Science & Technology

1978-11-01

Magnification Showing Aggregation of Ultrafine Particles ; Gap Between Bars Represents 0.5 pm. .......... ... 15 iv LIST OF FIGURES (CONCLUDED) Figure Title...subsequent forma- tion of smaller particulates. An unexpected phenomenon was the formation of ultrafine particles less than 0.1 pm in diameter. These...and the highly reactive nature of pyrophoric depleted uranium. Ti ese ultrafine particles exhibited an extreme tendency to coalesce, probably due to

Fast temporal correlation between hard X-ray and ultraviolet continuum brightenings

NASA Technical Reports Server (NTRS)

Machado, Marcos E.; Mauas, Pablo J.

1986-01-01

Recent Solar Maximum Mission (SMM) observations have shown fast and simultaneous increases in hard X-rays (HXR, E25 keV) and ultraviolet continuum (UVC, lambda lambda approx. equals 1600 and 1388 A) radiation. A simple and natural explanation is given for this phenomenon to happen, which does not involve extreme conditions for energy transport processes, and confirms earlier results on the effect of XUV photoionization in the solar atmosphere.

Statistical treatment for the wet bias in tree-ring chronologies: A case study from the InteriorWest, USA

Treesearch

Yan Sun; Matthew F. Bekker; R. Justin DeRose; Roger Kjelgren; S. -Y. Simon Wang

2017-01-01

Dendroclimatic research has long assumed a linear relationship between tree-ring increment and climate variables. However, ring width frequently underestimates extremely wet years, a phenomenon we refer to as ‘wet bias’. In this paper, we present statistical evidence for wet bias that is obscured by the assumption of linearity. To improve tree-ring-climate modeling, we...

Social percolation models

NASA Astrophysics Data System (ADS)

Solomon, Sorin; Weisbuch, Gerard; de Arcangelis, Lucilla; Jan, Naeem; Stauffer, Dietrich

2000-03-01

We here relate the occurrence of extreme market shares, close to either 0 or 100%, in the media industry to a percolation phenomenon across the social network of customers. We further discuss the possibility of observing self-organized criticality when customers and cinema producers adjust their preferences and the quality of the produced films according to previous experience. Comprehensive computer simulations on square lattices do indeed exhibit self-organized criticality towards the usual percolation threshold and related scaling behaviour.

Chronic Expanding Hematoma in the Extremities: A Clinical Problem of Adhesion to the Surrounding Tissues

PubMed Central

Okamoto, Takeshi; Matsuda, Shuichi

2017-01-01

Chronic expanding hematoma is characterized by continuous growth of a blood collection. We analyzed the clinical features of 7 patients with chronic expanding hematomas in the extremities, with an average age of 65.6 years. All lesions occurred in the lower extremities, with 4 seen in the thigh and 3 in the knee region. Six patients had subcutaneous hematomas, while 1 was deep-seated in the thigh. The magnetic resonance features of the lesion were compatible with those of a standard hematoma. A low signal intensity on T1- and T2-weighted imaging at the pseudocapsule was also characteristic. Cystic features were seen in 5 of 7 patients. All lesions were resected together with their pseudocapsule. In the subcutaneous lesions, it was necessary to resect adherent fascia, with or without involved skin. In the deep-seated thigh lesion, the common peroneal nerve was completely adherent to the pseudocapsule, a phenomenon from absence of the common peroneal nerve which appeared after resection. Chronic expanding hematomas of the extremities are predominantly located in the subcutaneous tissue of the lower extremity. The surrounding pseudocapsule is adherent to the adjacent tissues, and clinicians must be aware of this, especially when resecting a deep-seated lesion. PMID:28642872

Forecasts and Warnings of Extreme Solar Storms at the Sun

NASA Astrophysics Data System (ADS)

Lundstedt, H.

2015-12-01

The most pressing space weather forecasts and warnings are those of the most intense solar flares and coronal mass ejections. However, in trying to develop these forecasts and warnings, we are confronted to many fundamental questions. Some of those are: How to define an observable measure for an extreme solar storm? How extreme can a solar storm become and how long is the build up time? How to make forecasts and warnings? Many have contributed to clarifying these general questions. In his presentation we will describe our latest results on the topological complexity of magnetic fields and the use of SDO SHARP parameters. The complexity concept will then be used to discuss the second question. Finally we will describe probability estimates of extreme solar storms.

Grounding of space structures

NASA Astrophysics Data System (ADS)

Bosela, P. A.; Fertis, D. G.; Shaker, F. J.

1992-09-01

Space structures, such as the Space Station solar arrays, must be extremely light-weight, flexible structures. Accurate prediction of the natural frequencies and mode shapes is essential for determining the structural adequacy of components, and designing a controls system. The tension pre-load in the 'blanket' of photovoltaic solar collectors, and the free/free boundary conditions of a structure in space, causes serious reservations on the use of standard finite element techniques of solution. In particular, a phenomenon known as 'grounding', or false stiffening, of the stiffness matrix occurs during rigid body rotation. This paper examines the grounding phenomenon in detail. Numerous stiffness matrices developed by others are examined for rigid body rotation capability, and found lacking. A force imbalance inherent in the formulations examined is the likely cause of the grounding problem, suggesting the need for a directed force formulation.

Influence of Anthropogenic Climate Change on Planetary Wave Resonance and Extreme Weather Events.

PubMed

Mann, Michael E; Rahmstorf, Stefan; Kornhuber, Kai; Steinman, Byron A; Miller, Sonya K; Coumou, Dim

2017-03-27

Persistent episodes of extreme weather in the Northern Hemisphere summer have been shown to be associated with the presence of high-amplitude quasi-stationary atmospheric Rossby waves within a particular wavelength range (zonal wavenumber 6-8). The underlying mechanistic relationship involves the phenomenon of quasi-resonant amplification (QRA) of synoptic-scale waves with that wavenumber range becoming trapped within an effective mid-latitude atmospheric waveguide. Recent work suggests an increase in recent decades in the occurrence of QRA-favorable conditions and associated extreme weather, possibly linked to amplified Arctic warming and thus a climate change influence. Here, we isolate a specific fingerprint in the zonal mean surface temperature profile that is associated with QRA-favorable conditions. State-of-the-art ("CMIP5") historical climate model simulations subject to anthropogenic forcing display an increase in the projection of this fingerprint that is mirrored in multiple observational surface temperature datasets. Both the models and observations suggest this signal has only recently emerged from the background noise of natural variability.

Gender, Education, Extremism and Security

ERIC Educational Resources Information Center

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…

The Primary Physical Education Curriculum Process: More Complex That You Might Think!!

ERIC Educational Resources Information Center

Jess, Mike; Carse, Nicola; Keay, Jeanne

2016-01-01

In this paper, we present the curriculum development process as a complex, iterative and integrated phenomenon. Building on the early work of Stenhouse [1975, "An Introduction to Curriculum Research and Development". London: Heinemann Educational], we position the teacher at the heart of this process and extend his ideas by exploring how…

Deconstructing sexual orientation: understanding the phenomena of sexual orientation.

PubMed

Stein, T S

1997-01-01

The very terms of a debate about whether or not sexual orientation is primarily a biological phenomenon fail to consider the complex origins of the phenomenon. Deconstruction of the term "homosexuality" shows that it refers to multiple factors which cannot be studied as or subsumed under a unitary concept. Adequate understanding of sexual orientation must consider the developmental, interpersonal, experiential, and cultural dimensions of sexuality, as well as any biological contributions to sexual attraction, behavior, and identity.

Phenomenon of low-alloy steel parametrization transformation at cyclic loading in low-cyclic area

NASA Astrophysics Data System (ADS)

Shipachev, A. M.; Nazarova, M. N.

2017-10-01

Following the results of measurements of hardness, magnetizing force and the rate of ultrasonic longitudinal waves of 09G2S steel samples at various cyclic operating time values, there is a phenomenon of transformation from the normal law of speed distribution of these parameters in power-mode distribution. It shows the submission of the behavior of metal as a complex system to the theory of the self-organized criticality.

Genetic addiction: selfish gene's strategy for symbiosis in the genome.

PubMed

Mochizuki, Atsushi; Yahara, Koji; Kobayashi, Ichizo; Iwasa, Yoh

2006-02-01

The evolution and maintenance of the phenomenon of postsegregational host killing or genetic addiction are paradoxical. In this phenomenon, a gene complex, once established in a genome, programs death of a host cell that has eliminated it. The intact form of the gene complex would survive in other members of the host population. It is controversial as to why these genetic elements are maintained, due to the lethal effects of host killing, or perhaps some other properties are beneficial to the host. We analyzed their population dynamics by analytical methods and computer simulations. Genetic addiction turned out to be advantageous to the gene complex in the presence of a competitor genetic element. The advantage is, however, limited in a population without spatial structure, such as that in a well-mixed liquid culture. In contrast, in a structured habitat, such as the surface of a solid medium, the addiction gene complex can increase in frequency, irrespective of its initial density. Our demonstration that genomes can evolve through acquisition of addiction genes has implications for the general question of how a genome can evolve as a community of potentially selfish genes.

The Beaker phenomenon and the genomic transformation of northwest Europe.

PubMed

Olalde, Iñigo; Brace, Selina; Allentoft, Morten E; Armit, Ian; Kristiansen, Kristian; Booth, Thomas; Rohland, Nadin; Mallick, Swapan; Szécsényi-Nagy, Anna; Mittnik, Alissa; Altena, Eveline; Lipson, Mark; Lazaridis, Iosif; Harper, Thomas K; Patterson, Nick; Broomandkhoshbacht, Nasreen; Diekmann, Yoan; Faltyskova, Zuzana; Fernandes, Daniel; Ferry, Matthew; Harney, Eadaoin; de Knijff, Peter; Michel, Megan; Oppenheimer, Jonas; Stewardson, Kristin; Barclay, Alistair; Alt, Kurt Werner; Liesau, Corina; Ríos, Patricia; Blasco, Concepción; Miguel, Jorge Vega; García, Roberto Menduiña; Fernández, Azucena Avilés; Bánffy, Eszter; Bernabò-Brea, Maria; Billoin, David; Bonsall, Clive; Bonsall, Laura; Allen, Tim; Büster, Lindsey; Carver, Sophie; Navarro, Laura Castells; Craig, Oliver E; Cook, Gordon T; Cunliffe, Barry; Denaire, Anthony; Dinwiddy, Kirsten Egging; Dodwell, Natasha; Ernée, Michal; Evans, Christopher; Kuchařík, Milan; Farré, Joan Francès; Fowler, Chris; Gazenbeek, Michiel; Pena, Rafael Garrido; Haber-Uriarte, María; Haduch, Elżbieta; Hey, Gill; Jowett, Nick; Knowles, Timothy; Massy, Ken; Pfrengle, Saskia; Lefranc, Philippe; Lemercier, Olivier; Lefebvre, Arnaud; Martínez, César Heras; Olmo, Virginia Galera; Ramírez, Ana Bastida; Maurandi, Joaquín Lomba; Majó, Tona; McKinley, Jacqueline I; McSweeney, Kathleen; Mende, Balázs Gusztáv; Modi, Alessandra; Kulcsár, Gabriella; Kiss, Viktória; Czene, András; Patay, Róbert; Endrődi, Anna; Köhler, Kitti; Hajdu, Tamás; Szeniczey, Tamás; Dani, János; Bernert, Zsolt; Hoole, Maya; Cheronet, Olivia; Keating, Denise; Velemínský, Petr; Dobeš, Miroslav; Candilio, Francesca; Brown, Fraser; Fernández, Raúl Flores; Herrero-Corral, Ana-Mercedes; Tusa, Sebastiano; Carnieri, Emiliano; Lentini, Luigi; Valenti, Antonella; Zanini, Alessandro; Waddington, Clive; Delibes, Germán; Guerra-Doce, Elisa; Neil, Benjamin; Brittain, Marcus; Luke, Mike; Mortimer, Richard; Desideri, Jocelyne; Besse, Marie; Brücken, Günter; Furmanek, Mirosław; Hałuszko, Agata; Mackiewicz, Maksym; Rapiński, Artur; Leach, Stephany; Soriano, Ignacio; Lillios, Katina T; Cardoso, João Luís; Pearson, Michael Parker; Włodarczak, Piotr; Price, T Douglas; Prieto, Pilar; Rey, Pierre-Jérôme; Risch, Roberto; Rojo Guerra, Manuel A; Schmitt, Aurore; Serralongue, Joël; Silva, Ana Maria; Smrčka, Václav; Vergnaud, Luc; Zilhão, João; Caramelli, David; Higham, Thomas; Thomas, Mark G; Kennett, Douglas J; Fokkens, Harry; Heyd, Volker; Sheridan, Alison; Sjögren, Karl-Göran; Stockhammer, Philipp W; Krause, Johannes; Pinhasi, Ron; Haak, Wolfgang; Barnes, Ian; Lalueza-Fox, Carles; Reich, David

2018-03-08

From around 2750 to 2500 bc, Bell Beaker pottery became widespread across western and central Europe, before it disappeared between 2200 and 1800 bc. The forces that propelled its expansion are a matter of long-standing debate, and there is support for both cultural diffusion and migration having a role in this process. Here we present genome-wide data from 400 Neolithic, Copper Age and Bronze Age Europeans, including 226 individuals associated with Beaker-complex artefacts. We detected limited genetic affinity between Beaker-complex-associated individuals from Iberia and central Europe, and thus exclude migration as an important mechanism of spread between these two regions. However, migration had a key role in the further dissemination of the Beaker complex. We document this phenomenon most clearly in Britain, where the spread of the Beaker complex introduced high levels of steppe-related ancestry and was associated with the replacement of approximately 90% of Britain's gene pool within a few hundred years, continuing the east-to-west expansion that had brought steppe-related ancestry into central and northern Europe over the previous centuries.

Phytotoxic activity against Bromus tectorum for secondary metabolites of a seed-pathogenic Fusarium strain belonging to the F. tricinctum species complex

Treesearch

Marco Masi; Susan Meyer; Gennaro Pescitelli; Alessio Cimmino; Suzette Clement; Beth Peacock; Antonio Evidente

2017-01-01

The winter annual grass Bromus tectorum (cheatgrass) has become highly invasive in semiarid ecosystems of western North America. In these areas, a natural phenomenon, complete cheatgrass stand failure (‘die-off’), is apparently caused by a complex interaction among soilborne fungal pathogens. Several Fusarium strains belonging to the Fusarium tricinctum species complex...

Rethinking Use of the OML Model in Electric Sail Development

NASA Technical Reports Server (NTRS)

Stone, Nobie H.

2016-01-01

In 1924, Irvin Langmuir and H. M. Mott-Smith published a theoretical model for the complex plasma sheath phenomenon in which they identified some very special cases which greatly simplified the sheath and allowed a closed solution to the problem. The most widely used application is for an electrostatic, or "Langmuir," probe in laboratory plasma. Although the Langmuir probe is physically simple (a biased wire) the theory describing its functional behavior and its current-voltage characteristic is extremely complex and, accordingly, a number of assumptions and approximations are used in the LMS model. These simplifications, correspondingly, place limits on the model's range of application. Adapting the LMS model to real-life conditions is the subject of numerous papers and dissertations. The Orbit-Motion Limited (OML) model that is widely used today is one of these adaptions that is a convenient means of calculating sheath effects. Since the Langmuir probe is a simple biased wire immersed in plasma, it is particularly tempting to use the OML equation in calculating the characteristics of the long, highly biased wires of an Electric Sail in the solar wind plasma. However, in order to arrive at the OML equation, a number of additional simplifying assumptions and approximations (beyond those made by Langmuir-Mott-Smith) are necessary. The OML equation is a good approximation when all conditions are met, but it would appear that the Electric Sail problem lies outside of the limits of applicability.

Multimodal drugs and their future for Alzheimer's and Parkinson's disease.

PubMed

Van der Schyf, Cornelis J; Geldenhuys, Werner J

2011-01-01

This chapter discusses the rationale for developing multimodal or multifunctional drugs (also called designed multiple ligands or DMLs) aimed at disease-modifying treatment strategies for the most common neurodegenerative diseases Alzheimer's and Parkinson's disease (AD and PD). Both the prevalence and incidence of AD and PD have seen consistent and dramatic increases, a disconcerting phenomenon which, ironically, has been attributed to extended life expectancy brought about by better health care globally. In spite of these statistics, the development and introduction to the clinic of new therapies proven to prevent or delay the onset of AD and PD have been disappointing. Evidence has accumulated to suggest that the etiopathology of these diseases is extremely complex, with an array of potential drug targets located within a number of deleterious biochemical pathways. Therefore, in these diseases, it is unlikely that the complex pathoetiological cascade leading to disease initiation or progression will be mitigated by any one drug acting on a single pathway or target. The pursuit of novel DMLs may offer far better outcomes. Although certainly not the only, and perhaps not even the best, approach but farthest along the drug development pipeline in the DML paradigm are drugs that combine inhibition of monoamine oxidase with associated etiological targets unique to either AD or PD. These compounds will constitute the major focus of this chapter, which will also explore radically new paradigms that seek to combine cognitive enhancers with proneurogenesis compounds. Copyright © 2011 Elsevier Inc. All rights reserved.

Deciphering landscape complexity to predict (non)linear responses to extreme climatic events

USDA-ARS?s Scientific Manuscript database

Extreme events are increasing in frequency and magnitude for many landscapes globally. Ecologically, most of the focus on extreme climatic events has been on effects of either short-term pulses (floods, freezes) or long-term drought. Multi-year increases in precipitation are also occurring with litt...

Risk of Crew Adverse Health Event Due to Altered Immune Response

NASA Technical Reports Server (NTRS)

Crucian, Brian; Kunz, Hawley; Sams, Clarence F.

2015-01-01

Determining the effect of space travel on the human immune system has proven to be extremely challenging. Limited opportunities for in-flight studies, varying mission durations, technical and logistical obstacles, small subject numbers, and a broad range of potential assays have contributed to this problem. Additionally, the inherent complexity of the immune system, with its vast array of cell populations, sub-populations, diverse regulatory molecules, and broad interactions with other physiological systems, makes determining precise variables to measure very difficult. There is also the challenge of determining the clinical significance of any observed immune alterations. Will such a change lead to disease, or is it a transient subclinical observation related to short-term stress? The effect of this problem may be observed by scanning publications associated with immunity and spaceflight, which began to appear during the 1970s. Although individually they are each valid studies, the comprehensive literature to date suffers from widely varying sampling methods and assay techniques, low subject counts, and sometimes a disparate focus on narrow aspects of immunity. The most clinically relevant data are derived from in-flight human studies, which have demonstrated altered cell-mediated immunity and reactivation of latent herpes viruses. Much more data are available from post-flight testing of humans, with clear evidence of altered cytokine production patterns, altered leukocyte distribution, continued latent viral reactivation, and evidence of dramatically altered virus-specific immunity. It is unknown if post-flight assessments relate to the in-flight condition or are a response to landing stress and readaptation. In-flight culture of cells has clearly demonstrated that immune cells are gravity-sensitive and display altered functional characteristics. It is unknown if these data are related to in vivo immune cell function or are an artifact of microgravity culture. Ground analog testing of humans and animals, as well as microgravity-analog cell culture, has demonstrated utility. However, in all cases, it is not known with certainty if these data would reflect similar testing during space travel. Given their ready availability, ground analogs may be extremely useful for assay development and the evaluation of potential countermeasures. In general, the evidence base suffers from widely disparate studies on small numbers of subjects that do not directly correlate well with each other or spaceflight itself. Also lacking are investigations of the effect of gender on adaption to spaceflight. This results in significant knowledge 'gaps' that must be filled by future studies to completely determine any clinical risk related to immunity for human exploration-class space missions. These gaps include a significant lack of in-flight data, particularly during long-duration space missions. The International Space Station represents an excellent science platform with which to address this knowledge gap. Other knowledge gaps include lack of a single validated ground analog for the phenomenon and a lack of flight-compatible laboratory equipment capable of monitoring astronauts (for either clinical or research purposes). However, enough significant data exist, as described in this manuscript, to warrant addressing this phenomenon during the utilization phase of the ISS. A recent Space Shuttle investigation has confirmed the 31 in-flight nature of immune dysregulation, demonstrating that it is not merely a post-flight phenomenon. Several current studies are ongoing onboard the ISS that should thoroughly characterize the phenomenon. NASA recognizes that if spaceflight-associated immune dysregulation persists during exploration flights in conjunction with other dangers, such as high-energy radiation, the result may be a significant clinical risk. This emphasizes the need for a continued integrated comprehensive approach to determining the effect of prolonged spaceflight, separated from transient launch and landing stresses, on human immunity. After such studies, the phenomenon will be understood, and, hopefully, a monitoring strategy will have been developed that could be used to monitor the effectiveness of countermeasure

Spontaneous De-Icing Phenomena on Extremely Cold Surfaces

NASA Astrophysics Data System (ADS)

Song, Dong; Choi, Chang-Hwan

2017-11-01

Freezing of droplets on cold surfaces is universal phenomenon, while the mechanisms are still inadequately understood. Here we report spontaneous de-icing phenomena of an impacting droplet which occur on extreme cold surfaces. When a droplet impacts on cold surfaces lower than -80°, it takes more than two times longer for the droplet to freeze than the ones at -50°. Moreover, the frozen droplet below -80° breaks up into several large parts spontaneously in the end. When a droplet impacts on the extreme cold surfaces, evaporation and condensation occur immediately as the droplet approaches the substrate. A thick layer of frost forms between the droplet and substrate, decreasing the contact area of the droplet with substrate. It leads to impede the heat transfer and hence extends the freezing time significantly. On the extremely cold substrate, the droplet freezes from the center to the edge area, in contrast to a typical case freezing from the bottom to the top. This novel from-center-to-edge freezing process changes the internal tension of the frozen droplet and results in the instantaneous breakup and release eventually, which can be taken advantage of for effective deicing mechanisms.

Toward Zero Micro/Macro-Scale Wear Using Periodic Nano-Layered Coatings.

PubMed

Penkov, Oleksiy V; Devizenko, Alexander Yu; Khadem, Mahdi; Zubarev, Evgeniy N; Kondratenko, Valeriy V; Kim, Dae-Eun

2015-08-19

Wear is an important phenomenon that affects the efficiency and life of all moving machines. In this regard, extensive efforts have been devoted to achieve the lowest possible wear in sliding systems. With the advent of novel materials in recent years, technology is moving toward realization of zero wear. Here, we report on the development of new functional coatings comprising periodically stacked nanolayers of amorphous carbon and cobalt that are extremely wear resistant at the micro and macro scale. Because of their unique structure, these coatings simultaneously provide high elasticity and ultrahigh shear strength. As a result, almost zero wear was observed even after one million sliding cycles without any lubrication. The wear rate was reduced by 8-10-fold compared with the best previously reported data on extremely low wear materials.

Optical rogue waves and stimulated supercontinuum generation

NASA Astrophysics Data System (ADS)

Solli, Daniel R.; Ropers, Claus; Jalali, Bahram

2010-06-01

Nonlinear action is known for its ability to create unusual phenomena and unexpected events. Optical rogue waves-freak pulses of broadband light arising in nonlinear fiber-testify to the fact that optical nonlinearities are no less capable of generating anomalous events than those in other physical contexts. In this paper, we will review our work on optical rogue waves, an ultrafast phenomenon counterpart to the freak ocean waves known to roam the open oceans. We will discuss the experimental observation of these rare events in real time and the measurement of their heavytailed statistical properties-a probabilistic form known to appear in a wide variety of other complex systems from financial markets to genetics. The nonlinear Schrödinger equation predicts the existence of optical rogue waves, offering a means to study their origins with simulations. We will also discuss the type of initial conditions behind optical rogue waves. Because a subtle but specific fluctuation leads to extreme waves, the rogue wave instability can be harnessed to produce these events on demand. By exploiting this property, it is possible to produce a new type of optical switch as well as a supercontinuum source that operates in the long pulse regime but still achieves a stable, coherent output.

Modeling the melting of multicomponent systems: the case of MgSiO3 perovskite under lower mantle conditions

PubMed Central

Di Paola, Cono; P. Brodholt, John

2016-01-01

Knowledge of the melting properties of materials, especially at extreme pressure conditions, represents a long-standing scientific challenge. For instance, there is currently considerable uncertainty over the melting temperatures of the high-pressure mantle mineral, bridgmanite (MgSiO3-perovskite), with current estimates of the melting T at the base of the mantle ranging from 4800 K to 8000 K. The difficulty with experimentally measuring high pressure melting temperatures has motivated the use of ab initio methods, however, melting is a complex multi-scale phenomenon and the timescale for melting can be prohibitively long. Here we show that a combination of empirical and ab-initio molecular dynamics calculations can be used to successfully predict the melting point of multicomponent systems, such as MgSiO3 perovskite. We predict the correct low-pressure melting T, and at high-pressure we show that the melting temperature is only 5000 K at 120 GPa, a value lower than nearly all previous estimates. In addition, we believe that this strategy is of general applicability and therefore suitable for any system under physical conditions where simpler models fail. PMID:27444854

Modeling borderline personality disorder based on the neurobehavioral foundation of major personality traits.

PubMed

Depue, Richard A; Fu, Yu

2012-03-01

Borderline personality disorder (BPD) is an exceedingly complex behavioral phenomenon that is in need of conceptual clarification within a larger model of personality disorders (PDs). The association of personality traits to BPD is discussed initially as a means of introducing a dimensional personality approach to understanding BPD. While this model suggests that PDs emerge at the extremes of personality dimensions, attempts to demonstrate such an association have been empirically disappointing and conceptually unilluminating. Therefore, in this article, we attempt to extend such models by outlining the neurobehavioral systems that underlie major personality traits, and highlight the evidence that they are subject to experience-dependent modification that can be enduring through effects on genetic expression, mainly through processes known as epigenetics. It is through such processes that risk for personality disorder may be modified by experience at any point in development, but perhaps especially during early critical periods of development. We conclude by presenting a multidimensional model of PDs, in general, and BPD, in particular, that relies on the concepts developed earlier in the article. Our goal is to provide a guide for novel clinical conceptualization and assessment of PDs, as well as research on their psychobiological nature and pharmacological treatment.

A semi-analytical model of a time reversal cavity for high-amplitude focused ultrasound applications

NASA Astrophysics Data System (ADS)

Robin, J.; Tanter, M.; Pernot, M.

2017-09-01

Time reversal cavities (TRC) have been proposed as an efficient approach for 3D ultrasound therapy. They allow the precise spatio-temporal focusing of high-power ultrasound pulses within a large region of interest with a low number of transducers. Leaky TRCs are usually built by placing a multiple scattering medium, such as a random rod forest, in a reverberating cavity, and the final peak pressure gain of the device only depends on the temporal length of its impulse response. Such multiple scattering in a reverberating cavity is a complex phenomenon, and optimisation of the device’s gain is usually a cumbersome process, mostly empirical, and requiring numerical simulations with extremely long computation times. In this paper, we present a semi-analytical model for the fast optimisation of a TRC. This model decouples ultrasound propagation in an empty cavity and multiple scattering in a multiple scattering medium. It was validated numerically and experimentally using a 2D-TRC and numerically using a 3D-TRC. Finally, the model was used to determine rapidly the optimal parameters of the 3D-TRC which had been confirmed by numerical simulations.

A model for competitiveness level analysis in sports competitions: Application to basketball

NASA Astrophysics Data System (ADS)

de Saá Guerra, Y.; Martín González, J. M.; Sarmiento Montesdeoca, S.; Rodríguez Ruiz, D.; García-Rodríguez, A.; García-Manso, J. M.

2012-05-01

The degree of overall competitiveness of a sport league is a complex phenomenon. It is difficult to assess and quantify all elements that yield the final standing. In this paper, we analyze the general behavior of the result matrices of each season and we use the corresponding results as a probably density. Thus, the results of previous seasons are a way to investigate the probability that each team has to reach a certain number of victories. We developed a model based on Shannon entropy using two extreme competitive structures (a hierarchical structure and a random structure), and applied this model to investigate the competitiveness of two of the best professional basketball leagues: the NBA (USA) and the ACB (Spain). Both leagues’ entropy levels are high (NBA mean 0.983; ACB mean 0.980), indicating high competitiveness, although the entropy of the ACB (from 0.986 to 0.972) demonstrated more seasonal variability than that of the NBA (from 0.985 to 0.990), a possible result of greater sporting gradients in the ACB. The use of this methodology has proven useful for investigating the competitiveness of sports leagues as well as their underlying variability across time.

Photoacoustic detection of induced melanoma in vitro using a mouse model

NASA Astrophysics Data System (ADS)

Gupta, Sagar; Bhattacharya, Kiran; Newton, Jessica R.; Quinn, Thomas P.; Viator, John A.

2012-03-01

Metastasis is a life threatening complex physiological phenomenon that involves the movement of cancer cells from one organ to another by means of blood and lymph. An understanding about metastasis is extremely important to device diagnostic systems to detect and monitor its spread within the body. For the first time we report rapid photoacoustic detection of the induced metastatic melanoma in mice in vitro using photoacoustic flowmetry. A new photoacoustic flow system is developed, that employs photoacoustic excitation coupled with an ultrasound transducer capable of determining the presence of individual, induced mouse melanoma cells (B16/F10) within the circulating system in vitro. Tumor was induced in mice by injecting mouse melanoma cells through tail vein into the C57BL/6 mice. A luciferase based in vivo bioluminescence imaging is performed to confirm the tumor load and multiple metastases in the tumor-induced mice. 1ml of blood obtained through cardiac puncture of the induced metastasized mice was treated to lyse the red blood cells (RBC) and enriched, leaving the induced melanoma in the peripheral blood mononuclear suspension (PBMC). A photoacoustic flowsystem coupled with an ultrasound transducer is used to detect the individual circulating metastatic melanoma cells from the enriched cell suspension.

Highly sensitive protein detection using a plasmonic field effect transistor (Conference Presentation)

NASA Astrophysics Data System (ADS)

Shokri-Kojori, Hossein; Ji, Yiwen; Han, Xu; Paik, Younghun; Braunschweig, Adam; Kim, Sung Jin

2016-03-01

Localized surface Plasmon Resonance (LSPR) is a nanoscale phenomenon which presents strong resonance associated with noble metal nanostructures. This plasmon resonance based technology enables highly sensitive detection for chemical and biological applications. Recently, we have developed a plasmon field effect transistor (FET) that enables direct plasmonic-to-electric signal conversion with signal amplification. The plasmon FET consists of back-gated field effect transistor incorporated with gold nanoparticles on top of the FET channel. The gold nanostructures are physically separated from transistor electrodes and can be functionalized for a specific biological application. In this presentation, we report a successful demonstration of a model system to detect Con A proteins using Carbohydrate linkers as a capture molecule. The plasmon FET detected a very low concentration of Con A (0.006 mg/L) while it offers a wide dynamic range of 0.006-50 mg/L. In this demonstration, we used two-color light sources instead of a bulky spectrometer to achieve high sensitivity and wide dynamic range. The details of two-color based differential measurement method will be discussed. This novel protein-based sensor has several advantages such as extremely small size for point-of-care system, multiplexing capability, no need of complex optical geometry.

Fracture Mechanics Analyses of the Slip-Side Joggle Regions of Wing-Leading-Edge Panels

NASA Technical Reports Server (NTRS)

Raju, Ivatury S.; Knight, Norman F., Jr.; Song, Kyongchan; Phillips, Dawn R.

2011-01-01

The Space Shuttle wing-leading edge consists of panels that are made of reinforced carbon-carbon. Coating spallation was observed near the slip-side region of the panels that experience extreme heating. To understand this phenomenon, a root-cause investigation was conducted. As part of that investigation, fracture mechanics analyses of the slip-side joggle regions of the hot panels were conducted. This paper presents an overview of the fracture mechanics analyses.

PANORAMA: An approach to performance modeling and diagnosis of extreme-scale workflows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deelman, Ewa; Carothers, Christopher; Mandal, Anirban

Here we report that computational science is well established as the third pillar of scientific discovery and is on par with experimentation and theory. However, as we move closer toward the ability to execute exascale calculations and process the ensuing extreme-scale amounts of data produced by both experiments and computations alike, the complexity of managing the compute and data analysis tasks has grown beyond the capabilities of domain scientists. Therefore, workflow management systems are absolutely necessary to ensure current and future scientific discoveries. A key research question for these workflow management systems concerns the performance optimization of complex calculation andmore » data analysis tasks. The central contribution of this article is a description of the PANORAMA approach for modeling and diagnosing the run-time performance of complex scientific workflows. This approach integrates extreme-scale systems testbed experimentation, structured analytical modeling, and parallel systems simulation into a comprehensive workflow framework called Pegasus for understanding and improving the overall performance of complex scientific workflows.« less

PANORAMA: An approach to performance modeling and diagnosis of extreme-scale workflows

DOE PAGES

Deelman, Ewa; Carothers, Christopher; Mandal, Anirban; ...

2015-07-14

Here we report that computational science is well established as the third pillar of scientific discovery and is on par with experimentation and theory. However, as we move closer toward the ability to execute exascale calculations and process the ensuing extreme-scale amounts of data produced by both experiments and computations alike, the complexity of managing the compute and data analysis tasks has grown beyond the capabilities of domain scientists. Therefore, workflow management systems are absolutely necessary to ensure current and future scientific discoveries. A key research question for these workflow management systems concerns the performance optimization of complex calculation andmore » data analysis tasks. The central contribution of this article is a description of the PANORAMA approach for modeling and diagnosing the run-time performance of complex scientific workflows. This approach integrates extreme-scale systems testbed experimentation, structured analytical modeling, and parallel systems simulation into a comprehensive workflow framework called Pegasus for understanding and improving the overall performance of complex scientific workflows.« less

Personal storytelling and the metaphor of belonging.

PubMed

Griffith, E E

1995-01-01

The author uses the idiom of autobiographical storytelling to explicate two important themes: How the complex phenomenon of 'belonging' results from the interactions of members of a nondominant group and those of a dominant group; and how the author himself has dealt with this phenomenon in his own developmental adaptation over the years. The concept of belonging is a cultural principle that should be thoroughly understood by mental health professionals if they are to deal effectively with the problem of cross-cultural adaptation.

Intermittency of intermittencies

NASA Astrophysics Data System (ADS)

Hramov, Alexander E.; Koronovskii, Alexey A.; Moskalenko, Olga I.; Zhuravlev, Maxim O.; Ponomarenko, Vladimir I.; Prokhorov, Mikhail D.

2013-09-01

A phenomenon of intermittency of intermittencies is discovered in the temporal behavior of two coupled complex systems. We observe for the first time the coexistence of two types of intermittent behavior taking place simultaneously near the boundary of the synchronization regime of coupled chaotic oscillators. This phenomenon is found both in the numerical and physiological experiments. The laws for both the distribution and mean length of laminar phases versus the control parameter values are analytically deduced. A very good agreement between the theoretical results and simulation is shown.

On vibrational circular dichroism chirality transfer in electron donor-acceptor complexes: a prediction for the quinine···BF3 system.

PubMed

Rode, Joanna E; Jamróz, Michał H; Dobrowolski, Jan Cz; Sadlej, Joanna

2012-08-02

Vibrational circular dichroism (VCD) chirality transfer occurs when an achiral molecule interacts with a chiral one and becomes VCD-active. Unlike for H-bonds, for organic electron donor-acceptor (EDA) complexes this phenomenon remains almost unknown. Here, the VCD chirality transfer from chiral quinine to achiral BF3 is studied at the B3LYP/aug-cc-pVDZ level. Accessibility of four quinine electron donor sites changes with conformation. Therefore, the quinine conformational landscape was explored and a considerable agreement between X-ray and the most stable conformer geometries was achieved. The BF3 complex through the aliphatic quinuclidine N atom is definitely dominating and is predicted to be easily recognizable in the VCD spectrum. Out of several VCD chirality transfer modes, the ν(s)(BF3) mode, the most intense in the entire VCD spectrum, satisfies the VCD mode robustness criterion and can be used for monitoring the chirality transfer phenomenon in quinine···BF3 system.

Can a few fanatics influence the opinion of a large segment of a society?

NASA Astrophysics Data System (ADS)

Stauffer, D.; Sahimi, M.

2007-05-01

Models that provide insight into how extreme positions regarding any social phenomenon may spread in a society or at the global scale are of great current interest. A realistic model must account for the fact that globalization, internet, and other means of mass communications have given rise to scale-free networks of interactions between people. We propose a novel model which takes into account the nature of the interactions network, and provides some key insights into this phenomenon. These include, (1) the existence of a fundamental difference between a hierarchical network whereby people are influenced by those that are higher in the hierarchy but not by those below them, and a symmetrical network where person-on-person influence works mutually, and (2) that a few “fanatics” can influence a large fraction of the population either temporarily (in the hierarchical networks) or permanently (in symmetrical networks). Even if the “fanatics” disappear, the population may still remain susceptible to the positions originally advocated by them. The model is, however, general and applicable to any phenomenon for which there is a degree of enthusiasm or susceptibility to in the population.

From lepton protoplasm to the genesis of hadrons

NASA Astrophysics Data System (ADS)

Eliseev, S. M.; Kosmachev, O. S.

2016-01-01

Theory of matter under extreme conditions opens a new stage in particle physics. It is necessary here to combine Dirac's elementary particle physics with Prigogine's dynamics of nonequilibrium systems. In the article we discuss the problem of the hierarchy of complexity. What can be considered as the lowest level of the organization of extreme matter on the basis of which the self-organization of the complex form occur?

Harnessing the Power of Play: Opportunities for Children with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Mastrangelo, Sonia

2009-01-01

Play is a complex phenomenon that occurs naturally for most children; they move through the various stages of play development and are able to add complexity, imagination, and creativity to their thought processes and actions. However, for many children with autism spectrum disorders (ASD), the various stages of play never truly develop, or occur…

The Phenomenon of Learning: The Lived Experience of Distance Education Baccalaureate Nursing Students

ERIC Educational Resources Information Center

Della Vecchia, Elaine T.

2010-01-01

The complex profession of nursing requires the practitioner to be knowledgeable, skilled, and autonomous. It is estimated that only 34.2% of today's nurses hold degrees at the baccalaureate level and above. Growing evidence indicating baccalaureate-degreed nurses are better prepared to meet the demands of this complex profession has led to…

Capturing rogue waves by multi-point statistics

NASA Astrophysics Data System (ADS)

Hadjihosseini, A.; Wächter, Matthias; Hoffmann, N. P.; Peinke, J.

2016-01-01

As an example of a complex system with extreme events, we investigate ocean wave states exhibiting rogue waves. We present a statistical method of data analysis based on multi-point statistics which for the first time allows the grasping of extreme rogue wave events in a highly satisfactory statistical manner. The key to the success of the approach is mapping the complexity of multi-point data onto the statistics of hierarchically ordered height increments for different time scales, for which we can show that a stochastic cascade process with Markov properties is governed by a Fokker-Planck equation. Conditional probabilities as well as the Fokker-Planck equation itself can be estimated directly from the available observational data. With this stochastic description surrogate data sets can in turn be generated, which makes it possible to work out arbitrary statistical features of the complex sea state in general, and extreme rogue wave events in particular. The results also open up new perspectives for forecasting the occurrence probability of extreme rogue wave events, and even for forecasting the occurrence of individual rogue waves based on precursory dynamics.

Observation and theory of X-ray mirages

PubMed Central

Magnitskiy, Sergey; Nagorskiy, Nikolay; Faenov, Anatoly; Pikuz, Tatiana; Tanaka, Mamoko; Ishino, Masahiko; Nishikino, Masaharu; Fukuda, Yuji; Kando, Masaki; Kawachi, Tetsuya; Kato, Yoshiaki

2013-01-01

The advent of X-ray lasers allowed the realization of compact coherent soft X-ray sources, thus opening the way to a wide range of applications. Here we report the observation of unexpected concentric rings in the far-field beam profile at the output of a two-stage plasma-based X-ray laser, which can be considered as the first manifestation of a mirage phenomenon in X-rays. We have developed a method of solving the Maxwell–Bloch equations for this problem, and find that the experimentally observed phenomenon is due to the emergence of X-ray mirages in the plasma amplifier, appearing as phase-matched coherent virtual point sources. The obtained results bring a new insight into the physical nature of amplification of X-ray radiation in laser-induced plasma amplifiers and open additional opportunities for X-ray plasma diagnostics and extreme ultraviolet lithography. PMID:23733009

"Rogue" lymphocytes among Ukrainians not exposed to radioactive fall-out from the Chernobyl accident: the possible role of this phenomenon in oncogenesis, teratogenesis, and mutagenesis.

PubMed Central

Neel, J V; Awa, A A; Kodama, Y; Nakano, M; Mabuchi, K

1992-01-01

Cultured lymphocytes exhibiting extreme cytogenetic damage (rogue cells) were observed in preparations from 8 of 24 individuals sampled in Krasilovka, a Ukrainian village receiving little or no increased radiation after the Chernobyl disaster, but were not observed in an additional 24 persons from two Russian towns in the more contaminated area. This observation cements the worldwide occurrence of these cells. The present data plus a review of the literature establish that rogue cells appear in brief bursts simultaneously in certain individuals of discrete populations. We suggest that the pattern is consistent with the action of a viral trigger that acts directly or indirectly--the latter possibly through the activation of latent chromosomal retroposons. If this phenomenon occurs in other tissues, it may have important implications for oncogenesis, teratogenesis, mutagenesis, and evolution. Images PMID:1495988

Pathological Laughter as a Symptom of Midbrain Infarction

PubMed Central

Dabby, Ron; Watemberg, Nathan; Lampl, Yair; Eilam, Anda; Rapaport, Abraham; Sadeh, Menachem

2004-01-01

Pathological laughter is an uncommon symptom usually caused by bilateral, diffuse cerebral lesions. It has rarely been reported in association with isolated cerebral lesions. Midbrain involvement causing pathological laughter is extremely unusual. We describe three patients who developed pathological laughter after midbrain and pontine-midbrain infarction. In two patients a small infarction in the left paramedian midbrain was detected, whereas the third one sustained a massive bilateral pontine infarction extending to the midbrain. Laughter heralded stroke by one day in one patient and occurred as a delayed phenomenon three months after stroke in another. Pathological laughter ceased within a few days in two patients and was still present at a two year follow-up in the patient with delayed-onset laughter. Pathological laughter can herald midbrain infarction or follow stroke either shortly after onset of symptoms or as a delayed phenomenon. Furthermore, small unilateral midbrain infarctions can cause this rare complication. PMID:15706050

Self-peeling of impacting droplets

NASA Astrophysics Data System (ADS)

de Ruiter, Jolet; Soto, Dan; Varanasi, Kripa K.

2018-01-01

Whether an impacting droplet sticks or not to a solid surface has been conventionally controlled by functionalizing the target surface or by using additives in the drop. Here we report on an unexpected self-peeling phenomenon that can happen even on smooth untreated surfaces by taking advantage of the solidification of the impacting drop and the thermal properties of the substrate. We control this phenomenon by tuning the coupling of the short-timescale fluid dynamics--leading to interfacial defects upon local freezing--and the longer-timescale thermo-mechanical stresses--leading to global deformation. We establish a regime map that predicts whether a molten metal drop impacting onto a colder substrate will bounce, stick or self-peel. In many applications, avoiding adhesion of impacting droplets around designated target surfaces can be as crucial as bonding onto them to minimize waste or cleaning. These insights have broad applicability in processes ranging from thermal spraying and additive manufacturing to extreme ultraviolet lithography.

High precision position sensor based on CPA in a composite multi-layered system.

PubMed

Dey, Sanjeeb; Singh, Suneel; Rao, Desai Narayana

2018-04-16

We propose a scheme for high precision position sensing based on coherent perfect absorption (CPA) in a five-layered structure comprising three layers of metal-dielectric composites and two spacer (air) layers. Both the outermost interfaces of the five layered medium are irradiated by two identical coherent light waves at the same angle of incidence. We first investigate the occurrence of CPA in a symmetric layered structure as a function of different system parameters for oblique incidence. Thereafter, by shifting the middle layer, beginning from one end of the structure to the other, we observe the periodic occurrence of extremely narrow CPA resonances at several positions of the middle layer. Moreover this phenomenon is seen to recur even at many other wavelengths. We discuss how the position sensitivity of this phenomenon can be utilized for designing a CPA based high precision position sensing device.

Observation and theory of X-ray mirages.

PubMed

Magnitskiy, Sergey; Nagorskiy, Nikolay; Faenov, Anatoly; Pikuz, Tatiana; Tanaka, Mamoko; Ishino, Masahiko; Nishikino, Masaharu; Fukuda, Yuji; Kando, Masaki; Kawachi, Tetsuya; Kato, Yoshiaki

2013-01-01

The advent of X-ray lasers allowed the realization of compact coherent soft X-ray sources, thus opening the way to a wide range of applications. Here we report the observation of unexpected concentric rings in the far-field beam profile at the output of a two-stage plasma-based X-ray laser, which can be considered as the first manifestation of a mirage phenomenon in X-rays. We have developed a method of solving the Maxwell-Bloch equations for this problem, and find that the experimentally observed phenomenon is due to the emergence of X-ray mirages in the plasma amplifier, appearing as phase-matched coherent virtual point sources. The obtained results bring a new insight into the physical nature of amplification of X-ray radiation in laser-induced plasma amplifiers and open additional opportunities for X-ray plasma diagnostics and extreme ultraviolet lithography.

Exact simulation of max-stable processes.

PubMed

Dombry, Clément; Engelke, Sebastian; Oesting, Marco

2016-06-01

Max-stable processes play an important role as models for spatial extreme events. Their complex structure as the pointwise maximum over an infinite number of random functions makes their simulation difficult. Algorithms based on finite approximations are often inexact and computationally inefficient. We present a new algorithm for exact simulation of a max-stable process at a finite number of locations. It relies on the idea of simulating only the extremal functions, that is, those functions in the construction of a max-stable process that effectively contribute to the pointwise maximum. We further generalize the algorithm by Dieker & Mikosch (2015) for Brown-Resnick processes and use it for exact simulation via the spectral measure. We study the complexity of both algorithms, prove that our new approach via extremal functions is always more efficient, and provide closed-form expressions for their implementation that cover most popular models for max-stable processes and multivariate extreme value distributions. For simulation on dense grids, an adaptive design of the extremal function algorithm is proposed.

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

PubMed

Walston, Zachary; Hernandez, Luis; Yake, Dale

2018-06-06

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

Pattern Analysis of El Nino and La Nina Phenomenon Based on Sea Surface Temperature (SST) and Rainfall Intensity using Oceanic Nino Index (ONI) in West Java Area

NASA Astrophysics Data System (ADS)

Prasetyo, Yudo; Nabilah, Farras

2017-12-01

Climate change occurs in 1998-2016 brings significant alteration in the earth surface. It is affects an extremely anomaly temperature such as El Nino and La Nina or mostly known as ENSO (El Nino Southern Oscillation). West Java is one of the regions in Indonesia that encounters the impact of this phenomenon. Climate change due to ENSO also affects food production and other commodities. In this research, processing data method is conducted using programming language to process SST data and rainfall data from 1998 to 2016. The data are sea surface temperature from NOAA satellite, SST Reynolds (Sea Surface Temperature) and daily rainfall temperature from TRMM satellite. Data examination is done using analysis of rainfall spatial pattern and sea surface temperature (SST) where is affected by El Nino and La Nina phenomenon. This research results distribution map of SST and rainfall for each season to find out the impacts of El Nino and La Nina around West Java. El Nino and La Nina in Java Sea are occurring every August to February. During El Nino, sea surface temperature is between 27°C - 28°C with average temperature on 27.71°C. Rainfall intensity is 1.0 mm/day - 2.0 mm/day and the average are 1.63 mm/day. During La Nina, sea surface temperature is between 29°C - 30°C with average temperature on 29.06°C. Rainfall intensity is 9.0 mm/day - 10 mm/day, and the average is 9.74 mm/day. The correlation between rainfall and SST is 0,413 which is expresses a fairly strong correlation between parameters. The conclusion is, during La Nina SST and rainfall increase. While during El Nino SST and rainfall decrease. Hopefully this research could be a guideline to plan disaster mitigation in West Java region that is related extreme climate change.

Sedimentary condensation and authigenesis

NASA Astrophysics Data System (ADS)

Föllmi, Karl

2016-04-01

Most marine authigenic minerals form in sediments, which are subjected to condensation. Condensation processes lead to the formation of well individualized, extremely thin (< 1m) beds, which were accumulated during extremely long time periods (> 100ky), and which experienced authigenesis and the precipitation of glaucony, verdine, phosphate, iron and manganese oxyhydroxides, iron sulfide, carbonate and/or silica. They usually show complex internal stratigraphies, which result from an interplay of sediment accumulation, halts in sedimentation, sediment winnowing, erosion, reworking and bypass. They may include amalgamated faunas of different origin and age. Hardgrounds may be part of condensed beds and may embody strongly condensed beds by themselves. Sedimentary condensation is the result of a hydrodynamically active depositional regime, in which sediment accumulation, winnowing, erosion, reworking and bypass are processes, which alternate as a function of changes in the location and intensity of currents, and/or as the result of episodic high-energy events engendered by storms and gravity flow. Sedimentary condensation has been and still is a widespread phenomenon in past and present-day oceans. The present-day distribution of glaucony and verdine-rich sediments on shelves and upper slopes, phosphate-rich sediments and phosphorite on outer shelves and upper slopes, ferromanganese crusts on slopes, seamounts and submarine plateaus, and ferromanganese nodules on abyssal seafloors is a good indication of the importance of condensation processes today. In the past, we may add the occurrence of oolitic ironstone, carbonate hardgrounds, and eventually also silica layers in banded iron formations as indicators of the importance of condensation processes. Besides their economic value, condensed sediments are useful both as a carrier of geochemical proxies of paleoceanographic and paleoenvironmental change, as well as the product of episodes of paleoceanographic and paleoenvironmental change themselves.

A Multi-Scale Approach to Airway Hyperresponsiveness: From Molecule to Organ

PubMed Central

Lauzon, Anne-Marie; Bates, Jason H. T.; Donovan, Graham; Tawhai, Merryn; Sneyd, James; Sanderson, Michael J.

2012-01-01

Airway hyperresponsiveness (AHR), a characteristic of asthma that involves an excessive reduction in airway caliber, is a complex mechanism reflecting multiple processes that manifest over a large range of length and time scales. At one extreme, molecular interactions determine the force generated by airway smooth muscle (ASM). At the other, the spatially distributed constriction of the branching airways leads to breathing difficulties. Similarly, asthma therapies act at the molecular scale while clinical outcomes are determined by lung function. These extremes are linked by events operating over intermediate scales of length and time. Thus, AHR is an emergent phenomenon that limits our understanding of asthma and confounds the interpretation of studies that address physiological mechanisms over a limited range of scales. A solution is a modular computational model that integrates experimental and mathematical data from multiple scales. This includes, at the molecular scale, kinetics, and force production of actin-myosin contractile proteins during cross-bridge and latch-state cycling; at the cellular scale, Ca2+ signaling mechanisms that regulate ASM force production; at the tissue scale, forces acting between contracting ASM and opposing viscoelastic tissue that determine airway narrowing; at the organ scale, the topographic distribution of ASM contraction dynamics that determine mechanical impedance of the lung. At each scale, models are constructed with iterations between theory and experimentation to identify the parameters that link adjacent scales. This modular model establishes algorithms for modeling over a wide range of scales and provides a framework for the inclusion of other responses such as inflammation or therapeutic regimes. The goal is to develop this lung model so that it can make predictions about bronchoconstriction and identify the pathophysiologic mechanisms having the greatest impact on AHR and its therapy. PMID:22701430

Aggregating Hydrometeorological Data from International Monitoring Networks Across Earth's Largest Lake System to Quantify Uncertainty in Historical Water Budget Records, Improve Regional Water Budget Projections, and Differentiate Drivers Behind a Recent Record-Setting Surge in Water Levels

NASA Astrophysics Data System (ADS)

Gronewold, A.; Bruxer, J.; Smith, J.; Hunter, T.; Fortin, V.; Clites, A. H.; Durnford, D.; Qian, S.; Seglenieks, F.

2015-12-01

Resolving and projecting the water budget of the North American Great Lakes basin (Earth's largest lake system) requires aggregation of data from a complex array of in situ monitoring and remote sensing products that cross an international border (leading to potential sources of bias and other inconsistencies), and are relatively sparse over the surfaces of the lakes themselves. Data scarcity over the surfaces of the lakes is a particularly significant problem because, unlike Earth's other large freshwater basins, the Great Lakes basin water budget is (on annual scales) comprised of relatively equal contributions from runoff, over-lake precipitation, and over-lake evaporation. Consequently, understanding drivers behind changes in regional water storage and water levels requires a data management framework that can reconcile uncertainties associated with data scarcity and bias, and propagate those uncertainties into regional water budget projections and historical records. Here, we assess the development of a historical hydrometeorological database for the entire Great Lakes basin with records dating back to the late 1800s, and describe improvements that are specifically intended to differentiate hydrological, climatological, and anthropogenic drivers behind recent extreme changes in Great Lakes water levels. Our assessment includes a detailed analysis of the extent to which extreme cold winters in central North America in 2013-2014 (caused by the anomalous meridional upper air flow - commonly referred to in the public media as the "polar vortex" phenomenon) altered the thermal and hydrologic regimes of the Great Lakes and led to a record setting surge in water levels between January 2014 and December 2015.

Taking Stock.

ERIC Educational Resources Information Center

Merriam, Sharan B.

1993-01-01

A complete theory of adult learning must take into consideration the learner, learning process, and context. Andragogy, self-directed learning, consciousness, critical theory, feminism, transformational learning, and situated cognition contribute to understanding of this complex phenomenon. (SK)

Fractional conductivity in 2D and 3D crystals

NASA Astrophysics Data System (ADS)

Sidharth, B. G.; Das, Abhishek; Valluri, S. R.

2018-04-01

In this work, we show that the phenomenon of fractional quantum Hall effect can be obtained for 2D and 3D crystal structures, using the noncommutative nature of spacetime and the Lambert W function. This fractional conductivity has been shown to be a consequence of the noncommutative geometry underlying the structure of graphene. Also, it has been shown, for graphene, that in the 3D case the conductivity is extremely small and depends on the self-energy that arises due to random fluctuations or zitterbewegung.

Shocks near Jamming

NASA Astrophysics Data System (ADS)

Gómez, Leopoldo R.; Turner, Ari M.; van Hecke, Martin; Vitelli, Vincenzo

2012-02-01

Nonlinear sound is an extreme phenomenon typically observed in solids after violent explosions. But granular media are different. Right when they jam, these fragile and disordered solids exhibit a vanishing rigidity and sound speed, so that even tiny mechanical perturbations form supersonic shocks. Here, we perform simulations in which two-dimensional jammed granular packings are dynamically compressed and demonstrate that the elementary excitations are strongly nonlinear shocks, rather than ordinary phonons. We capture the full dependence of the shock speed on pressure and impact intensity by a surprisingly simple analytical model.

Measurements of car-body lateral vibration induced by high-speed trains negotiating complex terrain sections under strong wind conditions

NASA Astrophysics Data System (ADS)

Liu, Dongrun; Lu, Zhaijun; Zhong, Mu; Cao, Tianpei; Chen, Dong; Xiong, Yupu

2018-02-01

Assessment of the vibration of high-speed trains negotiating complex sections of terrain under strong wind conditions is very important for research into the operation safety and comfort of passengers on high-speed trains. To assess the vibration of high-speed trains negotiating complex sections of terrain under strong wind conditions, we performed a field measurement when the train passes through typical sections of complex terrain along the Lanzhou-Xinjiang high-speed railway in China. We selected the lateral vibration conditions, including the roll angle and lateral displacement of car-body gravity centre through two typical representative sections (embankment-tunnel-embankment and embankment-rectangular transition-cutting) for analysis. The results show that the severe car-swaying phenomenon occurs when the high-speed train moves through the test section, and the car-body lateral vibration characteristic is related significantly to the state of the terrain and topography along the railway. The main causes for this car-swaying phenomenon may be the transitions between different windproof structures, and the greater the scale of the transition region between different windproof structures or landform changes, the more obvious the car-swaying phenomenon becomes. The lateral vibration of the car-body is relatively steady when the train is running through terrain with minor changes in topography, such as the windbreak installed on the bridge and embankment, but the tail car sways more violently than the head car. When the vehicle runs from the windbreak installed on the embankment into the tunnel (or in the opposite direction), the tail car sways more intensely than the head car, and the head car runs relatively stable in the tunnel.

Mechanistic explanation of time-dependent cross-phenomenon based on quorum sensing: A case study of the mixture of sulfonamide and quorum sensing inhibitor to bioluminescence of Aliivibrio fischeri.

PubMed

Sun, Haoyu; Pan, Yongzheng; Gu, Yue; Lin, Zhifen

2018-07-15

Cross-phenomenon in which the concentration-response curve (CRC) for a mixture crosses the CRC for the reference model has been identified in many studies, expressed as a heterogeneous pattern of joint toxic action. However, a mechanistic explanation of the cross-phenomenon has thus far been extremely insufficient. In this study, a time-dependent cross-phenomenon was observed, in which the cross-concentration range between the CRC for the mixture of sulfamethoxypyridazine (SMP) and (Z-)-4-Bromo-5-(bromomethylene)-2(5H)-furanone (C30) to the bioluminescence of Aliivibrio fischeri (A. fischeri) and the CRC for independent action model with 95% confidence bands varied from low-concentration to higher-concentration regions in a timely manner expressed the joint toxic action of the mixture changing with an increase of both concentration and time. Through investigating the time-dependent hormetic effects of SMP and C30 (by measuring the expression of protein mRNA, simulating the bioluminescent reaction and analyzing the toxic action), the underlying mechanism was as follows: SMP and C30 acted on the quorum sensing (QS) system of A. fischeri, which induced low-concentration stimulatory effects and high-concentration inhibitory effects; in the low-concentration region, the stimulatory effects of SMP and C30 made the mixture produce a synergistic stimulation on the bioluminescence; thus, the joint toxic action exhibited antagonism. In the high-concentration region, the inhibitory effects of SMP and C30 in the mixture caused a double block in the loop circuit of the QS system; thus, the joint toxic action exhibited synergism. With the increase of time, these stimulatory and inhibitory effects of SMP and C30 were changed by the variation of the QS system at different growth phases, resulting in the time-dependent cross-phenomenon. This study proposes an induced mechanism for time-dependent cross-phenomenon based on QS, which may provide new insight into the mechanistic investigation of time-dependent cross-phenomenon, benefitting the environmental risk assessment of mixtures. Copyright © 2018 Elsevier B.V. All rights reserved.

Botox therapy for ischemic digits.

PubMed

Neumeister, Michael W; Chambers, Christopher B; Herron, Margo S; Webb, Kelli; Wietfeldt, Joel; Gillespie, Jessica N; Bueno, Rueben A; Cooney, Carisa M

2009-07-01

Treating patients with Raynaud's phenomenon who have chronic pain and ulcerations is extremely challenging. Unrelenting pain can lead to dysfunction and disuse, rendering the patient debilitated and/or chronically depressed. Pharmacologic vasodilators and surgical sympathectomies offer variable benefits. Outcomes of symptomatic patients treated with botulinum toxin type A (Botox) injections for Raynaud's phenomenon are presented. A retrospective study focused on patient outcomes was performed on 19 patients diagnosed with Raynaud's phenomenon. Patients suffered from chronic ischemic hand pain. All patients had vascular studies to rule out occlusive disease. Fifty to 100 units of Botox were injected into the palm around each involved neurovascular bundle. Preinjection and postinjection laser Doppler scanning was performed on most patients to measure blood flow. Sixteen of 19 patients (84 percent) reported pain reduction at rest. Thirteen patients reported immediate relief; three reported more gradual pain reduction over 1 to 2 months. Three patients had no or minimal pain relief. Tissue perfusion results demonstrated a marked change in blood flow (-48.15 percent to 425 percent) to the digits. All patients with chronic finger ulcers healed within 60 days. Most patients [n = 12 (63 percent)] remained pain-free (13 to 59 months) with a single-injection schedule. Four patients (21 percent) required repeated injections because of recurrent pain. Vascular function is abnormal in patients with Raynaud's phenomenon. Although its mechanism is unknown, Botox yielded a distinct improvement in perfusion and reduction in pain in patients failing conservative management. Continued research may lead to more specific and reliable treatment for Raynaud's patients.

Study on bouncing motion of a water drop collision on superhydrophobic surface under icing conditions

NASA Astrophysics Data System (ADS)

Maeda, Tetsuro; Morita, Katsuaki; Kimura, Shigeo

2017-11-01

When micro droplets in the air are supercooled and collide with the object, they froze on the surface at the time of a collision and can be defined as icing. If supercooled water droplets collide with an airfoil of an aircraft in flight and shape changes, there is a danger of losing lift and falling. Recently, the ice protection system using a heater and Anti- / Deicing (superhydrophobic) coating is focused. In this system, colliding water droplets are melted by the heat of the heater at the tip of the blade, and the water droplet is bounced by the aerodynamic force on the rear superhydrophobic coating. Thus, it prevents the phenomenon of icing again at the back of the wing (runback ice). Therefore, it is possible to suppress power consumption of the electric heater. In that system, it is important to withdraw water droplets at an extremely superhydrophobic surface at an early stage. However, research on bouncing phenomenon on superhydrophobic surface under icing conditions are not done much now. Therefore, in our research, we focus on one drop supercooled water droplet that collides with the superhydrophobic surface in the icing phenomenon, and aim to follow that phenomenon. In this report, the contact time is defined as the time from collision of a water droplet to bouncing from the superhydrophobic surface, and various parameters (temperature, speed, and diameter) on water droplets under icing conditions are set as the water drop bouncing time (contact time) of the product.

Human Nature and Research Paradigms: Theory Meets Physical Therapy Practice

ERIC Educational Resources Information Center

Plack, Margaret M.

2005-01-01

Human nature is a very complex phenomenon. In physical therapy this complexity is enhanced by the need to understand the intersection between the art and science of human behavior and patient care. A paradigm is a set of basic beliefs that represent a worldview, defines the nature of the world and the individual's place in it, and helps to…

Play Complexity and Toy Engagement in Preschoolers with Autism Spectrum Disorder: Do Girls and Boys Differ?

ERIC Educational Resources Information Center

Harrop, Clare; Green, Jonathan; Hudry, Kristelle

2017-01-01

While sex differences in play have been extensively observed in typical development, only a handful of studies have explored this phenomenon in depth with children with autism spectrum disorders. This study explored sex differences in play complexity and toy engagement within caregiver-child interaction samples for preschool-aged children (2-5…

How Can We Explain Poverty? Case Study of Dee Reveals the Complexities

ERIC Educational Resources Information Center

Seccombe, Karen

2011-01-01

Many theories have been offered to explain why people are impoverished. This article by Karen Seccombe uses the case study of "Dee," a newly single mother, to explore four of the most common: individualism, social structuralism, the culture of poverty, and fatalism. She concludes that poverty is a highly complex phenomenon, and it is likely that…

Epidemiological and clinical complexity of amoxicillin-clavulanate-resistant Escherichia coli.

PubMed

Rodríguez-Baño, Jesús; Oteo, Jesús; Ortega, Adriana; Villar, Macarena; Conejo, M Carmen; Bou, Germán; Aranzamendi-Zaldumbide, Maitane; Cercenado, Emilia; Gurguí, Mercè; Martínez-Martínez, Luis; Merino, María; Rivera, Alba; Oliver, Antonio; Weber, Irene; Pascual, Alvaro; Bartolomé, Rosa M; Gónzalez-López, Juan José; Campos, José

2013-07-01

Two hundred twelve patients with colonization/infection due to amoxicillin-clavulanate (AMC)-resistant Escherichia coli were studied. OXA-1- and inhibitor-resistant TEM (IRT)-producing strains were associated with urinary tract infections, while OXA-1 producers and chromosomal AmpC hyperproducers were associated with bacteremic infections. AMC resistance in E. coli is a complex phenomenon with heterogeneous clinical implications.

Developmental control of integrin expression regulates Th2 effector homing

USDA-ARS?s Scientific Manuscript database

Integrin CD18, a component of the LFA-1 complex that also includes CD11a, is essential for Th2, but not Th1, cell homing, but the explanation for this phenomenon remains obscure. In this study, we investigate the mechanism by which Th2 effector responses require the LFA-1 complex. CD11a-deficient T ...

When Simple Harmonic Motion Is Not that Simple: Managing Epistemological Complexity by Using Computer-Based Representations

ERIC Educational Resources Information Center

Parnafes, Orit

2010-01-01

Many real-world phenomena, even "simple" physical phenomena such as natural harmonic motion, are complex in the sense that they require coordinating multiple subtle foci of attention to get the required information when experiencing them. Moreover, for students to develop sound understanding of a concept or a phenomenon, they need to learn to get…

Projected Changes in Persistent Extreme Warm-Season Weather Events: The Role of Quasi-Resonant Amplification

NASA Astrophysics Data System (ADS)

Mann, M. E.; Rahmstorf, S.; Kornhuber, K.; Steinman, B. A.; Miller, S. K.; Coumou, D.

2017-12-01

Persistent episodes of extreme weather in the Northern Hemisphere summer are typically associated with high-amplitude quasi-stationary atmospheric Rossby waves with zonal wavenumbers. Such disturbances are favoured by the phenomenon of Quasi-Resonant Amplification (QRA). A fingerprint for the occurrence of QRA can be defined in terms of the zonally-averaged surface temperature field. Examining future state-of-the-art (CMIP5) climate model projections we find that such events are likely to increase by 50% over the next century under business-as-usual carbon emissions, but there is considerable variation among climate models, with some models predicting a near tripling of QRA events by the end of the century. These results are strongly dependent on assumptions regarding the prominence of changes in radiative forcing associated with anthropogenic aerosols over the next century.

Extreme-scale Algorithms and Solver Resilience

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dongarra, Jack

A widening gap exists between the peak performance of high-performance computers and the performance achieved by complex applications running on these platforms. Over the next decade, extreme-scale systems will present major new challenges to algorithm development that could amplify this mismatch in such a way that it prevents the productive use of future DOE Leadership computers due to the following; Extreme levels of parallelism due to multicore processors; An increase in system fault rates requiring algorithms to be resilient beyond just checkpoint/restart; Complex memory hierarchies and costly data movement in both energy and performance; Heterogeneous system architectures (mixing CPUs, GPUs,more » etc.); and Conflicting goals of performance, resilience, and power requirements.« less

[Injury mechanisms in extreme violence settings].

PubMed

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.

Influence of Anthropogenic Climate Change on Planetary Wave Resonance and Extreme Weather Events

PubMed Central

Mann, Michael E.; Rahmstorf, Stefan; Kornhuber, Kai; Steinman, Byron A.; Miller, Sonya K.; Coumou, Dim

2017-01-01

Persistent episodes of extreme weather in the Northern Hemisphere summer have been shown to be associated with the presence of high-amplitude quasi-stationary atmospheric Rossby waves within a particular wavelength range (zonal wavenumber 6–8). The underlying mechanistic relationship involves the phenomenon of quasi-resonant amplification (QRA) of synoptic-scale waves with that wavenumber range becoming trapped within an effective mid-latitude atmospheric waveguide. Recent work suggests an increase in recent decades in the occurrence of QRA-favorable conditions and associated extreme weather, possibly linked to amplified Arctic warming and thus a climate change influence. Here, we isolate a specific fingerprint in the zonal mean surface temperature profile that is associated with QRA-favorable conditions. State-of-the-art (“CMIP5”) historical climate model simulations subject to anthropogenic forcing display an increase in the projection of this fingerprint that is mirrored in multiple observational surface temperature datasets. Both the models and observations suggest this signal has only recently emerged from the background noise of natural variability. PMID:28345645

Global ecological success of Thalassoma fishes in extreme coral reef habitats.

PubMed

Fulton, Christopher J; Wainwright, Peter C; Hoey, Andrew S; Bellwood, David R

2017-01-01

Phenotypic adaptations can allow organisms to relax abiotic selection and facilitate their ecological success in challenging habitats, yet we have relatively little data for the prevalence of this phenomenon at macroecological scales. Using data on the relative abundance of coral reef wrasses and parrotfishes (f. Labridae) spread across three ocean basins and the Red Sea, we reveal the consistent global dominance of extreme wave-swept habitats by fishes in the genus Thalassoma , with abundances up to 15 times higher than any other labrid. A key locomotor modification-a winged pectoral fin that facilitates efficient underwater flight in high-flow environments-is likely to have underpinned this global success, as numerical dominance by Thalassoma was contingent upon the presence of high-intensity wave energy. The ecological success of the most abundant species also varied with species richness and the presence of congeneric competitors. While several fish taxa have independently evolved winged pectoral fins, Thalassoma appears to have combined efficient high-speed swimming (to relax abiotic selection) with trophic versatility (to maximize exploitation of rich resources) to exploit and dominate extreme coral reef habitats around the world.

Laser Sintering Technology and Balling Phenomenon.

PubMed

Oyar, Perihan

2018-02-01

The aim of this review was to evaluate the balling phenomenon which occurs typically in Selective Laser Sintering (SLS). The balling phenomenon is a typical SLS defect, and observed in laser sintered powder, significantly reduces the quality of SLS, and hinders the further development of SLS Technology. Electronic database searches were performed using Google Scholar. The keywords "laser sintering, selective laser sintering, direct metal laser melting, and balling phenomenon" were searched in title/abstract of publications, limited to December 31, 2016. The inclusion criteria were SLS, balling phenomenon, some alloys (such as Cr-Co, iron, stainless steel, and Cu-based alloys) mechanical properties, microstructure and bond strength between metal-ceramic crown, laboratory studies, full text, and in English language. A total of 100 articles were found the initial search and yielded a total of 50 studies, 30 of which did not fulfill the inclusion criteria and were therefore excluded. In addition, 20 studies were found by screening the reference list of all included publications. Finally, 40 studies were selected for this review. The method in question is regulated by powder material characteristics and the conditions of laser processing. The procedure of formation, affecting factors, and the mechanism of the balling effect are very complex.

Vertebral deformities and fractures are associated with MRI and pQCT measures obtained at the distal tibia and radius of postmenopausal women

PubMed Central

Rajapakse, C. S.; Phillips, E. A.; Sun, W.; Wald, M. J.; Magland, J. F.; Snyder, P. J.; Wehrli, F. W.

2016-01-01

Summary We investigated the association of postmenopausal vertebral deformities and fractures with bone parameters derived from distal extremities using MRI and pQCT. Distal extremity measures showed variable degrees of association with vertebral deformities and fractures, highlighting the systemic nature of postmenopausal bone loss. Introduction Prevalent vertebral deformities and fractures are known to predict incident further fractures. However, the association of distal extremity measures and vertebral deformities in postmenopausal women has not been fully established. Methods This study involved 98 postmenopausal women (age range 60–88 years, mean 70 years) with DXA BMD T-scores at either the hip or spine in the range of −1.5 to −3.5. Wedge, biconcavity, and crush deformities were computed on the basis of spine MRI. Vertebral fractures were assessed using Eastell's criterion. Distal tibia and radius stiffness was computed using MRI-based finite element analysis. BMD at the distal extremities were obtained using pQCT. Results Several distal extremity MRI and pQCT measures showed negative association with vertebral deformity on the basis of single parameter correlation (r up to 0.67) and two-parameter regression (r up to 0.76) models involving MRI stiffness and pQCT BMD. Subjects who had at least one prevalent vertebral fracture showed decreased MRI stiffness (up to 17.9 %) and pQCT density (up to 34.2 %) at the distal extremities compared to the non-fracture group. DXA lumbar spine BMD T-score was not associated with vertebral deformities. Conclusions The association between vertebral deformities and distal extremity measures supports the notion of postmenopausal osteoporosis as a systemic phenomenon. PMID:24221453

Learning Human Aspects of Collaborative Software Development

ERIC Educational Resources Information Center

Hadar, Irit; Sherman, Sofia; Hazzan, Orit

2008-01-01

Collaboration has become increasingly widespread in the software industry as systems have become larger and more complex, adding human complexity to the technological complexity already involved in developing software systems. To deal with this complexity, human-centric software development methods, such as Extreme Programming and other agile…

Survival in extreme environments - on the current knowledge of adaptations in tardigrades.

PubMed

Møbjerg, N; Halberg, K A; Jørgensen, A; Persson, D; Bjørn, M; Ramløv, H; Kristensen, R M

2011-07-01

Tardigrades are microscopic animals found worldwide in aquatic as well as terrestrial ecosystems. They belong to the invertebrate superclade Ecdysozoa, as do the two major invertebrate model organisms: Caenorhabditis elegans and Drosophila melanogaster. We present a brief description of the tardigrades and highlight species that are currently used as models for physiological and molecular investigations. Tardigrades are uniquely adapted to a range of environmental extremes. Cryptobiosis, currently referred to as a reversible ametabolic state induced by e.g. desiccation, is common especially among limno-terrestrial species. It has been shown that the entry and exit of cryptobiosis may involve synthesis of bioprotectants in the form of selective carbohydrates and proteins as well as high levels of antioxidant enzymes and other free radical scavengers. However, at present a general scheme of mechanisms explaining this phenomenon is lacking. Importantly, recent research has shown that tardigrades even in their active states may be extremely tolerant to environmental stress, handling extreme levels of ionizing radiation, large fluctuation in external salinity and avoiding freezing by supercooling to below -20 °C, presumably relying on efficient DNA repair mechanisms and osmoregulation. This review summarizes the current knowledge on adaptations found among tardigrades, and presents new data on tardigrade cell numbers and osmoregulation. © 2011 The Authors. Acta Physiologica © 2011 Scandinavian Physiological Society.

The Science of Flames.

ERIC Educational Resources Information Center

Cornia, Ray

1991-01-01

Describes an exercise using flames that allows students to explore the complexities of a seemingly simple phenomenon, the lighting of a candle. Contains a foldout that provides facts about natural gas flames and suggestions for classroom use. (ZWH)

Participatory Literacy Education: A Complex Phenomenon.

ERIC Educational Resources Information Center

Demetrion, George

1993-01-01

A case study of the Bob Steele Reading Center in Connecticut demonstrates problems inherent in participatory literacy education when the learners, the program's culture, and the sociocultural context are not grounded in the participatory democratic ethic. (SK)

An extreme-halophile archaebacterium possesses the interlock type of prephenate dehydratase characteristic of the Gram-positive eubacteria

NASA Technical Reports Server (NTRS)

Jensen, R. A.; d'Amato, T. A.; Hochstein, L. I.

1988-01-01

The focal point of phenylalanine biosynthesis is a dehydratase reaction which in different organisms may be prephenate dehydratase, arogenate dehydratase, or cyclohexadienyl dehydratase. Gram-positive, Gram-negative, and cyanobacterial divisions of the eubacterial kingdom exhibit different dehydratase patterns. A new extreme-halophile isolate, which grows on defined medium and is tentatively designated as Halobacterium vallismortis CH-1, possesses the interlock type of prephenate dehydratase present in Gram-positive bacteria. In addition to the conventional sensitivity to feedback inhibition by L-phenylalanine, the phenomenon of metabolic interlock was exemplified by the sensitivity of prephenate dehydratase to allosteric effects produced by extra-pathway (remote) effectors. Thus, L-tryptophan inhibited activity while L-tyrosine, L-methionine, L-leucine and L-isoleucine activated the enzyme. L-Isoleucine and L-phenylalanine were effective at micromolar levels; other effectors operated at mM levels. A regulatory mutant selected for resistance to growth inhibition caused by beta-2-thienylalanine possessed an altered prephenate dehydratase in which a phenomenon of disproportionately low activity at low enzyme concentration was abolished. Inhibition by L-tryptophan was also lost, and activation by allosteric activators was diminished. Not only was sensitivity to feedback inhibition by L-phenylalanine lost, but the mutant enzyme was now activated by this amino acid (a mutation type previously observed in Bacillus subtilis). It remains to be seen whether this type of prephenate dehydratase will prove to be characteristic of all archaebacteria or of some archaebacterial subgroup cluster.

Systemic sclerosis complicated with localized scleroderma-like lesions induced by Köbner phenomenon.

PubMed

Saigusa, Ryosuke; Asano, Yoshihide; Yamashita, Takashi; Takahashi, Takehiro; Nakamura, Kouki; Miura, Shunsuke; Ichimura, Yohei; Toyama, Tetsuo; Taniguchi, Takashi; Sumida, Hayakazu; Tamaki, Zenshiro; Miyazaki, Miki; Yoshizaki, Ayumi; Sato, Shinichi

2018-03-01

Scleroderma is a chronic disease of unknown etiology characterized by skin fibrosis and is divided into two clinical entities: systemic sclerosis (SSc) and localized scleroderma (LSc). In general, LSc is rarely complicated with SSc, but a certain portion of SSc patients manifests bilateral symmetric LSc-like lesions on the trunk and extremities. We investigated SSc patients with LSc-like lesions to clarify the underlying pathophysiology. Nine SSc cases complicated with LSc-like lesions were clinically and histologically characterized. SSc patients with LSc-like lesions exhibited multiple progressive hyper- and/or hypo-pigmented plaques with mild sclerosis symmetrically distributed on the trunk and extremities, especially abdominal region. In histological assessment, epidermal IL-1α expression was elevated in both forearms and LSc-like lesions of these patients to a greater extent than in forearms of control patients (SSc patients without LSc-like lesions). Of note, the infiltration and degranulation of mast cells were evident throughout the dermis of LSc-like lesions, while detectable to a lesser extent in forearms of SSc patients with LSc-like lesions and control patients. The epidermis of SSc patients with LSc-like lesions seems to possess an inflammatory phenotype, leading to the activation of mast cells in the dermis of mechanically stressed skin. Köbner phenomenon may be involved in the induction of LSc-like lesions in a certain subset of SSc. Copyright © 2017 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

A dependence modelling study of extreme rainfall in Madeira Island

NASA Astrophysics Data System (ADS)

Gouveia-Reis, Délia; Guerreiro Lopes, Luiz; Mendonça, Sandra

2016-08-01

The dependence between variables plays a central role in multivariate extremes. In this paper, spatial dependence of Madeira Island's rainfall data is addressed within an extreme value copula approach through an analysis of maximum annual data. The impact of altitude, slope orientation, distance between rain gauge stations and distance from the stations to the sea are investigated for two different periods of time. The results obtained highlight the influence of the island's complex topography on the spatial distribution of extreme rainfall in Madeira Island.

Study of Pure Proteins, Nucleic Acids and Their Complexes from Halobacteria of the Dead Sea: RNA Polymerase-DNA Interaction.

DTIC Science & Technology

1987-09-21

objectives of our program are to isolate and characterize a fully active DNA dependent RNA polymerase from the extremely halophilic archaebacteria of the genus...operons in II. Marismortui. The halobacteriaceae are extreme halophiles . They require 3.5 M NaCI for optimal growth an(l no growth is observed below 2...was difficutlt to perform due to the extreme genetic instability in this strain (6). In contrast, the genoine of the extreme halophilic and prototrophic

An articulated predictive model for fluid-free artificial basilar membrane as broadband frequency sensor

NASA Astrophysics Data System (ADS)

Ahmed, Riaz; Banerjee, Sourav

2018-02-01

In this article, an extremely versatile predictive model for a newly developed Basilar meta-Membrane (BM2) sensors is reported with variable engineering parameters that contribute to it's frequency selection capabilities. The predictive model reported herein is for advancement over existing method by incorporating versatile and nonhomogeneous (e.g. functionally graded) model parameters that could not only exploit the possibilities of creating complex combinations of broadband frequency sensors but also explain the unique unexplained physical phenomenon that prevails in BM2, e.g. tailgating waves. In recent years, few notable attempts were made to fabricate the artificial basilar membrane, mimicking the mechanics of the human cochlea within a very short range of frequencies. To explain the operation of these sensors a few models were proposed. But, we fundamentally argue the "fabrication to explanation" approach and proposed the model driven predictive design process for the design any (BM2) as broadband sensors. Inspired by the physics of basilar membrane, frequency domain predictive model is proposed where both the material and geometrical parameters can be arbitrarily varied. Broadband frequency is applicable in many fields of science, engineering and technology, such as, sensors for chemical, biological and acoustic applications. With the proposed model, which is three times faster than its FEM counterpart, it is possible to alter the attributes of the selected length of the designed sensor using complex combinations of model parameters, based on target frequency applications. Finally, the tailgating wave peaks in the artificial basilar membranes that prevails in the previously reported experimental studies are also explained using the proposed model.

A Project Manager’s Personal Attributes as Predictors for Success

DTIC Science & Technology

2007-03-01

Northouse (2004) explains that leadership is highly a researched topic with much written. Yet, a definitive description of this phenomenon is difficult to...express because of its complexity. Even though leadership has varied descriptions and conceptualizations, Northouse states that the concept of...characteristic of leadership is not an accurate predictor of performance. Leadership is a complex, multi-faceted attribute ( Northouse , 2004) and specific

Transient 5-oxoprolinuria: unusually high anion gap acidosis in an infant.

PubMed

Hulley, Sarah L; Perring, Jeff; Manning, Nigel; Olpin, Simon; Yap, Sufin

2015-12-01

Transient 5-oxoprolinuria is a phenomenon that is well recognised in adults. We illustrate an unusual paediatric case of transient 5-oxoprolinuria presenting during an episode of severe sepsis with concomitant paracetamol use. The 15-month-old patient had an extremely high anion gap metabolic acidosis. Adequate resuscitation failed to correct the biochemical disturbance, and high levels of 5-oxoproline were identified. A combination of haemofiltration, replenishment of glutathione stores with N-acetylcysteine and cessation of paracetamol administration resulted in the resolution of the acidosis. Subsequent testing following treatment of the sepsis revealed no ongoing 5-oxoprolinuria. Transient 5-oxoprolinuria has been previously reported in the adult population during episodes of severe sepsis and various pharmaceutical interventions. This case illustrates that it is a phenomenon that should be considered in paediatric patients where a very high anion gap metabolic acidosis exists that cannot be explained by the biochemical indices. • 5-oxoprolinuria in the paediatric population is usually secondary to an inborn error of metabolism. • Transient 5-oxoprolinuria is well recognised in adults during episodes of severe glutathione depletion. • Transient 5-oxoprolinuria is a phenomenon rarely reported in the paediatric population. • It highlights the importance of investigating a high anion gap such that unusual diagnoses are not missed.

One-shot Synesthesia.

PubMed

Kirschner, Alexandra; Nikolić, Danko

2017-01-01

Synesthesia is commonly thought to be a phenomenon of fixed associations between an outside inducer and a vivid concurrent experience. Hence, it has been proposed that synesthesia occurs due to additional connections in the brain with which synesthetes are born. Here we show that synesthesia can be a much richer and more flexible phenomenon with a capability to creatively construct novel synesthetic experiences as events unfold in people's lives. We describe here cases of synesthetes who occasionally generate novel synesthetic experience, called one-shot synesthesias. These synesthetic experiences seem to share all the properties with the classical synesthetic associations except that they occur extremely rarely, people recalling only a few events over the lifetime. It appears that these one-shots are not created at random but are instead responses to specific life events. We contrast the properties of those rare synesthetic events with other, more commonly known forms of synesthesia that also create novel synesthetic experiences, but at a high rate-sometimes creating novel experiences every few seconds. We argue that one-shot synesthesias indicate that synesthetic associations are by their nature not prewired at birth but are dynamically constructed through mental operations and according to the needs of a synesthetic mind. Our conclusions have implications for understanding the biological underpinnings of synesthesia and the role the phenomenon plays in the lives of people endowed with synesthetic capacities.

Complexity and Turbulence at the Substorm Onset

NASA Astrophysics Data System (ADS)

Consolini, G.; De Marco, R.; Acquaviva, E.

2014-12-01

Geomagnetic substorms are one of the principal manifestations of the Earth's magnetospheric complex dynamics in response to solar wind changes. In the last two decades, in-situ susbtorm related studies showed that the onset of this phenomenon is accompanied by fluctuations covering a wide range of scales from the MHD domain to the small non-MHD one. Furthermore, these fluctuations have a turbulent, sporadic and intermittent character. This is particularly true for the well-known current disruption (CD) process, occurring at the substorm onset. Here, the features of the turbulence observed during a CD phenomenon are investigated, with a particular attention to the genereation of a 1/f spectrum in the MHD domain and its connection with a competing direct and inverse cascading process. A comparison with Hall-MHD shell-model simulations will be presented and discussed. This research has received funding from the European Community's Seventh Framework Programme ([FP7/2007-2013]) under Grant agreement no. 313038/STORM.

[Systematization of nursing care: viewing care as interactive, complementary and multi-professional].

PubMed

do Nascimento, Keyla Cristiane; Backes, Dirce Stein; Koerich, Magda Santos; Erdmann, Alacoque Lorenzini

2008-12-01

This study is the result of an extended project, named: The systematization of nursing care in the perspective of complex thinking. The objective of this qualitative study is to better comprehend the meaning of the systematization of nursing care among healthcare professionals. The Data-Based Theory was used as a methodological reference. Data were collected by interviewing three sample groups, in a total of fifteen healthcare professionals. Data codification and analysis led us to the central theme: Viewing the Systematization of Nursing Care (SNC) as an Interactive and Complex Phenomenon. This theme is complemented by two phenomena. In this article, we discuss the phenomenon: Verifying the necessity of on interactive, complementary, and multi-professional process. The Systematization of Nursing Care is part of a process that has been developing over time by nurses committed to improve the care given to the patient, since they view the necessity for interactive, complementary, and multi-professional care.

[Investigative police work in relation to youth homicides in Belo Horizonte].

PubMed

Zilli, Luís Felipe; Vargas, Joana Domingues

2013-03-01

Over the course of the past 30 years, Brazil has experienced an exponential increase in its homicide rates, which is a problem that has been aggravated by the slaughter of young nonwhite, poor, males living in the shantytowns and communities. Given the complexity and the resurgence of the homicide phenomenon in Brazil, this article seeks to discuss some of the main effects that these trends have had on investigative police work. For this purpose, a long process of ethnographic research in six Specialized Homicide Police Units of Belo Horizonte (BH) was conducted between the years 2009 and 2010. During this period, researchers accompanied the daily routine of these units and conducted several in-depth interviews with investigators and civil police chiefs. Among the results, the mismatch between the increasing complexity of the homicide phenomenon and the legal procedures established for investigating the problem in BH should be stressed.

Facilitating Learning in SPI through Co-design

NASA Astrophysics Data System (ADS)

Seigerroth, Ulf; Lind, Mikael

Information system development (ISD) is not a stable discipline. On the contrary, ISD must constantly cope with rapidly changing and diversifying technologies, application domains, and organizational contexts [14]. ISD is a complex and a multi dimensional phenomenon [5, 15]. As a consequence of this. Software Process Improvement (SPI) can also be regarded as a complex and multi dimensional phenomenon [16]. Problems that are accentuated in relation to SPI are: SPI is in its current shape a quite young discipline [15], there is a sparse amount of SPI-theories that can guide SPI initiatives [19], SPI-initiatives often focus on the system development (SD)-process, methods and tools which is a narrow focus that leave out important aspects such as business orientation [6], organization and social factors [4, 5] and the learning process [19]. Arguments have therefore been raised that there is a need for both researchers and practitioners to better understand SD-organisations and their practice [5].

The filial piety complex: variations on the Oedipus theme in Chinese literature and culture.

PubMed

Gu, Ming Dong

2006-01-01

The Oedipus complex is central to Western tradition, but not to Chinese culture. Occurrence of oedipal themes in Chinese literature is almost negligible. This phenomenon seems to support a contra-Freud claim: that a theory of European origin, the Oedipus complex, is not universal to human experience in non-Western cultures. However, this article suggests that powerful moral repression may cause the Oedipus complex to undergo structural transformations in some cultures. Through studying a sample of Chinese literary and film representations, the author argues that the Oedipus complex in Chinese culture has been transformed into a filial piety complex. Some conceptual issues are considered from a cross-cultural perspective.

Effect of short-term subaerial exposure on the cauliflower coral, Pocillopora damicornis, during a simulated extreme low-tide event

NASA Astrophysics Data System (ADS)

Castrillón-Cifuentes, Ana Lucia; Lozano-Cortés, Diego F.; Zapata, Fernando A.

2017-06-01

There is increased interest in understanding how stress reduces coral resistance to disturbances and how acclimatization increases the ability of corals to resist future stress. Most extreme low tides at Gorgona Island, which expose reef flats to air, do not appear to negatively affect corals because corals usually do not undergo lethal bleaching during such events. However, coral physiology and fitness may be impacted by this phenomenon. The aim of this study was to evaluate whether corals exposed to air have modified biological functions to resist bleaching. To test this, an extreme low-tide event was simulated in the field. Colonies of Pocillopora damicornis were exposed to air for 15 or 40 min over the course of one, two, or three consecutive days. This procedure was repeated for one to three months. Colonies of P. damicornis exposed to air had reduced fecundity, decreased zooxanthellae density, and changed color from darker to lighter. However, the growth rate of exposed corals was similar to that of non-exposed colonies. We conclude that short periods of subaerial exposure during extreme low tides are not lethal to P. damicornis, but negatively affect sexual reproduction, which might have deleterious effects at the population level. The periodic occurrence of extreme low tides in the tropical eastern Pacific may be one factor responsible for the high rate of asexual reproduction (e.g., fragmentation) in pocilloporid corals of this region.

Changes in extreme events and the potential impacts on human health.

PubMed

Bell, Jesse E; Brown, Claudia Langford; Conlon, Kathryn; Herring, Stephanie; Kunkel, Kenneth E; Lawrimore, Jay; Luber, George; Schreck, Carl; Smith, Adam; Uejio, Christopher

2018-04-01

Extreme weather and climate-related events affect human health by causing death, injury, and illness, as well as having large socioeconomic impacts. Climate change has caused changes in extreme event frequency, intensity, and geographic distribution, and will continue to be a driver for change in the future. Some of these events include heat waves, droughts, wildfires, dust storms, flooding rains, coastal flooding, storm surges, and hurricanes. The pathways connecting extreme events to health outcomes and economic losses can be diverse and complex. The difficulty in predicting these relationships comes from the local societal and environmental factors that affect disease burden. More information is needed about the impacts of climate change on public health and economies to effectively plan for and adapt to climate change. This paper describes some of the ways extreme events are changing and provides examples of the potential impacts on human health and infrastructure. It also identifies key research gaps to be addressed to improve the resilience of public health to extreme events in the future. Extreme weather and climate events affect human health by causing death, injury, and illness, as well as having large socioeconomic impacts. Climate change has caused changes in extreme event frequency, intensity, and geographic distribution, and will continue to be a driver for change in the future. Some of these events include heat waves, droughts, wildfires, flooding rains, coastal flooding, surges, and hurricanes. The pathways connecting extreme events to health outcomes and economic losses can be diverse and complex. The difficulty in predicting these relationships comes from the local societal and environmental factors that affect disease burden.

Scaling properties of rainfall records in some Mexican zones

NASA Astrophysics Data System (ADS)

Angulo-Fernández, Fercia; Reyes-Ramírez, Israel; Flores-Márquez, Elsa Leticia

2018-04-01

Since the 1990 decade, it has been suggested that atmospheric processes associated with rainfall could be a self-organized critical (SOC) phenomenon similar, for example, to seismicity. In this sense, the rain events taken as the output of the complex atmospheric system (sun's radiation, water evaporation, clouds, etc.) are analogous to earthquakes, as the output of a relaxation process of the earth crust. A clue on this possible SOC behavior of rain phenomenon has been the ubiquitous presence of power laws in rain statistics. In the present article, we report the scaling properties of rain precipitation data taken from meteorological stations located at six zones of Mexico. Our results are consistent with those that assert that rainfall is a SOC phenomenon. We also analyze the Hurst exponent, which is appropriate to measure long-term memory of time series.

Transparency of near-critical density plasmas under extreme laser intensities

NASA Astrophysics Data System (ADS)

Ji, Liangliang; Shen, Baifei; Zhang, Xiaomei

2018-05-01

We investigated transparency of near-critical plasma targets for highly intense incident lasers and discovered that beyond relativistic transparency, there exists an anomalous opacity regime, where the plasma target tend to be opaque at extreme light intensities. The unexpected phenomenon is found to originate from the trapping of ions under exotic conditions. We found out the propagation velocity and the amplitude of the laser-driven charge separation field in a large parameter range and derived the trapping probability of ions. The model successfully interpolates the emergence of anomalous opacity in simulations. The trend is more significant when radiation reaction comes into effect, leaving a transparency window in the intensity domain. Transparency of a plasma target defines the electron dynamics and thereby the emission mechanisms of gamma-photons in the ultra-relativistic regime. Our findings are not only of fundamental interest but also imply the proper mechanisms for generating desired electron/gamma sources.

Synchronous volvulus of the sigmoid colon and caecum, a very rare cause of large bowel obstruction.

PubMed

Islam, Shariful; Hosein, Devin; Bheem, Vinoo; Dan, Dilip

2016-10-14

Colonic volvulus usually occurs as a single event that can affect various parts of the colon. The usual sites affected being the sigmoid colon (75%) and the caecum (22%). The phenomenon of multiple sites simultaneously undergoing volvulus is an extremely rare occurrence. Synchronous double colonic volvulus is extremely rare and to the best of our knowledge, this is the 4th reported case of simultaneous sigmoid and caecal volvulus in the English literature. The clinical presentation and the radiological findings are that of large bowel obstruction. Classic radiological findings may not be present or may be overlooked due to its rarity. Treatment of this condition is early surgical intervention to prevent the sequalae of a colonic volvulus and its associated mortality. We report a case of an 80-year-old man with synchronous volvulus of the sigmoid colon and caecum. 2016 BMJ Publishing Group Ltd.

Report of a Case and Review of Literature of Internal Hernia through Peritoneal Defect in Pouch of Douglas: A Rare Occurrence.

PubMed

Muthukumar, Vamseedharan; Venugopal, Sarveswaran; Subramaniam, Surees Kumar

2017-01-01

Intestinal obstruction attributable to internal hernia as a cause is a rare phenomenon with a reported incidence of 0.6%-5.8%. Internal hernias ensuing as a result of defect in the pouch of Douglas is extremely rare with only six such cases reported so far in the literature. We present a case of 74-year-old posthysterectomy status female who presented with features of intestinal obstruction. Intraoperatively, the site of obstruction was found to be a rent in the peritoneum of the pouch of Douglas through which a loop of ileum was found herniating. The viability of the bowel was confirmed, and the defect was closed. The postoperative course was uneventful. This report presents an extremely rare type of internal hernia caused by defect in the pouch of Douglas and review of the literature so far available.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luce, F. P.; Azevedo, G. de M.; Baptista, D. L.

The formation and time resolved behavior of individual Pb nanoparticles embedded in silica have been studied by in-situ transmission electron microscopy observations at high temperatures (400–1100 °C) and under 200 keV electron irradiation. It is shown that under such extreme conditions, nanoparticles can migrate at long distances presenting a Brownian-like behavior and eventually coalesce. The particle migration phenomenon is discussed considering the influence of the thermal energy and the electron irradiation effects on the atomic diffusion process which is shown to control particle migration. These results and comparison with ex-situ experiments tackle the stability and the microstructure evolution of nanoparticles systems undermore » extreme conditions. It elucidates on the effects of energetic particle irradiation-annealing treatments either as a tool or as a detrimental issue that could hamper their long-term applications in radiation-harsh environments such as in space or nuclear sectors.« less

Extreme Radio-wave Scattering Associated with Hot Stars

NASA Astrophysics Data System (ADS)

Walker, Mark A.; Tuntsov, Artem V.; Bignall, Hayley; Reynolds, Cormac; Bannister, Keith W.; Johnston, Simon; Stevens, Jamie; Ravi, Vikram

2017-07-01

We use data on extreme radio scintillation to demonstrate that this phenomenon is associated with hot stars in the solar neighborhood. The ionized gas responsible for the scattering is found at distances up to 1.75 {pc} from the host star, and on average must comprise ˜105 distinct structures per star. We detect azimuthal velocities of the plasma, relative to the host star, up to 9.7 {km} {{{s}}}-1, consistent with warm gas expanding at the sound speed. The circumstellar plasma structures that we infer are similar in several respects to the cometary knots seen in the Helix and in other planetary nebulae. There the ionized gas appears as a skin around tiny molecular clumps. Our analysis suggests that molecular clumps are ubiquitous circumstellar features, unrelated to the evolutionary state of the star. The total mass in such clumps is comparable to the stellar mass.

Model-Based Knowing: How Do Students Ground Their Understanding About Climate Systems in Agent-Based Computer Models?

NASA Astrophysics Data System (ADS)

Markauskaite, Lina; Kelly, Nick; Jacobson, Michael J.

2017-12-01

This paper gives a grounded cognition account of model-based learning of complex scientific knowledge related to socio-scientific issues, such as climate change. It draws on the results from a study of high school students learning about the carbon cycle through computational agent-based models and investigates two questions: First, how do students ground their understanding about the phenomenon when they learn and solve problems with computer models? Second, what are common sources of mistakes in students' reasoning with computer models? Results show that students ground their understanding in computer models in five ways: direct observation, straight abstraction, generalisation, conceptualisation, and extension. Students also incorporate into their reasoning their knowledge and experiences that extend beyond phenomena represented in the models, such as attitudes about unsustainable carbon emission rates, human agency, external events, and the nature of computational models. The most common difficulties of the students relate to seeing the modelled scientific phenomenon and connecting results from the observations with other experiences and understandings about the phenomenon in the outside world. An important contribution of this study is the constructed coding scheme for establishing different ways of grounding, which helps to understand some challenges that students encounter when they learn about complex phenomena with agent-based computer models.

The Embedding Problem for Markov Models of Nucleotide Substitution

PubMed Central

Verbyla, Klara L.; Yap, Von Bing; Pahwa, Anuj; Shao, Yunli; Huttley, Gavin A.

2013-01-01

Continuous-time Markov processes are often used to model the complex natural phenomenon of sequence evolution. To make the process of sequence evolution tractable, simplifying assumptions are often made about the sequence properties and the underlying process. The validity of one such assumption, time-homogeneity, has never been explored. Violations of this assumption can be found by identifying non-embeddability. A process is non-embeddable if it can not be embedded in a continuous time-homogeneous Markov process. In this study, non-embeddability was demonstrated to exist when modelling sequence evolution with Markov models. Evidence of non-embeddability was found primarily at the third codon position, possibly resulting from changes in mutation rate over time. Outgroup edges and those with a deeper time depth were found to have an increased probability of the underlying process being non-embeddable. Overall, low levels of non-embeddability were detected when examining individual edges of triads across a diverse set of alignments. Subsequent phylogenetic reconstruction analyses demonstrated that non-embeddability could impact on the correct prediction of phylogenies, but at extremely low levels. Despite the existence of non-embeddability, there is minimal evidence of violations of the local time homogeneity assumption and consequently the impact is likely to be minor. PMID:23935949

Preventing disasters: public health vulnerability reduction as a sustainable adaptation to climate change.

PubMed

Keim, Mark E

2011-06-01

Global warming could increase the number and severity of extreme weather events. These events are often known to result in public health disasters, but we can lessen the effects of these disasters. By addressing the factors that cause changes in climate, we can mitigate the effects of climate change. By addressing the factors that make society vulnerable to the effects of climate, we can adapt to climate change. To adapt to climate change, a comprehensive approach to disaster risk reduction has been proposed. By reducing human vulnerability to disasters, we can lessen--and at times even prevent--their impact. Human vulnerability is a complex phenomenon that comprises social, economic, health, and cultural factors. Because public health is uniquely placed at the community level, it has the opportunity to lessen human vulnerability to climate-related disasters. At the national and international level, a supportive policy environment can enable local adaptation to disaster events. The purpose of this article is to introduce the basic concept of disaster risk reduction so that it can be applied to preventing and mitigating the negative effects of climate change and to examine the role of community-focused public health as a means for lessening human vulnerability and, as a result, the overall risk of climate-related disasters.

High-Dimensional Brain: A Tool for Encoding and Rapid Learning of Memories by Single Neurons.

PubMed

Tyukin, Ivan; Gorban, Alexander N; Calvo, Carlos; Makarova, Julia; Makarov, Valeri A

2018-03-19

Codifying memories is one of the fundamental problems of modern Neuroscience. The functional mechanisms behind this phenomenon remain largely unknown. Experimental evidence suggests that some of the memory functions are performed by stratified brain structures such as the hippocampus. In this particular case, single neurons in the CA1 region receive a highly multidimensional input from the CA3 area, which is a hub for information processing. We thus assess the implication of the abundance of neuronal signalling routes converging onto single cells on the information processing. We show that single neurons can selectively detect and learn arbitrary information items, given that they operate in high dimensions. The argument is based on stochastic separation theorems and the concentration of measure phenomena. We demonstrate that a simple enough functional neuronal model is capable of explaining: (i) the extreme selectivity of single neurons to the information content, (ii) simultaneous separation of several uncorrelated stimuli or informational items from a large set, and (iii) dynamic learning of new items by associating them with already "known" ones. These results constitute a basis for organization of complex memories in ensembles of single neurons. Moreover, they show that no a priori assumptions on the structural organization of neuronal ensembles are necessary for explaining basic concepts of static and dynamic memories.

Equilibrative nucleoside transporter 1 (ENT1) regulates postischemic blood flow during acute kidney injury in mice

PubMed Central

Grenz, Almut; Bauerle, Jessica D.; Dalton, Julee H.; Ridyard, Douglas; Badulak, Alexander; Tak, Eunyoung; McNamee, Eóin N.; Clambey, Eric; Moldovan, Radu; Reyes, German; Klawitter, Jost; Ambler, Kelly; Magee, Kristann; Christians, Uwe; Brodsky, Kelley S.; Ravid, Katya; Choi, Doo-Sup; Wen, Jiaming; Lukashev, Dmitriy; Blackburn, Michael R.; Osswald, Hartmut; Coe, Imogen R.; Nürnberg, Bernd; Haase, Volker H.; Xia, Yang; Sitkovsky, Michail; Eltzschig, Holger K.

2012-01-01

A complex biologic network regulates kidney perfusion under physiologic conditions. This system is profoundly perturbed following renal ischemia, a leading cause of acute kidney injury (AKI) — a life-threatening condition that frequently complicates the care of hospitalized patients. Therapeutic approaches to prevent and treat AKI are extremely limited. Better understanding of the molecular pathways promoting postischemic reflow could provide new candidate targets for AKI therapeutics. Due to its role in adapting tissues to hypoxia, we hypothesized that extracellular adenosine has a regulatory function in the postischemic control of renal perfusion. Consistent with the notion that equilibrative nucleoside transporters (ENTs) terminate adenosine signaling, we observed that pharmacologic ENT inhibition in mice elevated renal adenosine levels and dampened AKI. Deletion of the ENTs resulted in selective protection in Ent1–/– mice. Comprehensive examination of adenosine receptor–knockout mice exposed to AKI demonstrated that renal protection by ENT inhibitors involves the A2B adenosine receptor. Indeed, crosstalk between renal Ent1 and Adora2b expressed on vascular endothelia effectively prevented a postischemic no-reflow phenomenon. These studies identify ENT1 and adenosine receptors as key to the process of reestablishing renal perfusion following ischemic AKI. If translatable from mice to humans, these data have important therapeutic implications. PMID:22269324

From drop impact physics to spray cooling models: a critical review

NASA Astrophysics Data System (ADS)

Breitenbach, Jan; Roisman, Ilia V.; Tropea, Cameron

2018-03-01

Spray-wall interaction is an important process encountered in a large number of existing and emerging technologies and is the underlying phenomenon associated with spray cooling. Spray cooling is a very efficient technology, surpassing all other conventional cooling methods, especially those not involving phase change and not exploiting the latent heat of vaporization. However, the effectiveness of spray cooling is dependent on a large number of parameters, including spray characteristics like drop size, velocity and number density, the surface morphology, but also on the temperature range and thermal properties of the materials involved. Indeed, the temperature of the substrate can have significant influence on the hydrodynamics of drop and spray impact, an aspect which is seldom considered in model formulation. This process is extremely complex, thus most design rules to date are highly empirical in nature. On the other hand, significant theoretical progress has been made in recent years about the interaction of single drops with heated walls and improvements to the fundamentals of spray cooling can now be anticipated. The present review has the objective of summarizing some of these recent advances and to establish a framework for future development of more reliable and universal physics-based correlations to describe quantities involved in spray cooling.

Ecological suicide in microbes.

PubMed

Ratzke, Christoph; Denk, Jonas; Gore, Jeff

2018-05-01

The growth and survival of organisms often depend on interactions between them. In many cases, these interactions are positive and caused by a cooperative modification of the environment. Examples are the cooperative breakdown of complex nutrients in microbes or the construction of elaborate architectures in social insects, in which the individual profits from the collective actions of her peers. However, organisms can similarly display negative interactions by changing the environment in ways that are detrimental for them, for example by resource depletion or the production of toxic byproducts. Here we find an extreme type of negative interactions, in which Paenibacillus sp. bacteria modify the environmental pH to such a degree that it leads to a rapid extinction of the whole population, a phenomenon that we call ecological suicide. Modification of the pH is more pronounced at higher population densities, and thus ecological suicide is more likely to occur with increasing bacterial density. Correspondingly, promoting bacterial growth can drive populations extinct whereas inhibiting bacterial growth by the addition of harmful substances-such as antibiotics-can rescue them. Moreover, ecological suicide can cause oscillatory dynamics, even in single-species populations. We found ecological suicide in a wide variety of microbes, suggesting that it could have an important role in microbial ecology and evolution.

Ultraviolet spectrophotometry from Gemini 11 of stars in Orion

NASA Technical Reports Server (NTRS)

Morgan, T. H.; Spear, G. G.; Kondo, Y.; Henize, K. G.

1975-01-01

Ultraviolet spectrophotometry in the wavelength region 2600-3600 A is reported for the bright early-type stars beta, eta, gamma, delta, iota, epsilon, sigma, zeta, and kappa Ori. The results are in good agreement with other observations, and, with the possible exception of the supergiants, are in good agreement with recent line-blanketed model atmospheres. There is evidence that the supergiants possess a small ultraviolet deficiency shortward of 3000 A relative to main-sequence stars of similar spectral type. The most extreme example of this phenomenon is the star kappa Ori.

Self-averaging in complex brain neuron signals

NASA Astrophysics Data System (ADS)

Bershadskii, A.; Dremencov, E.; Fukayama, D.; Yadid, G.

2002-12-01

Nonlinear statistical properties of Ventral Tegmental Area (VTA) of limbic brain are studied in vivo. VTA plays key role in generation of pleasure and in development of psychological drug addiction. It is shown that spiking time-series of the VTA dopaminergic neurons exhibit long-range correlations with self-averaging behavior. This specific VTA phenomenon has no relation to VTA rewarding function. Last result reveals complex role of VTA in limbic brain.

Testing HIV positive in pregnancy: A phenomenological study of women's experiences.

PubMed

Lingen-Stallard, Andrew; Furber, Christine; Lavender, Tina

2016-04-01

globally women receive HIV testing in pregnancy; however, limited information is available on their experiences of this potentially life-changing event. This study aims to explore women's experiences of receiving a positive HIV test result following antenatal screening. a qualitative, phenomenological approach. two public National Health Service (NHS) hospitals and HIV support organisations. a purposive sampling strategy was used. Thirteen black African women with a positive HIV result, in England, participated. data were collected using in-depth semi-structured interviews. An interpretive phenomenological approach to data analysis was used. the emergent phenomenon was transition and transformation of 'being,' as women accepted HIV as part of their lives. Paired themes support the phenomenon: shock and disbelief; anger and turmoil; stigma and confidentiality issues; acceptance and resilience. Women had extreme reactions to their positive HIV diagnosis, compounded by the cultural belief that they would die. Initial disbelief of the unexpected result developed into sadness at the loss of their old self. Turmoil was evident, as women considered termination of pregnancy, self-harm and suicide. Women felt isolated from others and relationship breakdowns often occurred. Most reported the pervasiveness of stigma, and how this was managed alongside living with HIV. Coping strategies included keeping HIV 'secret' and making their child(ren) the prime focus of life. Growing resilience was apparent with time. this study gives midwives unique understanding of the complexities and major implications for women who tested positive for HIV. Women's experiences resonated with processes of bereavement, providing useful insight into a transitional and transformational period, during which appropriate support can be targeted. midwives are crucial in improving the experience of women when they test HIV positive and to do this they need to be appropriately trained. Midwives need to acknowledge the social and psychological impact of HIV and pathways should be developed to support early referral for appropriate support. Copyright © 2016 Elsevier Ltd. All rights reserved.

Integration of modern statistical tools for the analysis of climate extremes into the web-GIS “CLIMATE”

NASA Astrophysics Data System (ADS)

Ryazanova, A. A.; Okladnikov, I. G.; Gordov, E. P.

2017-11-01

The frequency of occurrence and magnitude of precipitation and temperature extreme events show positive trends in several geographical regions. These events must be analyzed and studied in order to better understand their impact on the environment, predict their occurrences, and mitigate their effects. For this purpose, we augmented web-GIS called “CLIMATE” to include a dedicated statistical package developed in the R language. The web-GIS “CLIMATE” is a software platform for cloud storage processing and visualization of distributed archives of spatial datasets. It is based on a combined use of web and GIS technologies with reliable procedures for searching, extracting, processing, and visualizing the spatial data archives. The system provides a set of thematic online tools for the complex analysis of current and future climate changes and their effects on the environment. The package includes new powerful methods of time-dependent statistics of extremes, quantile regression and copula approach for the detailed analysis of various climate extreme events. Specifically, the very promising copula approach allows obtaining the structural connections between the extremes and the various environmental characteristics. The new statistical methods integrated into the web-GIS “CLIMATE” can significantly facilitate and accelerate the complex analysis of climate extremes using only a desktop PC connected to the Internet.

Intense tornadoes in Poland in the years 2000-2012 and their synoptic characteristics

NASA Astrophysics Data System (ADS)

Cwik, Paulina

2015-04-01

Tornadoes, or high speed rotating columns of air, are some of the most extreme natural processes occurring on Earth. Currently the trend towards more frequent and more severe occurrence of tornadoes appear also in Poland. So far, tornadoes in Poland resulted in very serious damage to infrastructure and led to injury or death many of the people. Forecast of tornados is not a easy task, especially when the phenomenon is local. Must be based on a comprehensive analysis of mesoscale numerical models, atmospheric soundings and radar data. Unfortunately, there are a number of limitations.One of it, is that the mesoscale weather models often do not capture local events, so forecast of the tornados in real time and place can not occur well in advance. The phenomenon of tornadoes must be better understood and become the object of a comprehensive analysis, so that the resulting information can be used both for research purposes as well as educational.

Optical analysis of nanoparticles via enhanced backscattering facilitated by 3-D photonic nanojets

NASA Astrophysics Data System (ADS)

Li, Xu; Chen, Zhigang; Taflove, Allen; Backman, Vadim

2005-01-01

We report the phenomenon of ultra-enhanced backscattering of visible light by nanoparticles facilitated by the 3-D photonic nanojet a sub-diffraction light beam appearing at the shadow side of a plane-waveilluminated dielectric microsphere. Our rigorous numerical simulations show that backscattering intensity of nanoparticles can be enhanced up to eight orders of magnitude when locating in the nanojet. As a result, the enhanced backscattering from a nanoparticle with diameter on the order of 10 nm is well above the background signal generated by the dielectric microsphere itself. We also report that nanojet-enhanced backscattering is extremely sensitive to the size of the nanoparticle, permitting in principle resolving sub-nanometer size differences using visible light. Finally, we show how the position of a nanoparticle could be determined with subdiffractional accuracy by recording the angular distribution of the backscattered light. These properties of photonic nanojets promise to make this phenomenon a useful tool for optically detecting, differentiating, and sorting nanoparticles.

Simple approach to superhydrophobic nanostructured Al for practical antifrosting application based on enhanced self-propelled jumping droplets.

PubMed

Kim, Aeree; Lee, Chan; Kim, Hyungmo; Kim, Joonwon

2015-04-08

Frost formation can cause operational difficulty and efficiency loss for many facilities such as aircraft, wind turbines, and outdoor heat exchangers. Self-propelled jumping by condensate droplets on superhydrophobic surfaces delays frost formation, so many attempts have been made to exploit this phenomenon. However, practical application of this phenomenon is currently unfeasible because many processes to fabricate the superhydrophobic surfaces are inefficient and because self-propelled jumping is difficult to be achieved in a humid and low-temperature environment because superhydrophobicity is degraded in these conditions. Here, we achieved significantly effective anti-icing superhydrophobic aluminum. Its extremely low adhesive properties allow self-propelled jumping under highly supersaturated conditions of high humidity or low surface temperature. As a result, this surface helps retard frost formation at that condition. The aluminum was made superhydrophobic by a simple and cost-effective process that is adaptable to any shape. Therefore, it has promise for use in practical and industrial applications.

A clinical interpretation of attitudes and behaviors associated with celebrity worship.

PubMed

Maltby, John; Houran, James; McCutcheon, Lynn E

2003-01-01

The phenomenon of celebrity worship is currently conceptualized as an abnormal type of parasocial relationship, driven by absorption and addictive elements and which potentially has significant clinical sequelae. The authors hypothesize that the three increasingly extreme sets of attitudes and behaviors associated with celebrity worship also partly reflect the three domains of personality discussed in Eysenckian theory. Specifically, celebrity worship for entertainment-social reasons may reflect extraversion personality traits; intense-personal attitudes and behaviors toward celebrities may reflect neuroticism traits; and celebrity worship of a borderline-pathological nature may reflect psychoticism traits. To test this idea, the authors administered the Celebrity Attitude Scale and the Abbreviated Form of the Revised Eysenck Personality Questionnaire to large convenience samples of students (N = 317) and community (N = 290) respondents. Results indicate that celebrity worship is not an uncommon phenomenon. Further, correlational analyses supported predictions and suggest that Eysenckian domains of personality may promote or hinder a person's progression along the continuum of behaviors associated with celebrity worship.

Atomic-Monolayer Two-Dimensional Lateral Quasi-Heterojunction Bipolar Transistors with Resonant Tunneling Phenomenon.

PubMed

Lin, Che-Yu; Zhu, Xiaodan; Tsai, Shin-Hung; Tsai, Shiao-Po; Lei, Sidong; Shi, Yumeng; Li, Lain-Jong; Huang, Shyh-Jer; Wu, Wen-Fa; Yeh, Wen-Kuan; Su, Yan-Kuin; Wang, Kang L; Lan, Yann-Wen

2017-11-28

High-frequency operation with ultrathin, lightweight, and extremely flexible semiconducting electronics is highly desirable for the development of mobile devices, wearable electronic systems, and defense technologies. In this work, the experimental observation of quasi-heterojunction bipolar transistors utilizing a monolayer of the lateral WSe 2 -MoS 2 junctions as the conducting p-n channel is demonstrated. Both lateral n-p-n and p-n-p heterojunction bipolar transistors are fabricated to exhibit the output characteristics and current gain. A maximum common-emitter current gain of around 3 is obtained in our prototype two-dimensional quasi-heterojunction bipolar transistors. Interestingly, we also observe the negative differential resistance in the electrical characteristics. A potential mechanism is that the negative differential resistance is induced by resonant tunneling phenomenon due to the formation of quantum well under applying high bias voltages. Our results open the door to two-dimensional materials for high-frequency, high-speed, high-density, and flexible electronics.

Priming Intelligent Behavior: An Elusive Phenomenon

PubMed Central

Shanks, David R.; Newell, Ben R.; Lee, Eun Hee; Balakrishnan, Divya; Ekelund, Lisa; Cenac, Zarus; Kavvadia, Fragkiski; Moore, Christopher

2013-01-01

Can behavior be unconsciously primed via the activation of attitudes, stereotypes, or other concepts? A number of studies have suggested that such priming effects can occur, and a prominent illustration is the claim that individuals' accuracy in answering general knowledge questions can be influenced by activating intelligence-related concepts such as professor or soccer hooligan. In 9 experiments with 475 participants we employed the procedures used in these studies, as well as a number of variants of those procedures, in an attempt to obtain this intelligence priming effect. None of the experiments obtained the effect, although financial incentives did boost performance. A Bayesian analysis reveals considerable evidential support for the null hypothesis. The results conform to the pattern typically obtained in word priming experiments in which priming is very narrow in its generalization and unconscious (subliminal) influences, if they occur at all, are extremely short-lived. We encourage others to explore the circumstances in which this phenomenon might be obtained. PMID:23637732

Isotopic Resonance Hypothesis: Experimental Verification by Escherichia coli Growth Measurements

NASA Astrophysics Data System (ADS)

Xie, Xueshu; Zubarev, Roman A.

2015-03-01

Isotopic composition of reactants affects the rates of chemical and biochemical reactions. As a rule, enrichment of heavy stable isotopes leads to progressively slower reactions. But the recent isotopic resonance hypothesis suggests that the dependence of the reaction rate upon the enrichment degree is not monotonous. Instead, at some ``resonance'' isotopic compositions, the kinetics increases, while at ``off-resonance'' compositions the same reactions progress slower. To test the predictions of this hypothesis for the elements C, H, N and O, we designed a precise (standard error +/-0.05%) experiment that measures the parameters of bacterial growth in minimal media with varying isotopic composition. A number of predicted resonance conditions were tested, with significant enhancements in kinetics discovered at these conditions. The combined statistics extremely strongly supports the validity of the isotopic resonance phenomenon (p << 10-15). This phenomenon has numerous implications for the origin of life studies and astrobiology, and possible applications in agriculture, biotechnology, medicine, chemistry and other areas.

Forced normalization at the interface between epilepsy and psychiatry.

PubMed

Krishnamoorthy, E S.; Trimble, M R.; Sander, J W.A.S.; Kanner, Andres M.

2002-08-01

In 1953, Landolt described a group of patients with poorly controlled epilepsy who had psychotic episodes associated with remission of their seizures and disappearance of epileptiform activity on their EEGs. He called this phenomenon "forced normalization." Since then, neurologists and psychiatrists have been intrigued by this phenomenon, and although it has been also reported by others, its existence continues to be the source of much debate. In this article, we review the clinical characteristics and potential pathogenic mechanisms of forced normalization and illustrate the complexities inherent in reaching this diagnosis, as well as its differential diagnosis in two representative cases.

Cyberinfrastructure: The Second Revolution

ERIC Educational Resources Information Center

Bement, Arden L.

2007-01-01

The engine of change for the next revolution is cyberinfrastructure, a comprehensive phenomenon that involves the creation, dissemination, preservation, and application of knowledge. It adds new dimensions that greatly increase transformational potential. Cyberinfrastructure combines complex elements to create a dynamic system. It eclipses its…

Art Therapy for Chronic Pain: Applications and Future Directions

ERIC Educational Resources Information Center

Angheluta, Anne-Marie; Lee, Bonnie K.

2011-01-01

Chronic pain is acknowledged as a phenomenological experience resulting from biological, psychological, and social interactions. Consequently, treatment for this complex and debilitating health phenomenon is often approached from multidisciplinary and biopsychosocial perspectives. One approach to treating chronic pain involves implementing…

Regulation of Expressive Behavior as Reflecting Affect Socialization.

ERIC Educational Resources Information Center

Saarni, Carolyn

Regulated expressiveness (the modification of expressive behavior) is a complex phenomenon. Accomplished basically in four ways, regulated expressiveness has developmental dimensions, motivational precursors, and cognitive antecedents, including perspective-taking ability and the growth of self-awareness. Ability to regulate expressiveness appears…

Dialogue-Based Research in Man-Machine Communication

DTIC Science & Technology

1975-11-01

This paper first surveys current knowledge of human communication from a point of view which seeks to find or develop knowledge that will be useful...complexity is explored. Building a useful knowledge of human communication is an extremely complex task. Controlling this complexity and its effects, without

Statistical complexity without explicit reference to underlying probabilities

NASA Astrophysics Data System (ADS)

Pennini, F.; Plastino, A.

2018-06-01

We show that extremely simple systems of a not too large number of particles can be simultaneously thermally stable and complex. To such an end, we extend the statistical complexity's notion to simple configurations of non-interacting particles, without appeal to probabilities, and discuss configurational properties.

Complex Fluids and Hydraulic Fracturing.

PubMed

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.

Geoethics and perception of seismic risk: the case of Pollino, Calabria, Southern Italy and the comparison with past societies

NASA Astrophysics Data System (ADS)

De Pascale, Francesco; Bernardo, Marcello; Muto, Francesco

2013-04-01

This work is a synthesis of research on the perception of seismic risk in the area of the Pollino, where it is been two years that an ongoing earthquake swarm is affecting the area between Calabria and Basilicata. Mr Downs has distinguished three different aspects in the perception of the environment: structural, preference and evaluation. Within this third aspect, the perception of seismic risk is an important dimension for the schedule. Starting from the territory, understood as the result of reciprocal interactions between humans and the physical space during the later stages of territorialization and reterritorialization, Geoethics can find a synthesis between humanistic and scientific knowledge in relating to the theme of disasters. The risk must be considered in its territorial nature, as a complex phenomenon which involves all aspects of the relations between man and environment. Assuming that the rupture of the dynamic equilibrium among population, environment and resources is the increasingly frequent causes of the outbreak of disasters in the academic increasing attention has been paid to the concept of resilience, for its potential to evaluate a system in a state of equilibrium and adaptation in response to a shock. Thus, the meaning adopted in the social sciences, not only in terms of natural disasters, but more generally for any change to the territory, refers to the ability to resist and recover their losses. Therefore, Geoethics can certainly help especially in educating the territory in terms of integrated risk management to become a tool that can enhance the resilience. In education-teaching, the concept of resilience is used especially for what concerns the sphere of the child's skills in effectively managing stress and difficulties of everyday life. In this context of risk, improve communications, awareness of the complexity of risk and the level of preparation would increase the resilience of the territory and to allow a more effective management and planning. In this context, a questionnaire was administered to the students of primary and secondary education in some cities and villages affected by the earthquake of Pollino, in order to bring out the knowledge actually possessed and tied to age, experience, areas of origin and the perceptions that learners show that they have in relation to seismic phenomenon. The data and opinions collected will be useful to design and build new information tools, more adapted to the needs of all citizens, compared to natural hazards such as earthquake, boosting the resilience of the territory. Keeping the memory of natural disasters could also mean knowing how to cope better and learn how to mitigate the risk. The comparison with the perception of the great earthquakes of the past, such as the 1783 in Calabria, help us to clarify the relationship between an extreme event, which is part of the dynamics of nature, and a disaster happens when human societies are not able to "absorb" an extreme event and collapse. Each company in the past has had its weaknesses that's why we must know what are the risks we are facing.

Extreme ultraviolet index due to broken clouds at a midlatitude site, Granada (southeastern Spain)

NASA Astrophysics Data System (ADS)

Antón, M.; Piedehierro, A. A.; Alados-Arboledas, L.; Wolfran, E.; Olmo, F. J.

2012-11-01

Cloud cover usually attenuates the ultraviolet (UV) solar radiation but, under certain sky conditions, the clouds may produce an enhancement effect increasing the UV levels at surface. The main objective of this paper is to analyze an extreme UV enhancement episode recorded on 16 June 2009 at Granada (southeastern Spain). This phenomenon was characterized by a quick and intense increase in surface UV radiation under broken cloud fields (5-7 oktas) in which the Sun was surrounded by cumulus clouds (confirmed with sky images). Thus, the UV index (UVI) showed an enhancement of a factor 4 in the course of only 30 min around midday, varying from 2.6 to 10.4 (higher than the corresponding clear-sky UVI value). Additionally, the UVI presented values higher than 10 (extreme erythemal risk) for about 20 min running, with a maximum value around 11.5. The use of an empirical model and the total ozone column (TOC) derived from the Global Ozone Monitoring Experiment (GOME) for the period 1995-2011 showed that the value of UVI ~ 11.5 is substantially larger than the highest index that could origin the natural TOC variations over Granada. Finally, the UV erythemal dose accumulated during the period of 20 min with the extreme UVI values under broken cloud fields was 350 J/m2 which surpass the energy required to produce sunburn of the most human skin types.

Combining local search with co-evolution in a remarkably simple way

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boettcher, S.; Percus, A.

2000-05-01

The authors explore a new general-purpose heuristic for finding high-quality solutions to hard optimization problem. The method, called extremal optimization, is inspired by self-organized criticality, a concept introduced to describe emergent complexity in physical systems. In contrast to genetic algorithms, which operate on an entire gene-pool of possible solutions, extremal optimization successively replaces extremely undesirable elements of a single sub-optimal solution with new, random ones. Large fluctuations, or avalanches, ensue that efficiently explore many local optima. Drawing upon models used to simulate far-from-equilibrium dynamics, extremal optimization complements heuristics inspired by equilibrium statistical physics, such as simulated annealing. With only onemore » adjustable parameter, its performance has proved competitive with more elaborate methods, especially near phase transitions. Phase transitions are found in many combinatorial optimization problems, and have been conjectured to occur in the region of parameter space containing the hardest instances. We demonstrate how extremal optimization can be implemented for a variety of hard optimization problems. We believe that this will be a useful tool in the investigation of phase transitions in combinatorial optimization, thereby helping to elucidate the origin of computational complexity.« less

Analysis and modelling of surface Urban Heat Island in 20 Canadian cities under climate and land-cover change.

PubMed

Gaur, Abhishek; Eichenbaum, Markus Kalev; Simonovic, Slobodan P

2018-01-15

Surface Urban Heat Island (SUHI) is an urban climate phenomenon that is expected to respond to future climate and land-use land-cover change. It is important to further our understanding of physical mechanisms that govern SUHI phenomenon to enhance our ability to model future SUHI characteristics under changing geophysical conditions. In this study, SUHI phenomenon is quantified and modelled at 20 cities distributed across Canada. By analyzing MODerate Resolution Imaging Spectroradiometer (MODIS) sensed surface temperature at the cities over 2002-2012, it is found that 16 out of 20 selected cities have experienced a positive SUHI phenomenon while 4 cities located in the prairies region and high elevation locations have experienced a negative SUHI phenomenon in the past. A statistically significant relationship between observed SUHI magnitude and city elevation is also recorded over the observational period. A Physical Scaling downscaling model is then validated and used to downscale future surface temperature projections from 3 GCMs and 2 extreme Representative Concentration Pathways in the urban and rural areas of the cities. Future changes in SUHI magnitudes between historical (2006-2015) and future timelines: 2030s (2026-2035), 2050s (2046-2055), and 2090s (2091-2100) are estimated. Analysis of future projected changes indicate that 15 (13) out of 20 cities can be expected to experience increases in SUHI magnitudes in future under RCP 2.6 (RCP 8.5). A statistically significant relationship between projected future SUHI change and current size of the cities is also obtained. The study highlights the role of city properties (i.e. its size, elevation, and surrounding land-cover) towards shaping their current and future SUHI characteristics. The results from this analysis will help decision-makers to manage Canadian cities more efficiently under rapidly changing geophysical and demographical conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Noise-induced volatility of collective dynamics

NASA Astrophysics Data System (ADS)

Harras, Georges; Tessone, Claudio J.; Sornette, Didier

2012-01-01

Noise-induced volatility refers to a phenomenon of increased level of fluctuations in the collective dynamics of bistable units in the presence of a rapidly varying external signal, and intermediate noise levels. The archetypical signature of this phenomenon is that—beyond the increase in the level of fluctuations—the response of the system becomes uncorrelated with the external driving force, making it different from stochastic resonance. Numerical simulations and an analytical theory of a stochastic dynamical version of the Ising model on regular and random networks demonstrate the ubiquity and robustness of this phenomenon, which is argued to be a possible cause of excess volatility in financial markets, of enhanced effective temperatures in a variety of out-of-equilibrium systems, and of strong selective responses of immune systems of complex biological organisms. Extensive numerical simulations are compared with a mean-field theory for different network topologies.

Historical review of die drool phenomenon during plastics extrusion

NASA Astrophysics Data System (ADS)

Musil, Jan; Zatloukal, Martin

2013-04-01

Die drool phenomenon is defined as unwanted spontaneous accumulation of extruded polymer melt on open faces of extrusion die during extrusion process. Such accumulated material builds up on the die exit and frequently or continually sticks onto the extruded product and thus damages it. Since die drool appears, extrusion process must be shut down and die exit must be manually cleaned which is time and money consuming. Although die drool is complex phenomenon and its formation mechanism is not fully understood yet, variety of proposed explanations of its formation mechanism and also many ways to its elimination can be found in open literature. Our review presents in historical order breakthrough works in the field of die drool research, shows many ways to suppress it, introduces methods for its quantitative evaluation and composition analysis and summarizes theories of die drool formation mechanism which can be helpful for extrusion experts.

An Approach to Experimental Design for the Computer Analysis of Complex Phenomenon

NASA Technical Reports Server (NTRS)

Rutherford, Brian

2000-01-01

The ability to make credible system assessments, predictions and design decisions related to engineered systems and other complex phenomenon is key to a successful program for many large-scale investigations in government and industry. Recently, many of these large-scale analyses have turned to computational simulation to provide much of the required information. Addressing specific goals in the computer analysis of these complex phenomenon is often accomplished through the use of performance measures that are based on system response models. The response models are constructed using computer-generated responses together with physical test results where possible. They are often based on probabilistically defined inputs and generally require estimation of a set of response modeling parameters. As a consequence, the performance measures are themselves distributed quantities reflecting these variabilities and uncertainties. Uncertainty in the values of the performance measures leads to uncertainties in predicted performance and can cloud the decisions required of the analysis. A specific goal of this research has been to develop methodology that will reduce this uncertainty in an analysis environment where limited resources and system complexity together restrict the number of simulations that can be performed. An approach has been developed that is based on evaluation of the potential information provided for each "intelligently selected" candidate set of computer runs. Each candidate is evaluated by partitioning the performance measure uncertainty into two components - one component that could be explained through the additional computational simulation runs and a second that would remain uncertain. The portion explained is estimated using a probabilistic evaluation of likely results for the additional computational analyses based on what is currently known about the system. The set of runs indicating the largest potential reduction in uncertainty is then selected and the computational simulations are performed. Examples are provided to demonstrate this approach on small scale problems. These examples give encouraging results. Directions for further research are indicated.

Extreme insular dwarfism evolved in a mammoth.

PubMed

Herridge, Victoria L; Lister, Adrian M

2012-08-22

The insular dwarfism seen in Pleistocene elephants has come to epitomize the island rule; yet our understanding of this phenomenon is hampered by poor taxonomy. For Mediterranean dwarf elephants, where the most extreme cases of insular dwarfism are observed, a key systematic question remains unresolved: are all taxa phyletic dwarfs of a single mainland species Palaeoloxodon antiquus (straight-tusked elephant), or are some referable to Mammuthus (mammoths)? Ancient DNA and geochronological evidence have been used to support a Mammuthus origin for the Cretan 'Palaeoloxodon' creticus, but these studies have been shown to be flawed. On the basis of existing collections and recent field discoveries, we present new, morphological evidence for the taxonomic status of 'P'. creticus, and show that it is indeed a mammoth, most probably derived from Early Pleistocene Mammuthus meridionalis or possibly Late Pliocene Mammuthus rumanus. We also show that Mammuthus creticus is smaller than other known insular dwarf mammoths, and is similar in size to the smallest dwarf Palaeoloxodon species from Sicily and Malta, making it the smallest mammoth species known to have existed. These findings indicate that extreme insular dwarfism has evolved to a similar degree independently in two elephant lineages.

Antarctic Temperature Extremes from MODIS Land Surface Temperatures: New Processing Methods Reveal Data Quality Puzzles

NASA Astrophysics Data System (ADS)

Grant, G.; Gallaher, D. W.

2017-12-01

New methods for processing massive remotely sensed datasets are used to evaluate Antarctic land surface temperature (LST) extremes. Data from the MODIS/Terra sensor (Collection 6) provides a twice-daily look at Antarctic LSTs over a 17 year period, at a higher spatiotemporal resolution than past studies. Using a data condensation process that creates databases of anomalous values, our processes create statistical images of Antarctic LSTs. In general, the results find few significant trends in extremes; however, they do reveal a puzzling picture of inconsistent cloud detection and possible systemic errors, perhaps due to viewing geometry. Cloud discrimination shows a distinct jump in clear-sky detections starting in 2011, and LSTs around the South Pole exhibit a circular cooling pattern, which may also be related to cloud contamination. Possible root causes are discussed. Ongoing investigations seek to determine whether the results are a natural phenomenon or, as seems likely, the results of sensor degradation or processing artefacts. If the unusual LST patterns or cloud detection discontinuities are natural, they point to new, interesting processes on the Antarctic continent. If the data artefacts are artificial, MODIS LST users should be alerted to the potential issues.

Trends in rainfall and rainfall-related extremes in the east coast of peninsular Malaysia

NASA Astrophysics Data System (ADS)

Mayowa, Olaniya Olusegun; Pour, Sahar Hadi; Shahid, Shamsuddin; Mohsenipour, Morteza; Harun, Sobri Bin; Heryansyah, Arien; Ismail, Tarmizi

2015-12-01

The coastlines have been identified as the most vulnerable regions with respect to hydrological hazards as a result of climate change and variability. The east of peninsular Malaysia is not an exception for this, considering the evidence of heavy rainfall resulting in floods as an annual phenomenon and also water scarcity due to long dry spells in the region. This study examines recent trends in rainfall and rainfall- related extremes such as, maximum daily rainfall, number of rainy days, average rainfall intensity, heavy rainfall days, extreme rainfall days, and precipitation concentration index in the east coast of peninsular Malaysia. Recent 40 years (1971-2010) rainfall records from 54 stations along the east coast of peninsular Malaysia have been analyzed using the non-parametric Mann-Kendall test and the Sen's slope method. The Monte Carlo simulation technique has been used to determine the field significance of the regional trends. The results showed that there was a substantial increase in the annual rainfall as well as the rainfall during the monsoon period. Also, there was an increase in the number of heavy rainfall days during the past four decades.

[Sensitive Determination of Chondroitin Sulfate by Fluorescence Recovery of an Anionic Aluminum Phthalocyanine-Cationic Surfactant Ion-Association Complex Used as a Fluorescent Probe Emitting at Red Region].

PubMed

Chen, Lin; Huang, Ping; Yang, Hui-qing; Deng, Ya-bin; Guo, Meng-lin; Li, Dong-hui

2015-08-01

Determination of chondroitin sulfate in the biomedical field has an important value. The conventional methods for the assay of chondroitin sulfate are still unsatisfactory in sensitivity, selectivity or simplicity. This work aimed at developing a novel method for sensitive and selective determination of chondroitin sulfate by fluorimetry. We found that some kinds of cationic surfactants have the ability to quench the fluorescence of tetrasulfonated aluminum phthalocyanine (AlS4Pc), a strongly fluorescent compound which emits at red region, with high efficiency. But, the fluorescence of the above-mentioned fluorescence quenching system recovered significantly when chondroitin sulfate (CS) exits. Tetradecyl dimethyl benzyl ammonium chloride(TDBAC) which was screened from all of the candidates of cationic surfactants was chosen as the quencher because it shows the most efficient quenching effect. It was found that the fluorescence of AlS4Pc was extremely quenched by TDBAC because of the formation of association complex between AlS4Pc and TDBAC. Fluorescence of the association complex recovered dramatically after the addition of chondroitin sulfate (CS) due to the ability of chondroitin sulfate to shift the association equilibrium of the association, leading to the release of AlS4Pc, thus resulting in an increase in the fluorescence of the reaction system. Based on this phenomenon, a novel method with simplicity, accuracy and sensitivity was developed for quantitative determination of CS. Factors including the reaction time, influencing factors and the effect of coexisting substances were investigated and discussed. Under optimum conditions the linear range of the calibration curve was 0.20~10.0 μg · mL(-1). The detection limit for CS was 0.070 μg · mL(-1). The method has been applied to the analysis of practical samples with satisfied results. This work expands the applications of AlS4Pc in biomedical area.

Plastic Surgery Challenges in War Wounded I: Flap-Based Extremity Reconstruction

PubMed Central

Sabino, Jennifer M.; Slater, Julia; Valerio, Ian L.

2016-01-01

Scope and Significance: Reconstruction of traumatic injuries requiring tissue transfer begins with aggressive resuscitation and stabilization. Systematic advances in acute casualty care at the point of injury have improved survival and allowed for increasingly complex treatment before definitive reconstruction at tertiary medical facilities outside the combat zone. As a result, the complexity of the limb salvage algorithm has increased over 14 years of combat activities in Iraq and Afghanistan. Problem: Severe poly-extremity trauma in combat casualties has led to a large number of extremity salvage cases. Advanced reconstructive techniques coupled with regenerative medicine applications have played a critical role in the restoration, recovery, and rehabilitation of functional limb salvage. Translational Relevance: The past 14 years of war trauma have increased our understanding of tissue transfer for extremity reconstruction in the treatment of combat casualties. Injury patterns, flap choice, and reconstruction timing are critical variables to consider for optimal outcomes. Clinical Relevance: Subacute reconstruction with specifically chosen flap tissue and donor site location based on individual injuries result in successful tissue transfer, even in critically injured patients. These considerations can be combined with regenerative therapies to optimize massive wound coverage and limb salvage form and function in previously active patients. Summary: Traditional soft tissue reconstruction is integral in the treatment of war extremity trauma. Pedicle and free flaps are a critically important part of the reconstructive ladder for salvaging extreme extremity injuries that are seen as a result of the current practice of war. PMID:27679751

Foehn-induced effects on local dust pollution, frontal clouds and solar radiation in the Dead Sea valley

NASA Astrophysics Data System (ADS)

Kishcha, Pavel; Starobinets, Boris; Savir, Amit; Alpert, Pinhas; Kaplan, Michael

2018-06-01

Despite the long history of investigation of foehn phenomena, there are few studies of the influence of foehn winds on air pollution and none in the Dead Sea valley. For the first time the foehn phenomenon and its effects on local dust pollution, frontal cloudiness and surface solar radiation were analyzed in the Dead Sea valley, as it occurred on 22 March 2013. This was carried out using both numerical simulations and observations. The foehn winds intensified local dust emissions, while the foehn-induced temperature inversion trapped dust particles beneath this inversion. These two factors caused extreme surface dust concentration in the western Dead Sea valley. The dust pollution was transported by west winds eastward, to the central Dead Sea valley, where the speed of these winds sharply decreased. The transported dust was captured by the ascending airflow contributing to the maximum aerosol optical depth (AOD) over the central Dead Sea valley. On the day under study, the maximum surface dust concentration did not coincide with the maximum AOD: this being one of the specific effects of the foehn phenomenon on dust pollution in the Dead Sea valley. Radar data showed a passage of frontal cloudiness through the area of the Dead Sea valley leading to a sharp drop in noon solar radiation. The descending airflow over the downwind side of the Judean Mountains led to the formation of a cloud-free band followed by only the partial recovery of solar radiation because of the extreme dust pollution caused by foehn winds.

Complex Regional Pain Syndrome

MedlinePlus

Complex regional pain syndrome (CRPS) is a chronic pain condition. It causes intense pain, usually in the arms, hands, legs, or feet. ... in skin temperature, color, or texture Intense burning pain Extreme skin sensitivity Swelling and stiffness in affected ...

Repeated polyploidization of Gossypium genomes and the evolution of spinnable cotton fibres

USDA-ARS?s Scientific Manuscript database

Emergent phenotypes are common in polyploids relative to their diploid progenitors, a phenomenon exemplified by spinnable cotton fibers. Following 15-18 fold paleopolyploidy, allopolyploidy 1-2 million years ago reunited divergent Gossypium genomes, imparting new combinatorial complexity that might ...

Leadership as an Emergent Phenomenon: A Framework for Complexity and Adaptability

DTIC Science & Technology

2008-06-01

psychologists, including Kegan (Kegan, 1994; Torbert, 1991), Alexander (Alexander and Langer, 1990), Kohlberg (1984...development stages from symbiosis to conscious universal embeddedness. In M. L. Commons, C. Armon, L. Kohlberg , F. A. Richards, T. A. Grotzer, and J. D

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

PubMed

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

2006-05-14

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

EFFECTS OF ULTRAVIOLET RADIATION ON THE MODERATE HALOPHILE HALOMONAS ELONGATA AND THE EXTREME HALOPHILE HALOBACTERIUM SALINARUM

EPA Science Inventory

Both the moderately halophilic bacterium, Halomonas elongata, and the extremely halophilic archaea, Halobacterium salinarum, can be found in hypersaline environments (e.g., salterns). On complex media, H. elongata grows over a salt range of 0.05-5.2 M, whereas, H. salinarum multi...

Complex negotiations: the lived experience of enacting agency after a stroke.

PubMed

Bergström, Aileen L; Eriksson, Gunilla; Asaba, Eric; Erikson, Anette; Tham, Kerstin

2015-01-01

This qualitative, longitudinal, descriptive study aimed to understand the lived experience of enacting agency, and to describe the phenomenon of agency and the meaning structure of the phenomenon during the year after a stroke. Agency is defined as making things happen in everyday life through one's actions. This study followed six persons (three men and three women, ages 63 to 89), interviewed on four separate occasions. Interview data were analysed using the Empirical Phenomenological Psychological method. The main findings showed that the participants experienced enacting agency in their everyday lives after stroke as negotiating different characteristics over a span of time, a range of difficulty, and in a number of activities, making these negotiations complex. The four characteristics described how the participants made things happen in their everyday lives through managing their disrupted bodies, taking into account their past and envisioning their futures, dealing with the world outside themselves, and negotiating through internal dialogues. This empirical evidence regarding negotiations challenges traditional definitions of agency and a new definition of agency is proposed. Understanding clients' complex negotiations and offering innovative solutions to train in real-life situations may help in the process of enabling occupations after a stroke.

Streamwise Vorticity Generation in Laminar and Turbulent Jets

NASA Technical Reports Server (NTRS)

Demuren, Aodeji O.; Wilson, Robert V.

1999-01-01

Complex streamwise vorticity fields are observed in the evolution of non-circular jets. Generation mechanisms are investigated via Reynolds-averaged (RANS), large-eddy (LES) and direct numerical (DNS) simulations of laminar and turbulent rectangular jets. Complex vortex interactions are found in DNS of laminar jets, but axis-switching is observed only when a single instability mode is present in the incoming mixing layer. With several modes present, the structures are not coherent and no axis-switching occurs, RANS computations also produce no axis-switching. On the other hand, LES of high Reynolds number turbulent jets produce axis-switching even for cases with several instability modes in the mixing layer. Analysis of the source terms of the mean streamwise vorticity equation through post-processing of the instantaneous results shows that, complex interactions of gradients of the normal and shear Reynolds stresses are responsible for the generation of streamwise vorticity which leads to axis-switching. RANS computations confirm these results. k - epsilon turbulence model computations fail to reproduce the phenomenon, whereas algebraic Reynolds stress model (ASM) computations, in which the secondary normal and shear stresses are computed explicitly, succeeded in reproducing the phenomenon accurately.

Towards a unified study of extreme events using universality concepts and transdisciplinary analysis methods

NASA Astrophysics Data System (ADS)

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.

One-shot Synesthesia

PubMed Central

Kirschner, Alexandra; Nikolić, Danko

2017-01-01

Abstract Synesthesia is commonly thought to be a phenomenon of fixed associations between an outside inducer and a vivid concurrent experience. Hence, it has been proposed that synesthesia occurs due to additional connections in the brain with which synesthetes are born. Here we show that synesthesia can be a much richer and more flexible phenomenon with a capability to creatively construct novel synesthetic experiences as events unfold in people’s lives. We describe here cases of synesthetes who occasionally generate novel synesthetic experience, called one-shot synesthesias. These synesthetic experiences seem to share all the properties with the classical synesthetic associations except that they occur extremely rarely, people recalling only a few events over the lifetime. It appears that these one-shots are not created at random but are instead responses to specific life events. We contrast the properties of those rare synesthetic events with other, more commonly known forms of synesthesia that also create novel synesthetic experiences, but at a high rate—sometimes creating novel experiences every few seconds. We argue that one-shot synesthesias indicate that synesthetic associations are by their nature not prewired at birth but are dynamically constructed through mental operations and according to the needs of a synesthetic mind. Our conclusions have implications for understanding the biological underpinnings of synesthesia and the role the phenomenon plays in the lives of people endowed with synesthetic capacities. PMID:29188078

Unique Results and Lessons Learned from the TSS Missions

NASA Technical Reports Server (NTRS)

Stone, Nobie H.

2016-01-01

In 1924, Irvin Langmuir and H. M. Mott-Smith published a theoretical model for the complex plasma sheath phenomenon in which they identified some very special cases which greatly simplified the sheath and allowed a closed solution to the problem. The most widely used application is for an electrostatic, or "Langmuir," probe in laboratory plasma. Although the Langmuir probe is physically simple (a biased wire) the theory describing its functional behavior and its current-voltage characteristic is extremely complex and, accordingly, a number of assumptions and approximations are used in the LMS model. These simplifications, correspondingly, place limits on the model's range of application. Adapting the LMS model to real-life conditions is the subject of numerous papers and dissertations. The Orbit-Motion Limited (OML) model that is widely used today is one of these adaptions that is a convenient means of calculating sheath effects. The OML equation for electron current collection by a positively biased body is simply: I is approximately equal to A x j(sub eo) x 2/v??(phi)(exp ½) where A is the area of the body and phi is the electric potential on the body with respect to the plasma. Since the Langmuir probe is a simple biased wire immersed in plasma, it is particularly tempting to use the OML equation in calculating the characteristics of the long, highly biased wires of an Electric Sail in the solar wind plasma. However, in order to arrive at the OML equation, a number of additional simplifying assumptions and approximations (beyond those made by Langmuir-Mott-Smith) are necessary. The OML equation is a good approximation when all conditions are met, but it would appear that the Electric Sail problem lies outside of the limits of applicability.

Processes influencing the duration and decline of epizootics in Schistocephalus solidus.

PubMed

Heins, David C; Baker, John A; Green, Dillon M

2011-06-01

The interplay of intermediate host fish and plerocercoids of diphyllobothriidean cestodes results in epizootics that are deceptively simple, but conceal complex biotic and abiotic interactions shaping each event independently. Although general descriptions of epizootics and some details of biotic interactions between enemies are known, much remains to be discovered about the abiotic and biotic forces and their interactions driving epizootics. This study shows that the duration of an epizootic of Schistocephalus solidus was sustained by high prevalence, mean intensity, and PI (parasite index-parasite : host biomass ratio) levels among young-of-the-year and 1-yr-old threespine sticklebacks. Many infections and most parasite growth in young-of-the-year fish apparently occurred under the ice during the winter. Few new infections appear to have occurred among 1-yr-old fish, which may live 2 yr and sometimes 3 yr. The decline of the epizootic occurred as the recruitment of 1 to 2-yr-old hosts decreased significantly, followed by reduced infections of young-of-the-year fish. Thus, a major factor influencing parasite population dynamics was reduced transmission (probability of infection) as a result of overwinter host mortality among 1-yr-old fish. Mega-epizootics, named and described herein, appear to represent a "perfect storm" phenomenon dependent on a particular and rare combination of circumstances. Less extreme and more gradual epizootics may be more common and play out in myriad ways, because of complex abiotic and biotic factors influencing both parasite and host populations. The interplay of parasite and host resulting in reciprocal effects upon one another occurs during both the emergence and decline phases of an epizootic.

Correlated Topics in a Scalable Multidimensional Text Cube: Algorithms and Aviation Safety Case Study

NASA Technical Reports Server (NTRS)

Zhao, Bo; Lin, Cindy X.; Srivastava, Ashok N.; Oza, Nikunj C.; Han, Jiawei

2010-01-01

As world-wide air traffic continues to grow even at a modest pace, the overall complexity of the system will increase significantly. This increased complexity can lead to a larger number of fatalities per year even if the extremely low fatality rate that we currently enjoy is maintained. One important source of information about the safety of the aviation system is in Aviation Safety Text Reports which are written by members of the flight crew, air traffic controllers, and other parties involved with the aviation system. These anonymized narrative reports contain fixed-field contextual information about the flight but also contain free-form narratives that describe, in the author s own words, the nature of the safety incident and, in many cases, the contributing factors that led to the safety incident. Several thousand such reports are filed each month, each of which is read and analyzed by highly trained experts. However, it is possible that there are emerging safety issues due to the fact that they may be reported very infrequently and in different contexts with different descriptions. The goal of this research paper is to develop correlated topic models which uncover correlations in the subspaces defined by the intersection of numerous fixed fields and discovered correlated topics. This task requires the discovery of latent topics in the text reports and the creation of a topic cube. Furthermore, because the number of potential cells in the topic cube is very large, we discuss novel methods of pruning the search space in the topic cells, thereby making the analysis feasible. We demonstrate the new algorithms on an analysis of pilot fatigue and its contributing factors, as well as the safety incidents that are correlated with this phenomenon.

Effects of impurity doping on ionic conductivity and polarization phenomenon in TlBr

NASA Astrophysics Data System (ADS)

Du, Mao-Hua

2013-02-01

Ionic conductivity due to vacancy diffusion and the resulting polarization phenomenon are major challenges to the development of TlBr radiation detector. It had been proposed that impurity doping of TlBr can suppress the ionic conductivity because the impurities can getter vacancies to form neutral complexes. This paper shows that the isolated vacancies can maintain their equilibrium concentrations even at room temperature, rendering any gettering methods ineffective. The main effect of doping is to change the Fermi level and consequently the vacancy concentration. The minimal ionic conductivity is reached at the donor concentration of [D+] = 4 × 1016 cm-3.

Interaction of nanoparticles for the peristaltic flow in an asymmetric channel with the induced magnetic field

NASA Astrophysics Data System (ADS)

Akbar, Noreen Sher; Raza, M.; Ellahi, R.

2014-07-01

In the present investigation, we examined the interaction of nanoparticle copper with the base fluid water in an asymmetric channel in the presence of an induced magnetic field. The complexity of equations describing the flow of the nanofluid is reduced by applying the low-Reynolds number and long-wavelength approximations. The resulting equations are solved exactly. The obtained expressions for the velocity and temperature phenomenon are sketched in graphs. The resulting relations for pressure gradient and pressure rise are plotted for various pertinent parameters. The streamlines are drawn for some physical quantities to discuss the trapping phenomenon.

Political efficacy and familiarity as predictors of attitudes towards electric transmission lines in the United States

DOE PAGES

Joe, Jeffrey C.; Hendrickson, Kelsie; Wong, Maria; ...

2016-05-18

Public opposition to the construction (i.e., siting) of new high voltage overhead transmission lines is not a new or isolated phenomenon. Past research has posited a variety of reasons, applied general theories, and has provided empirical evidence to explain public opposition. The existing literature, while clarifying many elements of the issue, does not yet fully explain the complexities underlying this public opposition phenomenon. As a result, the current study demonstrated how two overlooked factors, people’s sense of political efficacy and their familiarity (i.e., prior exposure) with transmission lines, explained attitudes of support and opposition to siting new power lines.

Political efficacy and familiarity as predictors of attitudes towards electric transmission lines in the United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joe, Jeffrey C.; Hendrickson, Kelsie; Wong, Maria

Public opposition to the construction (i.e., siting) of new high voltage overhead transmission lines is not a new or isolated phenomenon. Past research has posited a variety of reasons, applied general theories, and has provided empirical evidence to explain public opposition. The existing literature, while clarifying many elements of the issue, does not yet fully explain the complexities underlying this public opposition phenomenon. As a result, the current study demonstrated how two overlooked factors, people’s sense of political efficacy and their familiarity (i.e., prior exposure) with transmission lines, explained attitudes of support and opposition to siting new power lines.

Unidirectional invisibility and non-reciprocal transmission in two and three dimensions.

PubMed

Loran, Farhang; Mostafazadeh, Ali

2016-07-01

We explore the phenomenon of unidirectional invisibility in two dimensions, examine its optical realizations and discuss its three-dimensional generalization. In particular, we construct an infinite class of unidirectionally invisible optical potentials that describe the scattering of normally incident transverse electric waves by an infinite planar slab with refractive-index modulations along both the normal directions to the electric field. A by-product of this investigation is a demonstration of non-reciprocal transmission in two dimensions. To elucidate this phenomenon, we state and prove a general reciprocity theorem that applies to quantum scattering theory of real and complex potentials in two and three dimensions.

Menstruation during a lifespan: A qualitative study of women's experiences.

PubMed

Brantelid, Ida Emilie; Nilvér, Helena; Alehagen, Siw

2014-01-01

Menstruation is a natural phenomenon for women during their reproductive years. Our aim was to describe women's experiences of menstruation across the lifespan. Qualitative interviews with a narrative approach were conducted with 12 women between 18 and 48 years of age in Sweden. Using thematic analysis, we found menstruation to be a complex phenomenon that binds women together. It is perceived as an intimate and private matter, which makes women want to conceal the occurrence of menstrual bleeding. Over time, menstruation becomes a natural part of women's lives and gender identity. Health professionals play a central role supporting women to deal with menstruation.

A solar burst with a spectral component observed only above 100 GHz during an M class flare

NASA Astrophysics Data System (ADS)

Cristiani, G.; Giménez de Castro, C. G.; Mandrini, C. H.; Machado, M. E.; Silva, I. De Benedetto E.; Kaufmann, P.; Rovira, M. G.

2008-12-01

Context: Since the installation of submillimeter solar radio telescopes, a new spectral burst component was discovered at frequencies above 100 GHz, creating the THz burst category. In all the reported cases, the events were X-class flares and the THz component was increasing. Aims: We report for the first time an M class flare that shows a different submillimeter radio spectral component from the microwave classical burst. Two successive bursts of 2 min duration and separated by 2 min occurred in active region NOAA 10226, starting around 13:15 UT and having an M 6.8 maximum intensity in soft X-rays. Methods: Submillimeter flux density measured by the Solar Submillimeter Telescope (SST) is used, in addition to microwave total Sun patrol telescope observations. Images with Hα filters, from the Hα Solar Telescope for Argentina (HASTA), and extreme UV observations, from the Extreme-ultraviolet Imaging Telescope (EIT) aboard the Solar and Heliospheric Observatory (SoHO), are used to characterize the flaring region. An extensive analysis of the magnetic topology evolution is derived from the Michelson Doppler Imager (SoHO, MDI) magnetograms and used to constrain the solution space of the possible emission mechanisms. Results: The submillimeter component is only observed at 212 GHz. We have upper limits for the emission at 89.4 and 405 GHz, which are less than the observed flux density at 212 GHz. The analysis of the magnetic topology reveals a very compact and complex system of arches that reconnects at low heights, while from the soft X-ray observations we deduce that the flaring area is dense (n ˜ 1012 cm-3). The reconnected arches are anchored in regions with magnetic field intensity differing by an order of magnitude. Accordingly, we conclude that the microwave emission comes from mildly relativistic electrons spiraling down along the reconnected loops. A very small portion of the accelerated electrons can reach the footpoint with the stronger magnetic field (2000 G) and produce synchrotron emission, which is observed at submillimeter frequencies. Conclusions: The finding of a submillimeter burst component in a medium-size flare indicates that the phenomenon is more universal than shown until now. The multiwavelength analysis reveals that neither positron synchrotron nor free-free emission could produce the submillimeter component, which is explained here by synchrotron of accelerated electrons in a rather complex and compact magnetic configuration.

Simulating Life

ERIC Educational Resources Information Center

Sinclair, Michael; Dauerty, Helene; Alber, Mark

2016-01-01

Biomodeling is the study of the structures and behaviors of interacting biological entities such as molecules, cells, or organisms. While physical and chemical processes give rise to various spatial and temporal structures, even the simplest biological phenomenon is infinitely more complex (Kling 2004). Over the past decade, much of biomodeling…

Global trade and assisted reproductive technologies: regulatory challenges in international surrogacy.

PubMed

Nelson, Erin

2013-01-01

International surrogacy is an increasingly common phenomenon and an important global health challenge. Legal rules are a key consideration for the participants in international surrogacy arrangements. In some cases the law can help to resolve the complex issues that arise in this context, but it is important to consider the role played by law in contributing to the complex conflicts that such arrangements can generate. © 2013 American Society of Law, Medicine & Ethics, Inc.

Effect of Environment-Based Coursework on the Nature of Attitudes toward the Endangered Species Act.

ERIC Educational Resources Information Center

Bright, Alan D.; Tarrant, Michael A.

2002-01-01

Examines college students' attitudes and complexity of thinking about the Endangered Species Act (ESA) and the effects of environment-based coursework on their attitudes and thinking. Investigates attitudes in terms of their direction, extremity, ambivalence, and importance and measures complexity of thinking as integrative complexity. (Contains…

Dismounted Complex Blast Injury.

PubMed

Andersen, Romney C; Fleming, Mark; Forsberg, Jonathan A; Gordon, Wade T; Nanos, George P; Charlton, Michael T; Ficke, James R

2012-01-01

The severe Dismounted Complex Blast Injury (DCBI) is characterized by high-energy injuries to the bilateral lower extremities (usually proximal transfemoral amputations) and/or upper extremity (usually involving the non-dominant side), in addition to open pelvic injuries, genitourinary, and abdominal trauma. Initial resuscitation and multidisciplinary surgical management appear to be the keys to survival. Definitive treatment follows general principals of open wound management and includes decontamination through aggressive and frequent debridement, hemorrhage control, viable tissue preservation, and appropriate timing of wound closure. These devastating injuries are associated with paradoxically favorable survival rates, but associated injuries and higher amputation levels lead to more difficult reconstructive challenges.

Spectral study and protein labeling of inclusion complex between dye and calixarene sulfonate.

PubMed

Fei, Xuening; Zhang, Yong; Zhu, Sen; Liu, Lijuan; Yu, Lu

2013-05-01

The host-guest inclusion complex of calix[6]arene sulfonate (SCA6) with thiazole orange (TO) formed in aqueous solution was studied. Absorption and fluorescence techniques were used for the analysis of this inclusion complex. The addition of calixarene sulfonate leads to a decrease in both absorption and fluorescence intensity of the dye, indicating that the inclusion complex was formed. Simultaneously, the inclusion phenomenon of another cyanine dye, Cy3, with calixarene sulfonate was investigated. The stability constant of the two complexes was determined, and the results were compared. The water solubility of TO dye was increased in the presence of calixarene sulfonate, and further protein labeling experiments suggested that this TO-SCA6 complex can act as a fluorescent probe for labeling of biomolecules.

Teasing Apart Complex Motions using VideoPoint

NASA Astrophysics Data System (ADS)

Fischer, Mark

2002-10-01

Using video analysis software such as VideoPoint, it is possible to explore the physics of any phenomenon that can be captured on videotape. The good news is that complex motions can be filmed and analyzed. The bad news is that the motions can become very complex very quickly. An example of such a complicated motion, the 2-dimensional motion of an object as filmed by a camera that is moving and rotating in the same plane will be discussed. Methods for extracting the desired object motion will be given as well as suggestions for shooting more easily analyzable video clips.

Safety assessment for the postictal confusional phase following complex partial seizure.

PubMed

Tucker, C

1985-06-01

Misunderstanding of the postictal confusional state that follows the complex partial seizure has caused emotional and physical harm to patients. Concern about this phenomenon and its effects upon the patient prompted this study to explore, describe, and document one method of intervention to lessen these harmful effects. An evaluative descriptive research design was employed to assess patient safety during and after the postictal confusional phase following a complex partial seizure. A closed-structured questionnaire and participant observation were the methods used to collect data for this study. A Level of Safety Tool was specifically designed for this study.

Oklahoma City bombing: exacerbation of symptoms in veterans with PTSD.

PubMed

Moyers, F

1996-02-01

Posttraumatic stress disorder (PTSD) develops following exposure to an extremely traumatic stressor and consists of reexperiencing, avoidance, and hyperarousal symptoms. Exposure to stimuli reminiscent of the original trauma often causes an exacerbation of symptoms. Models attempting to explain this phenomenon include classical conditioning, emotional network imagery, and memory consolidation. The recent bombing in Oklahoma City caused an exacerbation of symptoms in veterans from World War II, the Korean War, and Vietnam, ranging from images of combat to memories of being called "baby-killer." These various responses to identical stimuli might help to explain the importance of attached meaning to traumatic events.

Fatigue in industry.

PubMed Central

Grandjean, E

1979-01-01

Physical fatigue is a painful phenomenon which is localised in overstressed muscles. Mental fatigue is a diffuse sensation of weariness; it is a functional state, one of several intermediate conditions between the two extremes of alarm and sleep. A neurophysiological model of fatigue, involving an activating and inhibitory system has been developed. Fatigue in industrial practice has clinical symptoms: psychic instability, fits of depression and increased liability to illness. Indicators of fatigue are work of performance, subjective feelings of fatigue, electroencephalography, flicker-fusion frequency and various psychomotor and mental tests. Several field studies do, to some extent, confirm the above-mentioned concept of fatigue. PMID:40999

Cross border reproductive care (CBRC): a growing global phenomenon with multidimensional implications (a systematic and critical review).

PubMed

Salama, Mahmoud; Isachenko, Vladimir; Isachenko, Evgenia; Rahimi, Gohar; Mallmann, Peter; Westphal, Lynn M; Inhorn, Marcia C; Patrizio, Pasquale

2018-05-28

Many people travel abroad to access fertility treatments. This growing phenomenon is known as cross border reproductive care (CBRC) or fertility tourism. Due to its complex nature and implications worldwide, CBRC has become an emerging dilemma deserving more attention on the global healthcare agenda. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic review of the literature was performed for all relevant full-text articles published in PubMed in English during the past 18 years to explore CBRC phenomenon in the new millennium. Little is known about the accurate magnitude and scope of CBRC around the globe. In this systematic and critical review, we identify three major dimensions of CBRC: legal, economic, and ethical. We analyze each of these dimensions from clinical and practical perspectives. CBRC is a growing reality worldwide with potential benefits and risks. Therefore, it is very crucial to regulate the global market of CBRC on legal, economic, and ethical bases in order to increase harmonization and reduce any forms of exploitation. Establishment of accurate international statistics and a global registry will help diminish the current information gap surrounding the CBRC phenomenon.

Dimensional analysis yields the general second-order differential equation underlying many natural phenomena: the mathematical properties of a phenomenon's data plot then specify a unique differential equation for it.

PubMed

Kepner, Gordon R

2014-08-27

This study uses dimensional analysis to derive the general second-order differential equation that underlies numerous physical and natural phenomena described by common mathematical functions. It eschews assumptions about empirical constants and mechanisms. It relies only on the data plot's mathematical properties to provide the conditions and constraints needed to specify a second-order differential equation that is free of empirical constants for each phenomenon. A practical example of each function is analyzed using the general form of the underlying differential equation and the observable unique mathematical properties of each data plot, including boundary conditions. This yields a differential equation that describes the relationship among the physical variables governing the phenomenon's behavior. Complex phenomena such as the Standard Normal Distribution, the Logistic Growth Function, and Hill Ligand binding, which are characterized by data plots of distinctly different sigmoidal character, are readily analyzed by this approach. It provides an alternative, simple, unifying basis for analyzing each of these varied phenomena from a common perspective that ties them together and offers new insights into the appropriate empirical constants for describing each phenomenon.

The Ischia island flash flood of November 2009 (Italy): Phenomenon analysis and flood hazard

NASA Astrophysics Data System (ADS)

Santo, A.; Di Crescenzo, G.; Del Prete, S.; Di Iorio, L.

The island of Ischia is particularly susceptible to landslides and flash floods due to its particular geological and geomorphological context. Urbanization in recent decades coupled with the development of tourism has increased the risk. After the November 10, 2009 event occurring in the northern sector of the island (the town of Casamicciola), a detailed geo-morphological survey was conducted to ascertain the evolution of the phenomenon. In the watersheds upstream of Casamicciola, many landslides were mapped and the volume of material involved during detachment and sliding was estimated. In the lower course area, near the town and towards the sea, flow pathways were reconstructed with the aid of extensive video footage taken during the event. Rainfall data were also analyzed and a relationship was established between the hourly rainfall rate and the flash flood. The phenomenon was found to be quite complex, with many upstream landslides stopping before reaching the urban area. In the lower course the alluvial event occurred as a flood with a very small sediment discharge, which left a very thin layer of sediment. Reconstruction of the flash flood phenomenon suggested possible action for future risk mitigation, early warning and civil protection plans.

Changes in Extreme Events and the Potential Impacts on National Security

NASA Astrophysics Data System (ADS)

Bell, J.

2017-12-01

Extreme weather and climate events affect human health by causing death, injury, and illness, as well as having large socio-economic impacts. Climate change has caused changes in extreme event frequency, intensity and geographic distribution, and will continue to be a driver for changes in the future. Some of the extreme events that have already changed are heat waves, droughts, wildfires, flooding rains, coastal flooding, storm surge, and hurricanes. The pathways connecting extreme events to health outcomes and economic losses can be diverse and complex. The difficulty in predicting these relationships comes from the local intricacies of societal and environmental factors that influences the level of exposure. The goal of this presentation is to discuss the national security implications of changes in extreme weather events and demonstrate how changes in extremes can lead to a host cascading issues. To illustrate this point, this presentation will provide examples of the various pathways that extreme events can increase disease burden and cause economic stress.

Notes sur les mouvements recursifs (Notes on Regressive Moves).

ERIC Educational Resources Information Center

Auchlin, Antoine; And Others

1981-01-01

Examines the phenomenon of regressive moves (retro-interpretation) in the light of a hypothesis according to which the formation of complex and hierarchically organized conversation units is subordinated to the linearity of discourse. Analyzes a transactional exchange, describing the interplay of integration, anticipation, and retro-interpretation…

A Professional Development School Partnership: Conflict and Collaboration.

ERIC Educational Resources Information Center

Campoy, Renee W.

This book describes complex issues involved in an elementary Professional Development School (PDS) partnership. Section one presents contextual information on the nature of the PDS phenomenon. It includes three chapters: (1) "Introduction and PDS as a Reform Initiative"; (2) "Methodology of the Case Study"; and (3)…

Early Humour Production

ERIC Educational Resources Information Center

Hoicka, Elena; Akhtar, Nameera

2012-01-01

The current studies explored early humour as a complex socio-cognitive phenomenon by examining 2- and 3-year-olds' humour production with their parents. We examined whether children produced novel humour, whether they cued their humour, and the types of humour produced. Forty-seven parents were interviewed, and videotaped joking with their…

Physician Verbal Compliance-Gaining Strategies and Patient Satisfaction

ERIC Educational Resources Information Center

Olynick, Janna; Iliopulos, Alexandra; Li, Han Z.

2017-01-01

Purpose: The patient healthcare experience is a complex phenomenon, as is encouraging patient compliance with medical advice. To address this multifaceted relationship, the purpose of this paper is to explore the ways resident physicians verbally encourage patient compliance and the relationship between these compliance-seeking strategies and…

Phase synchronization based on a Dual-Tree Complex Wavelet Transform

NASA Astrophysics Data System (ADS)

Ferreira, Maria Teodora; Domingues, Margarete Oliveira; Macau, Elbert E. N.

2016-11-01

In this work, we show the applicability of our Discrete Complex Wavelet Approach (DCWA) to verify the phenomenon of phase synchronization transition in two coupled chaotic Lorenz systems. DCWA is based on the phase assignment from complex wavelet coefficients obtained by using a Dual-Tree Complex Wavelet Transform (DT-CWT). We analyzed two coupled chaotic Lorenz systems, aiming to detect the transition from non-phase synchronization to phase synchronization. In addition, we check how good is the method in detecting periods of 2π phase-slips. In all experiments, DCWA is compared with classical phase detection methods such as the ones based on arctangent and Hilbert transform showing a much better performance.

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

PubMed Central

Koumoutsakos, Petros

2018-01-01

The prediction of extreme events, from avalanches and droughts to tsunamis and epidemics, depends on the formulation and analysis of relevant, complex dynamical systems. Such dynamical systems are characterized by high intrinsic dimensionality with extreme events having the form of rare transitions that are several standard deviations away from the mean. Such systems are not amenable to classical order-reduction methods through projection of the governing equations due to the large intrinsic dimensionality of the underlying attractor as well as the complexity of the transient events. Alternatively, data-driven techniques aim to quantify the dynamics of specific, critical modes by utilizing data-streams and by expanding the dimensionality of the reduced-order model using delayed coordinates. In turn, these methods have major limitations in regions of the phase space with sparse data, which is the case for extreme events. In this work, we develop a novel hybrid framework that complements an imperfect reduced order model, with data-streams that are integrated though a recurrent neural network (RNN) architecture. The reduced order model has the form of projected equations into a low-dimensional subspace that still contains important dynamical information about the system and it is expanded by a long short-term memory (LSTM) regularization. The LSTM-RNN is trained by analyzing the mismatch between the imperfect model and the data-streams, projected to the reduced-order space. The data-driven model assists the imperfect model in regions where data is available, while for locations where data is sparse the imperfect model still provides a baseline for the prediction of the system state. We assess the developed framework on two challenging prototype systems exhibiting extreme events. We show that the blended approach has improved performance compared with methods that use either data streams or the imperfect model alone. Notably the improvement is more significant in regions associated with extreme events, where data is sparse. PMID:29795631

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

PubMed

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

2018-01-01

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

Extreme Facial Expressions Classification Based on Reality Parameters

NASA Astrophysics Data System (ADS)

Rahim, Mohd Shafry Mohd; Rad, Abdolvahab Ehsani; Rehman, Amjad; Altameem, Ayman

2014-09-01

Extreme expressions are really type of emotional expressions that are basically stimulated through the strong emotion. An example of those extreme expression is satisfied through tears. So to be able to provide these types of features; additional elements like fluid mechanism (particle system) plus some of physics techniques like (SPH) are introduced. The fusion of facile animation with SPH exhibits promising results. Accordingly, proposed fluid technique using facial animation is the real tenor for this research to get the complex expression, like laugh, smile, cry (tears emergence) or the sadness until cry strongly, as an extreme expression classification that's happens on the human face in some cases.

Sonar gas seepage characterization using high resolution systems at short ranges

NASA Astrophysics Data System (ADS)

Schneider von Deimling, J.; Lohrberg, A.; Mücke, I.

2017-12-01

Sonar is extremely sensitive in regard to submarine remote sensing of free gas bubbles. Known reasons for this are (1) high impedance contrast between water and gas, holding true also at larger depths with higher hydrostatic pressures and thus greater mole density in a gas bubble; (2) resonating behavior at a specific depth-frequency-size/shape relation with highly non-linear behavior; (3) an overlooked property being valuable for gas seepage detection and characterization is the movement of bubbles controlled by their overall trajectory governed by buoyancy, upwelling effects, tides, eddies, and currents. Moving objects are an unusual seismo-acoustic target in solid earth geophysics, and most processors hardly consider such short term movement. However, analyzing movement pattern over time and space highly improves human and algorithmic bubble detection and helps mitigation of false alarms often caused by fish's swim bladders. We optimized our sonar surveys for gas bubble trajectory analyses using calibrated split-beam and broadband/short pulse multibeam to gather very high quality sonar images. Thus we present sonar data patterns of gas seepage sites recorded at shorter ranges showing individual bubbles or groups of bubbles. Subsequent analyses of bubble trajectories and sonar strength can be used to quantify minor gas fluxes with high accuracy. Moreover, we analyzed strong gas bubble seepage sites with significant upwelling. Acoustic inversion of such major seep fluxes is extremely challenging if not even impossible given uncertainties in bubble size spectra, upwelling velocities, and beam geometry position of targets. Our 3D analyses of the water column multibeam data unraveled that some major bubble flows prescribe spiral vortex trajectories. The phenomenon was first found at an abandoned well site in the North Sea, but our recent investigations confirm such complex bubble trajectories exist at natural seeps, i.e. at the CO2 seep site Panarea (Italy). We hypothesize that accurate 3D analyses of plume shape and trajectory analyses might help to estimate threshold for fluxes.

Peripheral circulatory disorders in essential thrombocythemia.

PubMed

Małecki, Rafał; Gacka, Małgorzata; Fiodorenko-Dumas, Żanna; Dumas, Ilias; Kwiatkowski, Jacek; Adamiec, Rajmund; Kuliszkiewicz-Janus, Małgorzata

2018-03-01

A significant number of patients with essential thrombocythemia (ET) complain of symptoms including distal parts of the extremities (e.g., paresthesias or Raynaud's phenomenon). The aim of the present study was to examine peripheral circulation in the upper extremities of individuals with ET. The study included 45 ET patients and 30 control subjects. All participants were subjected to thermography, photoplethysmography, impedance plethysmography, and applanation tonometry pulse wave analysis. The patients with ET differed significantly from the control subjects in terms of 3rd finger skin temperature (mean 31.04 vs. 32.45°C), skin temperature gradient (mean 1.82 vs. 0.11°C), photoplethysmographic amplitude (median 0.25 vs. 0.74%), and pulse waveform in the radial artery (more frequent occurrence of type B waveform). Pulse wave parameters correlated with the skin temperature gradient. The study findings imply the altered regulation of peripheral circulation in ET, including a decreased flow and an increased resistance. Copyright © 2017 Elsevier Inc. All rights reserved.

Correlations in electrically coupled chaotic lasers.

PubMed

Rosero, E J; Barbosa, W A S; Martinez Avila, J F; Khoury, A Z; Rios Leite, J R

2016-09-01

We show how two electrically coupled semiconductor lasers having optical feedback can present simultaneous antiphase correlated fast power fluctuations, and strong in-phase synchronized spikes of chaotic power drops. This quite counterintuitive phenomenon is demonstrated experimentally and confirmed by numerical solutions of a deterministic dynamical system of rate equations. The occurrence of negative and positive cross correlation between parts of a complex system according to time scales, as proved in our simple arrangement, is relevant for the understanding and characterization of collective properties in complex networks.

The cosmological model of eternal inflation and the transition from chance to biological evolution in the history of life

PubMed Central

Koonin, Eugene V

2007-01-01

Background Recent developments in cosmology radically change the conception of the universe as well as the very notions of "probable" and "possible". The model of eternal inflation implies that all macroscopic histories permitted by laws of physics are repeated an infinite number of times in the infinite multiverse. In contrast to the traditional cosmological models of a single, finite universe, this worldview provides for the origin of an infinite number of complex systems by chance, even as the probability of complexity emerging in any given region of the multiverse is extremely low. This change in perspective has profound implications for the history of any phenomenon, and life on earth cannot be an exception. Hypothesis Origin of life is a chicken and egg problem: for biological evolution that is governed, primarily, by natural selection, to take off, efficient systems for replication and translation are required, but even barebones cores of these systems appear to be products of extensive selection. The currently favored (partial) solution is an RNA world without proteins in which replication is catalyzed by ribozymes and which serves as the cradle for the translation system. However, the RNA world faces its own hard problems as ribozyme-catalyzed RNA replication remains a hypothesis and the selective pressures behind the origin of translation remain mysterious. Eternal inflation offers a viable alternative that is untenable in a finite universe, i.e., that a coupled system of translation and replication emerged by chance, and became the breakthrough stage from which biological evolution, centered around Darwinian selection, took off. A corollary of this hypothesis is that an RNA world, as a diverse population of replicating RNA molecules, might have never existed. In this model, the stage for Darwinian selection is set by anthropic selection of complex systems that rarely but inevitably emerge by chance in the infinite universe (multiverse). Conclusion The plausibility of different models for the origin of life on earth directly depends on the adopted cosmological scenario. In an infinite universe (multiverse), emergence of highly complex systems by chance is inevitable. Therefore, under this cosmology, an entity as complex as a coupled translation-replication system should be considered a viable breakthrough stage for the onset of biological evolution. Reviewers This article was reviewed by Eric Bapteste, David Krakauer, Sergei Maslov, and Itai Yanai. PMID:17540027

The cosmological model of eternal inflation and the transition from chance to biological evolution in the history of life.

PubMed

Koonin, Eugene V

2007-05-31

Recent developments in cosmology radically change the conception of the universe as well as the very notions of "probable" and "possible". The model of eternal inflation implies that all macroscopic histories permitted by laws of physics are repeated an infinite number of times in the infinite multiverse. In contrast to the traditional cosmological models of a single, finite universe, this worldview provides for the origin of an infinite number of complex systems by chance, even as the probability of complexity emerging in any given region of the multiverse is extremely low. This change in perspective has profound implications for the history of any phenomenon, and life on earth cannot be an exception. Origin of life is a chicken and egg problem: for biological evolution that is governed, primarily, by natural selection, to take off, efficient systems for replication and translation are required, but even barebones cores of these systems appear to be products of extensive selection. The currently favored (partial) solution is an RNA world without proteins in which replication is catalyzed by ribozymes and which serves as the cradle for the translation system. However, the RNA world faces its own hard problems as ribozyme-catalyzed RNA replication remains a hypothesis and the selective pressures behind the origin of translation remain mysterious. Eternal inflation offers a viable alternative that is untenable in a finite universe, i.e., that a coupled system of translation and replication emerged by chance, and became the breakthrough stage from which biological evolution, centered around Darwinian selection, took off. A corollary of this hypothesis is that an RNA world, as a diverse population of replicating RNA molecules, might have never existed. In this model, the stage for Darwinian selection is set by anthropic selection of complex systems that rarely but inevitably emerge by chance in the infinite universe (multiverse). The plausibility of different models for the origin of life on earth directly depends on the adopted cosmological scenario. In an infinite universe (multiverse), emergence of highly complex systems by chance is inevitable. Therefore, under this cosmology, an entity as complex as a coupled translation-replication system should be considered a viable breakthrough stage for the onset of biological evolution. This article was reviewed by Eric Bapteste, David Krakauer, Sergei Maslov, and Itai Yanai.

Effect of elevation on extreme precipitation of short durations: evidences of orographic signature on the parameters of Depth-Duration-Frequency curves

NASA Astrophysics Data System (ADS)

Avanzi, Francesco; De Michele, Carlo; Gabriele, Salvatore; Ghezzi, Antonio; Rosso, Renzo

2015-04-01

Here, we show how atmospheric circulation and topography rule the variability of depth-duration-frequency (DDF) curves parameters, and we discuss how this variability has physical implications on the formation of extreme precipitations at high elevations. A DDF is a curve ruling the value of the maximum annual precipitation H as a function of duration D and the level of probability F. We consider around 1500 stations over the Italian territory, with at least 20 years of data of maximum annual precipitation depth at different durations. We estimated the DDF parameters at each location by using the asymptotic distribution of extreme values, i.e. the so-called Generalized Extreme Value (GEV) distribution, and considering a statistical simple scale invariance hypothesis. Consequently, a DDF curve depends on five different parameters. A first set relates H with the duration (namely, the mean value of annual maximum precipitation depth for unit duration and the scaling exponent), while a second set links H to F (namely, a scale, position and shape parameter). The value of the shape parameter has consequences on the type of random variable (unbounded, upper or lower bounded). This extensive analysis shows that the variability of the mean value of annual maximum precipitation depth for unit duration obeys to the coupled effect of topography and modal direction of moisture flux during extreme events. Median values of this parameter decrease with elevation. We called this phenomenon "reverse orographic effect" on extreme precipitation of short durations, since it is in contrast with general knowledge about the orographic effect on mean precipitation. Moreover, the scaling exponent is mainly driven by topography alone (with increasing values of this parameter at increasing elevations). Therefore, the quantiles of H(D,F) at durations greater than unit turn to be more variable at high elevations than at low elevations. Additionally, the analysis of the variability of the shape parameter with elevation shows that extreme events at high elevations appear to be distributed according to an upper bounded probability distribution. These evidences could be a characteristic sign of the formation of extreme precipitation events at high elevations.

The attitudes of neonatal nurses towards extremely preterm infants.

PubMed

Gallagher, Katie; Marlow, Neil; Edgley, Alison; Porock, Davina

2012-08-01

The paper is a report of a study of the attitudes of neonatal nurses towards extremely preterm infants. Alongside advancing survival at extremely preterm gestational ages, ethical debates concerning the provision of invasive care have proliferated in light of the high morbidity. Despite nurses being the healthcare professionals who work closest with the infant and their family, their potential influence is usually ignored when determining how parents come to decisions about future care for their extremely premature infant. A Q methodology was employed to explore the attitudes of neonatal nurses towards caring for extremely preterm infants. Data were collected between 2007 and 2008 and analysed using PQMethod and Card Content Analysis. Thirty-six nurses from six neonatal units in the United Kingdom participated. Although there was consensus around the professional role of the nurse, when faced with the complexities of neonatal nursing three distinguishing factors emerged: the importance of parental choice in decision-making, the belief that technology should be used to assess response to treatment, and the belief that healthcare professionals should undertake difficult decisions. Neonatal nurses report unexpected difficulties in upholding their professionally defined role through highly complex and ever varied decision-making processes. Recognition of individual attitudes to the care of extremely preterm infants and the role of the family in the face of difficult decisions should facilitate more open communication between the nurse and the parents and improve the experience of both the nurse and the family during these emotional situations. © 2011 Blackwell Publishing Ltd.

The "Facebook-self": characteristics and psychological predictors of false self-presentation on Facebook.

PubMed

Gil-Or, Oren; Levi-Belz, Yossi; Turel, Ofir

2015-01-01

In this study we present and empirically examine a new phenomenon related to social networking sites, such as Facebook, the "false Facebook-self." Arguably false self-presentation on Facebook is a growing phenomenon, and in extreme cases; i.e., when ones Facebook image substantially deviates from their true image, it may serve as a gateway behavior to more problematic behaviors which may lead to psychological problems and even pathologies. In this study we show that certain users are more vulnerable to such false self-presentation than others. The study involved 258 Facebook users. Applying ANOVA and SEM analyses we show that users with low self-esteem and low trait authenticity are more likely than others to present a Facebook-self which deviates from their true selves. These social-interaction-related traits are influenced by one's upbringing and the anxious and avoidant attachment styles he or she has developed. Several cases (7.5%) with large gaps between the true and false Facebook-self were detected, which implies that future research should consider the adverse consequences and treatments of high levels of false Facebook-self.

Long range transport of colloids in aqueous solutions

NASA Astrophysics Data System (ADS)

Florea, Daniel; Musa, Sami; Huyghe, Jacques M. R. J.; Wyss, Hans M.

2013-03-01

Colloids in aqueous suspensions can experience strong, extremely long range repulsive forces near interfaces such as biological tissues, gels, ion exchange resins or metals. As a result exclusion zones extending over several millimeters can be formed. While this phenomenon has been previously described, a physical understanding of this process is still lacking. This exclusion zone formation is puzzling because the typical forces acting on colloidal particles are limited to much shorter distances and external fields that could drive the particles are absent. Here we study the exclusion zone formation in detail by following the time and distance-dependent forces acting on the particles. We present a simple model that accounts for our experimental data and directly links the exclusion zone formation to an already known physical transport phenomenon. We show that the effect can be tuned by changing the zeta potential of the particles or by varying the species present in the aqueous solution. We thus provide a direct physical explanation for the intriguing exclusion zone formation and we illustrate how this effect can be exploited in a range of industrial applications.

The Erosion of expansive soils through a zoning of Taza (Morocco)

NASA Astrophysics Data System (ADS)

Demehati, A.; Abidi, A.; El Qandil, M.

2018-05-01

Like other cities in the region of Fez-Meknes, Taza undergoes the phenomena of erosion of soils facing the builder in general and the town planner in particular. This type of aggression of the land is sometimes amplified by the swelling-withdrawal of soils. In effect the marl clay layers are considered as unstable soils because of their volumetric changes depending on the duration and intensity of extreme climate changes (weather, droughts, ventilation.). This phenomenon, which is part directly or indirectly so-called natural disasters, can lead to significant costly damage and particularly intense (soil erosion, landslides, obstruction of the course of the water, hydraulic works and sanitation networks, cracks of the constructions and their annexes’, deformations of pavements, etc.). The knowledge and mastery of this phenomenon are essential to prevent, limit or remedy the consequences and damage related to their impacts. We focus as well our contribution on the geotechnical characteristics of the soils of the city of Taza with highlighting of the hazards in susceptibility to erosion of soils in particular through their potential of swelling-removing and this for the benefit geotechnical zoning of Taza.

The Picture Complexity Effect: Another List Composition Paradox

ERIC Educational Resources Information Center

Nguyen, Khuyen; McDaniel, Mark A.

2015-01-01

"List composition effects" refer to the findings in which a given memory phenomenon shows discrepant patterns across different list designs (i.e., mixed or pure lists). These effects have typically been reported with verbal materials (e.g., word lists, paired associates, sentences); much less research has examined whether these effects…

Introductory Analysis of Benard-Marangoni Convection

ERIC Educational Resources Information Center

Maroto, J. A.; Perez-Munuzuri, V.; Romero-Cano, M. S.

2007-01-01

We describe experiments on Benard-Marangoni convection which permit a useful understanding of the main concepts involved in this phenomenon such as, for example, Benard cells, aspect ratio, Rayleigh and Marangoni numbers, Crispation number and critical conditions. In spite of the complexity of convection theory, we carry out a simple and…

Learning and Classroom Preferences of Gifted Eighth Graders: A Qualitative Study

ERIC Educational Resources Information Center

Samardzija, Nadine; Peterson, Jean Sunde

2015-01-01

The purpose of this phenomenological qualitative study was to explore how academically gifted eighth graders experience learning, with special attention to learning and classroom preferences. Twenty-three students were interviewed individually. The central phenomenon was that their learning preferences were complex, nuanced, and idiosyncratic, and…

A Phenomenographic Investigation of the Ways Engineering Students Experience Innovation

ERIC Educational Resources Information Center

Fila, Nicholas David

2017-01-01

Innovation has become an important phenomenon in engineering and engineering education. By developing novel, feasible, viable, and valued solutions to complex technical and human problems, engineers support the economic competitiveness of organizations, make a difference in the lives of users and other stakeholders, drive societal and scientific…

School Choice Acceptance: An Exploratory Explication

ERIC Educational Resources Information Center

Koven, Steven G.; Khan, Mobin

2014-01-01

School choice is presented by some as a panacea to the challenges facing education in the United States. Acceptance of choice as a solution, however, is far from universal. This article examines two possible contributors to choice adoption: ideology and political culture. Political culture was found to better explain the complex phenomenon of…

Conservatism in America--What Does it Mean for Teacher Education?

ERIC Educational Resources Information Center

Dolce, Carl J.

The current conflict among opposing sets of cultural ideals is illustrated by several interrelated conditions. The conservative phenomenon is more complex than the traditional liberal-conservative dichotomy would suggest. Changes in societal conditions invite a reexamination of basic assumptions across the broad spectrum of political ideology.…

Students Learning Agroecology: Phenomenon-Based Education for Responsible Action

ERIC Educational Resources Information Center

Ostergaard, Edvin; Lieblein, Geir; Breland, Tor Arvid; Francis, Charles

2010-01-01

Preparing students for a complex and dynamic future is a challenge for educators. This article explores three crucial issues related to agroecological education and learning: (1) the phenomenological foundation for learning agroecology in higher education; (2) the process of students' interactions with a wide range of various learners within and…

Smashing into the Glass Ceiling for Women Managers.

ERIC Educational Resources Information Center

Veale, Camilla; Gold, Jeff

1998-01-01

Interviews with 10 women administrators in a British metropolitan district council revealed the glass ceiling to be a complex phenomenon reaching beyond the employment sphere. Their career progression was hindered by lack of career counseling, family-work conflicts, lack of management development for women, and particularly a managerial culture…

What School Boards Can Do to Improve Teacher Competency.

ERIC Educational Resources Information Center

Karagan, Nicholas J.

The school board's role in improving teacher competency involves avoiding incompetent teachers, improving competent ones, and maintaining highly competent ones. Because teacher competence is a complex social phenomenon, affected by many different variables, boards should keep in mind that actions to improve competency may not be preferred by…

The Truthiness about the Colbert Report

ERIC Educational Resources Information Center

Derby, John

2013-01-01

In this article, John Derby examines "The Colbert Report" as a complex visual culture phenomenon that is highly relevant to young art learners, and offers curricular strategies that build on the show's Web content (www.colbertnation.com). As media studies scholar Baym (2010) has argued, "The Colbert Report" represents a…

Is Relaxation Training Effective in the Treatment of Clinical Depression?

ERIC Educational Resources Information Center

Beaty, Lee A.

The process of relaxation is a complex triarchic phenomenon that incorporates behavioral, cognitive, and physiological components. Existing literature is surveyed in order to determine the efficacy of treating various forms of depression with cognitive-behavioral relaxation strategies. Relaxation training has been shown to be effective in treating…

The Successful Black Male Student-Athlete: A Qualitative Study

ERIC Educational Resources Information Center

Price, Raphael Levon

2017-01-01

In recent years, researchers have noted disparate academic achievement outcomes among different ethnic groups in higher education. The complexity of this phenomenon is, arguably, nowhere more pronounced than among Black male students/student-athletes (BMSA) at Division-I Predominantly White Institutions. A central aspect of the research on BMSAs…

Tools to study and manage grazing behavior at multiple scales to enhance the sustainability of livestock

USDA-ARS?s Scientific Manuscript database

Free-ranging animal behavior is a multifaceted and complex phenomenon within rangeland ecology that must be understood and ultimately managed. Improving behavioral studies requires tools appropriate for use at the landscape scale. Though tools alone do not assure research will generate accurate in...

Logged On for Learning. An "Education Week" Special Report.

ERIC Educational Resources Information Center

West, Peter

1995-01-01

This document and accompanying disk contain all of the articles from an "Education Week" special report examining the complex phenomenon commonly known as the "information highway" and how it affects the nation's schools. The articles, all by Peter West, include: (1) "Logged On for Learning," an overview of the…

Supporting LGBTQ Students in Physical Education: Changing the Movement Landscape

ERIC Educational Resources Information Center

Block, Betty Ann

2014-01-01

Scholars have sought to identify the complexity and multidimensionality of the phenomenon of sexual identity formation since the American Psychiatric Association declassified homosexuality as a mental disorder in 1973 (Bayer, 1981). This article addresses the manner in which the needs of lesbian, gay, bisexual, transgender, and queer [LGBTQ]…

Understanding Catalan University Dropout from a Cross-National Approach

ERIC Educational Resources Information Center

Rodríguez-Gómez, David; Feixas, Mònica; Gairín, Joaquín; Muñoz, José Luís

2015-01-01

The dropout rate is an indicator of complex analysis and there is no consensus on its significance. Universities lack systematized, univocal methods for collecting student dropout data, making measurement problematic. In consequence, the formulas applied to analyze this phenomenon differ between countries and it is therefore an immense challenge…

"No Soy de Aqui ni Soy de Alla": Transgenerational Cultural Identity Formation

ERIC Educational Resources Information Center

Cardona, Jose Ruben Parra; Busby, Dean M.; Wampler, Richard S.

2004-01-01

The transgenerational cultural identity model offers a detailed understanding of the immigration experience by challenging agendas of assimilation and by expanding on existing theories of cultural identity. Based on this model, immigration is a complex phenomenon influenced by many variables such as sociopsychological dimensions, family,…

Investigating Sense of Community in First-Year College Students

ERIC Educational Resources Information Center

Jacobs, Jeff; Archie, Tim

2008-01-01

Why do students leave college and how can colleges retain them? Researchers and administrators have been asking these questions for decades and have discovered that student persistence is a complex phenomenon. First-year student departure from postsecondary institutions is a concern for most colleges and universities. U.S. colleges and…

Water Quality Field Guide.

ERIC Educational Resources Information Center

Soil Conservation Service (USDA), Washington, DC.

Nonpoint source pollution is both a relatively recent concern and a complex phenomenon with many unknowns. Knowing the extent to which agricultural sources contribute to the total pollutant load, the extent to which various control practices decrease this load, and the effect of reducing the pollutants delivered to a water body are basic to the…

Big Data Goes Personal: Privacy and Social Challenges

ERIC Educational Resources Information Center

Bonomi, Luca

2015-01-01

The Big Data phenomenon is posing new challenges in our modern society. In addition to requiring information systems to effectively manage high-dimensional and complex data, the privacy and social implications associated with the data collection, data analytics, and service requirements create new important research problems. First, the high…

Alive with the sound of music: a case series on patients presenting with musical hallucinations in a general hospital.

PubMed

Kinson, Rochelle Melina; Lim, Wen Phei; Rahman, Habeebul

2015-01-01

Musical hallucinations are a rare phenomenon that renders appropriate identification and treatment a challenge. This case series describes three women who presented with hearing complex, familiar melodies in the absence of external stimuli on a background of hearing impairment.

The Madness of Weighted Mean Faculty Salaries

ERIC Educational Resources Information Center

Micceri, Theodore

2009-01-01

Higher education frequently uses weighted mean faculty salaries to compare either across institutions, or to evaluate an institution's salary growth over time. Unfortunately, faculty salaries are an extraordinarily complex phenomenon that cannot be legitimately reduced to a single number any more than the academic construct of skills, knowledge,…

Just a Good Story? Shaping Organizational Learning through Storytelling

ERIC Educational Resources Information Center

Whitener, J. Kori

2007-01-01

Organizational learning is a complex phenomenon, the collective nature of which makes it difficult to study and examine. Organizational stories are cultural forms that facilitate the sensemaking processes and capabilities of the individuals and teams that form the collective organization. This paper utilizes literature to suggest possible impacts…

Physician Migration, Education, and Health Care

ERIC Educational Resources Information Center

Norcini, John J.; Mazmanian, Paul E.

2005-01-01

Physician migration is a complex and multifaceted phenomenon that is intimately intertwined with medical education. Imbalances in the production of physicians lead to workforce shortages and surpluses that compromise the ability to deliver adequate and equitable health care to large parts of the world's population. In this overview, we address a…

What Is Missing in Counseling Research? Reporting Missing Data

ERIC Educational Resources Information Center

Sterner, William R.

2011-01-01

Missing data have long been problematic in quantitative research. Despite the statistical and methodological advances made over the past 3 decades, counseling researchers fail to provide adequate information on this phenomenon. Interpreting the complex statistical procedures and esoteric language seems to be a contributing factor. An overview of…

Grief and Needs of Adults with Acquired Visual Impairments

ERIC Educational Resources Information Center

Murray, Shirley A.; McKay, Robert C.; Nieuwoudt, Johan M.

2010-01-01

This report aims to illuminate the complex phenomenon of grief and the needs experienced throughout the time course of their impairments by adults with acquired visual impairments. The study applied a phenomenological research strategy using 10 case studies of South African adults, visually impaired within and beyond six years. Qualitative…

Polytobacco Use and the "Customization Generation"--New Perspectives for Tobacco Control

ERIC Educational Resources Information Center

Horn, Kimberly; Pearson, Jennifer L.; Villanti, Andrea C.

2016-01-01

In recent years, the United States observed a significant uptake in concurrent use of multiple tobacco products and alternative nicotine delivery devices among youth--a phenomenon identified as polytobacco use--making tobacco control efforts more complex for clinicians, policy makers, and scientists, alike.The present commentary stimulates new…

Leaves of field-grown mastic trees suffer oxidative stress at the two extremes of their lifespan.

PubMed

Juvany, Marta; Müller, Maren; Munné-Bosch, Sergi

2012-08-01

Leaf senescence is a complex phenomenon occurring in all plant species, but it is still poorly understood in plants grown in Mediterranean field conditions and well-adapted to harsh climatic conditions. To better understand the physiological processes underlying leaf senescence in mastic trees (Pistacia lentiscus L.), we evaluated leaf growth, water and N content, photosystem II (PSII) photochemistry, lipid peroxidation and levels of photosynthetic pigments, antioxidants, abscisic acid, and salicylic acid and jasmonic acid during the complete leaf lifespan, from early expansion to late senescence in relation to natural climatic conditions in the field. While mature leaves suffered from water and N deficit during late spring and summer, both young (emerging) and old (senescing) leaves were most sensitive to photo-oxidative stress, as indicated by reductions in the F(v)/F(m) ratio and enhanced lipid peroxidation during late autumn and winter. Reductions in the F(v)/F(m) ratio were associated with low α-tocopherol (vitamin E) levels, while very old, senescing leaves additionally showed severe anthocyanin losses. We have concluded that both young (emerging) and old (senescing) leaves suffer oxidative stress in mastic trees, which may be linked in part to suboptimal temperatures during late autumn and winter as well as to low vitamin E levels. © 2012 Institute of Botany, Chinese Academy of Sciences.

Computational Study of Scenarios Regarding Explosion Risk Mitigation

NASA Astrophysics Data System (ADS)

Vlasin, Nicolae-Ioan; Mihai Pasculescu, Vlad; Florea, Gheorghe-Daniel; Cornel Suvar, Marius

2016-10-01

Exploration in order to discover new deposits of natural gas, upgrading techniques to exploit these resources and new ways to convert the heat capacity of these gases into industrial usable energy is the research areas of great interest around the globe. But all activities involving the handling of natural gas (exploitation, transport, combustion) are subjected to the same type of risk: the risk to explosion. Experiments carried out physical scenarios to determine ways to reduce this risk can be extremely costly, requiring suitable premises, equipment and apparatus, manpower, time and, not least, presenting the risk of personnel injury. Taking in account the above mentioned, the present paper deals with the possibility of studying the scenarios of gas explosion type events in virtual domain, exemplifying by performing a computer simulation of a stoichiometric air - methane explosion (methane is the main component of natural gas). The advantages of computer-assisted imply are the possibility of using complex virtual geometries of any form as the area of deployment phenomenon, the use of the same geometry for an infinite number of settings of initial parameters as input, total elimination the risk of personnel injury, decrease the execution time etc. Although computer simulations are hardware resources consuming and require specialized personnel to use the CFD (Computational Fluid Dynamics) techniques, the costs and risks associated with these methods are greatly diminished, presenting, in the same time, a major benefit in terms of execution time.

Widespread fatigue damage monitoring: Issues and concerns

NASA Technical Reports Server (NTRS)

Swift, T.

1994-01-01

This paper is intended to illustrate the considerable effect that small in-service undetectable multi-site-damage (MSD) can have on the residual strength capability of aging aircraft structures. In general, very few people in the industry believe that tiny cracks of undetectable size are a problem because they know that many aircraft have been able to survive much larger damage. In fact they have been certified for this large damage capability. However, this is not the issue. The real issue is the effect the tiny cracks, at multiple sites, have on the large damage capability which the industry has become accustomed to expect and which the aircraft have been certified to sustain. The concern is that this message does not appear to be fully understood by many people outside the fracture community. The prime purpose of this paper, therefore, has been to convey this message by describing in simple terms the net section yielding phenomenon in ductile materials which causes loss in lead crack residual strength in the presence of MSD. The explanation continues with a number of examples on complex stiffened structures, using the results of previous finite element analyses, which illustrate that the effect of MSD is extremely sensitive to structural configuration. It is hoped that those members of the aviation community who believe that tiny cracks are not a problem will read this paper very carefully.

The social structure of microbial community involved in colonization resistance.

PubMed

He, Xuesong; McLean, Jeffrey S; Guo, Lihong; Lux, Renate; Shi, Wenyuan

2014-03-01

It is well established that host-associated microbial communities can interfere with the colonization and establishment of microbes of foreign origins, a phenomenon often referred to as bacterial interference or colonization resistance. However, due to the complexity of the indigenous microbiota, it has been extremely difficult to elucidate the community colonization resistance mechanisms and identify the bacterial species involved. In a recent study, we have established an in vitro mice oral microbial community (O-mix) and demonstrated its colonization resistance against an Escherichia coli strain of mice gut origin. In this study, we further analyzed the community structure of the O-mix by using a dilution/regrowth approach and identified the bacterial species involved in colonization resistance against E. coli. Our results revealed that, within the O-mix there were three different types of bacterial species forming unique social structure. They act as 'Sensor', 'Mediator' and 'Killer', respectively, and have coordinated roles in initiating the antagonistic action and preventing the integration of E. coli. The functional role of each identified bacterial species was further confirmed by E. coli-specific responsiveness of the synthetic communities composed of different combination of the identified players. The study reveals for the first time the sophisticated structural and functional organization of a colonization resistance pathway within a microbial community. Furthermore, our results emphasize the importance of 'Facilitation' or positive interactions in the development of community-level functions, such as colonization resistance.

Food limitation leads to behavioral diversification and dietary specialization in sea otters

USGS Publications Warehouse

Tinker, M.T.; Bentall, G.; Estes, J.A.

2008-01-01

Dietary diversity often varies inversely with prey resource abundance. This pattern, although typically measured at the population level, is usually assumed to also characterize the behavior of individual animals within the population. However, the pattern might also be produced by changes in the degree of variation among individuals. Here we report on dietary and associated behavioral changes that occurred with the experimental translocation of sea otters from a food-poor to a food-rich environment. Although the diets of all individuals were broadly similar in the food-rich environment, a behaviorally based dietary polymorphism existed in the food-poor environment. Higher dietary diversity under low resource abundance was largely driven by greater variation among individuals. We further show that the dietary polymorphism in the food-poor environment included a broad suite of correlated behavioral variables and that the individuals that comprised specific behavioral clusters benefited from improved foraging efficiency on their individually preferred prey. Our findings add to the growing list of examples of extreme individuality in behavior and prey choice within populations and suggest that this phenomenon can emerge as a behavioral manifestation of increased population density. Individuality in foraging behavior adds complexity to both the fitness consequences of prey selection and food web dynamics, and it may figure prominently as a diversifying process over evolutionary timescales. ?? 2008 by The National Academy of Sciences of the USA.

General Psychological Implications of the Human Capacity for Grief.

PubMed

Brinkmann, Svend

2018-06-01

Much theorizing in psychology and related disciplines begins with a given model of the mind that is then applied in research projects to study concrete phenomena. Sometimes psychological research can be theory-driven in quite an explicit way, approaching the logic of the hypothetico-deductive method. Others reject this and prefer to work inductively, and, in the extreme case of positivism, perhaps try to avoid theorizing altogether. In this article I shall suggest another way to think of the relationship between psychological theories and psychological phenomena. My suggestion is not simply to replace the hypothetico-deductive model with an inductive one, but to argue that the most direct route to theories of the human mind that grasp its complexity is to begin with the Kantian question of transcendental philosophy: X exists - how is X possible? In the context of this article, I apply this questioning to the phenomenon of grief: Grief exists - what general psychological theory of the mind do we need in order to account for its possibility? I attempt to extract three general psychological points from the existence of grief, viz. (1) the deep relationality of the self, (2) the limitations of evolutionary accounts, and (3) the normativity of psychological phenomena. I shall argue that these are general psychological lessons to be learned from grief, although they could also be arrived at by considering several other significant psychological phenomena.

Wind Turbine Tribology Seminar - A Recap

DOE Office of Scientific and Technical Information (OSTI.GOV)

Errichello, R.; Sheng, S.; Keller, J.

Tribology is the science and engineering of interacting surfaces in relative motion. It includes the study and application of the principles of friction, lubrication, and wear. It is an important phenomenon that not only impacts the design and operation of wind turbine gearboxes, but also their subsequent maintenance requirements and overall reliability. With the major growth and increasing dependency on renewable energy, mechanical reliability is an extremely important issue. The Wind Turbine Tribology Seminar was convened to explore the state-of-the-art in wind turbine tribology and lubricant technologies, raise industry awareness of a very complex topic, present the science behind eachmore » technology, and identify possible R&D areas. To understand the background of work that had already been accomplished, and to consolidate some level of collective understanding of tribology by acknowledged experts, the National Renewable Energy Laboratory (NREL), Argonne National Laboratory (ANL), and the U.S. Department of Energy (DOE) hosted a wind turbine tribology seminar. It was held at the Renaissance Boulder Flatiron Hotel in Broomfield, Colorado on November 15-17, 2011. This report is a summary of the content and conclusions. The presentations given at the meeting can be downloaded. Interested readers who were not at the meeting may wish to consult the detailed publications listed in the bibliography section, obtain the cited articles in the public domain, or contact the authors directly.« less

β-CD-dextran polymer for efficient sequestration of cholesterol from phospholipid bilayers: Mechanistic and safe-toxicity investigations.

PubMed

Stelzl, Dominik; Nielsen, Thorbjørn Terndrup; Hansen, Terkel; di Cagno, Massimiliano

2015-12-30

The aim of this work was to investigate the suitability of β-cyclodextrin-dextran (BCD-dextran) polymer as cholesterol sequestering agent in vitro. For this purpose, BCD-dextran-cholesterol complexation was studied by phase solubility studies as well as with a specifically designed in vitro model based on giant unilamellar vesicles (GUVs) to evaluate the ability of this polymer to sequestrate cholesterol from phospholipid bilayers. Cholesterol-sequestering ability of BCD-dextran was also investigated on different cell lines relevant for the hematopoietic system and results were correlated to cells toxicity. BCD-dextran polymer was capable of extracting significant amount of cholesterol from phospholipid bilayers and to a higher extent in comparison to available β-cyclodextrins (BCDs). The ability of BCD-dextran in sequestering cholesterol resulted also very high on cell lines relevant for the hematopoietic system. Moreover, BCD-dextran resulted less toxic on cell cultures due to higher selectivity in sequestering cholesterol in comparison to MBCD (that sequestrated also significant amounts of cholesteryl esters). In conclusion, BCD-dextran resulted an extremely efficient cholesterol-sequestering agent and BCD-dextran resulted more selective to cholesterol extraction in comparison to other BCDs (therefore of lower cytotoxicity). This phenomenon might play a key role to develop an efficient treatment for hypercholesterolemia based on cholesterol segregation. Copyright © 2015 Elsevier B.V. All rights reserved.

The role of activity complexes in the distribution of solar magnetic fields.

NASA Astrophysics Data System (ADS)

García de La Rosa, J. I.; Reyes, R. C.

Using published data on the large-scale distribution of solar activity, the authors conclude that the longlived coronal holes are formed and maintained by the unbalanced magnetic flux which developes at both extremes of the complexes of activity.

The Seasonal Predictability of Extreme Wind Events in the Southwest United States

NASA Astrophysics Data System (ADS)

Seastrand, Simona Renee

Extreme wind events are a common phenomenon in the Southwest United States. Entities such as the United States Air Force (USAF) find the Southwest appealing for many reasons, primarily for the an expansive, unpopulated, and electronically unpolluted space for large-scale training and testing. However, wind events can cause hazards for the USAF including: surface wind gusts can impact the take-off and landing of all aircraft, can tip the airframes of large wing-surface aircraft during the performance of maneuvers close to the ground, and can even impact weapons systems. This dissertation is comprised of three sections intended to further our knowledge and understanding of wind events in the Southwest. The first section builds a climatology of wind events for seven locations in the Southwest during the twelve 3-month seasons of the year. The first section further examines the wind events in relation to terrain and the large-scale flow of the atmosphere. The second section builds upon the first by taking the wind events and generating mid-level composites for each of the twelve 3-month seasons. In the third section, teleconnections identified as consistent with the large-scale circulation in the second paper were used as predictor variables to build a Poisson regression model for each of the twelve 3-month seasons. The purpose of this research is to increase our understanding of the climatology of extreme wind events, increase our understanding of how the large-scale circulation influences extreme wind events, and create a model to enhance predictability of extreme wind events in the Southwest. Knowledge from this paper will help protect personnel and property associated with not only the USAF, but all those in the Southwest.

Urban Heat Island phenomenon in extreme continental climate (Astana, Kazakhstan)

NASA Astrophysics Data System (ADS)

Konstantinov, Pavel; Akhmetova, Alina

2015-04-01

Urban Heat Island (UHI) phenomenon is well known in scientific literature since first half of the 19th century [1]. By now a wide number of world capitals is described from climatological point of view, especially in mid-latitudes. In beginning of XXI century new studies focus on heat island of tropical cities. However dynamics UHI in extreme continental climates is insufficiently investigated, due to the fact that there isn't large cities in Europe and Northern America within that climate type. In this paper we investigate seasonal and diurnal dynamics UHI intensity for Astana, capital city of Kazakhstan (population larger than 835 000 within the city) including UHI intensity changes on different time scales. Now (since 1998) Astana is the second coldest capital city in the world after Ulaanbaatar, Mongolia [3] For this study we use the UHI investigation technology, described in [2]. According to this paper, we selected three stations: one located into city in high and midrise buildings area (including extensive lowrise and high-energy industrial - LCZ classification) and two others located in rural site (sparsely built or open-set and lightweight lowrise according LCZ classification). Also these stations must be close by distance (less than 100 km) and altitude. Therefore, first for Astana city were obtained numerical evaluations for UHI climate dynamics, UHI dependence of synoptic situations and total UHI climatology on monthly and daily averages. References: 1.Howard, L. (1833) The Climate of London, Deduced from Meteorological Observations. Volume 2, London. 2.Kukanova E.A., Konstantinov P.I. An urban heat islands climatology in Russia and linkages to the climate change In Geophysical Research Abstracts, volume 16 of EGU General Assembly, pages EGU2014-10833-1, Germany, 2014. Germany. 3.www.pogoda.ru.net

Relationships between Rwandan seasonal rainfall anomalies and ENSO events

NASA Astrophysics Data System (ADS)

Muhire, I.; Ahmed, F.; Abutaleb, K.

2015-10-01

This study aims primarily at investigating the relationships between Rwandan seasonal rainfall anomalies and El Niño-South Oscillation phenomenon (ENSO) events. The study is useful for early warning of negative effects associated with extreme rainfall anomalies across the country. It covers the period 1935-1992, using long and short rains data from 28 weather stations in Rwanda and ENSO events resourced from Glantz (2001). The mean standardized anomaly indices were calculated to investigate their associations with ENSO events. One-way analysis of variance was applied on the mean standardized anomaly index values per ENSO event to explore the spatial correlation of rainfall anomalies per ENSO event. A geographical information system was used to present spatially the variations in mean standardized anomaly indices per ENSO event. The results showed approximately three climatic periods, namely, dry period (1935-1960), semi-humid period (1961-1976) and wet period (1977-1992). Though positive and negative correlations were detected between extreme short rains anomalies and El Niño events, La Niña events were mostly linked to negative rainfall anomalies while El Niño events were associated with positive rainfall anomalies. The occurrence of El Niño and La Niña in the same year does not show any clear association with rainfall anomalies. However, the phenomenon was more linked with positive long rains anomalies and negative short rains anomalies. The normal years were largely linked with negative long rains anomalies and positive short rains anomalies, which is a pointer to the influence of other factors other than ENSO events. This makes projection of seasonal rainfall anomalies in the country by merely predicting ENSO events difficult.

DNA double-strand break in vivo at the 3' extremity of exons located upstream of group II introns. Senescence and circular DNA introns in Podospora mitochondria.

PubMed

Sainsard-Chanet, A; Begel, O; Belcour, L

1994-10-07

In the filamentous fungus Podospora anserina, the unavoidable phenomenon of senescence is associated with the amplification of the first intron of the mitochondrial cox1 that accumulates as circular DNA molecules consisting of tandem repeats. This group II intron (cox1-i1 or alpha) is able to transpose and contains an open reading frame with significant amino acid similarity with reverse transcriptases. The generation of these intronic circular DNA molecules, their amplification and their involvement in the senescence process are unresolved questions. We demonstrate here that: (1) another group II intron, the fourth intron of gene cox1, cox1-i4, is also able to give precise DNA end to end junctions; (2) this intronic sequence can be found amplified during senescence, although to a lesser extent than cox1-i1; (3) the amplification of the DNA multimeric cox1-i1 molecules likely does not proceed by autonomous replication; (4) the generation of the DNA intronic circles does not require efficient intron splicing; (5) a DNA double-strand break occurs in vivo at the 3' extremity of the cox1-e1 and cox1-e4 exons preceding the group II introns that form circular DNAs. On the whole, these results show that the ability to form DNA circular molecules is a property of some group II introns and they demonstrate the occurrence of a specific DNA cleavage at or near the integration site of these group II introns. The results strongly suggest that this cleavage is involved in the formation of the group II intronic DNA circles and could also be involved in the phenomenon of group II intron homing.

Hubble Sees a “Behemoth” Bleeding Atmosphere Around a Warm Exoplanet

NASA Image and Video Library

2015-06-24

Astronomers using NASA’s Hubble Space Telescope have discovered an immense cloud of hydrogen dubbed “The Behemoth” bleeding from a planet orbiting a nearby star. The enormous, comet-like feature is about 50 times the size of the parent star. The hydrogen is evaporating from a warm, Neptune-sized planet, due to extreme radiation from the star. This phenomenon has never been seen around an exoplanet so small. It may offer clues to how other planets with hydrogen-enveloped atmospheres could have their outer layers evaporated by their parent star, leaving behind solid, rocky cores. Hot, rocky planets such as these that roughly the size of Earth are known as Hot-Super Earths. “This cloud is very spectacular, though the evaporation rate does not threaten the planet right now,” explains the study’s leader, David Ehrenreich of the Observatory of the University of Geneva in Switzerland. “But we know that in the past, the star, which is a faint red dwarf, was more active. This means that the planet evaporated faster during its first billion years of existence because of the strong radiation from the young star. Overall, we estimate that it may have lost up to 10 percent of its atmosphere over the past several billion years.” Caption: This artist's concept shows "The Behemoth," an enormous comet-like cloud of hydrogen bleeding off of a warm, Neptune-sized planet just 30 light-years from Earth. Also depicted is the parent star, which is a faint red dwarf named GJ 436. The hydrogen is evaporating from the planet due to extreme radiation from the star. A phenomenon this large has never before been seen around any exoplanet. Credits: NASA, ESA, and G. Bacon (STScI)

Why does high pressure destroy co-non-solvency of PNIPAm in aqueous methanol?

PubMed

de Oliveira, Tiago E; Netz, Paulo A; Mukherji, Debashish; Kremer, Kurt

2015-11-28

It is well known that poly(N-isopropylacrylamide) (PNIPAm) exhibits an interesting, yet puzzling, phenomenon of co-non-solvency. Co-non-solvency occurs when two competing good solvents for PNIPAm, such as water and alcohol, are mixed together. As a result, the same PNIPAm collapses within intermediate mixing ratios. This complex conformational transition is driven by preferential binding of methanol with PNIPAm. Interestingly, co-non-solvency can be destroyed when applying high hydrostatic pressures. In this work, using a large scale molecular dynamics simulation employing high pressures, we propose a microscopic picture behind the suppression of the co-non-solvency phenomenon. Based on thermodynamic and structural analysis, our results suggest that the preferential binding of methanol with PNIPAm gets partially lost at high pressures, making the background fluid reasonably homogeneous for the polymer. This is consistent with the hypothesis that the co-non-solvency phenomenon is driven by preferential binding and is not based on depletion effects.

Improving Joint Formation and Tensile Properties of Dissimilar Friction Stir Welding of Aluminum and Magnesium Alloys by Solving the Pin Adhesion Problem

NASA Astrophysics Data System (ADS)

Liu, Zhenlei; Ji, Shude; Meng, Xiangchen

2018-03-01

Friction stir welding (FSW), as a solid-state welding technology invented by TWI in 1991, has potential to join dissimilar Al/Mg alloys. In this study, the pin adhesion phenomenon affecting joint quality during FSW of 6061-T6 aluminum and AZ31B magnesium alloys was investigated. The adhesion phenomenon induced by higher heat input easily transformed the tapered-and-screwed pin into a tapered pin, which greatly reduced the tool's ability to drive the plasticized materials and further deteriorated joint formation. Under the condition without the pin adhesion, the complex intercalated interlayer at the bottom of stir zone was beneficial to mechanical interlocking of Al/Mg alloys, improving tensile properties. However, the formation of intermetallic compounds was still the main reason of the joint fracture, significantly deteriorating tensile properties. Under the welding speed of 60 mm/min without the pin adhesion phenomenon, the maximum tensile strength of 107 MPa and elongation of 1.2% were achieved.

An Organismal CNV Mutator Phenotype Restricted to Early Human Development.

PubMed

Liu, Pengfei; Yuan, Bo; Carvalho, Claudia M B; Wuster, Arthur; Walter, Klaudia; Zhang, Ling; Gambin, Tomasz; Chong, Zechen; Campbell, Ian M; Coban Akdemir, Zeynep; Gelowani, Violet; Writzl, Karin; Bacino, Carlos A; Lindsay, Sarah J; Withers, Marjorie; Gonzaga-Jauregui, Claudia; Wiszniewska, Joanna; Scull, Jennifer; Stankiewicz, Paweł; Jhangiani, Shalini N; Muzny, Donna M; Zhang, Feng; Chen, Ken; Gibbs, Richard A; Rautenstrauss, Bernd; Cheung, Sau Wai; Smith, Janice; Breman, Amy; Shaw, Chad A; Patel, Ankita; Hurles, Matthew E; Lupski, James R

2017-02-23

De novo copy number variants (dnCNVs) arising at multiple loci in a personal genome have usually been considered to reflect cancer somatic genomic instabilities. We describe a multiple dnCNV (MdnCNV) phenomenon in which individuals with genomic disorders carry five to ten constitutional dnCNVs. These CNVs originate from independent formation incidences, are predominantly tandem duplications or complex gains, exhibit breakpoint junction features reminiscent of replicative repair, and show increased de novo point mutations flanking the rearrangement junctions. The active CNV mutation shower appears to be restricted to a transient perizygotic period. We propose that a defect in the CNV formation process is responsible for the "CNV-mutator state," and this state is dampened after early embryogenesis. The constitutional MdnCNV phenomenon resembles chromosomal instability in various cancers. Investigations of this phenomenon may provide unique access to understanding genomic disorders, structural variant mutagenesis, human evolution, and cancer biology. Copyright © 2017 Elsevier Inc. All rights reserved.

The complexity of nectar: secretion and resorption dynamically regulate nectar features

NASA Astrophysics Data System (ADS)

Nepi, Massimo; Stpiczyńska, Małgorzata

2008-03-01

In this paper, we review the phenomenon of nectar resorption, focusing on its physiological and ecological meaning. Nectar resorption is a phenomenon that has long been known but was rarely reported until the1990s. It has more recently been demonstrated in several species by various direct and indirect methodologies. It has generally been demonstrated in senescent flowers as a phenomenon separate in time from, and independent of, nectar secretion. The significance of this type of resorption is generally recognized as a resource-recovery strategy, recycling at least some materials invested in nectar production. Nevertheless, nectar resorption can occur concomitantly with nectar secretion. Nectar production is therefore best considered as a unified process comprising nectar secretion and resorption. The modulation of these two opposite phases allows nectar concentration to be maintained in a range suitable for pollinators (nectar homeostasis). The mechanism of nectar resorption at the cell level has received little attention, and its molecular basis can only be hypothesized on the basis of recent studies concerning sugar sensing.

Investigating the multi-causal and complex nature of the accident causal influence of construction project features.

PubMed

Manu, Patrick A; Ankrah, Nii A; Proverbs, David G; Suresh, Subashini

2012-09-01

Construction project features (CPFs) are organisational, physical and operational attributes that characterise construction projects. Although previous studies have examined the accident causal influence of CPFs, the multi-causal attribute of this causal phenomenon still remain elusive and thus requires further investigation. Aiming to shed light on this facet of the accident causal phenomenon of CPFs, this study examines relevant literature and crystallises the attained insight of the multi-causal attribute by a graphical model which is subsequently operationalised by a derived mathematical risk expression that offers a systematic approach for evaluating the potential of CPFs to cause harm and consequently their health and safety (H&S) risk implications. The graphical model and the risk expression put forth by the study thus advance current understanding of the accident causal phenomenon of CPFs and they present an opportunity for project participants to manage the H&S risk associated with CPFs from the early stages of project procurement. Copyright © 2011 Elsevier Ltd. All rights reserved.

Extreme events as foundation of Lévy walks with varying velocity

NASA Astrophysics Data System (ADS)

Kutner, Ryszard

2002-11-01

In this work we study the role of extreme events [E.W. Montroll, B.J. West, in: J.L. Lebowitz, E.W. Montrell (Eds.), Fluctuation Phenomena, SSM, vol. VII, North-Holland, Amsterdam, 1979, p. 63; J.-P. Bouchaud, M. Potters, Theory of Financial Risks from Statistical Physics to Risk Management, Cambridge University Press, Cambridge, 2001; D. Sornette, Critical Phenomena in Natural Sciences. Chaos, Fractals, Selforganization and Disorder: Concepts and Tools, Springer, Berlin, 2000] in determining the scaling properties of Lévy walks with varying velocity. This model is an extension of the well-known Lévy walks one [J. Klafter, G. Zumofen, M.F. Shlesinger, in M.F. Shlesinger, G.M. Zaslavsky, U. Frisch (Eds.), Lévy Flights and Related Topics ion Physics, Lecture Notes in Physics, vol. 450, Springer, Berlin, 1995, p. 196; G. Zumofen, J. Klafter, M.F. Shlesinger, in: R. Kutner, A. Pȩkalski, K. Sznajd-Weron (Eds.), Anomalous Diffusion. From Basics to Applications, Lecture Note in Physics, vol. 519, Springer, Berlin, 1999, p. 15] introduced in the context of chaotic dynamics where a fixed value of the walker velocity is assumed for simplicity. Such an extension seems to be necessary when the open and/or complex system is studied. The model of Lévy walks with varying velocity is spanned on two coupled velocity-temporal hierarchies: the first one consisting of velocities and the second of corresponding time intervals which the walker spends between the successive turning points. Both these hierarchical structures are characterized by their own self-similar dimensions. The extreme event, which can appear within a given time interval, is defined as a single random step of the walker having largest length. By finding power-laws which describe the time-dependence of this displacement and its statistics we obtained two independent diffusion exponents, which are related to the above-mentioned dimensions and which characterize the extreme event kinetics. In this work we show the principal influence of extreme events on the basic quantities (one-step distributions and moments as well as two-step correlation functions) of the continuous-time random walk formalism. Besides, we construct both the waiting-time distribution and sojourn probability density directly in a real space and time in the scaling form by proper component analysis which takes into account all possible fluctuations of the walker steps in contrast to the extreme event analysis. In this work we pay our attention to the basic quantities, since the summarized multi-step ones were already discussed earlier [Physica A 264 (1999) 107; Comp. Phys. Commun. 147 (2002) 565]. Moreover, we study not only the scaling phenomena but also, assuming a finite number of hierarchy levels, the breaking of scaling and its dependence on control parameters. This seems to be important for studying empirical systems the more so as there are still no closed formulae describing this phenomenon except the one for truncated Lévy flights [Phys. Rev. Lett. 73 (1994) 2946]. Our formulation of the model made possible to develop an efficient Monte Carlo algorithm [Physica A 264 (1999) 107; Comp. Phys. Commun. 147 (2002) 565] where no MC step is lost.

The phenomenon of cathodoluminescence in tooth hard tissues

NASA Astrophysics Data System (ADS)

Bessudnova, Nadezda O.; Matasov, Maxim D.

2012-03-01

The phenomenon of luminescence in tooth hard tissues under the hits of electrons accelerated up to 3keV has been investigated and the nature of luminescence has been described. It has been discovered that the change in luminescence color depends on the place of the impingement of primary electrons. The latter could be explained by different chemical compositions of compounds and complexes where luminescence is observed. Based on the analysis of RGB color bar charts, the correlation between the color of luminescence and calcium-phosphorus ratio in tooth hard tissues has been investigated. Thus, cathodoluminescence can be considered as a tool for in vitro quantitative assessment of tooth hard tissues compositions.

Nursing care systematization as a multidimensional and interactive phenomenon.

PubMed

Backes, Dirce Stein; Koerich, Magda Santos; Nascimento, Keyla Cristiane do; Erdmann, Alacoque Lorenzini

2008-01-01

This study aimed to understand the meaning of Nursing Care Systematization (NCS) for multiprofessional health team professionals based on the relationships, interactions and associations of Complex thought. This qualitative study uses Grounded Theory as a methodological reference framework. Data were obtained through interviews with three sample groups, totaling 15 professionals from different institutions. Simultaneous data codification and analysis identified the central theme: 'Glimpsing nursing care systematization as an interactive and multidimensional phenomenon' and the respective reference model. NCS appoints, in addition to interactivity and professional complementarity, the importance of dialog and connection between the academy, health practices and regulatory offices, based on new reference frameworks for the organization of health practices.

Trends in autumn rain of West China from 1961 to 2014

NASA Astrophysics Data System (ADS)

Zhang, Chi; Wang, Zunya; Zhou, Botao; Li, Yonghua; Tang, Hongyu; Xiang, Bo

2018-02-01

Autumn rain of West China is a typical climate phenomenon, which is characterized by continuous rainy days and large rainfall amounts and exerts profound impacts on the economic society. Based on daily precipitation data from 524 observation stations for the period of 1961-2014, this article comprehensively examined secular changes in autumn rain of West China, including its amount, frequency, intensity, and associated extremes. The results generally show a significant reduction of rainfall amount and rainy days and a significant enhancement of mean rainfall intensity for the average of West China during autumn (September-October) since 1961. Meanwhile, decreasing trends are consistently observed in the maximum daily rainfall, the longest consecutive rainy days, the greatest consecutive rainfall amount, and the frequencies of the extreme daily rainfall, consecutive rainfall, and consecutive rainfall process. Further analysis indicates that the decreases of autumn rainfall and related extremes in West China are associated with the decreases in both water vapor content and atmospheric unstable stratification during the past decades. On the regional scale, some differences exist in the changes of autumn rainfall between the eastern and western parts of West China. Besides, it is found that the autumn rainy season tends to start later and terminate earlier particularly in eastern West China.

New localized/delocalized emitting state of Eu 2+ in orange-emitting hexagonal EuAl 2O 4

DOE PAGES

Liu, Feng; Meltzer, Richard S.; Li, Xufan; ...

2014-11-18

Eu 2+-activated phosphors are being widely used in illuminations and displays. Some of these phosphors feature an extremely broad and red-shifted Eu 2+ emission band; however, convincing explanation of this phenomenon is lacking. Here we report a new localized/delocalized emitting state of Eu 2+ ions in a new hexagonal EuAl 2O 4 phosphor whose Eu 2+ luminescence exhibits a very large bandwidth and an extremely large Stokes shift. At 77 K, two luminescent sites responsible for 550 nm and 645 nm broadband emissions are recognized, while at room temperature only the 645 nm emission band emits. The 645 nm emissionmore » exhibits a typical radiative lifetime of 1.27 μs and an unusually large Stokes shift of 0.92 eV. We identify the 645 nm emission as originating from a new type of emitting state whose composition is predominantly that of localized 4f 65d character but which also contains a complementary component with delocalized conduction-band-like character. This investigation gives new insights into a unique type of Eu 2+ luminescence in solids whose emission exhibits both a very large bandwidth and an extremely large Stokes shift.« less

On the shape and likelihood of oceanic rogue waves.

PubMed

Benetazzo, Alvise; Ardhuin, Fabrice; Bergamasco, Filippo; Cavaleri, Luigi; Guimarães, Pedro Veras; Schwendeman, Michael; Sclavo, Mauro; Thomson, Jim; Torsello, Andrea

2017-08-15

We consider the observation and analysis of oceanic rogue waves collected within spatio-temporal (ST) records of 3D wave fields. This class of records, allowing a sea surface region to be retrieved, is appropriate for the observation of rogue waves, which come up as a random phenomenon that can occur at any time and location of the sea surface. To verify this aspect, we used three stereo wave imaging systems to gather ST records of the sea surface elevation, which were collected in different sea conditions. The wave with the ST maximum elevation (happening to be larger than the rogue threshold 1.25H s ) was then isolated within each record, along with its temporal profile. The rogue waves show similar profiles, in agreement with the theory of extreme wave groups. We analyze the rogue wave probability of occurrence, also in the context of ST extreme value distributions, and we conclude that rogue waves are more likely than previously reported; the key point is coming across them, in space as well as in time. The dependence of the rogue wave profile and likelihood on the sea state conditions is also investigated. Results may prove useful in predicting extreme wave occurrence probability and strength during oceanic storms.

Bactericidal effects of low-intensity extremely high frequency electromagnetic field: an overview with phenomenon, mechanisms, targets and consequences.

PubMed

Torgomyan, Heghine; Trchounian, Armen

2013-02-01

Low-intensity electromagnetic field (EMF) of extremely high frequencies is a widespread environmental factor. This field is used in telecommunication systems, therapeutic practices and food protection. Particularly, in medicine and food industries EMF is used for its bactericidal effects. The significant targets of cellular mechanisms for EMF effects at resonant frequencies in bacteria could be water (H(2)O), cell membrane and genome. The changes in H(2)O cluster structure and properties might be leading to increase of chemical activity or hydration of proteins and other cellular structures. These effects are likely to be specific and long-term. Moreover, cell membrane with its surface characteristics, substance transport and energy-conversing processes is also altered. Then, the genome is affected because the conformational changes in DNA and the transition of bacterial pro-phages from lysogenic to lytic state have been detected. The consequences for EMF interaction with bacteria are the changes in their sensitivity to different chemicals, including antibiotics. These effects are important to understand distinguishing role of bacteria in environment, leading to changed metabolic pathways in bacteria and their antibiotic resistance. This EMF may also affect the cell-to-cell interactions in bacterial populations, since bacteria might interact with each other through EMF of sub-extremely high frequency range.

Right hemispheric dominance of visual phenomena evoked by intracerebral stimulation of the human visual cortex.

PubMed

Jonas, Jacques; Frismand, Solène; Vignal, Jean-Pierre; Colnat-Coulbois, Sophie; Koessler, Laurent; Vespignani, Hervé; Rossion, Bruno; Maillard, Louis

2014-07-01

Electrical brain stimulation can provide important information about the functional organization of the human visual cortex. Here, we report the visual phenomena evoked by a large number (562) of intracerebral electrical stimulations performed at low-intensity with depth electrodes implanted in the occipito-parieto-temporal cortex of 22 epileptic patients. Focal electrical stimulation evoked primarily visual hallucinations with various complexities: simple (spot or blob), intermediary (geometric forms), or complex meaningful shapes (faces); visual illusions and impairments of visual recognition were more rarely observed. With the exception of the most posterior cortical sites, the probability of evoking a visual phenomenon was significantly higher in the right than the left hemisphere. Intermediary and complex hallucinations, illusions, and visual recognition impairments were almost exclusively evoked by stimulation in the right hemisphere. The probability of evoking a visual phenomenon decreased substantially from the occipital pole to the most anterior sites of the temporal lobe, and this decrease was more pronounced in the left hemisphere. The greater sensitivity of the right occipito-parieto-temporal regions to intracerebral electrical stimulation to evoke visual phenomena supports a predominant role of right hemispheric visual areas from perception to recognition of visual forms, regardless of visuospatial and attentional factors. Copyright © 2013 Wiley Periodicals, Inc.

Trapping-charging ability and electrical properties study of amorphous insulator by dielectric spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mekni, Omar, E-mail: omarmekni-lmop@yahoo.fr; Arifa, Hakim; Askri, Besma

2014-09-14

Usually, the trapping phenomenon in insulating materials is studied by injecting charges using a Scanning Electron Microscope. In this work, we use the dielectric spectroscopy technique for showing a correlation between the dielectric properties and the trapping-charging ability of insulating materials. The evolution of the complex permittivity (real and imaginary parts) as a function of frequency and temperature reveals different types of relaxation according to the trapping ability of the material. We found that the space charge relaxation at low frequencies affects the real part of the complex permittivity ε{sup ´} and the dissipation factor Tan(δ). We prove that themore » evolution of the imaginary part of the complex permittivity against temperature ε{sup ′′}=f(T) reflects the phenomenon of charge trapping and detrapping as well as trapped charge evolution Q{sub p}(T). We also use the electric modulus formalism to better identify the space charge relaxation. The investigation of trapping or conductive nature of insulating materials was mainly made by studying the activation energy and conductivity. The conduction and trapping parameters are determined using the Correlated Barrier Hopping (CBH) model in order to confirm the relation between electrical properties and charge trapping ability.« less

Entropy-driven complex formation of malvidin-3- O-glucoside with common polyphenols in ethanol-water binary solutions

NASA Astrophysics Data System (ADS)

Kunsági-Máté, Sándor; Ortmann, Erika; Kollár, László; Nikfardjam, Martin Pour

2008-09-01

The complex formation of malvidin-3- O-glucoside with several polyphenols, the so-called "copigmentation" phenomenon, was studied in aqueous solutions. To simulate the copigmentation process during fermentation, the stability of the formed complexes was examined in dependence of the ethanol content of the aqueous solution. Results indicate that stronger and larger complexes are formed, when the ethanol content exceeds a critical margin of 8 vol.% However, the size of complexes of malvidin/procyanidin and malvidin/epicatechin is drastically reduced above this critical concentration. Fluorescence lifetime and solvent relaxation measurements give insight into the particular processes at molecular level and will help us comprehend the first important steps during winemaking in order to recommend an optimized winemaking technology to ensure extraordinary colour stability in red wines.

Using complexity theory to analyse the organisational response to resurgent tuberculosis across London.

PubMed

Trenholm, Susan; Ferlie, Ewan

2013-09-01

We employ complexity theory to analyse the English National Health Service (NHS)'s organisational response to resurgent tuberculosis across London. Tennison (2002) suggests that complexity theory could fruitfully explore a healthcare system's response to this complex and emergent phenomenon: we explore this claim here. We also bring in established New Public Management principles to enhance our empirical analysis, which is based on data collected between late 2009 and mid-2011. We find that the operation of complexity theory based features, especially self-organisation, are significantly impacted by the macro context of a New Public Management-based regime which values control, measurement and risk management more than innovation, flexibility and lateral system building. We finally explore limitations and suggest perspectives for further research. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

PubMed

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.

The influence of organic-mineral complexes on micro-elements dynamic in ecological systems of vegetables cultivation

NASA Astrophysics Data System (ADS)

Bulgariu, D.; Buzgar, N.; Bulgariu, L.; Rusu, C.; Munteanu, N.

2009-04-01

In ecological systems of vegetable cultivation (hortic antrosols; soils from greenhouses), exists an ensemble of equilibriums between organic-mineral combinations, very sensitive even to relatively small variations of physical-chemical conditions in soils. As such, these can manifest a strong influence on organic matter, clay minerals and microelements from soil, which in turn impacts on the productivity of these soils and the quality of obtained products (vegetables, fruit). Although many studies consider these organic-mineral combinations are meta-stable combinations, our work has shown that the stability of organic-mineral combinations in hortic antrosols (especially for clay-humic, clay-ironhumic combinations and chelates) is higher. We believe that this is due to the higher flexibility of these combinations' structures with the variation of chemical-mineralogical composition and physical-chemical conditions in soil. This paper highlights the results of our research on the differentiation possibility of organic-mineral complexes, depending on their structure and composition (using Raman and FT-IR spectrometry) and the influences manifested by the organic-mineral complexes on the micro-elements dynamic from ecological systems of fresh vegetable cultivation. The non-destructive separation of organic-mineral compounds from soil samples was carried out through iso-dynamic magnetic separation and extraction in aqueous two-phase systems (PEG-based). The Raman and FT-IR spectrometry analyses on raw soil samples, extracts obtained from soil samples and separated mineral fractions have been supplemented by the results obtained through chemical, microscopic and thermal analyses and by UV-VIS absorption spectrometry. Ours experimental studies have been done on representative samples of hortic antrosol from Copou glasshouse (Iasi, Romania), and was studied five micro-elements: Zn, Ni, Cu, Mn, Cr and P. The total contents of the five microelements and their fractions differential bonded on mineral and organic components of hortic antrosols, have been determined by atomic absorption spectrometry after combined sequential extraction in solid phase extraction - aqueous biphasic (PEG based) systems. The specific mechanisms of the microelements interaction with organic components have been estimated on the basis of studies realized on fractions obtained after each extraction step by Raman and FTIR spectrometry. These data have been correlated with those obtained by chemical analysis and UV-VIS spectrometry. In conditions of hortic antrosol, from total contents of Zn, Ni, Cu, Mn and Cr, more than 65 % are binding on organic components. A specific phenomenon of hortic antrosols is the microelements complexation exclusively with the functional groups of organic macromolecules. This phenomenon has two important consequences: (i) the strong fixation of microelements (these can be extracted only in very extremely conditions, which implied the organic part destroying) and (ii) their presence determined major modifications in the structure, conformation and stability of organic macromolecules. Under these conditions, the type and structure of organic-mineral compounds represent determinant factors for the dynamic of micro-elements and organic compounds in ecological systems of vegetables cultivation. Acknowledgments The authors would like to acknowledge the financial support from Romanian Ministry of Education and Research (Project PNCDI 2-D5 no. 51045/07 an Project PNCDI 2-D5 no. 52141 / 08).

Revisiting the Quantum Brain Hypothesis: Toward Quantum (Neuro)biology?

PubMed Central

Jedlicka, Peter

2017-01-01

The nervous system is a non-linear dynamical complex system with many feedback loops. A conventional wisdom is that in the brain the quantum fluctuations are self-averaging and thus functionally negligible. However, this intuition might be misleading in the case of non-linear complex systems. Because of an extreme sensitivity to initial conditions, in complex systems the microscopic fluctuations may be amplified and thereby affect the system’s behavior. In this way quantum dynamics might influence neuronal computations. Accumulating evidence in non-neuronal systems indicates that biological evolution is able to exploit quantum stochasticity. The recent rise of quantum biology as an emerging field at the border between quantum physics and the life sciences suggests that quantum events could play a non-trivial role also in neuronal cells. Direct experimental evidence for this is still missing but future research should address the possibility that quantum events contribute to an extremely high complexity, variability and computational power of neuronal dynamics. PMID:29163041

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

NASA Astrophysics Data System (ADS)

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

2017-12-01

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

Winds, Mountains, and Wildland Fire: Improved Understanding of Coupled Atmosphere-Topography-Fire Interactions Through Large-Eddy Simulation

NASA Astrophysics Data System (ADS)

Munoz-Esparza, D.; Sauer, J.; Linn, R.

2015-12-01

Anomalous and unexpected fire behavior in complex terrain continues to result in substantial loss of property and extremely dangerous conditions for firefighting field personnel. We briefly discuss proposed hypotheses of fire interactions with atmospheric flows over complex terrain that can lead to poorly-understood and potentially catastrophic scenarios. Then, our recent results of numerical investigations via large-eddy simulation of coupled atmosphere-topography-fire phenomenology with the Los Alamos National Laboratory, HiGrad-Firetec model are presented as an example of the potential for increased understanding of these complex processes. This investigation focuses on the influence of downslope surface wind enhancement through stably stratified flow over an isolated hill, and the resulting dramatic changes in fire behavior including spread rate, and intensity. Implications with respect to counter-intuitive fire behavior and extreme fire events are discussed. This work demonstrates a tremendous opportunity to immediately create safer and more effective policy for field personnel through improved predictability of atmospheric conditions over complex terrain

Revisiting the Quantum Brain Hypothesis: Toward Quantum (Neuro)biology?

PubMed

Jedlicka, Peter

2017-01-01

The nervous system is a non-linear dynamical complex system with many feedback loops. A conventional wisdom is that in the brain the quantum fluctuations are self-averaging and thus functionally negligible. However, this intuition might be misleading in the case of non-linear complex systems. Because of an extreme sensitivity to initial conditions, in complex systems the microscopic fluctuations may be amplified and thereby affect the system's behavior. In this way quantum dynamics might influence neuronal computations. Accumulating evidence in non-neuronal systems indicates that biological evolution is able to exploit quantum stochasticity. The recent rise of quantum biology as an emerging field at the border between quantum physics and the life sciences suggests that quantum events could play a non-trivial role also in neuronal cells. Direct experimental evidence for this is still missing but future research should address the possibility that quantum events contribute to an extremely high complexity, variability and computational power of neuronal dynamics.

Forest operations, extreme flooding events, and considerations for hydrologic modeling in the Appalachians--A review

Treesearch

M.A. Eisenbies; W.M. Aust; J.A. Burger; M.B. Adams

2007-01-01

The connection between forests and water resources is well established, but the relationships among controlling factors are only partly understood. Concern over the effects of forestry operations, particularly harvesting, on extreme flooding events is a recurrent issue in forest and watershed management. Due to the complexity of the system, and the cost of installing...

Microbial communities and their predicted metabolic functions in a desiccating acid salt lake.

PubMed

Zaikova, Elena; Benison, Kathleen C; Mormile, Melanie R; Johnson, Sarah Stewart

2018-05-01

The waters of Lake Magic in Western Australia are among the most geochemically extreme on Earth. This ephemeral saline lake is characterized by pH as low as 1.6 salinity as high as 32% total dissolved solids, and unusually complex geochemistry, including extremely high concentrations of aluminum, silica, and iron. We examined the microbial composition and putative function in this extreme acid brine environment by analyzing lake water, groundwater, and sediment samples collected during the austral summer near peak evapoconcentration. Our results reveal that the lake water metagenome, surprisingly, was comprised of mostly eukaryote sequences, particularly fungi and to a lesser extent, green algae. Groundwater and sediment samples were dominated by acidophilic Firmicutes, with eukaryotic community members only detected at low abundances. The lake water bacterial community was less diverse than that in groundwater and sediment, and was overwhelmingly represented by a single OTU affiliated with Salinisphaera. Pathways associated with halotolerance were found in the metagenomes, as were genes associated with biosynthesis of protective carotenoids. During periods of complete desiccation of the lake, we hypothesize that dormancy and entrapment in fluid inclusions in halite crystals may increase long-term survival, leading to the resilience of complex eukaryotes in this extreme environment.

Teaching for Diversity: Addressing Diversity Issues in Responsive ESL Instruction

ERIC Educational Resources Information Center

Fu, Jing

2013-01-01

Student diversity has become a typical phenomenon in American public schools. The impact of increasing diversity on literacy instruction is unchallenged. Teachers reinforce this message by often citing ESL student diversity as a barrier for literacy teaching. In order to better understand the complexity of diversity issues, I explored two ESL…

Real Time Big Data Analytics for Predicting Terrorist Incidents

ERIC Educational Resources Information Center

Toure, Ibrahim

2017-01-01

Terrorism is a complex and evolving phenomenon. In the past few decades, we have witnessed an increase in the number of terrorist incidents in the world. The security and stability of many countries is threatened by terrorist groups. Perpetrators now use sophisticated weapons and the attacks are more and more lethal. Currently, terrorist incidents…

Chasing the Butterfly Effect: Informal Language Learning Online as a Complex System

ERIC Educational Resources Information Center

Godwin-Jones, Robert

2018-01-01

Evidence is accumulating that a major shift is underway in the ways that second language (L2) development is taking place. Increasingly, especially among young people, that process is occurring outside of institutional settings, predominately through the use of online networks and media. That phenomenon has been particularly noticed for learners…

A sexy spin on nonrandom chromosome segregation.

PubMed

Charville, Gregory W; Rando, Thomas A

2013-06-06

Nonrandom chromosome segregation is an intriguing phenomenon linked to certain asymmetric stem cell divisions. In a recent report in Nature, Yadlapalli and Yamashita (2013) observe nonrandom segregation of X and Y chromosomes in Drosophila germline stem cells and shed light on the complex mechanisms of this fascinating process. Copyright © 2013 Elsevier Inc. All rights reserved.

Quasi-Clinical Inquiry in Research on Classroom Teaching and Learning.

ERIC Educational Resources Information Center

Fisher, Charles W.; Berliner, David C.

In this paper a broad perspective on the phenomenon of teaching and learning is presented. The complex dynamics of interaction between teacher, student, and educational researcher are explored. Conventional research in education is characterized as relying heavily on methods adopted from other types of research in such fields as agriculture and…

Investigating Syntactical and Lexical Complexity in Gendered and Same-Sex Interactions

ERIC Educational Resources Information Center

Long, Robert W., III.

2018-01-01

For many sociolinguists, the issue of shyness and hesitation phenomenon has been problematic for Japanese L1 and L2 speakers, particularly in gendered interactions. Over the past decade, more Japanese are shunning conversations, relationships, and isolating themselves, which is accelerating the demographic crisis in Japan. Thus, this paper focuses…

Giftedness and Genetics: The Emergenic-Epigenetic Model and Its Implications

ERIC Educational Resources Information Center

Simonton, Dean Keith

2005-01-01

The genetic endowment underlying giftedness may operate in a far more complex manner than often expressed in most theoretical accounts of the phenomenon. First, an endowment may be emergenic. That is, a gift may consist of multiple traits (multidimensional) that are inherited in a multiplicative (configurational), rather than an additive (simple)…

Transitional Leadership: Perceptions of Interim Mid-Level Student Affairs Professionals

ERIC Educational Resources Information Center

Boerner, William A.

2011-01-01

It has been estimated that, due to increased turnover, an aging population, growing complexities and sizes of institutions, as well as the bureaucratization of searches, college and universities will see a continued increase in the utilization of interim leadership (Padilla, 2004). Student affairs divisions are not immune to this phenomenon and…

Encoding Strategy Changes and Spacing Effects in the Free Recall of Unmixed Lists

ERIC Educational Resources Information Center

Delaney, P.F.; Knowles, M.E.

2005-01-01

Memory for repeated items often improves when repetitions are separated by other items-a phenomenon called the spacing effect. In two experiments, we explored the complex interaction between study strategies, serial position, and spacing effects. When people studied several unmixed lists, they initially used mainly rote rehearsal, but some people…

Associations of Acculturation with Self-Report and Objective Physical Activity and Sedentary Behaviors among Latinas

ERIC Educational Resources Information Center

Perez, Lilian G.; Chavez, Adrian; Marquez, David X.; Soto, Sandra C.; Haughton, Jessica; Arredondo, Elva M.

2017-01-01

Background: Less than 50% of Latinas meet physical activity (PA) recommendations. Acculturation is a complex cultural phenomenon that may influence health behaviors, but associations between acculturation and Latinas' activity and sedentary levels are unclear. Aim: To examine associations of acculturation with Latinas' domain-specific and total PA…

Gentrification and Neo-Rural Populations in the Quebec Countryside: Representations of Various Actors

ERIC Educational Resources Information Center

Guimond, Laurie; Simard, Myriam

2010-01-01

Rural gentrification, which is linked in particular to the migration and permanent settlement in the countryside of middle-class or affluent urbanites, is increasingly affecting contemporary rural communities. Despite the significance of this trend, the complex and many-sided phenomenon of rural gentrification has hardly been explored in scholarly…

Essential Properties of Language, or, Why Language Is Not a Code

ERIC Educational Resources Information Center

Kravchenko, Alexander V.

2007-01-01

Despite a strong tradition of viewing "coded equivalence" as the underlying principle of linguistic semiotics, it lacks the power needed to understand and explain language as an empirical phenomenon characterized by complex dynamics. Applying the biology of cognition to the nature of the human cognitive/linguistic capacity as rooted in the…

The Transformative Role of ePortfolios: Feedback in Healthcare Learning

ERIC Educational Resources Information Center

Peacock, Susi; Murray, Sue; Scott, Alison; Kelly, Jacquie

2011-01-01

This article reports findings of a study based in Scotland that explored healthcare learners' experiences of feedback and ePortfolios. Feedback is a highly complex, multi-dimensional phenomenon, and healthcare learners consider it essential for their learning, recognizing that without it patient safety may be compromised. This study sought to…

Fire behavior modeling-a decision tool

Treesearch

Jack Cohen; Bill Bradshaw

1986-01-01

The usefulness of an analytical model as a fire management decision tool is determined by the correspondence of its descriptive capability to the specific decision context. Fire managers must determine the usefulness of fire models as a decision tool when applied to varied situations. Because the wildland fire phenomenon is complex, analytical fire spread models will...

Exploring the Diverse Motivations of Transnational Higher Education in China: Complexities and Contradictions

ERIC Educational Resources Information Center

Hou, Junxia; Montgomery, Catherine; McDowell, Liz

2014-01-01

This article analyses the current situation of transnational higher education (TNE) in China by conducting a comprehensive documentary analysis. It first situates the phenomenon in global transnational mobility in higher education and then explores the diverse motivations of importing and exporting countries taking China and the UK as linked…

Experiences of Bereaved Secondary Students in the High School Environment

ERIC Educational Resources Information Center

Myers-Autrey, Roberta Lee

2010-01-01

Bereaved high school adolescents are often affected in a myriad of ways by the death of a loved one. The traumatic experience and bereavement process add complexity to high school adolescents' development and this phenomenon is not fully understood, in particular in regards to communication and relationships in the school environment. The…

Developing Pre-Professional Identity in Undergraduates through Work-Integrated Learning

ERIC Educational Resources Information Center

Jackson, Denise

2017-01-01

Pre-professional identity is a complex phenomenon spanning awareness of and connection with the skills, qualities, behaviours, values and standards of a student's chosen profession, as well as one's understanding of professional self in relation to the broader general self. It is an important, yet under-explored, aspect of graduate employability…

Hemispheric Asymmetry in the Efficiency of Attentional Networks

ERIC Educational Resources Information Center

Asanowicz, Dariusz; Marzecova, Anna; Jaskowski, Piotr; Wolski, Piotr

2012-01-01

Despite the fact that hemispheric asymmetry of attention has been widely studied, a clear picture of this complex phenomenon is still lacking. The aim of the present study was to provide an efficient and reliable measurement of potential hemispheric asymmetries of three attentional networks, i.e. alerting, orienting and executive attention.…

Teaching, Learning, and the Human Quest: Wisdom

ERIC Educational Resources Information Center

Jarvis, Peter

2011-01-01

Wisdom is a complex phenomenon: it finds its home primarily but not exclusively in theology, philosophy, psychology, education--that is, in the humanities--and in life itself. In a paradoxical manner, wisdom finds its home in the world of the unanswerable, where there are no empirical proofs and no obvious answers. Wisdom actually finds its place…

Student Homicidal Violence in Schools: An International Problem

ERIC Educational Resources Information Center

Bondu, Rebecca; Cornell, Dewey G.; Scheithauer, Herbert

2011-01-01

School homicides have become a worldwide phenomenon. In the decade following the Columbine shooting there have been at least forty similar events in other countries. This article addresses the international scope of this problem and some of the complex conceptual issues that make student homicidal violence difficult to define and study. Meaningful…

Net Neutrality and Its Implications to Online Learning

ERIC Educational Resources Information Center

Yamagata-Lynch, Lisa C.; Despande, Deepa R.; Do, Jaewoo; Garty, Erin; Mastrogiovanni, Jason M.; Teagu, Stephanie J.

2017-01-01

In this article, we studied net neutrality as a complex sociocultural phenomenon that can affect the works of distance education scholars and online learners. We decided to take part in this research because many distance education scholars and learners take net neutrality for granted. We engaged in a qualitative investigation of US public…

The Placebo Effect and Learning: Implications for Counsellors

ERIC Educational Resources Information Center

Hagen, Brad; Gunn, Thelma

2006-01-01

The placebo effect is a fascinating and complex phenomenon, and may well account for much of the effectiveness of many medical therapies, such as pain medications and antidepressants. While health professionals have long debated the role that placebos may play in health care, the counselling profession has devoted less attention to the placebo…

Blueberries and strawberries activate neuronal housekeeping in critical brain regions of stress-induced young rats

USDA-ARS?s Scientific Manuscript database

Dysfunctional autophagy, where accumulation of damaged or complex cellular components in neurons in response to sublethal cell stress has been implicated in an array of brain disorders. This phenomenon plays a pivotal role in aging, because of the increased vulnerability of the aging brain to incre...

Numbers and Narratives: What Can Schoolteachers Tell Us about College Drop-Out?

ERIC Educational Resources Information Center

Page, Mich

2004-01-01

Student drop-out is a complex phenomenon; this paper addresses some dysfunctional precursors, which may predispose college students to drop out of further education. These precursors are seen in the light of institutional failure to transmit appropriate, positive values to children in schools, in respect of vocational education and training. Two…

Dynamic Temporal Processing of Nonspeech Acoustic Information by Children with Specific Language Impairment.

ERIC Educational Resources Information Center

Visto, Jane C.; And Others

1996-01-01

Ten children (ages 12-16) with specific language impairments (SLI) and controls matched for chronological or language age were tested with measures of complex sound localization involving the precedence effect phenomenon. SLI children exhibited tracking skills similar to language-age matched controls, indicating impairment in their ability to use…

Advancing Bullying Research from a Social-Ecological Lens: An Introduction to the Special Issue

ERIC Educational Resources Information Center

Rose, Chad A.; Nickerson, Amanda B.; Stormont, Melissa

2015-01-01

Bullying has emerged as a distinct, pervasive subset of peer aggression that affects youth worldwide. Although bullying is a complex phenomenon, some subgroups of youth are at escalated risk based on individual characteristics, skill deficits, and peer group or societal norms. Therefore, the field needs reliable measurement systems, precise…

The Corruption Bogey in South Africa: Is Public Education Safe?

ERIC Educational Resources Information Center

Serfontein, Erika; de Waal, Elda

2015-01-01

Corruption is a constant global phenomenon, which is becoming more complex and intense as competition for resources increases. It is even more so amongst those living in developing countries, particularly emerging economies such as South Africa. Acts of corruption directly contest the basic principles of South Africa's Constitution, which aims at…

Corruption in Higher Education: Conceptual Approaches and Measurement Techniques

ERIC Educational Resources Information Center

Osipian, Ararat L.

2007-01-01

Corruption is a complex and multifaceted phenomenon. Forms of corruption are multiple. Measuring corruption is necessary not only for getting ideas about the scale and scope of the problem, but for making simple comparisons between the countries and conducting comparative analysis of corruption. While the total impact of corruption is indeed…

Navigating Individual and Collective Notions of Teacher Wellbeing as a Complex Phenomenon Shaped by National Context

ERIC Educational Resources Information Center

Liu, Laura B.; Song, Huan; Miao, Pei

2018-01-01

In an era of globalisation (Spring 2008), wellbeing no longer can be explored within one's own national borders, but necessitates cultivating shared international understandings to maintain healthy twenty-first-century classrooms. This literature review across Chinese and English international publications contends that understanding wellbeing…

Enzymes and Metabolites in Carbohydrate Metabolism of Desiccation Tolerant Plants

PubMed Central

Zhang, Qingwei; Song, Xiaomin; Bartels, Dorothea

2016-01-01

Resurrection plants can tolerate extreme water loss. Substantial sugar accumulation is a phenomenon in resurrection plants during dehydration. Sugars have been identified as one important factor contributing to desiccation tolerance. Phylogenetic diversity of resurrection plants reflects the diversity of sugar metabolism in response to dehydration. Sugars, which accumulate during dehydration, have been shown to protect macromolecules and membranes and to scavenge reactive oxygen species. This review focuses on the performance of enzymes participating in sugar metabolism during dehydration stress. The relation between sugar metabolism and other biochemical activities is discussed and open questions as well as potential experimental approaches are proposed. PMID:28248249

Structure of the exotic He 9 nucleus from the no-core shell model with continuum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vorabbi, Matteo; Calci, Angelo; Navratil, Petr

2018-03-13

Here, the exotic 9He nucleus, which presents one of the most extreme neutron-to-proton ratios, belongs to the N = 7 isotonic chain famous for the phenomenon of ground-state parity inversion with decreasing number of protons. Consequently, it would be expected to have an unnatural (positive) parity ground state similar to 11Be and 10Li. Despite many experimental and theoretical investigations, its structure remains uncertain. Apart from the fact that it is unbound, other properties including the spin and parity of its ground state, and the very existence of additional low-lying resonances are still a matter of debate

Antarctic Air Visits Paranal — Opening New Science Windows

NASA Astrophysics Data System (ADS)

Kerber, F.; Kuntschner, H.; Querel, R. R.; van den Ancker, M.

2014-03-01

Extremely low humidity (precipitable water vapour [PWV] of ~ 0.1 mm) in the atmosphere above Paranal has been measured by a water vapour radiometer over a period of about 12 hours. PWV values < 0.2 mm are usually only found at very high altitude or in Antarctica. In fact a pocket of Antarctic air has been shown to be responsible for this phenomenon and it may occur a few times per year at Paranal. We highlight the science opportunities — created by new atmospheric windows — that arise in such conditions. The community is invited to provide feedback on how to make best use of low PWV with the VLT.

STS-41G earth observations

NASA Image and Video Library

1984-10-12

41G-34-098 (5-13 Oct 1984) --- Strait of Gibraltar and western Mediterranean photographed sunglint. Sun reflection on water delineates surface texture, which corresponds to the ocean's dynamics. The large group of waves connecting Gibraltar with the Moroccan coast is the response of the ocean to a tidal pulse moving into the Mediterranean. The low level wing shear line extending out from the Moroccan coastline into the Mediterranean for approximately 40 miles is the southern extremity of the wind funneling through the strait. This is the first high resolution photograph ever taken of this phenomenon permitting detailed delineation of individual waves which comprise the wave packet.

[Urbanization in tropical countries].

PubMed

Amat-Roze, J M

1983-01-01

Rural populations are still the most numerous in tropical countries. But we can witness an unprecedent process of urbanization. However the dynamics of the phenomenon differs greatly in different countries and in different towns. As a matter of fact, the greatest overcrowded metropolis attract the greatest part of the migrants from rural areas; the attractive factors are multifarious and universal. This not easily controllable trend seems to be irreversible. The migrant farmers will generally find a job within the informed economic sector. The zones of spontaneous and precarious settlement are often their first environmental living conditions. Some of these unhealthy dwelling areas are subject to development plans; some of them being extremely well designed.

Effect of solution concentration on the structured order and optical properties of short-chain polyene biomolecules

NASA Astrophysics Data System (ADS)

Ouyang, Shunli; Sun, Chenglin; Zhou, Mi; Li, Dongfei; Wang, Weiwei; Qu, Guannan; Li, Zuowei; Gao, Shuqin; Yang, Jiange

2010-09-01

We have measured the Raman spectra and UV-Vis absorption spectra of linear polyene biomolecules (β-carotene and lycopene) in CS2 at low concentrations (10-6-10-10 mol/L). With decreasing concentration, all the carbon-carbon vibrations form a coherent mode in ordered β-carotene and lycopene due to extended π-conjugation that gives strong electron-phonon coupling, which leads to an anomalous experimental phenomenon. We observed an extremely high Raman scattering cross section( RSCS) and the Raman activities in β-carotene and lycopene are characterized by intensive overtones and combinations. Further, the UV-Vis absorption bands become narrower.

Electric foot shock stress adaptation: Does it exist or not?

PubMed

Bali, Anjana; Jaggi, Amteshwar Singh

2015-06-01

Stress adaptation is a protective phenomenon against repeated stress exposure and is characterized by a decreased responsiveness to a repeated stress stimulus. The adaptation is associated with a complex cascade of events, including the changes in behavior, neurotransmitter and gene expression levels. The non-adaptation or maladaptation to stress may underlie the affective disorders, such as anxiety, depression and post-traumatic stress disorder (PTSD). Electric foot shock is a complex stressor, which includes both physical and emotional components. Unlike immobilization, restraint and cold immersion stress, the phenomenon of stress adaptation is not very well defined in response to electric foot shock. A number of preclinical studies have reported the development of adaptation to electric foot shock stress. However, evidence also reveals the non-adaptive behavior in response to foot shocks. The distinct adaptive/non-adaptive responses may be possibly influenced by the type, intensity, and duration of the stress. The present review discusses the existence or non-existence of adaptation to electric foot shock stress along with possible mechanism. Copyright © 2015 Elsevier Inc. All rights reserved.

Optical vortex knots – one photon at a time

PubMed Central

Tempone-Wiltshire, Sebastien J.; Johnstone, Shaun P.; Helmerson, Kristian

2016-01-01

Feynman described the double slit experiment as “a phenomenon which is impossible, absolutely impossible, to explain in any classical way and which has in it the heart of quantum mechanics”. The double-slit experiment, performed one photon at a time, dramatically demonstrates the particle-wave duality of quantum objects by generating a fringe pattern corresponding to the interference of light (a wave phenomenon) from two slits, even when there is only one photon (a particle) at a time passing through the apparatus. The particle-wave duality of light should also apply to complex three dimensional optical fields formed by multi-path interference, however, this has not been demonstrated. Here we observe particle-wave duality of a three dimensional field by generating a trefoil optical vortex knot – one photon at a time. This result demonstrates a fundamental physical principle, that particle-wave duality implies interference in both space (between spatially distinct modes) and time (through the complex evolution of the superposition of modes), and has implications for topologically entangled single photon states, orbital angular momentum multiplexing and topological quantum computing. PMID:27087642

Fenomen (re)konstrukcji zespołów architektonicznych

NASA Astrophysics Data System (ADS)

Paczos, Joanna

2009-01-01

Complexes of architectural (re)contructions created not in situ, have existed in European culture since the ancient until present times. According to the time and place of their creation they used diferrent types of spatial compositions such as a villa suburbana (e.g. Villa Adriana in Tivoli near Rome), castle (e.g. Vajdahunyad Castle in Budapest), village (e.g. Poble Espanyol in Barcelona), town square (e.g. Nádvorie Európy in Komárno) etc. Firstly, they acted only as a cultural reminiscence, later they began to be also a kind of the scenographic setting of international and national exhibitions, and finally a specific kind of tourist attraction or architectural adaptation of urban space. The complex of architectural (re)constructions is characteristic of both eclectic culture and cultural eclecticism, it is an architectural pastiche of a structure of a cultural rebus, it is also an image of a permanently intensifying cultural phenomenon reflecting a process of condensation mixed simultaneously with fragmentation of the traditional culture, a phenomenon which is unfortunately current in a contemporary cultural tourism, too.

Comparative outcome of bomb explosion injuries versus high-powered gunshot injuries of the upper extremity in a civilian setting.

PubMed

Luria, Shai; Rivkin, Gurion; Avitzour, Malka; Liebergall, Meir; Mintz, Yoav; Mosheiff, Ram

2013-03-01

Explosion injuries to the upper extremity have specific clinical characteristics that differ from injuries due to other mechanisms. To evaluate the upper extremity injury pattern of attacks on civilian targets, comparing bomb explosion injuries to gunshot injuries and their functional recovery using standard outcome measures. Of 157 patients admitted to the hospital between 2000 and 2004, 72 (46%) sustained explosion injuries and 85 (54%) gunshot injuries. The trauma registry files were reviewed and the patients completed the DASH Questionnaire (Disabilities of Arm, Shoulder and Hand) and SF-12 (Short Form-12) after a minimum period of 1 year. Of the 157 patients, 72 (46%) had blast injuries and 85 (54%) had shooting injuries. The blast casualties had higher Injury Severity Scores (47% vs. 22% with a score of > 16, P = 0.02) and higher percent of patients treated in intensive care units (47% vs. 28%, P = 0.02). Although the Abbreviated Injury Scale score of the upper extremity injury was similar in the two groups, the blast casualties were found to have more bilateral and complex soft tissue injuries and were treated surgically more often. No difference was found in the SF-12 or DASH scores between the groups at follow up. The casualties with upper extremity blast injuries were more severely injured and sustained more bilateral and complex soft tissue injuries to the upper extremity. However, the rating of the local injury to the isolated limb is similar, as was the subjective functional recovery.

Complexity-aware simple modeling.

PubMed

Gómez-Schiavon, Mariana; El-Samad, Hana

2018-02-26

Mathematical models continue to be essential for deepening our understanding of biology. On one extreme, simple or small-scale models help delineate general biological principles. However, the parsimony of detail in these models as well as their assumption of modularity and insulation make them inaccurate for describing quantitative features. On the other extreme, large-scale and detailed models can quantitatively recapitulate a phenotype of interest, but have to rely on many unknown parameters, making them often difficult to parse mechanistically and to use for extracting general principles. We discuss some examples of a new approach-complexity-aware simple modeling-that can bridge the gap between the small-scale and large-scale approaches. Copyright © 2018 Elsevier Ltd. All rights reserved.

Progress on high-performance rapid prototype aluminum mirrors

NASA Astrophysics Data System (ADS)

Woodard, Kenneth S.; Myrick, Bruce H.

2017-05-01

Near net shape parts can be produced using some very old processes (investment casting) and the relatively new direct metal laser sintering (DMLS) process. These processes have significant advantages for complex blank lightweighting and costs but are not inherently suited for producing high performance mirrors. The DMLS process can provide extremely complex lightweight structures but the high residual stresses left in the material results in unstable mirror figure retention. Although not to the extreme intricacy of DMLS, investment casting can also provide complex lightweight structures at considerably lower costs than DMLS and even conventional wrought mirror blanks but the less than 100% density for casting (and also DMLS) limits finishing quality. This paper will cover the progress that has been made to make both the DMLS and investment casting processes into viable near net shape blank options for high performance aluminum mirrors. Finish and figure results will be presented to show performance commensurate with existing conventional processes.

Difficult Decisions Made Easier

NASA Technical Reports Server (NTRS)

2006-01-01

NASA missions are extremely complex and prone to sudden, catastrophic failure if equipment falters or if an unforeseen event occurs. For these reasons, NASA trains to expect the unexpected. It tests its equipment and systems in extreme conditions, and it develops risk-analysis tests to foresee any possible problems. The Space Agency recently worked with an industry partner to develop reliability analysis software capable of modeling complex, highly dynamic systems, taking into account variations in input parameters and the evolution of the system over the course of a mission. The goal of this research was multifold. It included performance and risk analyses of complex, multiphase missions, like the insertion of the Mars Reconnaissance Orbiter; reliability analyses of systems with redundant and/or repairable components; optimization analyses of system configurations with respect to cost and reliability; and sensitivity analyses to identify optimal areas for uncertainty reduction or performance enhancement.

Characterization of wave phenomena in the relaxation of flash-induced chlorophyll fluorescence yield in cyanobacteria.

PubMed

Deák, Zsuzsanna; Sass, László; Kiss, Eva; Vass, Imre

2014-09-01

Fluorescence yield relaxation following a light pulse was studied in various cyanobacteria under aerobic and microaerobic conditions. In Synechocystis PCC 6803 fluorescence yield decays in a monotonous fashion under aerobic conditions. However, under microaerobic conditions the decay exhibits a wave feature showing a dip at 30-50 ms after the flash followed by a transient rise, reaching maximum at ~1s, before decaying back to the initial level. The wave phenomenon can also be observed under aerobic conditions in cells preilluminated with continuous light. Illumination preconditions cells for the wave phenomenon transiently: for few seconds in Synechocystis PCC 6803, but up to one hour in Thermosynechocystis elongatus BP-1. The wave is eliminated by inhibition of plastoquinone binding either to the QB site of Photosystem-II or the Qo site of cytochrome b6f complex by 3-(3',4'-dichlorophenyl)-1,1-dimethylurea or 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone, respectively. The wave is also absent in mutants, which lack either Photosystem-I or the NAD(P)H-quinone oxidoreductase (NDH-1) complex. Monitoring the redox state of the plastoquinone pool revealed that the dip of the fluorescence wave corresponds to transient oxidation, whereas the following rise to re-reduction of the plastoquinone pool. It is concluded that the unusual wave feature of fluorescence yield relaxation reflects transient oxidation of highly reduced plastoquinone pool by Photosystem-I followed by its re-reduction from stromal components via the NDH-1 complex, which is transmitted back to the fluorescence yield modulator primary quinone electron acceptor via charge equilibria. Potential applications of the wave phenomenon in studying photosynthetic and respiratory electron transport are discussed. This article is part of a special issue entitled: photosynthesis research for sustainability: keys to produce clean energy. Copyright © 2014 Elsevier B.V. All rights reserved.

Guidelines to Support Professional Copyright Practice

ERIC Educational Resources Information Center

Dryden, Jean

2012-01-01

Copyright is extremely complex, and it is difficult to convey its complexities in a clear and concise form. Through decades of experience, archivists developed informal best practices for dealing with copyright in the analog world; however the application of copyright in the digital environment is evolving in response to rapidly changing…

Modeling of thermomechanical changes of extreme-ultraviolet mask and their dependence on absorber variation

NASA Astrophysics Data System (ADS)

Ban, Chung-Hyun; Park, Eun-Sang; Park, Jae-Hun; Oh, Hye-Keun

2018-06-01

Thermal and structural deformation of extreme-ultraviolet lithography (EUVL) masks during the exposure process may become important issues as these masks are subject to rigorous image placement and flatness requirements. The reflective masks used for EUVL absorb energy during exposure, and the temperature of the masks rises as a result. This can cause thermomechanical deformation that can reduce the pattern quality. The use of very thick low-thermal-expansion substrate materials (LTEMs) may reduce energy absorption, but they do not completely eliminate mask deformation. Therefore, it is necessary to predict and optimize the effects of energy transferred from the extreme-ultraviolet (EUV) light source and the resultant patterns of structured EUV masks with complex multilayers. Our study shows that heat accumulates in the masks as exposure progresses. It has been found that a higher absorber ratio (pattern density) applied to the patterning of EUV masks exacerbates the problem, especially in masks with more complex patterns.

A Large-Scale Multi-Hop Localization Algorithm Based on Regularized Extreme Learning for Wireless Networks.

PubMed

Zheng, Wei; Yan, Xiaoyong; Zhao, Wei; Qian, Chengshan

2017-12-20

A novel large-scale multi-hop localization algorithm based on regularized extreme learning is proposed in this paper. The large-scale multi-hop localization problem is formulated as a learning problem. Unlike other similar localization algorithms, the proposed algorithm overcomes the shortcoming of the traditional algorithms which are only applicable to an isotropic network, therefore has a strong adaptability to the complex deployment environment. The proposed algorithm is composed of three stages: data acquisition, modeling and location estimation. In data acquisition stage, the training information between nodes of the given network is collected. In modeling stage, the model among the hop-counts and the physical distances between nodes is constructed using regularized extreme learning. In location estimation stage, each node finds its specific location in a distributed manner. Theoretical analysis and several experiments show that the proposed algorithm can adapt to the different topological environments with low computational cost. Furthermore, high accuracy can be achieved by this method without setting complex parameters.

Phenomenon of statistical instability of the third type systems—complexity

NASA Astrophysics Data System (ADS)

Eskov, V. V.; Gavrilenko, T. V.; Eskov, V. M.; Vokhmina, Yu. V.

2017-11-01

The problem of the existence and special properties of third type systems has been formulated within the new chaos-self-organization theory. In fact, a global problem of the possibility of the existence of steady-state regimes for homeostatic systems has been considered. These systems include not only medical and biological systems, but also the dynamics of meteorological parameters, as well as the ambient parameters of the environment in which humans are located. The new approach has been used to give a new definition for homeostatic systems (complexity).

Combination of complex momentum representation and Green's function methods in relativistic mean-field theory

NASA Astrophysics Data System (ADS)

Shi, Min; Niu, Zhong-Ming; Liang, Haozhao

2018-06-01

We have combined the complex momentum representation method with the Green's function method in the relativistic mean-field framework to establish the RMF-CMR-GF approach. This new approach is applied to study the halo structure of 74Ca. All the continuum level density of concerned resonant states are calculated accurately without introducing any unphysical parameters, and they are independent of the choice of integral contour. The important single-particle wave functions and densities for the halo phenomenon in 74Ca are discussed in detail.

ICPP: Approach for Understanding Complexity of Plasma

NASA Astrophysics Data System (ADS)

Sato, Tetsuya

2000-10-01

In this talk I wish to present an IT system that could promote Science of Complexity. In order to deal with a seemingly `complex' phenomenon, which means `beyond analytical manipulation', computer simulation is a viable powerful tool. However, complexity implies a concept beyond the horizon of reductionism. Therefore, rather than simply solving a complex phenomenon for a given boundary condition, one must establish an intelligent way of attacking mutual evolution of a system and its environment. NIFS-TCSC has been developing a prototype system that consists of supercomputers, virtual reality devices and high-speed network system. Let us explain this by picking up a global atmospheric circulation group, global oceanic circulation group and local weather prediction group. Local weather prediction group predicts the local change of the weather such as the creation of cloud and rain in the near future under the global conditions obtained by the global atmospheric and ocean groups. The global groups run simulations by modifying the local heat source/sink evaluated by the local weather prediction and then obtain the global conditions in the next time step. By repeating such a feedback performance one can predict the mutual evolution of the local system and its environment. Mutual information exchanges among multiple groups are carried out instantaneously by the networked common virtual reality space in which 3-D global and local images of the atmospheric and oceanic circulation and the cloud and rain maps are arbitrarily manipulated by any of the groups and commonly viewed. The present networking system has a great advantage that any simulation groups can freely and arbitrarily change their alignment, so that mutual evolution of any stratum system can become tractable by utilizing this network system.

Extreme ultraviolet and X-ray spectroheliograph for OSO-H

NASA Technical Reports Server (NTRS)

Sterk, A. A.; Kieser, F.; Peck, S.; Knox, E.

1972-01-01

A complex scientific instrument was designed, fabricated, tested, and calibrated for launch onboard OSO-H. This instrument consisted of four spectroheliographs and an X-ray polarimeter. The instrument is designed to study solar radiation at selected wavelengths in the X-ray and the extreme ultraviolet ranges, make observations at the H-alpha wavelength, and measure the degree of polarization of X-ray emissions.

Upper Extremity Injuries in Tennis Players: Diagnosis, Treatment, and Management

PubMed Central

Chung, Kevin C.; Lark, Meghan E.

2016-01-01

Synopsis Upper extremity tennis injuries are most commonly characterized as overuse injuries to the wrist, elbow and shoulder. The complex anatomy of these structures and their interaction with biomechanical properties of tennis strokes contributes to the diagnostic challenges. A thorough understanding of tennis kinetics, in combination with the current literature surrounding diagnostic and treatment methods, will improve clinical decision-making. PMID:27886833

Acidic Ribosomal Proteins from the Extreme ’Halobacterium cutirubrum’,

DTIC Science & Technology

the extreme halophilic bacterium, Halobacterium cutirubrum. The identification of the protein moieties involved in these and other interactions in...the halophile ribosome requires a rapid and reproducible screening method for the separation, enumeration and identification of these acidic...polypeptides in the complex ribosomal protein mixtures. In this paper the authors present the results of analyses of the halophile ribosomal proteins using a

Life in extreme environments: how will humans perform on Mars?

NASA Technical Reports Server (NTRS)

Newman, D. J.

2000-01-01

This review of astronaut extravehicular activity (EVA) and the details of American and Soviet/Russian spacesuit design focuses on design recommendations to enhance astronaut safety and effectiveness. Innovative spacesuit design is essential, given the challenges of future exploration-class missions in which astronauts will be called upon to perform increasingly complex and physically demanding tasks in the extreme environments of microgravity and partial gravity.

Settlement-Size Scaling among Prehistoric Hunter-Gatherer Settlement Systems in the New World

PubMed Central

Haas, W. Randall; Klink, Cynthia J.; Maggard, Greg J.; Aldenderfer, Mark S.

2015-01-01

Settlement size predicts extreme variation in the rates and magnitudes of many social and ecological processes in human societies. Yet, the factors that drive human settlement-size variation remain poorly understood. Size variation among economically integrated settlements tends to be heavy tailed such that the smallest settlements are extremely common and the largest settlements extremely large and rare. The upper tail of this size distribution is often formalized mathematically as a power-law function. Explanations for this scaling structure in human settlement systems tend to emphasize complex socioeconomic processes including agriculture, manufacturing, and warfare—behaviors that tend to differentially nucleate and disperse populations hierarchically among settlements. But, the degree to which heavy-tailed settlement-size variation requires such complex behaviors remains unclear. By examining the settlement patterns of eight prehistoric New World hunter-gatherer settlement systems spanning three distinct environmental contexts, this analysis explores the degree to which heavy-tailed settlement-size scaling depends on the aforementioned socioeconomic complexities. Surprisingly, the analysis finds that power-law models offer plausible and parsimonious statistical descriptions of prehistoric hunter-gatherer settlement-size variation. This finding reveals that incipient forms of hierarchical settlement structure may have preceded socioeconomic complexity in human societies and points to a need for additional research to explicate how mobile foragers came to exhibit settlement patterns that are more commonly associated with hierarchical organization. We propose that hunter-gatherer mobility with preferential attachment to previously occupied locations may account for the observed structure in site-size variation. PMID:26536241

The Influence of Coral Reef Benthic Condition on Associated Fish Assemblages

PubMed Central

Chong-Seng, Karen M.; Mannering, Thomas D.; Pratchett, Morgan S.; Bellwood, David R.; Graham, Nicholas A. J.

2012-01-01

Accumulative disturbances can erode a coral reef’s resilience, often leading to replacement of scleractinian corals by macroalgae or other non-coral organisms. These degraded reef systems have been mostly described based on changes in the composition of the reef benthos, and there is little understanding of how such changes are influenced by, and in turn influence, other components of the reef ecosystem. This study investigated the spatial variation in benthic communities on fringing reefs around the inner Seychelles islands. Specifically, relationships between benthic composition and the underlying substrata, as well as the associated fish assemblages were assessed. High variability in benthic composition was found among reefs, with a gradient from high coral cover (up to 58%) and high structural complexity to high macroalgae cover (up to 95%) and low structural complexity at the extremes. This gradient was associated with declining species richness of fishes, reduced diversity of fish functional groups, and lower abundance of corallivorous fishes. There were no reciprocal increases in herbivorous fish abundances, and relationships with other fish functional groups and total fish abundance were weak. Reefs grouping at the extremes of complex coral habitats or low-complexity macroalgal habitats displayed markedly different fish communities, with only two species of benthic invertebrate feeding fishes in greater abundance in the macroalgal habitat. These results have negative implications for the continuation of many coral reef ecosystem processes and services if more reefs shift to extreme degraded conditions dominated by macroalgae. PMID:22870294

The influence of coral reef benthic condition on associated fish assemblages.

PubMed

Chong-Seng, Karen M; Mannering, Thomas D; Pratchett, Morgan S; Bellwood, David R; Graham, Nicholas A J

2012-01-01

Accumulative disturbances can erode a coral reef's resilience, often leading to replacement of scleractinian corals by macroalgae or other non-coral organisms. These degraded reef systems have been mostly described based on changes in the composition of the reef benthos, and there is little understanding of how such changes are influenced by, and in turn influence, other components of the reef ecosystem. This study investigated the spatial variation in benthic communities on fringing reefs around the inner Seychelles islands. Specifically, relationships between benthic composition and the underlying substrata, as well as the associated fish assemblages were assessed. High variability in benthic composition was found among reefs, with a gradient from high coral cover (up to 58%) and high structural complexity to high macroalgae cover (up to 95%) and low structural complexity at the extremes. This gradient was associated with declining species richness of fishes, reduced diversity of fish functional groups, and lower abundance of corallivorous fishes. There were no reciprocal increases in herbivorous fish abundances, and relationships with other fish functional groups and total fish abundance were weak. Reefs grouping at the extremes of complex coral habitats or low-complexity macroalgal habitats displayed markedly different fish communities, with only two species of benthic invertebrate feeding fishes in greater abundance in the macroalgal habitat. These results have negative implications for the continuation of many coral reef ecosystem processes and services if more reefs shift to extreme degraded conditions dominated by macroalgae.

[Sociophysiology: basic processes of empathy].

PubMed

Haker, Helene; Schimansky, Jenny; Rössler, Wulf

2010-01-01

The aim of this review is to describe sociophysiological and social cognitive processes that underlie the complex phenomenon of human empathy. Automatic reflexive processes such as physiological contagion and action mirroring are mediated by the mirror neuron system. They are a basis for further processing of social signals and a physiological link between two individuals. This link comprises simultaneous activation of shared motor representations. Shared representations lead implicitly via individual associations in the limbic and vegetative system to a shared affective state. These processes are called sociophysiology. Further controlled- reflective, self-referential processing of those social signals leads to explicit, conscious representations of others' minds. Those higher-order processes are called social cognition. The interaction of physiological and cognitive social processes lets arise the phenomenon of human empathy.

The influence of obesity, constitution and physical work on the phenomenon of urinary incontinence in women.

PubMed

Sustersic, O; Kralj, B

1998-01-01

Urinary incontinence in women is a common and complex problem which can be defined and classified as stress, urge and mixed incontinence. Three of the eight most common risk factors are obesity, constitution and physical work, in addition to age, length of menstrual cycle, number of pregnancies, education and level of health awareness. Women with the diagnosis of urinary incontinence were invited to respond to questionnaires on a voluntary basis. The three factors found to be associated with urinary incontinence are increased body weight, strong osteomuscular structure and hard physical work. These indicate that the work of a health team must take a holistic approach to women even before the phenomenon of urinary incontinence occurs.

Is extreme climate or moderate climate more conducive to longevity in China?

NASA Astrophysics Data System (ADS)

Huang, Yi; Rosenberg, Mark; Wang, Yingli

2018-02-01

Climate is closely related to human longevity. In China, there are many climate types. According to national population censuses from 1982 to 2000, most provinces with a high ratio of centenarians are located in western and northwestern China far from the sea; these areas are characterized by a dry, cold climate, very high altitude, very high daily temperature range, strong winds, and partial hypoxia. Meanwhile, provinces with a high ratio of nonagenarians from 1982 to 2000 are located in southern China near the sea. Previous studies have attributed the high ratio of centenarians in western and northwestern China to the extreme local climate. However, centenarians in these areas decreased greatly in 2010, whereas residents in southern China frequently reached 90 to 100 years old in 2010. This study aims to explain this strange phenomenon and find whether extreme climate in Tibetan plateau and northwestern China or moderate climate in southern China is more conducive to longevity. The study found that mortality rate in Tibetan plateau is much higher than southern China, then a population evolution experiment was proposed to compare longevity indicators between low mortality rate and high mortality rate and shows that longevity indicators will decrease in the near future and increase above their original levels after several decades when the mortality rate is decreased. Results of this study show individuals in northwestern China do not live as long as those in eastern and southern China. A moderate climate is more conducive to longevity than extreme climate in China. The longevity of a region should be judged by long-term longevity indicators.

Is extreme climate or moderate climate more conducive to longevity in China?

PubMed

Huang, Yi; Rosenberg, Mark; Wang, Yingli

2018-06-01

Climate is closely related to human longevity. In China, there are many climate types. According to national population censuses from 1982 to 2000, most provinces with a high ratio of centenarians are located in western and northwestern China far from the sea; these areas are characterized by a dry, cold climate, very high altitude, very high daily temperature range, strong winds, and partial hypoxia. Meanwhile, provinces with a high ratio of nonagenarians from 1982 to 2000 are located in southern China near the sea. Previous studies have attributed the high ratio of centenarians in western and northwestern China to the extreme local climate. However, centenarians in these areas decreased greatly in 2010, whereas residents in southern China frequently reached 90 to 100 years old in 2010. This study aims to explain this strange phenomenon and find whether extreme climate in Tibetan plateau and northwestern China or moderate climate in southern China is more conducive to longevity. The study found that mortality rate in Tibetan plateau is much higher than southern China, then a population evolution experiment was proposed to compare longevity indicators between low mortality rate and high mortality rate and shows that longevity indicators will decrease in the near future and increase above their original levels after several decades when the mortality rate is decreased. Results of this study show individuals in northwestern China do not live as long as those in eastern and southern China. A moderate climate is more conducive to longevity than extreme climate in China. The longevity of a region should be judged by long-term longevity indicators.

Water storage equity and safety assurance policy to mitigate potential 'dual-extreme cumulative threats' in agricultural catchments

NASA Astrophysics Data System (ADS)

Pisaniello, John D.; Tingey-Holyoak, Joanne L.

2017-02-01

Farm dams that are not managed properly at the individual level can create water storage equity and safety threats to downstream communities and the environment that aggregate at the catchment level: a potential 'dual-extreme cumulative' problem. The paper provides indicative evidence and develops understanding of this novel phenomenon and associated policy needs within the Australian setting comprising dual hydrologic extremes of floods and droughts, further exacerbated by climate change. This is achieved through comparative case studies involving surveys of both dam owner perceptions and dam management practices in four States representing a complete range of integrated policy approaches from weak to strong. Survey results find most farmers do not believe dam maintenance is important, will undertake spillway blocking and do not plan for emergencies. These results are supported by physical on-site findings of farmers neglecting dams and blocking or under-designing spillways, in turn storing more water than they are entitled and creating unsafe dams at both the individual and cumulative levels. From detailed cross-case comparative assessment against policy context, it emerges that on-farm perceptions and practices form a range of 'acceptability' of dam management that directly reflects policy strength and integration in each setting. The paper advances the international small dams policy, agricultural water management and hydrology literatures, evidencing the need for effective integrated policy to mitigate dual extreme cumulative threats. Importantly, guidance is provided to jurisdictions internationally with high inter-annual rainfall variation on how best to design integrated policy that can achieve both water storage equity and safety in agricultural catchments.

Synchrony, Weather, and Cycles in Southern Pine Beetle (Coleoptera: Curculionidae).

PubMed

Reeve, John D

2018-02-08

Spatial synchrony and cycles are common features of forest insect pests, but are often studied as separate phenomenon. Using time series of timber damage caused by Dendroctonus frontalis Zimmermann (Coleoptera: Curculionidae) (southern pine beetle) in 10 states within the southern United States, this study examines synchrony in D. frontalis abundance, the synchronizing effects of temperature extremes, and the evidence for shared cycles among state populations. Cross-correlation and cluster analyses are used to quantify synchrony across a range of geographic distances and to identify groups of states with synchronous dynamics. Similar techniques are used to quantify spatial synchrony in temperature extremes and to examine their relationship to D. frontalis fluctuations. Cross-wavelet analysis is then used to examine pairs of time series for shared cycles. These analyses suggest there is substantial synchrony among states in D. frontalis fluctuations, and there are regional groups of states with similar dynamics. Synchrony in D. frontalis fluctuations also appears related to spatial synchrony in summer and winter temperature extremes. The cross-wavelet results suggest that D. frontalis dynamics may differ among regions and are not stationary. Significant oscillations were present in some states over certain time intervals, suggesting an endogenous feedback mechanism. Management of D. frontalis outbreaks could potentially benefit from a multistate regional approach because populations are synchronous on this level. Extreme summer temperatures are likely to become the most important synchronizing agent due to climate change. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Is extreme climate or moderate climate more conducive to longevity in China?

NASA Astrophysics Data System (ADS)

Huang, Yi; Rosenberg, Mark; Wang, Yingli

2018-06-01

Climate is closely related to human longevity. In China, there are many climate types. According to national population censuses from 1982 to 2000, most provinces with a high ratio of centenarians are located in western and northwestern China far from the sea; these areas are characterized by a dry, cold climate, very high altitude, very high daily temperature range, strong winds, and partial hypoxia. Meanwhile, provinces with a high ratio of nonagenarians from 1982 to 2000 are located in southern China near the sea. Previous studies have attributed the high ratio of centenarians in western and northwestern China to the extreme local climate. However, centenarians in these areas decreased greatly in 2010, whereas residents in southern China frequently reached 90 to 100 years old in 2010. This study aims to explain this strange phenomenon and find whether extreme climate in Tibetan plateau and northwestern China or moderate climate in southern China is more conducive to longevity. The study found that mortality rate in Tibetan plateau is much higher than southern China, then a population evolution experiment was proposed to compare longevity indicators between low mortality rate and high mortality rate and shows that longevity indicators will decrease in the near future and increase above their original levels after several decades when the mortality rate is decreased. Results of this study show individuals in northwestern China do not live as long as those in eastern and southern China. A moderate climate is more conducive to longevity than extreme climate in China. The longevity of a region should be judged by long-term longevity indicators.

[Extreme (complicated, ultra-high) refractive errors: terminological misconceptions!?

PubMed

Avetisov, S E

2018-01-01

The article reviews development mechanisms of different refractive errors accompanied by marked defocus of light rays reaching the retina. Terminology used for such ametropias includes terms extreme, ultra-high and complicated. Justification of their usage for primary ametropias, whose symptom complex is based on changes in axial eye length, is an ongoing discussion. To comply with thesaurus definitions of 'diagnosis' and 'pathogenesis', to characterize refractive and anatomical-functional disorders in patients with primary ametropias it is proposed to use the terms 'hyperaxial and hypoaxial syndromes' with elaboration of specific symptoms instead of such expressions as extreme (ultra-high) myopia and hypermetropia.

Tying Variability in Summertime North American Extreme Weather Regimes to the Boreal Summer Intraseasonal Oscillation

NASA Astrophysics Data System (ADS)

Jenney, A. M.; Randall, D. A.

2017-12-01

Tropical intraseasonal oscillations are known to be a source of extratropical variability. We show that subseasonal variability in observed North American epidemiologically significant regional extreme weather regimes is teleconnected to the boreal summer intraseasonal oscillation (BSISO)—a complex tropical weather system that is active during the northern summer and has a 30-50 day timescale. The dynamics of the teleconnection are examined. We also find that interannual variability of the tropical mean-state can modulate the teleconnection. Our results suggest that the BSISO may enable subseasonal to seasonal predictions of North American summertime weather extremes.

The Impact of Different Environmental Conditions on Cognitive Function: A Focused Review

PubMed Central

Taylor, Lee; Watkins, Samuel L.; Marshall, Hannah; Dascombe, Ben J.; Foster, Josh

2016-01-01

Cognitive function defines performance in objective tasks that require conscious mental effort. Extreme environments, namely heat, hypoxia, and cold can all alter human cognitive function due to a variety of psychological and/or biological processes. The aims of this Focused Review were to discuss; (1) the current state of knowledge on the effects of heat, hypoxic and cold stress on cognitive function, (2) the potential mechanisms underpinning these alterations, and (3) plausible interventions that may maintain cognitive function upon exposure to each of these environmental stressors. The available evidence suggests that the effects of heat, hypoxia, and cold stress on cognitive function are both task and severity dependent. Complex tasks are particularly vulnerable to extreme heat stress, whereas both simple and complex task performance appear to be vulnerable at even at moderate altitudes. Cold stress also appears to negatively impact both simple and complex task performance, however, the research in this area is sparse in comparison to heat and hypoxia. In summary, this focused review provides updated knowledge regarding the effects of extreme environmental stressors on cognitive function and their biological underpinnings. Tyrosine supplementation may help individuals maintain cognitive function in very hot, hypoxic, and/or cold conditions. However, more research is needed to clarify these and other postulated interventions. PMID:26779029

Sympathetic blocks for the treatment of complex regional pain syndrome: A case series.

PubMed

Gungor, Semih; Aiyer, Rohit; Baykoca, Buse

2018-05-01

To present the successful treatment of complex regional pain syndrome type -1 utilizing sympathetic blocks. Severe pain interfering with activities of daily living and temporary disability secondary to complex regional pain syndrome. Complex regional pain syndrome type-1 with involvement of lower extremity (2 patients), and upper extremity (1 patient). We report the management of 3 patients with diagnosis of complex regional pain syndrome type-1 by early institution of sympathetic blocks for diagnostic and therapeutic purposes. All 3 patients were able to tolerate physical therapy only after adequate pain relief had been achieved with institution of sympathetic blocks. All 3 patients responded very favorably to sympathetic blocks with dramatic reversal of pathology. All patients reported almost complete resolution of pain, symptoms, and signs within 6 months duration after diagnosis of complex regional pain syndrome. All 3 patients were able to wean their pain medications and achieve normal activities of daily living without any significant limitations. All patients were able to return to full-time employment. Treatment options are limited and there is lack of high quality research regarding the efficacy of sympathetic blocks in the treatment of complex regional pain syndrome. As presented in this case series, sympathetic blocks maybe very effective in the treatment of complex regional pain syndrome in a subset of patients. Thus, early institution of sympathetic blocks should be considered in complex regional pain syndrome prior to physical therapy and consideration of more invasive pain management interventions.

Feed-back between geriatric syndromes: general system theory in geriatrics.

PubMed

Musso, Carlos G; Núñez, Juan F Macías

2006-01-01

Geriatrics has described three entities: confusional syndrome, incontinente and gait disorders, calling them geriatric giants. Aging process also induces changes in renal physiology such as glomerular filtration rate reduction, and alteration in water and electrolytes handling. These ageing renal changes have been named as nephrogeriatric giants. These two groups of giants, geriatric and nephrogeriatric, can predispose and potentiate each other leading old people to fatal outcomes. These phenomenon of feed-back between these geriatric syndromes has its roots in the loss of complexity that the ageing process has. Complexity means that all the body systems work harmoniously. The process of senescence weakens this coordination among systems undermining complexity and making the old person frail.

[Role of environment in complex diseases: air pollution and food contaminants].

PubMed

Scheen, A J; Giet, D

2012-01-01

Our polluted environment exposes human beings, along their life, to various toxic compounds that could trigger and aggravate different complex diseases. Such a phenomenon is well recognized for cardiovascular diseases, respiratory diseases and cancers, but other chronic inflammatory disorders may also been implicated. The most common factors, but also the most toxic, and thereby the most extensively investigated, are air pollutants (both indoor and outdoor pollution) and various contaminants present in drinking water and food (organic compounds, chemical products, heavy metals, ...). The complex interrelationships between food and pollutants, on the one hand, and between gene and environmental pollutants, including the influence of epigenetics, on the other hand, deserve further careful studies.

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

PubMed

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 algorithm should also be very useful in other applications requiring the classification of very large datasets. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Vibrational dephasing and frequency shifts of hydrogen-bonded pyridine-water complexes

NASA Astrophysics Data System (ADS)

Kalampounias, A. G.; Tsilomelekis, G.; Boghosian, S.

2015-01-01

In this paper we present the picosecond vibrational dynamics and Raman shifts of hydrogen-bonded pyridine-water complexes present in aqueous solutions in a wide concentration range from dense to extreme dilute solutions. We studied the vibrational dephasing and vibrational frequency modulation by calculating time correlation functions of vibrational relaxation by fits in the frequency domain. The concentration induced variations in bandwidths, band frequencies and characteristic dephasing times have been estimated and interpreted as effects due to solute-solvent interactions. The time-correlation functions of vibrational dephasing were obtained for the ring breathing mode of both "free" and hydrogen-bonded pyridine molecules and it was found that sufficiently deviate from the Kubo model. There is a general agreement in the whole concentration range with the modeling proposed by the Rothschild approach, which applies to complex liquids. The results have shown that the reorientation of pyridine aqueous solutions is very slow and hence in both scattering geometries only vibrational dephasing is probed. It is proposed that the spectral changes depend on the perturbations induced by the dynamics of the water molecules in the first hydration cell and water in bulk, while at extreme dilution conditions, the number of bulk water molecules increases and the interchange between molecules belonging to the first hydration cell may not be the predominant modulation mechanism. The evolution of several parameters, such as the characteristic times, the percentage of Gaussian character in the peak shape and the a parameter are indicative of drastic variations at extreme dilution revealing changes in the vibrational relaxation of the pyridine complexes in the aqueous environment. The higher dilution is correlated to diffusion of water molecules into the reference pyridine system in agreement with the jump diffusion model, while at extreme dilutions, almost all pyridine molecules are elaborated in hydrogen bonding. The results are discussed in the framework of the current phenomenological status of the field.

Outcomes and Disability After Massive Proximal Upper Extremity Reconstruction in a Resource-Limited Setting.

PubMed

Giladi, Aviram M; Shanmugakrishnan, R Raja; Venkatramani, Hari; Raja Sekaran, S; Chung, Kevin C; Sabapathy, S Raja

2017-06-01

At Ganga Hospital in Coimbatore, India, a unique approach is applied to treat massive upper limb injuries. However, long-term outcomes of complex reconstruction performed in the resource-limited setting are not known. This hinders understanding of outcomes and disability from these injuries and prevents systematically addressing care delivery around upper extremity trauma in the developing world. This project aims to analyze the details of the unique Ganga Hospital reconstruction experience and use patient-reported outcome measures for the first time in this patient population to evaluate post-injury recovery and disability . Forty-six patients were evaluated 6 months or more after massive proximal upper extremity reconstruction at Ganga Hospital. Patients completed functional tests, Jebsen-Taylor test (JTT), and patient-reported outcomes (PROs)-Michigan Hand Questionnaire (MHQ), Disability of Arm, Shoulder, and Hand questionnaire (DASH), and Short-Form 36 (SF-36). Correlations between metrics were assessed with Pearson's correlation coefficients. Linear regression modeling evaluated associations between severity, reconstruction, and outcomes. MHQ and DASH results correlated with functional test performance, JTT performance, and SF-36 scores (Pearson's coefficients all ≥0.33, p ≤ 0.05). In this cohort, mean MHQ score was 79 ± 15 and mean DASH score was 13 ± 15, which are not significantly different than scores for long-term outcomes after other complex upper extremity procedures. The following factors predicted PROs and functional performance after reconstruction: extent of soft tissue reconstruction, multi-segmental ulna fractures, median nerve injury, and ability for patients to return to work and maintain their job after injury. Complex proximal upper extremity salvage can be performed in the resource-limited setting with excellent long-term functional and patient-reported outcomes. PRO questionnaires are useful for reporting outcomes that correlate to functional and sensory testing and may be used to assess post-traumatic disability.

Extreme Weather Events and Climate Change Attribution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas, Katherine

A report from the National Academies of Sciences, Engineering, and Medicine concludes it is now possible to estimate the influence of climate change on some types of extreme events. The science of extreme event attribution has advanced rapidly in recent years, giving new insight to the ways that human-caused climate change can influence the magnitude or frequency of some extreme weather events. This report examines the current state of science of extreme weather attribution, and identifies ways to move the science forward to improve attribution capabilities. Confidence is strongest in attributing types of extreme events that are influenced by climatemore » change through a well-understood physical mechanism, such as, the more frequent heat waves that are closely connected to human-caused global temperature increases, the report finds. Confidence is lower for other types of events, such as hurricanes, whose relationship to climate change is more complex and less understood at present. For any extreme event, the results of attribution studies hinge on how questions about the event's causes are posed, and on the data, modeling approaches, and statistical tools chosen for the analysis.« less

The importance of correct specification of tribological parameters in dynamical systems modelling

NASA Astrophysics Data System (ADS)

Alaci, S.; Ciornei, F. C.; Romanu, I. C.; Ciornei, M. C.

2018-01-01

When modelling the behaviour of dynamical systems, the friction phenomenon cannot be neglected. Dry and fluid friction may occur, but dry friction has more severe effects upon the behaviour of the systems, based on the fact that the introduced discontinuities are more important. In the modelling of dynamical systems, dry friction is the main cause of occurrence of the bifurcation phenomenon. These aspects become more complex if, in the case of dry friction, static and dynamic frictions are put forward. The behaviour of a simple dynamical system is studied, consisting in a prismatic body linked to the ground by a spring, placed on a conveyor belt. The theoretical model is described by a nonlinear differential equation which after numerical integration leads to the conclusion that the steady motion of the prism is an un-damped oscillatory motion. The system was qualitatively modelled using specialised software for dynamical analysis. It was impractical to obtain a steady uniform translational motion of a rigid, therefore the conveyor belt was replaced by a metallic disc in uniform rotation motion. The attempts to compare the CAD model to the theoretical model were unsuccessful because the efforts of selecting the tribological parameters directed to the conclusion that the motion of the prism is a damped oscillation. To decide which of the methods depicts reality, a test-rig was assembled and it indicated a sustained oscillation. The conclusion is that the model employed by the dynamical analysis software cannot describe the actual model and a more complex model is required in the description of the friction phenomenon.

Guided waves propagating in sandwich structures made of anisotropic, viscoelastic, composite materials

NASA Astrophysics Data System (ADS)

Castaings, Michel; Hosten, Bernard

2003-05-01

The propagation of Lamb-like waves in sandwich plates made of anisotropic and viscoelastic material layers is studied. A semi-analytical model is described and used for predicting the dispersion curves (phase velocity, energy velocity, and complex wave-number) and the through-thickness distribution fields (displacement, stress, and energy flow). Guided modes propagating along a test-sandwich plate are shown to be quite different than classical Lamb modes, because this structure does not have the mirror symmetry, contrary to most of composite material plates. Moreover, the viscoelastic material properties imply complex roots of the dispersion equation to be found that lead to connections between some of the dispersion curves, meaning that some of the modes get coupled together. Gradual variation from zero to nominal values of the imaginary parts of the viscoelastic moduli shows that the mode coupling depends on the level of material viscoelasticity, except for one particular case where this phenomenon exists whether the medium is viscoelastic or not. The model is used to quantify the sensitivity of both the dispersion curves and the through-thickness mode shapes to the level of material viscoelasticity, and to physically explain the mode-coupling phenomenon. Finite element software is also used to confirm results obtained for the purely elastic structure. Finally, experiments are made using ultrasonic, air-coupled transducers for generating and detecting guided modes in the test-sandwich structure. The mode-coupling phenomenon is then confirmed, and the potential of the air-coupled system for developing single-sided, contactless, NDT applications of such structures is discussed.

Molecular Self-Assembly of Group 11 Pyrazolate Complexes as Phosphorescent Chemosensors for Detection of Benzene

NASA Astrophysics Data System (ADS)

Ghazalli, N. F.; Yuliati, L.; Lintang, H. O.

2018-01-01

We highlight the systematic study on vapochromic sensing of aromatic vapors such as benzene using phosphorescent trinuclear pyrazolate complexes (2) with supramolecular assembly of a weak intermolecular metal-metal interaction consisting of 4-(3,5-dimethoxybenzyl)-3,5-dimethyl pyrazole ligand (1) and group 11 metal ions (Cu(I), Ag(I), Au(I)). The resulting chemosensor 2(Cu) revealed positive response to benzene vapors in 5 mins by blue-shifting its emission band in 44 nm (from 616 to 572 nm) and emitted bright orange to green, where this change cannot be recovered even with external stimuli. Comparing to 2(Ag) with longer metal-metal distance (473 nm) with same sensing time and quenching in 37%, 2(Au) gave quenching in 81% from its original intensity at 612 nm with reusability in 82% without external stimuli and emitted less emissive of red-orange from its original color. The shifting phenomenon in 2(Cu) suggests diffusion of benzene vapors to inside molecules for formation of intermolecular interaction with Cu(I)-Cu(I) interaction while quenching phenomenon in 2(Au) suggests diffusion of benzene vapors to between the Au(I)-Au(I) interaction. These results indicate that suitable molecular structure of ligand and metal ion in pyrazolate complex is important for designing chemosensor in the detection of benzene vapors.

Leidenfrost Phenomenon-assisted Thermal Desorption (LPTD) and Its Application to Open Ion Sources at Atmospheric Pressure Mass Spectrometry

NASA Astrophysics Data System (ADS)

Saha, Subhrakanti; Chen, Lee Chuin; Mandal, Mridul Kanti; Hiraoka, Kenzo

2013-03-01

This work describes the development and application of a new thermal desorption technique that makes use of the Leidenfrost phenomenon in open ion sources at atmospheric pressure for direct mass spectrometric detection of ultratrace levels of illicit, therapeutic, and stimulant drugs, toxicants, and peptides (molecular weight above 1 kDa) in their unaltered state from complex real world samples without or with minor sample pretreatment. A low temperature dielectric barrier discharge ion source was used throughout the experiments and the analytical figures of merit of this technique were investigated. Further, this desorption technique coupled with other ionization sources such as electrospray ionization (ESI) and dc corona discharge atmospheric pressure chemical ionization (APCI) in open atmosphere was also investigated. The use of the high-resolution `Exactive Orbitrap' mass spectrometer provided unambiguous identification of trace levels of the targeted compounds from complex mixtures and background noise; the limits of detection for various small organic molecules and peptides treated with this technique were at the level of parts per trillion and 10-9 M, respectively. The high sensitivity of the present technique is attributed to the spontaneous enrichment of analyte molecules during the slow evaporation of the solvent, as well as to the sequential desorption of molecules from complex mixtures based on their volatilities. This newly developed desorption technique is simple and fast, while molecular ions are observed as the major ions.

Modern Warfare: An M and S Examination of the Dynamic Impact of Warlords and Insurgents on State Stability

NASA Technical Reports Server (NTRS)

Jones, Phillip N.; Drucker, Nick; Schwartz, Noah

2012-01-01

9/11 changed the world as we knew it. Part of this change was to redirect the military of the United States away from focusing primarily on conventional conflict to a primary focus on unconventional or irregular conflict. This change required a tremendous learning effort by the military and their supporting research and development community. This learning effort included relearning of old but largely forgotten lessons as well as acquiring newly discovered knowledge. During the process of our immediate 9/11 response, we identified that we were engaged in Iraq and Afghanistan in an insurgency. Subsequently, our focus converged upon the description of insurgencies and the requirements for counterinsurgency. This paper argues that emerging conditions now allow the re-evaluation of the type of conflict occurring today and into the foreseeable future: that we, including the modeling and simulation world, emerge from a singular focus on orthodox insurgencies and start to consider the consequences and opportunities of the complexity of current conflicts. As an example of complexity, this paper will use the relatively common phenomenon of the Warlord or Warlordism. The paper will provide a definition of this phenomenon and then describe the implications for modelers. The paper will conclude by demonstrating the impact of incorporating this one rather prosaic complexity into an insurgency model, using agent based modeling (ABM).

Efficient Transmission of Subthreshold Signals in Complex Networks of Spiking Neurons

PubMed Central

Torres, Joaquin J.; Elices, Irene; Marro, J.

2015-01-01

We investigate the efficient transmission and processing of weak, subthreshold signals in a realistic neural medium in the presence of different levels of the underlying noise. Assuming Hebbian weights for maximal synaptic conductances—that naturally balances the network with excitatory and inhibitory synapses—and considering short-term synaptic plasticity affecting such conductances, we found different dynamic phases in the system. This includes a memory phase where population of neurons remain synchronized, an oscillatory phase where transitions between different synchronized populations of neurons appears and an asynchronous or noisy phase. When a weak stimulus input is applied to each neuron, increasing the level of noise in the medium we found an efficient transmission of such stimuli around the transition and critical points separating different phases for well-defined different levels of stochasticity in the system. We proved that this intriguing phenomenon is quite robust, as it occurs in different situations including several types of synaptic plasticity, different type and number of stored patterns and diverse network topologies, namely, diluted networks and complex topologies such as scale-free and small-world networks. We conclude that the robustness of the phenomenon in different realistic scenarios, including spiking neurons, short-term synaptic plasticity and complex networks topologies, make very likely that it could also occur in actual neural systems as recent psycho-physical experiments suggest. PMID:25799449

Relating the Stored Magnetic Energy of a Parallel-Plate Inductor to the Work of External Forces

ERIC Educational Resources Information Center

Gauthier, N.

2007-01-01

Idealized models are often used in introductory physics courses. For one, such models involve simple mathematics, which is a definite plus since complex mathematical manipulations quickly become an obstacle rather than a tool for a beginner. Idealized models facilitate a student's understanding and grasp of a given physical phenomenon, yet they…