Surprise: a belief or an emotion?

Science.gov (United States)

Mellers, Barbara; Fincher, Katrina; Drummond, Caitlin; Bigony, Michelle

2013-01-01

Surprise is a fundamental link between cognition and emotion. It is shaped by cognitive assessments of likelihood, intuition, and superstition, and it in turn shapes hedonic experiences. We examine this connection between cognition and emotion and offer an explanation called decision affect theory. Our theory predicts the affective consequences of mistaken beliefs, such as overconfidence and hindsight. It provides insight about why the pleasure of a gain can loom larger than the pain of a comparable loss. Finally, it explains cross-cultural differences in emotional reactions to surprising events. By changing the nature of the unexpected (from chance to good luck), one can alter the emotional reaction to surprising events. Copyright © 2013 Elsevier B.V. All rights reserved.

The role of surprise in satisfaction judgements

NARCIS (Netherlands)

Vanhamme, J.; Snelders, H.M.J.J.

2001-01-01

Empirical findings suggest that surprise plays an important role in consumer satisfaction, but there is a lack of theory to explain why this is so. The present paper provides explanations for the process through which positive (negative) surprise might enhance (reduce) consumer satisfaction. First,

A Dichotomic Analysis of the Surprise Examination Paradox

OpenAIRE

Franceschi, Paul

2002-01-01

This paper presents a dichotomic analysis of the surprise examination paradox. In section 1, I analyse the surprise notion in detail. I introduce then in section 2, the distinction between a monist and dichotomic analysis of the paradox. I also present there a dichotomy leading to distinguish two basically and structurally different versions of the paradox, respectively based on a conjoint and a disjoint definition of the surprise. In section 3, I describe the solution to SEP corresponding to...

Exploration, Novelty, Surprise and Free Energy Minimisation

Directory of Open Access Journals (Sweden)

Philipp eSchwartenbeck

2013-10-01

Full Text Available This paper reviews recent developments under the free energy principle that introduce a normative perspective on classical economic (utilitarian decision-making based on (active Bayesian inference. It has been suggested that the free energy principle precludes novelty and complexity, because it assumes that biological systems – like ourselves - try to minimise the long-term average of surprise to maintain their homeostasis. However, recent formulations show that minimising surprise leads naturally to concepts such as exploration and novelty bonuses. In this approach, agents infer a policy that minimises surprise by minimising the difference (or relative entropy between likely and desired outcomes, which involves both pursuing the goal-state that has the highest expected utility (often termed ‘exploitation’ and visiting a number of different goal-states (‘exploration’. Crucially, the opportunity to visit new states increases the value of the current state. Casting decision-making problems within a variational framework, therefore, predicts that our behaviour is governed by both the entropy and expected utility of future states. This dissolves any dialectic between minimising surprise and exploration or novelty seeking.

Spatiotemporal neural characterization of prediction error valence and surprise during reward learning in humans.

Science.gov (United States)

Fouragnan, Elsa; Queirazza, Filippo; Retzler, Chris; Mullinger, Karen J; Philiastides, Marios G

2017-07-06

Reward learning depends on accurate reward associations with potential choices. These associations can be attained with reinforcement learning mechanisms using a reward prediction error (RPE) signal (the difference between actual and expected rewards) for updating future reward expectations. Despite an extensive body of literature on the influence of RPE on learning, little has been done to investigate the potentially separate contributions of RPE valence (positive or negative) and surprise (absolute degree of deviation from expectations). Here, we coupled single-trial electroencephalography with simultaneously acquired fMRI, during a probabilistic reversal-learning task, to offer evidence of temporally overlapping but largely distinct spatial representations of RPE valence and surprise. Electrophysiological variability in RPE valence correlated with activity in regions of the human reward network promoting approach or avoidance learning. Electrophysiological variability in RPE surprise correlated primarily with activity in regions of the human attentional network controlling the speed of learning. Crucially, despite the largely separate spatial extend of these representations our EEG-informed fMRI approach uniquely revealed a linear superposition of the two RPE components in a smaller network encompassing visuo-mnemonic and reward areas. Activity in this network was further predictive of stimulus value updating indicating a comparable contribution of both signals to reward learning.

Pupil size tracks perceptual content and surprise.

Science.gov (United States)

Kloosterman, Niels A; Meindertsma, Thomas; van Loon, Anouk M; Lamme, Victor A F; Bonneh, Yoram S; Donner, Tobias H

2015-04-01

Changes in pupil size at constant light levels reflect the activity of neuromodulatory brainstem centers that control global brain state. These endogenously driven pupil dynamics can be synchronized with cognitive acts. For example, the pupil dilates during the spontaneous switches of perception of a constant sensory input in bistable perceptual illusions. It is unknown whether this pupil dilation only indicates the occurrence of perceptual switches, or also their content. Here, we measured pupil diameter in human subjects reporting the subjective disappearance and re-appearance of a physically constant visual target surrounded by a moving pattern ('motion-induced blindness' illusion). We show that the pupil dilates during the perceptual switches in the illusion and a stimulus-evoked 'replay' of that illusion. Critically, the switch-related pupil dilation encodes perceptual content, with larger amplitude for disappearance than re-appearance. This difference in pupil response amplitude enables prediction of the type of report (disappearance vs. re-appearance) on individual switches (receiver-operating characteristic: 61%). The amplitude difference is independent of the relative durations of target-visible and target-invisible intervals and subjects' overt behavioral report of the perceptual switches. Further, we show that pupil dilation during the replay also scales with the level of surprise about the timing of switches, but there is no evidence for an interaction between the effects of surprise and perceptual content on the pupil response. Taken together, our results suggest that pupil-linked brain systems track both the content of, and surprise about, perceptual events. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Decision-making under surprise and uncertainty: Arsenic contamination of water supplies

Science.gov (United States)

Randhir, Timothy O.; Mozumder, Pallab; Halim, Nafisa

2018-05-01

With ignorance and potential surprise dominating decision making in water resources, a framework for dealing with such uncertainty is a critical need in hydrology. We operationalize the 'potential surprise' criterion proposed by Shackle, Vickers, and Katzner (SVK) to derive decision rules to manage water resources under uncertainty and ignorance. We apply this framework to managing water supply systems in Bangladesh that face severe, naturally occurring arsenic contamination. The uncertainty involved with arsenic in water supplies makes the application of conventional analysis of decision-making ineffective. Given the uncertainty and surprise involved in such cases, we find that optimal decisions tend to favor actions that avoid irreversible outcomes instead of conventional cost-effective actions. We observe that a diversification of the water supply system also emerges as a robust strategy to avert unintended outcomes of water contamination. Shallow wells had a slight higher optimal level (36%) compare to deep wells and surface treatment which had allocation levels of roughly 32% under each. The approach can be applied in a variety of other cases that involve decision making under uncertainty and surprise, a frequent situation in natural resources management.

Large-scale biophysical evaluation of protein PEGylation effects

DEFF Research Database (Denmark)

Vernet, Erik; Popa, Gina; Pozdnyakova, Irina

2016-01-01

PEGylation is the most widely used method to chemically modify protein biopharmaceuticals, but surprisingly limited public data is available on the biophysical effects of protein PEGylation. Here we report the first large-scale study, with site-specific mono-PEGylation of 15 different proteins...... of PEGylation on the thermal stability of a protein based on data generated by circular dichroism (CD), differential scanning calorimetry (DSC), or differential scanning fluorimetry (DSF). In addition, DSF was validated as a fast and inexpensive screening method for thermal unfolding studies of PEGylated...... proteins. Multivariate data analysis revealed clear trends in biophysical properties upon PEGylation for a subset of proteins, although no universal trends were found. Taken together, these findings are important in the consideration of biophysical methods and evaluation of second...

A Contrast-Based Computational Model of Surprise and Its Applications.

Science.gov (United States)

Macedo, Luis; Cardoso, Amílcar

2017-11-19

We review our work on a contrast-based computational model of surprise and its applications. The review is contextualized within related research from psychology, philosophy, and particularly artificial intelligence. Influenced by psychological theories of surprise, the model assumes that surprise-eliciting events initiate a series of cognitive processes that begin with the appraisal of the event as unexpected, continue with the interruption of ongoing activity and the focusing of attention on the unexpected event, and culminate in the analysis and evaluation of the event and the revision of beliefs. It is assumed that the intensity of surprise elicited by an event is a nonlinear function of the difference or contrast between the subjective probability of the event and that of the most probable alternative event (which is usually the expected event); and that the agent's behavior is partly controlled by actual and anticipated surprise. We describe applications of artificial agents that incorporate the proposed surprise model in three domains: the exploration of unknown environments, creativity, and intelligent transportation systems. These applications demonstrate the importance of surprise for decision making, active learning, creative reasoning, and selective attention. Copyright © 2017 Cognitive Science Society, Inc.

The Role of Surprise in Game-Based Learning for Mathematics

NARCIS (Netherlands)

Wouters, Pieter; van Oostendorp, Herre; ter Vrugte, Judith; Vandercruysse, Sylke; de Jong, Anthonius J.M.; Elen, Jan; De Gloria, Alessandro; Veltkamp, Remco

2016-01-01

In this paper we investigate the potential of surprise on learning with prevocational students in the domain of proportional reasoning. Surprise involves an emotional reaction, but it also serves a cognitive goal as it directs attention to explain why the surprising event occurred and to learn for

The Value of Surprising Findings for Research on Marketing

OpenAIRE

JS Armstrong

2004-01-01

In the work of Armstrong (Journal of Business Research, 2002), I examined empirical research on the scientific process and related these to marketing science. The findings of some studies were surprising. In this reply, I address surprising findings and other issues raised by commentators.

An efficient community detection algorithm using greedy surprise maximization

International Nuclear Information System (INIS)

Jiang, Yawen; Jia, Caiyan; Yu, Jian

2014-01-01

Community detection is an important and crucial problem in complex network analysis. Although classical modularity function optimization approaches are widely used for identifying communities, the modularity function (Q) suffers from its resolution limit. Recently, the surprise function (S) was experimentally proved to be better than the Q function. However, up until now, there has been no algorithm available to perform searches to directly determine the maximal surprise values. In this paper, considering the superiority of the S function over the Q function, we propose an efficient community detection algorithm called AGSO (algorithm based on greedy surprise optimization) and its improved version FAGSO (fast-AGSO), which are based on greedy surprise optimization and do not suffer from the resolution limit. In addition, (F)AGSO does not need the number of communities K to be specified in advance. Tests on experimental networks show that (F)AGSO is able to detect optimal partitions in both simple and even more complex networks. Moreover, algorithms based on surprise maximization perform better than those algorithms based on modularity maximization, including Blondel–Guillaume–Lambiotte–Lefebvre (BGLL), Clauset–Newman–Moore (CNM) and the other state-of-the-art algorithms such as Infomap, order statistics local optimization method (OSLOM) and label propagation algorithm (LPA). (paper)

Radar Design to Protect Against Surprise

Energy Technology Data Exchange (ETDEWEB)

Doerry, Armin W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-02-01

Technological and doctrinal surprise is about rendering preparations for conflict as irrelevant or ineffective . For a sensor, this means essentially rendering the sensor as irrelevant or ineffective in its ability to help determine truth. Recovery from this sort of surprise is facilitated by flexibility in our own technology and doctrine. For a sensor, this mean s flexibility in its architecture, design, tactics, and the designing organizations ' processes. - 4 - Acknowledgements This report is the result of a n unfunded research and development activity . Sandia National Laboratories is a multi - program laboratory manage d and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000.

Models of Automation surprise : results of a field survey in aviation

NARCIS (Netherlands)

De Boer, Robert; Dekker, Sidney

2017-01-01

Automation surprises in aviation continue to be a significant safety concern and the community’s search for effective strategies to mitigate them are ongoing. The literature has offered two fundamentally divergent directions, based on different ideas about the nature of cognition and collaboration

Surprise as a design strategy

NARCIS (Netherlands)

Ludden, G.D.S.; Schifferstein, H.N.J.; Hekkert, P.P.M.

2008-01-01

Imagine yourself queuing for the cashier’s desk in a supermarket. Naturally, you have picked the wrong line, the one that does not seem to move at all. Soon, you get tired of waiting. Now, how would you feel if the cashier suddenly started to sing? Many of us would be surprised and, regardless of

Models of Automation Surprise: Results of a Field Survey in Aviation

Directory of Open Access Journals (Sweden)

Robert De Boer

2017-09-01

Full Text Available Automation surprises in aviation continue to be a significant safety concern and the community’s search for effective strategies to mitigate them are ongoing. The literature has offered two fundamentally divergent directions, based on different ideas about the nature of cognition and collaboration with automation. In this paper, we report the results of a field study that empirically compared and contrasted two models of automation surprises: a normative individual-cognition model and a sensemaking model based on distributed cognition. Our data prove a good fit for the sense-making model. This finding is relevant for aviation safety, since our understanding of the cognitive processes that govern human interaction with automation drive what we need to do to reduce the frequency of automation-induced events.

Surprising Incentive: An Instrument for Promoting Safety Performance of Construction Employees

Directory of Open Access Journals (Sweden)

Fakhradin Ghasemi

2015-09-01

Conclusion: The results of this study proved that the surprising incentive would improve the employees' safety performance just in the short term because the surprising value of the incentives dwindle over time. For this reason and to maintain the surprising value of the incentive system, the amount and types of incentives need to be evaluated and modified annually or biannually.

Surprises in the suddenly-expanded infinite well

International Nuclear Information System (INIS)

Aslangul, Claude

2008-01-01

I study the time evolution of a particle prepared in the ground state of an infinite well after the latter is suddenly expanded. It turns out that the probability density |Ψ(x, t)| 2 shows up quite a surprising behaviour: for definite times, plateaux appear for which |Ψ(x, t)| 2 is constant on finite intervals for x. Elements of theoretical explanation are given by analysing the singular component of the second derivative ∂ xx Ψ(x, t). Analytical closed expressions are obtained for some specific times, which easily allow us to show that, at these times, the density organizes itself into regular patterns provided the size of the box is large enough; more, above some critical size depending on the specific time, the density patterns are independent of the expansion parameter. It is seen how the density at these times simply results from a construction game with definite rules acting on the pieces of the initial density

Dividend announcements reconsidered: Dividend changes versus dividend surprises

OpenAIRE

Andres, Christian; Betzer, André; van den Bongard, Inga; Haesner, Christian; Theissen, Erik

2012-01-01

This paper reconsiders the issue of share price reactions to dividend announcements. Previous papers rely almost exclusively on a naive dividend model in which the dividend change is used as a proxy for the dividend surprise. We use the difference between the actual dividend and the analyst consensus forecast as obtained from I/B/E/S as a proxy for the dividend surprise. Using data from Germany, we find significant share price reactions after dividend announcements. Once we control for analys...

Charming surprise

CERN Multimedia

Antonella Del Rosso

2011-01-01

The CP violation in charm quarks has always been thought to be extremely small. So, looking at particle decays involving matter and antimatter, the LHCb experiment has recently been surprised to observe that things might be different. Theorists are on the case.   The study of the physics of the charm quark was not in the initial plans of the LHCb experiment, whose letter “b” stands for “beauty quark”. However, already one year ago, the Collaboration decided to look into a wider spectrum of processes that involve charm quarks among other things. The LHCb trigger allows a lot of these processes to be selected, and, among them, one has recently shown interesting features. Other experiments at b-factories have already performed the same measurement but this is the first time that it has been possible to achieve such high precision, thanks to the huge amount of data provided by the very high luminosity of the LHC. “We have observed the decay modes of t...

Salience and attention in surprisal-based accounts of language processing

Directory of Open Access Journals (Sweden)

Alessandra eZarcone

2016-06-01

Full Text Available The notion of salience has been singled out as the explanatory factor for a diverse range oflinguistic phenomena. In particular, perceptual salience (e.g. visual salience of objects in the world,acoustic prominence of linguistic sounds and semantic-pragmatic salience (e.g. prominence ofrecently mentioned or topical referents have been shown to influence language comprehensionand production. A different line of research has sought to account for behavioral correlates ofcognitive load during comprehension as well as for certain patterns in language usage usinginformation-theoretic notions, such as surprisal. Surprisal and salience both affect languageprocessing at different levels, but the relationship between the two has not been adequatelyelucidated, and the question of whether salience can be reduced to surprisal / predictability isstill open. Our review identifies two main challenges in addressing this question: terminologicalinconsistency and lack of integration between high and low levels of representations in salience-based accounts and surprisal-based accounts. We capitalise upon work in visual cognition inorder to orient ourselves in surveying the different facets of the notion of salience in linguisticsand their relation with models of surprisal. We find that work on salience highlights aspects oflinguistic communication that models of surprisal tend to overlook, namely the role of attentionand relevance to current goals, and we argue that the Predictive Coding framework provides aunified view which can account for the role played by attention and predictability at different levelsof processing and which can clarify the interplay between low and high levels of processes andbetween predictability-driven expectation and attention-driven focus.

Viral marketing: the use of surprise

NARCIS (Netherlands)

Lindgreen, A.; Vanhamme, J.; Clarke, I.; Flaherty, T.B.

2005-01-01

Viral marketing involves consumers passing along a company's marketing message to their friends, family, and colleagues. This chapter reviews viral marketing campaigns and argues that the emotion of surprise often is at work and that this mechanism resembles that of word-of-mouth marketing.

Distinct medial temporal networks encode surprise during motivation by reward versus punishment

Science.gov (United States)

Murty, Vishnu P.; LaBar, Kevin S.; Adcock, R. Alison

2016-01-01

Adaptive motivated behavior requires predictive internal representations of the environment, and surprising events are indications for encoding new representations of the environment. The medial temporal lobe memory system, including the hippocampus and surrounding cortex, encodes surprising events and is influenced by motivational state. Because behavior reflects the goals of an individual, we investigated whether motivational valence (i.e., pursuing rewards versus avoiding punishments) also impacts neural and mnemonic encoding of surprising events. During functional magnetic resonance imaging (fMRI), participants encountered perceptually unexpected events either during the pursuit of rewards or avoidance of punishments. Despite similar levels of motivation across groups, reward and punishment facilitated the processing of surprising events in different medial temporal lobe regions. Whereas during reward motivation, perceptual surprises enhanced activation in the hippocampus, during punishment motivation surprises instead enhanced activation in parahippocampal cortex. Further, we found that reward motivation facilitated hippocampal coupling with ventromedial PFC, whereas punishment motivation facilitated parahippocampal cortical coupling with orbitofrontal cortex. Behaviorally, post-scan testing revealed that reward, but not punishment, motivation resulted in greater memory selectivity for surprising events encountered during goal pursuit. Together these findings demonstrate that neuromodulatory systems engaged by anticipation of reward and punishment target separate components of the medial temporal lobe, modulating medial temporal lobe sensitivity and connectivity. Thus, reward and punishment motivation yield distinct neural contexts for learning, with distinct consequences for how surprises are incorporated into predictive mnemonic models of the environment. PMID:26854903

Distinct medial temporal networks encode surprise during motivation by reward versus punishment.

Science.gov (United States)

Murty, Vishnu P; LaBar, Kevin S; Adcock, R Alison

2016-10-01

Adaptive motivated behavior requires predictive internal representations of the environment, and surprising events are indications for encoding new representations of the environment. The medial temporal lobe memory system, including the hippocampus and surrounding cortex, encodes surprising events and is influenced by motivational state. Because behavior reflects the goals of an individual, we investigated whether motivational valence (i.e., pursuing rewards versus avoiding punishments) also impacts neural and mnemonic encoding of surprising events. During functional magnetic resonance imaging (fMRI), participants encountered perceptually unexpected events either during the pursuit of rewards or avoidance of punishments. Despite similar levels of motivation across groups, reward and punishment facilitated the processing of surprising events in different medial temporal lobe regions. Whereas during reward motivation, perceptual surprises enhanced activation in the hippocampus, during punishment motivation surprises instead enhanced activation in parahippocampal cortex. Further, we found that reward motivation facilitated hippocampal coupling with ventromedial PFC, whereas punishment motivation facilitated parahippocampal cortical coupling with orbitofrontal cortex. Behaviorally, post-scan testing revealed that reward, but not punishment, motivation resulted in greater memory selectivity for surprising events encountered during goal pursuit. Together these findings demonstrate that neuromodulatory systems engaged by anticipation of reward and punishment target separate components of the medial temporal lobe, modulating medial temporal lobe sensitivity and connectivity. Thus, reward and punishment motivation yield distinct neural contexts for learning, with distinct consequences for how surprises are incorporated into predictive mnemonic models of the environment. Copyright © 2016 Elsevier Inc. All rights reserved.

Salience and Attention in Surprisal-Based Accounts of Language Processing.

Science.gov (United States)

Zarcone, Alessandra; van Schijndel, Marten; Vogels, Jorrig; Demberg, Vera

2016-01-01

The notion of salience has been singled out as the explanatory factor for a diverse range of linguistic phenomena. In particular, perceptual salience (e.g., visual salience of objects in the world, acoustic prominence of linguistic sounds) and semantic-pragmatic salience (e.g., prominence of recently mentioned or topical referents) have been shown to influence language comprehension and production. A different line of research has sought to account for behavioral correlates of cognitive load during comprehension as well as for certain patterns in language usage using information-theoretic notions, such as surprisal. Surprisal and salience both affect language processing at different levels, but the relationship between the two has not been adequately elucidated, and the question of whether salience can be reduced to surprisal / predictability is still open. Our review identifies two main challenges in addressing this question: terminological inconsistency and lack of integration between high and low levels of representations in salience-based accounts and surprisal-based accounts. We capitalize upon work in visual cognition in order to orient ourselves in surveying the different facets of the notion of salience in linguistics and their relation with models of surprisal. We find that work on salience highlights aspects of linguistic communication that models of surprisal tend to overlook, namely the role of attention and relevance to current goals, and we argue that the Predictive Coding framework provides a unified view which can account for the role played by attention and predictability at different levels of processing and which can clarify the interplay between low and high levels of processes and between predictability-driven expectation and attention-driven focus.

Salience and Attention in Surprisal-Based Accounts of Language Processing

Science.gov (United States)

Zarcone, Alessandra; van Schijndel, Marten; Vogels, Jorrig; Demberg, Vera

2016-01-01

The notion of salience has been singled out as the explanatory factor for a diverse range of linguistic phenomena. In particular, perceptual salience (e.g., visual salience of objects in the world, acoustic prominence of linguistic sounds) and semantic-pragmatic salience (e.g., prominence of recently mentioned or topical referents) have been shown to influence language comprehension and production. A different line of research has sought to account for behavioral correlates of cognitive load during comprehension as well as for certain patterns in language usage using information-theoretic notions, such as surprisal. Surprisal and salience both affect language processing at different levels, but the relationship between the two has not been adequately elucidated, and the question of whether salience can be reduced to surprisal / predictability is still open. Our review identifies two main challenges in addressing this question: terminological inconsistency and lack of integration between high and low levels of representations in salience-based accounts and surprisal-based accounts. We capitalize upon work in visual cognition in order to orient ourselves in surveying the different facets of the notion of salience in linguistics and their relation with models of surprisal. We find that work on salience highlights aspects of linguistic communication that models of surprisal tend to overlook, namely the role of attention and relevance to current goals, and we argue that the Predictive Coding framework provides a unified view which can account for the role played by attention and predictability at different levels of processing and which can clarify the interplay between low and high levels of processes and between predictability-driven expectation and attention-driven focus. PMID:27375525

Charming surprise

CERN Multimedia

Antonella Del Rosso

2011-01-01

The CP violation in charm quarks has always been thought to be extremely small. So, looking at particle decays involving matter and antimatter, the LHCb experiment has recently been surprised to observe that things might be different. Theorists are on the case. The study of the physics of the charm quark was not in the initial plans of the LHCb experiment, whose letter “b” stands for “beauty quark”. However, already one year ago, the Collaboration decided to look into a wider spectrum of processes that involve charm quarks among other things. The LHCb trigger allows a lot of these processes to be selected, and, among them, one has recently shown interesting features. Other experiments at b-factories have already performed the same measurement but this is the first time that it has been possible to achieve such high precision, thanks to the huge amount of data provided by the very high luminosity of the LHC. “We have observed the decay modes of the D0, a pa...

The Surprise Examination Paradox and the Second Incompleteness Theorem

OpenAIRE

Kritchman, Shira; Raz, Ran

2010-01-01

We give a new proof for Godel's second incompleteness theorem, based on Kolmogorov complexity, Chaitin's incompleteness theorem, and an argument that resembles the surprise examination paradox. We then go the other way around and suggest that the second incompleteness theorem gives a possible resolution of the surprise examination paradox. Roughly speaking, we argue that the flaw in the derivation of the paradox is that it contains a hidden assumption that one can prove the consistency of the...

Self-organizing weights for Internet AS-graphs and surprisingly simple routing metrics

DEFF Research Database (Denmark)

Scholz, Jan Carsten; Greiner, Martin

2011-01-01

The transport capacity of Internet-like communication networks and hence their efficiency may be improved by a factor of 5–10 through the use of highly optimized routing metrics, as demonstrated previously. The numerical determination of such routing metrics can be computationally demanding...... to an extent that prohibits both investigation of and application to very large networks. In an attempt to find a numerically less expensive way of constructing a metric with a comparable performance increase, we propose a local, self-organizing iteration scheme and find two surprisingly simple and efficient...... metrics. The new metrics have negligible computational cost and result in an approximately 5-fold performance increase, providing distinguished competitiveness with the computationally costly counterparts. They are applicable to very large networks and easy to implement in today's Internet routing...

The conceptualization model problem—surprise

Science.gov (United States)

Bredehoeft, John

2005-03-01

The foundation of model analysis is the conceptual model. Surprise is defined as new data that renders the prevailing conceptual model invalid; as defined here it represents a paradigm shift. Limited empirical data indicate that surprises occur in 20-30% of model analyses. These data suggest that groundwater analysts have difficulty selecting the appropriate conceptual model. There is no ready remedy to the conceptual model problem other than (1) to collect as much data as is feasible, using all applicable methods—a complementary data collection methodology can lead to new information that changes the prevailing conceptual model, and (2) for the analyst to remain open to the fact that the conceptual model can change dramatically as more information is collected. In the final analysis, the hydrogeologist makes a subjective decision on the appropriate conceptual model. The conceptualization problem does not render models unusable. The problem introduces an uncertainty that often is not widely recognized. Conceptual model uncertainty is exacerbated in making long-term predictions of system performance. C'est le modèle conceptuel qui se trouve à base d'une analyse sur un modèle. On considère comme une surprise lorsque le modèle est invalidé par des données nouvelles; dans les termes définis ici la surprise est équivalente à un change de paradigme. Des données empiriques limitées indiquent que les surprises apparaissent dans 20 à 30% des analyses effectuées sur les modèles. Ces données suggèrent que l'analyse des eaux souterraines présente des difficultés lorsqu'il s'agit de choisir le modèle conceptuel approprié. Il n'existe pas un autre remède au problème du modèle conceptuel que: (1) rassembler autant des données que possible en utilisant toutes les méthodes applicables—la méthode des données complémentaires peut conduire aux nouvelles informations qui vont changer le modèle conceptuel, et (2) l'analyste doit rester ouvert au fait

Glial heterotopia of maxilla: A clinical surprise

Directory of Open Access Journals (Sweden)

Santosh Kumar Mahalik

2011-01-01

Full Text Available Glial heterotopia is a rare congenital mass lesion which often presents as a clinical surprise. We report a case of extranasal glial heterotopia in a neonate with unusual features. The presentation, management strategy, etiopathogenesis and histopathology of the mass lesion has been reviewed.

Beyond surprise : A longitudinal study on the experience of visual-tactual incongruities in products

NARCIS (Netherlands)

Ludden, G.D.S.; Schifferstein, H.N.J.; Hekkert, P.

2012-01-01

When people encounter products with visual-tactual incongruities, they are likely to be surprised because the product feels different than expected. In this paper, we investigate (1) the relationship between surprise and the overall liking of the products, (2) the emotions associated with surprise,

Semantic relation vs. surprise: the differential effects of related and unrelated co-verbal gestures on neural encoding and subsequent recognition.

Science.gov (United States)

Straube, Benjamin; Meyer, Lea; Green, Antonia; Kircher, Tilo

2014-06-03

Speech-associated gesturing leads to memory advantages for spoken sentences. However, unexpected or surprising events are also likely to be remembered. With this study we test the hypothesis that different neural mechanisms (semantic elaboration and surprise) lead to memory advantages for iconic and unrelated gestures. During fMRI-data acquisition participants were presented with video clips of an actor verbalising concrete sentences accompanied by iconic gestures (IG; e.g., circular gesture; sentence: "The man is sitting at the round table"), unrelated free gestures (FG; e.g., unrelated up down movements; same sentence) and no gestures (NG; same sentence). After scanning, recognition performance for the three conditions was tested. Videos were evaluated regarding semantic relation and surprise by a different group of participants. The semantic relationship between speech and gesture was rated higher for IG (IG>FG), whereas surprise was rated higher for FG (FG>IG). Activation of the hippocampus correlated with subsequent memory performance of both gesture conditions (IG+FG>NG). For the IG condition we found activation in the left temporal pole and middle cingulate cortex (MCC; IG>FG). In contrast, for the FG condition posterior thalamic structures (FG>IG) as well as anterior and posterior cingulate cortices were activated (FG>NG). Our behavioral and fMRI-data suggest different mechanisms for processing related and unrelated co-verbal gestures, both of them leading to enhanced memory performance. Whereas activation in MCC and left temporal pole for iconic co-verbal gestures may reflect semantic memory processes, memory enhancement for unrelated gestures relies on the surprise response, mediated by anterior/posterior cingulate cortex and thalamico-hippocampal structures. Copyright © 2014 Elsevier B.V. All rights reserved.

A Statistical Analysis of the Relationship between Harmonic Surprise and Preference in Popular Music.

Science.gov (United States)

Miles, Scott A; Rosen, David S; Grzywacz, Norberto M

2017-01-01

Studies have shown that some musical pieces may preferentially activate reward centers in the brain. Less is known, however, about the structural aspects of music that are associated with this activation. Based on the music cognition literature, we propose two hypotheses for why some musical pieces are preferred over others. The first, the Absolute-Surprise Hypothesis, states that unexpected events in music directly lead to pleasure. The second, the Contrastive-Surprise Hypothesis, proposes that the juxtaposition of unexpected events and subsequent expected events leads to an overall rewarding response. We tested these hypotheses within the framework of information theory, using the measure of "surprise." This information-theoretic variable mathematically describes how improbable an event is given a known distribution. We performed a statistical investigation of surprise in the harmonic structure of songs within a representative corpus of Western popular music, namely, the McGill Billboard Project corpus. We found that chords of songs in the top quartile of the Billboard chart showed greater average surprise than those in the bottom quartile. We also found that the different sections within top-quartile songs varied more in their average surprise than the sections within bottom-quartile songs. The results of this study are consistent with both the Absolute- and Contrastive-Surprise Hypotheses. Although these hypotheses seem contradictory to one another, we cannot yet discard the possibility that both absolute and contrastive types of surprise play roles in the enjoyment of popular music. We call this possibility the Hybrid-Surprise Hypothesis. The results of this statistical investigation have implications for both music cognition and the human neural mechanisms of esthetic judgments.

Surprising results: HIV testing and changes in contraceptive practices among young women in Malawi

Science.gov (United States)

Sennott, Christie; Yeatman, Sara

2015-01-01

This study uses eight waves of data from the population-based Tsogolo la Thanzi study (2009–2011) in rural Malawi to examine changes in young women’s contraceptive practices, including the use of condoms, non-barrier contraceptive methods, and abstinence, following positive and negative HIV tests. The analysis factors in women’s prior perceptions of their HIV status that may already be shaping their behaviour and separates surprise HIV test results from those that merely confirm what was already believed. Fixed effects logistic regression models show that HIV testing frequently affects the contraceptive practices of young Malawian women, particularly when the test yields an unexpected result. Specifically, women who are surprised to test HIV positive increase their condom use and are more likely to use condoms consistently. Following an HIV negative test (whether a surprise or expected), women increase their use of condoms and decrease their use of non-barrier contraceptives; the latter may be due to an increase in abstinence following a surprise negative result. Changes in condom use following HIV testing are robust to the inclusion of potential explanatory mechanisms including fertility preferences, relationship status, and the perception that a partner is HIV positive. The results demonstrate that both positive and negative tests can influence women’s sexual and reproductive behaviours, and emphasise the importance of conceptualizing of HIV testing as offering new information only insofar as results deviate from prior perceptions of HIV status. PMID:26160156

Ignorance, Vulnerability and the Occurrence of "Radical Surprises": Theoretical Reflections and Empirical Findings

Science.gov (United States)

Kuhlicke, C.

2009-04-01

By definition natural disasters always contain a moment of surprise. Their occurrence is mostly unforeseen and unexpected. They hit people unprepared, overwhelm them and expose their helplessness. Yet, there is surprisingly little known on the reasons for their being surprised. Aren't natural disasters expectable and foreseeable after all? Aren't the return rates of most hazards well known and shouldn't people be better prepared? The central question of this presentation is hence: Why do natural disasters so often radically surprise people at all (and how can we explain this being surprised)? In the first part of the presentation, it is argued that most approaches to vulnerability are not able to grasp this moment of surprise. On the contrary, they have their strength in unravelling the expectable: A person who is marginalized or even oppressed in everyday life is also vulnerable during times of crisis and stress, at least this is the central assumption of most vulnerability studies. In the second part, an understanding of vulnerability is developed, which allows taking into account such radical surprises. First, two forms of the unknown are differentiated: An area of the unknown an actor is more or less aware of (ignorance), and an area, which is not even known to be not known (nescience). The discovery of the latter is mostly associated with a "radical surprise", since it is per definition impossible to prepare for it. Second, a definition of vulnerability is proposed, which allows capturing the dynamics of surprises: People are vulnerable when they discover their nescience exceeding by definition previously established routines, stocks of knowledge and resources—in a general sense their capacities—to deal with their physical and/or social environment. This definition explicitly takes the view of different actors serious and departs from their being surprised. In the third part findings of a case study are presented, the 2002 flood in Germany. It is shown

The Value of Change: Surprises and Insights in Stellar Evolution

Science.gov (United States)

Bildsten, Lars

2018-01-01

Astronomers with large-format cameras regularly scan the sky many times per night to detect what's changing, and telescopes in space such as Kepler and, soon, TESS obtain very accurate brightness measurements of nearly a million stars over time periods of years. These capabilities, in conjunction with theoretical and computational efforts, have yielded surprises and remarkable new insights into the internal properties of stars and how they end their lives. I will show how asteroseismology reveals the properties of the deep interiors of red giants, and highlight how astrophysical transients may be revealing unusual thermonuclear outcomes from exploding white dwarfs and the births of highly magnetic neutron stars. All the while, stellar science has been accelerated by the availability of open source tools, such as Modules for Experiments in Stellar Astrophysics (MESA), and the nearly immediate availability of observational results.

Sleeping beauties in theoretical physics 26 surprising insights

CERN Document Server

Padmanabhan, Thanu

2015-01-01

This book addresses a fascinating set of questions in theoretical physics which will both entertain and enlighten all students, teachers and researchers and other physics aficionados. These range from Newtonian mechanics to quantum field theory and cover several puzzling issues that do not appear in standard textbooks. Some topics cover conceptual conundrums, the solutions to which lead to surprising insights; some correct popular misconceptions in the textbook discussion of certain topics; others illustrate deep connections between apparently unconnected domains of theoretical physics; and a few provide remarkably simple derivations of results which are not often appreciated. The connoisseur of theoretical physics will enjoy a feast of pleasant surprises skilfully prepared by an internationally acclaimed theoretical physicist. Each topic is introduced with proper background discussion and special effort is taken to make the discussion self-contained, clear and comprehensible to anyone with an undergraduate e...

The June surprises: balls, strikes, and the fog of war.

Science.gov (United States)

Fried, Charles

2013-04-01

At first, few constitutional experts took seriously the argument that the Patient Protection and Affordable Care Act exceeded Congress's power under the commerce clause. The highly political opinions of two federal district judges - carefully chosen by challenging plaintiffs - of no particular distinction did not shake that confidence that the act was constitutional. This disdain for the challengers' arguments was only confirmed when the act was upheld by two highly respected conservative court of appeals judges in two separate circuits. But after the hostile, even mocking questioning of the government's advocate in the Supreme Court by the five Republican-appointed justices, the expectation was that the act would indeed be struck down on that ground. So it came as no surprise when the five opined the act did indeed exceed Congress's commerce clause power. But it came as a great surprise when Chief Justice John Roberts, joined by the four Democrat-appointed justices, ruled that the act could be sustained as an exercise of Congress's taxing power - a ground urged by the government almost as an afterthought. It was further surprising, even shocking, that Justices Antonin Scalia, Anthony Kennedy, Clarence Thomas, and Samuel Alito not only wrote a joint opinion on the commerce clause virtually identical to that of their chief, but that in writing it they did not refer to or even acknowledge his opinion. Finally surprising was the fact that Justices Ruth Bader Ginsburg and Stephen Breyer joined the chief in holding that aspects of the act's Medicaid expansion were unconstitutional. This essay ponders and tries to unravel some of these puzzles.

Smartphone Response System Using Twitter to Enable Effective Interaction and Improve Engagement in Large Classrooms

Science.gov (United States)

Kim, Yeongjun; Jeong, Soonmook; Ji, Yongwoon; Lee, Sangeun; Kwon, Key Ho; Jeon, Jae Wook

2015-01-01

This paper proposes a method for seamless interaction between students and their professor using Twitter, one of the typical social network service (SNS) platforms, in large lectures. During the lecture, the professor poses surprise questions in the form of a quiz on an overhead screen at unexpected moments, and students submit their answers…

The Ultraviolet Surprise. Efficient Soft X-Ray High Harmonic Generation in Multiply-Ionized Plasmas

International Nuclear Information System (INIS)

Popmintchev, Dimitar; Hernandez-Garcia, Carlos; Dollar, Franklin; Mancuso, Christopher; Perez-Hernandez, Jose A.; Chen, Ming-Chang; Hankla, Amelia; Gao, Xiaohui; Shim, Bonggu; Gaeta, Alexander L.; Tarazkar, Maryam; Romanov, Dmitri A.; Levis, Robert J.; Gaffney, Jim A.; Foord, Mark; Libby, Stephen B.; Jaron-Becker, Agnieskzka; Becker, Andreas; Plaja, Luis; Muranane, Margaret M.; Kapteyn, Henry C.; Popmintchev, Tenio

2015-01-01

High-harmonic generation is a universal response of matter to strong femtosecond laser fields, coherently upconverting light to much shorter wavelengths. Optimizing the conversion of laser light into soft x-rays typically demands a trade-off between two competing factors. Reduced quantum diffusion of the radiating electron wave function results in emission from each species which is highest when a short-wavelength ultraviolet driving laser is used. But, phase matching - the constructive addition of x-ray waves from a large number of atoms - favors longer-wavelength mid-infrared lasers. We identified a regime of high-harmonic generation driven by 40-cycle ultraviolet lasers in waveguides that can generate bright beams in the soft x-ray region of the spectrum, up to photon energies of 280 electron volts. Surprisingly, the high ultraviolet refractive indices of both neutral atoms and ions enabled effective phase matching, even in a multiply ionized plasma. We observed harmonics with very narrow linewidths, while calculations show that the x-rays emerge as nearly time-bandwidt-limited pulse trains of ~100 attoseconds

Distinct medial temporal networks encode surprise during motivation by reward versus punishment

OpenAIRE

Murty, Vishnu P.; LaBar, Kevin S.; Adcock, R. Alison

2016-01-01

Adaptive motivated behavior requires predictive internal representations of the environment, and surprising events are indications for encoding new representations of the environment. The medial temporal lobe memory system, including the hippocampus and surrounding cortex, encodes surprising events and is influenced by motivational state. Because behavior reflects the goals of an individual, we investigated whether motivational valence (i.e., pursuing rewards versus avoiding punishments) also...

Human Amygdala Tracks a Feature-Based Valence Signal Embedded within the Facial Expression of Surprise.

Science.gov (United States)

Kim, M Justin; Mattek, Alison M; Bennett, Randi H; Solomon, Kimberly M; Shin, Jin; Whalen, Paul J

2017-09-27

Human amygdala function has been traditionally associated with processing the affective valence (negative vs positive) of an emotionally charged event, especially those that signal fear or threat. However, this account of human amygdala function can be explained by alternative views, which posit that the amygdala might be tuned to either (1) general emotional arousal (activation vs deactivation) or (2) specific emotion categories (fear vs happy). Delineating the pure effects of valence independent of arousal or emotion category is a challenging task, given that these variables naturally covary under many circumstances. To circumvent this issue and test the sensitivity of the human amygdala to valence values specifically, we measured the dimension of valence within the single facial expression category of surprise. Given the inherent valence ambiguity of this category, we show that surprised expression exemplars are attributed valence and arousal values that are uniquely and naturally uncorrelated. We then present fMRI data from both sexes, showing that the amygdala tracks these consensus valence values. Finally, we provide evidence that these valence values are linked to specific visual features of the mouth region, isolating the signal by which the amygdala detects this valence information. SIGNIFICANCE STATEMENT There is an open question as to whether human amygdala function tracks the valence value of cues in the environment, as opposed to either a more general emotional arousal value or a more specific emotion category distinction. Here, we demonstrate the utility of surprised facial expressions because exemplars within this emotion category take on valence values spanning the dimension of bipolar valence (positive to negative) at a consistent level of emotional arousal. Functional neuroimaging data showed that amygdala responses tracked the valence of surprised facial expressions, unconfounded by arousal. Furthermore, a machine learning classifier identified

Managing Uncertainity: Soviet Views on Deception, Surprise, and Control

National Research Council Canada - National Science Library

Hull, Andrew

1989-01-01

.... In the first two cases (deception and surprise), the emphasis is on how the Soviets seek to sow uncertainty in the minds of the enemy and how the Soviets then plan to use that uncertainty to gain military advantage...

Effect of Temperature Shock and Inventory Surprises on Natural Gas and Heating Oil Futures Returns

Science.gov (United States)

Hu, John Wei-Shan; Lin, Chien-Yu

2014-01-01

The aim of this paper is to examine the impact of temperature shock on both near-month and far-month natural gas and heating oil futures returns by extending the weather and storage models of the previous study. Several notable findings from the empirical studies are presented. First, the expected temperature shock significantly and positively affects both the near-month and far-month natural gas and heating oil futures returns. Next, significant temperature shock has effect on both the conditional mean and volatility of natural gas and heating oil prices. The results indicate that expected inventory surprises significantly and negatively affects the far-month natural gas futures returns. Moreover, volatility of natural gas futures returns is higher on Thursdays and that of near-month heating oil futures returns is higher on Wednesdays than other days. Finally, it is found that storage announcement for natural gas significantly affects near-month and far-month natural gas futures returns. Furthermore, both natural gas and heating oil futures returns are affected more by the weighted average temperature reported by multiple weather reporting stations than that reported by a single weather reporting station. PMID:25133233

Surprise and Memory as Indices of Concrete Operational Development

Science.gov (United States)

Achenbach, Thomas M.

1973-01-01

Normal and retarded children's use of color, number, length and continuous quantity as attributes of identification was assessed by presenting them with contrived changes in three properties. Surprise and correct memory responses for color preceded those to number, which preceded logical verbal responses to a conventional number-conservation task.…

Things may not be as expected: Surprising findings when updating ...

African Journals Online (AJOL)

2015-05-14

May 14, 2015 ... Things may not be as expected: Surprising findings when updating .... (done at the end of three months after the first review month) ..... Allen G. Getting beyond form filling: The role of institutional governance in human research ...

Large Data Set Mining

NARCIS (Netherlands)

Leemans, I.B.; Broomhall, Susan

2017-01-01

Digital emotion research has yet to make history. Until now large data set mining has not been a very active field of research in early modern emotion studies. This is indeed surprising since first, the early modern field has such rich, copyright-free, digitized data sets and second, emotion studies

Estimations of expectedness and potential surprise in possibility theory

Science.gov (United States)

Prade, Henri; Yager, Ronald R.

1992-01-01

This note investigates how various ideas of 'expectedness' can be captured in the framework of possibility theory. Particularly, we are interested in trying to introduce estimates of the kind of lack of surprise expressed by people when saying 'I would not be surprised that...' before an event takes place, or by saying 'I knew it' after its realization. In possibility theory, a possibility distribution is supposed to model the relative levels of mutually exclusive alternatives in a set, or equivalently, the alternatives are assumed to be rank-ordered according to their level of possibility to take place. Four basic set-functions associated with a possibility distribution, including standard possibility and necessity measures, are discussed from the point of view of what they estimate when applied to potential events. Extensions of these estimates based on the notions of Q-projection or OWA operators are proposed when only significant parts of the possibility distribution are retained in the evaluation. The case of partially-known possibility distributions is also considered. Some potential applications are outlined.

Automation surprise : results of a field survey of Dutch pilots

NARCIS (Netherlands)

de Boer, R.J.; Hurts, Karel

2017-01-01

Automation surprise (AS) has often been associated with aviation safety incidents. Although numerous laboratory studies have been conducted, few data are available from routine flight operations. A survey among a representative sample of 200 Dutch airline pilots was used to determine the prevalence

The Impact of a Surprise Dividend Increase on a Stocks Performance : the Analysis of Companies Listed on the Warsaw Stock Exchange

Directory of Open Access Journals (Sweden)

Tomasz Słoński

2012-01-01

Full Text Available The reaction of marginal investors to the announcement of a surprise dividend increase has been measured. Although field research is performed on companies listed on the Warsaw Stock Exchange, the paper has important theoretical implications. Valuation theory gives many clues for the interpretation of changes in dividends. At the start of the literature review, the assumption of the irrelevance of dividends (to investment decisions is described. This assumption is the basis for up-to-date valuation procedures leading to fundamental and fair market valuation of equity (shares. The paper is designed to verify whether the market value of stock is immune to the surprise announcement of a dividend increase. This study of the effect of a surprise dividend increase gives the chance to partially isolate such an event from dividend changes based on long-term expectations. The result of the research explicitly shows that a surprise dividend increase is on average welcomed by investors (an average abnormal return of 2.24% with an associated p-value of 0.001. Abnormal returns are realized by investors when there is a surprise increase in a dividend payout. The subsample of relatively high increases in a dividend payout enables investors to gain a 3.2% return on average. The results show that valuation models should be revised to take into account a possible impact of dividend changes on investors behavior. (original abstract

ORMS IN SURPRISING PLACES: CLINICAL AND MORPHOLOGICAL FEATURES

Directory of Open Access Journals (Sweden)

Myroshnychenko MS

2013-06-01

Full Text Available Helminthes are the most common human diseases, which are characterized by involvement in the pathological process of all organs and systems. In this article, the authors discuss a few cases of typical and atypical localizations for parasitic worms such as filarial and pinworms which were recovered from surprising places in the bodies of patients in Kharkiv region. This article will allow the doctors of practical health care to pay special attention to the timely prevention and diagnostics of this pathology.

'Surprise': Outbreak of Campylobacter infection associated with chicken liver pâté at a surprise birthday party, Adelaide, Australia, 2012.

Science.gov (United States)

Parry, Amy; Fearnley, Emily; Denehy, Emma

2012-10-01

In July 2012, an outbreak of Campylobacter infection was investigated by the South Australian Communicable Disease Control Branch and Food Policy and Programs Branch. The initial notification identified illness at a surprise birthday party held at a restaurant on 14 July 2012. The objective of the investigation was to identify the potential source of infection and institute appropriate intervention strategies to prevent further illness. A guest list was obtained and a retrospective cohort study undertaken. A combination of paper-based and telephone questionnaires were used to collect exposure and outcome information. An environmental investigation was conducted by Food Policy and Programs Branch at the implicated premises. All 57 guests completed the questionnaire (100% response rate), and 15 met the case definition. Analysis showed a significant association between illness and consumption of chicken liver pâté (relative risk: 16.7, 95% confidence interval: 2.4-118.6). No other food or beverage served at the party was associated with illness. Three guests submitted stool samples; all were positive for Campylobacter. The environmental investigation identified that the cooking process used in the preparation of chicken liver pâté may have been inconsistent, resulting in some portions not cooked adequately to inactivate potential Campylobacter contamination. Chicken liver products are a known source of Campylobacter infection; therefore, education of food handlers remains a high priority. To better identify outbreaks among the large number of Campylobacter notifications, routine typing of Campylobacter isolates is recommended.

Primary Care Practice: Uncertainty and Surprise

Science.gov (United States)

Crabtree, Benjamin F.

I will focus my comments on uncertainty and surprise in primary care practices. I am a medical anthropologist by training, and have been a full-time researcher in family medicine for close to twenty years. In this talk I want to look at primary care practices as complex systems, particularly taking the perspective of translating evidence into practice. I am going to discuss briefly the challenges we have in primary care, and in medicine in general, of translating new evidence into the everyday care of patients. To do this, I will look at two studies that we have conducted on family practices, then think about how practices can be best characterized as complex adaptive systems. Finally, I will focus on the implications of this portrayal for disseminating new knowledge into practice.

Carbon Dioxide: Surprising Effects on Decision Making and Neurocognitive Performance

Science.gov (United States)

James, John T.

2013-01-01

The occupants of modern submarines and the International Space Station (ISS) have much in common as far as their air quality is concerned. Air is polluted by materials offgassing, use of utility compounds, leaks of systems chemicals, and anthropogenic sources. The primary anthropogenic compound of concern to submariners and astronauts has been carbon dioxide (CO2). NASA and the US Navy rely on the National Research Council Committee on Toxicology (NRC-COT) to help formulate exposure levels to CO2 that are thought to be safe for exposures of 3-6 months. NASA calls its limits Spacecraft Maximum Allowable Concentrations (SMACs). Years of experience aboard the ISS and a recent publication on deficits in decision making in ground-based subjects exposed briefly to 0.25% CO2 suggest that exposure levels that have been presumed acceptable to preserve health and performance need to be reevaluated. The current CO2 exposure limits for 3-6 months set by NASA and the UK Navy are 0.7%, and the limit for US submariners is 0.5%, although the NRC-COT recommended a 90-day level of 0.8% as safe a few years ago. NASA has set a 1000-day SMAC at 0.5% for exploration-class missions. Anecdotal experience with ISS operations approaching the current 180-day SMAC of 0.7% suggest that this limit is too high. Temporarily, NASA has limited exposures to 0.5% until further peer-reviewed data become available. In the meantime, a study published last year in the journal Environmental Health Perspectives (Satish U, et al. 2012) demonstrated that complexdecision- making performance is somewhat affected at 0.1% CO2 and becomes "dysfunctional" for at least half of the 9 indices of performance at concentrations approaching 0.25% CO2. The investigators used the Strategic Management Simulation (SMS) method of testing for decisionmaking ability, and the results were so surprising to the investigators that they declared that their findings need to be independently confirmed. NASA has responded to the

What is a surprise earthquake? The example of the 2002, San Giuliano (Italy event

Directory of Open Access Journals (Sweden)

M. Mucciarelli

2005-06-01

Full Text Available Both in scientific literature and in the mass media, some earthquakes are defined as «surprise earthquakes». Based on his own judgment, probably any geologist, seismologist or engineer may have his own list of past «surprise earthquakes». This paper tries to quantify the underlying individual perception that may lead a scientist to apply such a definition to a seismic event. The meaning is different, depending on the disciplinary approach. For geologists, the Italian database of seismogenic sources is still too incomplete to allow for a quantitative estimate of the subjective degree of belief. For seismologists, quantification is possible defining the distance between an earthquake and its closest previous neighbor. Finally, for engineers, the San Giuliano quake could not be considered a surprise, since probabilistic site hazard estimates reveal that the change before and after the earthquake is just 4%.

Analysis of physiological signals for recognition of boredom, pain, and surprise emotions.

Science.gov (United States)

Jang, Eun-Hye; Park, Byoung-Jun; Park, Mi-Sook; Kim, Sang-Hyeob; Sohn, Jin-Hun

2015-06-18

The aim of the study was to examine the differences of boredom, pain, and surprise. In addition to that, it was conducted to propose approaches for emotion recognition based on physiological signals. Three emotions, boredom, pain, and surprise, are induced through the presentation of emotional stimuli and electrocardiography (ECG), electrodermal activity (EDA), skin temperature (SKT), and photoplethysmography (PPG) as physiological signals are measured to collect a dataset from 217 participants when experiencing the emotions. Twenty-seven physiological features are extracted from the signals to classify the three emotions. The discriminant function analysis (DFA) as a statistical method, and five machine learning algorithms (linear discriminant analysis (LDA), classification and regression trees (CART), self-organizing map (SOM), Naïve Bayes algorithm, and support vector machine (SVM)) are used for classifying the emotions. The result shows that the difference of physiological responses among emotions is significant in heart rate (HR), skin conductance level (SCL), skin conductance response (SCR), mean skin temperature (meanSKT), blood volume pulse (BVP), and pulse transit time (PTT), and the highest recognition accuracy of 84.7% is obtained by using DFA. This study demonstrates the differences of boredom, pain, and surprise and the best emotion recognizer for the classification of the three emotions by using physiological signals.

Teacher Supply and Demand: Surprises from Primary Research

Directory of Open Access Journals (Sweden)

Andrew J. Wayne

2000-09-01

Full Text Available An investigation of primary research studies on public school teacher supply and demand revealed four surprises. Projections show that enrollments are leveling off. Relatedly, annual hiring increases should be only about two or three percent over the next few years. Results from studies of teacher attrition also yield unexpected results. Excluding retirements, only about one in 20 teachers leaves each year, and the novice teachers who quit mainly cite personal and family reasons, not job dissatisfaction. Each of these findings broadens policy makers' options for teacher supply.

Conference of “Uncertainty and Surprise: Questions on Working with the Unexpected and Unknowable”

CERN Document Server

McDaniel, Reuben R; Uncertainty and Surprise in Complex Systems : Questions on Working with the Unexpected

2005-01-01

Complexity science has been a source of new insight in physical and social systems and has demonstrated that unpredictability and surprise are fundamental aspects of the world around us. This book is the outcome of a discussion meeting of leading scholars and critical thinkers with expertise in complex systems sciences and leaders from a variety of organizations sponsored by the Prigogine Center at The University of Texas at Austin and the Plexus Institute to explore strategies for understanding uncertainty and surprise. Besides distributions to the conference it includes a key digest by the editors as well as a commentary by the late nobel laureat Ilya Prigogine, "Surprises in half of a century". The book is intended for researchers and scientists in complexity science as well as for a broad interdisciplinary audience of both practitioners and scholars. It will well serve those interested in the research issues and in the application of complexity science to physical and social systems.

Atom Surprise: Using Theatre in Primary Science Education

Science.gov (United States)

Peleg, Ran; Baram-Tsabari, Ayelet

2011-10-01

Early exposure to science may have a lifelong effect on children's attitudes towards science and their motivation to learn science in later life. Out-of-class environments can play a significant role in creating favourable attitudes, while contributing to conceptual learning. Educational science theatre is one form of an out-of-class environment, which has received little research attention. This study aims to describe affective and cognitive learning outcomes of watching such a play and to point to connections between theatrical elements and specific outcomes. "Atom Surprise" is a play portraying several concepts on the topic of matter. A mixed methods approach was adopted to investigate the knowledge and attitudes of children (grades 1-6) from two different school settings who watched the play. Data were gathered using questionnaires and in-depth interviews. Analysis suggested that in both schools children's knowledge on the topic of matter increased after the play with younger children gaining more conceptual knowledge than their older peers. In the public school girls showed greater gains in conceptual knowledge than boys. No significant changes in students' general attitudes towards science were found, however, students demonstrated positive changes towards science learning. Theatrical elements that seemed to be important in children's recollection of the play were the narrative, props and stage effects, and characters. In the children's memory, science was intertwined with the theatrical elements. Nonetheless, children could distinguish well between scientific facts and the fictive narrative.

On the surprising rigidity of the Pauli exclusion principle

International Nuclear Information System (INIS)

Greenberg, O.W.

1989-01-01

I review recent attempts to construct a local quantum field theory of small violations of the Pauli exclusion principle and suggest a qualitative reason for the surprising rigidity of the Pauli principle. I suggest that small violations can occur in our four-dimensional world as a consequence of the compactification of a higher-dimensional theory in which the exclusion principle is exactly valid. I briefly mention a recent experiment which places a severe limit on possible violations of the exclusion principle. (orig.)

On predicting quantal cross sections by interpolation: Surprisal analysis of j/sub z/CCS and statistical j/sub z/ results

International Nuclear Information System (INIS)

Goldflam, R.; Kouri, D.J.

1976-01-01

New methods for predicting the full matrix of integral cross sections are developed by combining the surprisal analysis of Bernstein and Levine with the j/sub z/-conserving coupled states method (j/sub z/CCS) of McGuire, Kouri, and Pack and with the statistical j/sub z/ approximation (Sj/sub z/) of Kouri, Shimoni, and Heil. A variety of approaches is possible and only three are studied in the present work. These are (a) a surprisal fit of the j=0→j' column of the j/sub z/CCS cross section matrix (thereby requiring only a solution of the lambda=0 set of j/sub z/CCS equations), (b) a surprisal fit of the lambda-bar=0 Sj/sub z/ cross section matrix (again requiring solution of the lambda=0 set of j/sub z/CCS equations only), and (c) a surprisal fit of a lambda-bar not equal to 0 Sj/sub z/ submatrix (involving input cross sections for j,j'> or =lambda-bar transitions only). The last approach requires the solution of the lambda=lambda-bar set of j/sub z/CCS equations only, which requires less computation effort than the effective potential method. We explore three different choices for the prior and two-parameter (i.e., linear) and three-parameter (i.e., parabolic) fits as applied to Ar--N 2 collisions. The results are in general very encouraging and for one choice of prior give results which are within 20% of the exact j/sub z/CCS results

Cloud Surprises in Moving NASA EOSDIS Applications into Amazon Web Services

Science.gov (United States)

Mclaughlin, Brett

2017-01-01

NASA ESDIS has been moving a variety of data ingest, distribution, and science data processing applications into a cloud environment over the last 2 years. As expected, there have been a number of challenges in migrating primarily on-premises applications into a cloud-based environment, related to architecture and taking advantage of cloud-based services. What was not expected is a number of issues that were beyond purely technical application re-architectures. We ran into surprising network policy limitations, billing challenges in a government-based cost model, and difficulty in obtaining certificates in an NASA security-compliant manner. On the other hand, this approach has allowed us to move a number of applications from local hosting to the cloud in a matter of hours (yes, hours!!), and our CMR application now services 95% of granule searches and an astonishing 99% of all collection searches in under a second. And most surprising of all, well, you'll just have to wait and see the realization that caught our entire team off guard!

The influence of psychological resilience on the relation between automatic stimulus evaluation and attentional breadth for surprised faces.

Science.gov (United States)

Grol, Maud; De Raedt, Rudi

2015-01-01

The broaden-and-build theory relates positive emotions to resilience and cognitive broadening. The theory proposes that the broadening effects underly the relation between positive emotions and resilience, suggesting that resilient people can benefit more from positive emotions at the level of cognitive functioning. Research has investigated the influence of positive emotions on attentional broadening, but the stimulus in the target of attention may also influence attentional breadth, depending on affective stimulus evaluation. Surprised faces are particularly interesting as they are valence ambiguous, therefore, we investigated the relation between affective evaluation--using an affective priming task--and attentional breadth for surprised faces, and how this relation is influenced by resilience. Results show that more positive evaluations are related to more attentional broadening at high levels of resilience, while this relation is reversed at low levels. This indicates that resilient individuals can benefit more from attending to positively evaluated stimuli at the level of attentional broadening.

Risk, surprises and black swans fundamental ideas and concepts in risk assessment and risk management

CERN Document Server

Aven, Terje

2014-01-01

Risk, Surprises and Black Swans provides an in depth analysis of the risk concept with a focus on the critical link to knowledge; and the lack of knowledge, that risk and probability judgements are based on.Based on technical scientific research, this book presents a new perspective to help you understand how to assess and manage surprising, extreme events, known as 'Black Swans'. This approach looks beyond the traditional probability-based principles to offer a broader insight into the important aspects of uncertain events and in doing so explores the ways to manage them.

Effective Conformal Descriptions of Black Hole Entropy

Directory of Open Access Journals (Sweden)

Steven Carlip

2011-07-01

Full Text Available It is no longer considered surprising that black holes have temperatures and entropies. What remains surprising, though, is the universality of these thermodynamic properties: their exceptionally simple and general form, and the fact that they can be derived from many very different descriptions of the underlying microscopic degrees of freedom. I review the proposal that this universality arises from an approximate conformal symmetry, which permits an effective “conformal dual” description that is largely independent of the microscopic details.

Surprises and counterexamples in real function theory

CERN Document Server

Rajwade, A R

2007-01-01

This book presents a variety of intriguing, surprising and appealing topics and nonroutine theorems in real function theory. It is a reference book to which one can turn for finding that arise while studying or teaching analysis.Chapter 1 is an introduction to algebraic, irrational and transcendental numbers and contains the Cantor ternary set. Chapter 2 contains functions with extraordinary properties; functions that are continuous at each point but differentiable at no point. Chapters 4 and intermediate value property, periodic functions, Rolle's theorem, Taylor's theorem, points of tangents. Chapter 6 discusses sequences and series. It includes the restricted harmonic series, of alternating harmonic series and some number theoretic aspects. In Chapter 7, the infinite peculiar range of convergence is studied. Appendix I deal with some specialized topics. Exercises at the end of chapters and their solutions are provided in Appendix II.This book will be useful for students and teachers alike.

The influence of the surprising decay properties of element 108 on search experiments for new elements

International Nuclear Information System (INIS)

Hofmann, S.; Armbruster, P.; Muenzenberg, G.; Reisdorf, W.; Schmidt, K.H.; Burkhard, H.G.; Hessberger, F.P.; Schoett, H.J.; Agarwal, Y.K.; Berthes, G.; Gollerthan, U.; Folger, H.; Hingmann, J.G.; Keller, J.G.; Leino, M.E.; Lemmertz, P.; Montoya, M.; Poppensieker, K.; Quint, B.; Zychor, I.

1986-01-01

Results of experiments to synthesize the heaviest elements are reported. Surprising is the high stability against fission not only of the odd and odd-odd nuclei but also of even isotopes of even elements. Alpha decay data gave an increasing stability of nuclei by shell effects up to 266 109, the heaviest known element. Theoretically, the high stability is explained by an island of nuclei with big quadrupole and hexadecapole deformations around Z=109 and N=162. Future experiments will be planned to prove the island character of these heavy nuclei. (orig.)

How to use the Fast Fourier Transform in Large Finite Fields

OpenAIRE

Petersen, Petur Birgir

2011-01-01

The article contents suggestions on how to perform the Fast Fourier Transform over Large Finite Fields. The technique is to use the fact that the multiplicative groups of specific prime fields are surprisingly composite.

Monitoring the effects of floods on submerged macrophytes in a large river.

Science.gov (United States)

Ibáñez, Carles; Caiola, Nuno; Rovira, Albert; Real, Montserrat

2012-12-01

The lower Ebro River (Catalonia, Spain) has recently undergone a regime shift from a phytoplankton to a macrophyte-dominated system. Macrophytes started to spread at the end of the 1990s and since 2002 artificial floods (flushing flows) of short duration (1-2 days) are released from the Riba-roja dam once or twice a year in order to reduce macrophyte density. The aim of this study was to analyse the spatiotemporal trends of the submerged macrophytes in two stretches of the lower Ebro River using high-resolution hydroacoustic methods, in order to elucidate the effects of artificial floods and natural floods on its distribution and abundance. Results showed that the mean cover in the two studied stretches (Móra and Ginestar) was not reduced after a flushing flow (from 36.59% to 55.85% in Móra, and from 21.18% to 21.05% in Ginestar), but it was greatly reduced after the natural flood (down to 9.79% in Móra and 2.04% in Ginestar); surprisingly the cover increased in Móra after the artificial flood. In order to increase the efficiency of floods in controlling macrophyte spreading, the magnitude and frequency of them should largely increase, as well as the suspended sediment load, approaching as much as possible to the original flood pattern before dam construction. Hydroacoustic methods combined with geostatistics and interpolation in GIS can accurately monitor spatiotemporal trends of submerged macrophytes in large rivers. This is the first article to apply this monitoring system to submerged macrophytes in rivers. Copyright © 2012 Elsevier B.V. All rights reserved.

Environmental effects and large space systems

Science.gov (United States)

Garrett, H. B.

1981-01-01

When planning large scale operations in space, environmental impact must be considered in addition to radiation, spacecraft charging, contamination, high power and size. Pollution of the atmosphere and space is caused by rocket effluents and by photoelectrons generated by sunlight falling on satellite surfaces even light pollution may result (the SPS may reflect so much light as to be a nuisance to astronomers). Large (100 Km 2) structures also will absorb the high energy particles that impinge on them. Altogether, these effects may drastically alter the Earth's magnetosphere. It is not clear if these alterations will in any way affect the Earth's surface climate. Large structures will also generate large plasma wakes and waves which may cause interference with communications to the vehicle. A high energy, microwave beam from the SPS will cause ionospheric turbulence, affecting UHF and VHF communications. Although none of these effects may ultimately prove critical, they must be considered in the design of large structures.

A Shocking Surprise in Stephan's Quintet

Science.gov (United States)

2006-01-01

This false-color composite image of the Stephan's Quintet galaxy cluster clearly shows one of the largest shock waves ever seen (green arc). The wave was produced by one galaxy falling toward another at speeds of more than one million miles per hour. The image is made up of data from NASA's Spitzer Space Telescope and a ground-based telescope in Spain. Four of the five galaxies in this picture are involved in a violent collision, which has already stripped most of the hydrogen gas from the interiors of the galaxies. The centers of the galaxies appear as bright yellow-pink knots inside a blue haze of stars, and the galaxy producing all the turmoil, NGC7318b, is the left of two small bright regions in the middle right of the image. One galaxy, the large spiral at the bottom left of the image, is a foreground object and is not associated with the cluster. The titanic shock wave, larger than our own Milky Way galaxy, was detected by the ground-based telescope using visible-light wavelengths. It consists of hot hydrogen gas. As NGC7318b collides with gas spread throughout the cluster, atoms of hydrogen are heated in the shock wave, producing the green glow. Spitzer pointed its infrared spectrograph at the peak of this shock wave (middle of green glow) to learn more about its inner workings. This instrument breaks light apart into its basic components. Data from the instrument are referred to as spectra and are displayed as curving lines that indicate the amount of light coming at each specific wavelength. The Spitzer spectrum showed a strong infrared signature for incredibly turbulent gas made up of hydrogen molecules. This gas is caused when atoms of hydrogen rapidly pair-up to form molecules in the wake of the shock wave. Molecular hydrogen, unlike atomic hydrogen, gives off most of its energy through vibrations that emit in the infrared. This highly disturbed gas is the most turbulent molecular hydrogen ever seen. Astronomers were surprised not only by the turbulence

X-rays from comets - a surprising discovery

CERN Document Server

CERN. Geneva

2000-01-01

Comets are kilometre-size aggregates of ice and dust, which remained from the formation of the solar system. It was not obvious to expect X-ray emission from such objects. Nevertheless, when comet Hyakutake (C/1996 B2) was observed with the ROSAT X-ray satellite during its close approach to Earth in March 1996, bright X-ray emission from this comet was discovered. This finding triggered a search in archival ROSAT data for comets, which might have accidentally crossed the field of view during observations of unrelated targets. To increase the surprise even more, X-ray emission was detected from four additional comets, which were optically 300 to 30 000 times fainter than Hyakutake. For one of them, comet Arai (C/1991 A2), X-ray emission was even found in data which were taken six weeks before the comet was optically discovered. These findings showed that comets represent a new class of celestial X-ray sources. The subsequent detection of X-ray emission from several other comets in dedicated observations confir...

Communication Management and Trust: Their Role in Building Resilience to "Surprises" Such As Natural Disasters, Pandemic Flu, and Terrorism

Directory of Open Access Journals (Sweden)

P. H. Longstaff

2008-06-01

Full Text Available In times of public danger such as natural disasters and health emergencies, a country's communication systems will be some of its most important assets because access to information will make individuals and groups more resilient. Communication by those charged with dealing with the situation is often critical. We analyzed reports from a wide variety of crisis incidents and found a direct correlation between trust and an organization's preparedness and internal coordination of crisis communication and the effectiveness of its leadership. Thus, trust is one of the most important variables in effective communication management in times of "surprise."

Bagpipes and Artichokes: Surprise as a Stimulus to Learning in the Elementary Music Classroom

Science.gov (United States)

Jacobi, Bonnie Schaffhauser

2016-01-01

Incorporating surprise into music instruction can stimulate student attention, curiosity, and interest. Novelty focuses attention in the reticular activating system, increasing the potential for brain memory storage. Elementary ages are ideal for introducing novel instruments, pieces, composers, or styles of music. Young children have fewer…

The Educational Philosophies of Mordecai Kaplan and Michael Rosenak: Surprising Similarities and Illuminating Differences

Science.gov (United States)

Schein, Jeffrey; Caplan, Eric

2014-01-01

The thoughts of Mordecai Kaplan and Michael Rosenak present surprising commonalities as well as illuminating differences. Similarities include the perception that Judaism and Jewish education are in crisis, the belief that Jewish peoplehood must include commitment to meaningful content, the need for teachers to teach from a position of…

Dealing with unexpected events on the flight deck : A conceptual model of startle and surprise

NARCIS (Netherlands)

Landman, H.M.; Groen, E.L.; Paassen, M.M. van; Bronkhorst, A.W.; Mulder, M.

2017-01-01

Objective: A conceptual model is proposed in order to explain pilot performance in surprising and startling situations. Background: Today’s debate around loss of control following in-flight events and the implementation of upset prevention and recovery training has highlighted the importance of

Hepatobiliary fascioliasis in non-endemic zones: a surprise diagnosis.

Science.gov (United States)

Jha, Ashish Kumar; Goenka, Mahesh Kumar; Goenka, Usha; Chakrabarti, Amrita

2013-03-01

Fascioliasis is a zoonotic infection caused by Fasciola hepatica. Because of population migration and international food trade, human fascioliasis is being an increasingly recognised entity in nonendemic zones. In most parts of Asia, hepatobiliary fascioliasis is sporadic. Human hepatobiliary infection by this trematode has two distinct phases: an acute hepatic phase and a chronic biliary phase. Hepatobiliary infection is mostly associated with intense peripheral eosinophilia. In addition to classically defined hepatic phase and biliary phase fascioliasis, some cases may have an overlap of these two phases. Chronic liver abscess formation is a rare presentation. We describe a surprise case of hepatobiliary fascioliasis who presented to us with liver abscess without intense peripheral eosinophilia, a rare presentation of human fascioliasis especially in non-endemic zones. Copyright © 2013 Arab Journal of Gastroenterology. Published by Elsevier Ltd. All rights reserved.

Large complex ovarian cyst managed by laparoscopy

OpenAIRE

Dipak J. Limbachiya; Ankit Chaudhari; Grishma P. Agrawal

2017-01-01

Complex ovarian cyst with secondary infection is a rare disease that hardly responds to the usual antibiotic treatment. Most of the times, it hampers day to day activities of women. It is commonly known to cause pain and fever. To our surprise, in our case the cyst was large enough to compress the ureter and it was adherent to the surrounding structures. Laparoscopic removal of the cyst was done and specimen was sent for histopathological examination.

The acoustic environment in large HTGR's

International Nuclear Information System (INIS)

Burton, T.E.

1979-01-01

Well-known techniques for estimating acoustic vibration of structures have been applied to a General Atomic high-temperature gas-cooled reactor (HTGR) design. It is shown that one must evaluate internal loss factors for both fluid and structure modes, as well as radiation loss factors, to avoid large errors in estimated structural response. At any frequency above 1350 rad/s there are generally at least 20 acoustic modes contributing to acoustic pressure, so statistical energy analysis may be employed. But because the gas circuit consists mainly of high-aspect-ratio cavities, reverberant fields are nowhere isotropic below 7500 rad/s, and in some regions are not isotropic below 60 000 rad/s. In comparison with isotropic reverberant fields, these anistropic fields enhance the radiation efficiencies of some structural modes at low frequencies, but have surprisingly little effect at most frequencies. The efficiency of a dipole sound source depends upon its orientation. (Auth.)

Team play with a powerful and independent agent: operational experiences and automation surprises on the Airbus A-320

Science.gov (United States)

Sarter, N. B.; Woods, D. D.

1997-01-01

Research and operational experience have shown that one of the major problems with pilot-automation interaction is a lack of mode awareness (i.e., the current and future status and behavior of the automation). As a result, pilots sometimes experience so-called automation surprises when the automation takes an unexpected action or fails to behave as anticipated. A lack of mode awareness and automation surprises can he viewed as symptoms of a mismatch between human and machine properties and capabilities. Changes in automation design can therefore he expected to affect the likelihood and nature of problems encountered by pilots. Previous studies have focused exclusively on early generation "glass cockpit" aircraft that were designed based on a similar automation philosophy. To find out whether similar difficulties with maintaining mode awareness are encountered on more advanced aircraft, a corpus of automation surprises was gathered from pilots of the Airbus A-320, an aircraft characterized by high levels of autonomy, authority, and complexity. To understand the underlying reasons for reported breakdowns in human-automation coordination, we also asked pilots about their monitoring strategies and their experiences with and attitude toward the unique design of flight controls on this aircraft.

Surprisal analysis of Glioblastoma Multiform (GBM) microRNA dynamics unveils tumor specific phenotype.

Science.gov (United States)

Zadran, Sohila; Remacle, Francoise; Levine, Raphael

2014-01-01

Gliomablastoma multiform (GBM) is the most fatal form of all brain cancers in humans. Currently there are limited diagnostic tools for GBM detection. Here, we applied surprisal analysis, a theory grounded in thermodynamics, to unveil how biomolecule energetics, specifically a redistribution of free energy amongst microRNAs (miRNAs), results in a system deviating from a non-cancer state to the GBM cancer -specific phenotypic state. Utilizing global miRNA microarray expression data of normal and GBM patients tumors, surprisal analysis characterizes a miRNA system response capable of distinguishing GBM samples from normal tissue biopsy samples. We indicate that the miRNAs contributing to this system behavior is a disease phenotypic state specific to GBM and is therefore a unique GBM-specific thermodynamic signature. MiRNAs implicated in the regulation of stochastic signaling processes crucial in the hallmarks of human cancer, dominate this GBM-cancer phenotypic state. With this theory, we were able to distinguish with high fidelity GBM patients solely by monitoring the dynamics of miRNAs present in patients' biopsy samples. We anticipate that the GBM-specific thermodynamic signature will provide a critical translational tool in better characterizing cancer types and in the development of future therapeutics for GBM.

Pseudohalide (SCN(-))-Doped MAPbI3 Perovskites: A Few Surprises.

Science.gov (United States)

Halder, Ansuman; Chulliyil, Ramya; Subbiah, Anand S; Khan, Tuhin; Chattoraj, Shyamtanu; Chowdhury, Arindam; Sarkar, Shaibal K

2015-09-03

Pseudohalide thiocyanate anion (SCN(-)) has been used as a dopant in a methylammonium lead tri-iodide (MAPbI3) framework, aiming for its use as an absorber layer for photovoltaic applications. The substitution of SCN(-) pseudohalide anion, as verified using Fourier transform infrared (FT-IR) spectroscopy, results in a comprehensive effect on the optical properties of the original material. Photoluminescence measurements at room temperature reveal a significant enhancement in the emission quantum yield of MAPbI3-x(SCN)x as compared to MAPbI3, suggestive of suppression of nonradiative channels. This increased intensity is attributed to a highly edge specific emission from MAPbI3-x(SCN)x microcrystals as revealed by photoluminescence microscopy. Fluoresence lifetime imaging measurements further established contrasting carrier recombination dynamics for grain boundaries and the bulk of the doped material. Spatially resolved emission spectroscopy on individual microcrystals of MAPbI3-x(SCN)x reveals that the optical bandgap and density of states at various (local) nanodomains are also nonuniform. Surprisingly, several (local) emissive regions within MAPbI3-x(SCN)x microcrystals are found to be optically unstable under photoirradiation, and display unambiguous temporal intermittency in emission (blinking), which is extremely unusual and intriguing. We find diverse blinking behaviors for the undoped MAPbI3 crystals as well, which leads us to speculate that blinking may be a common phenomenon for most hybrid perovskite materials.

Physics Nobel prize 2004: Surprising theory wins physics Nobel

CERN Multimedia

2004-01-01

From left to right: David Politzer, David Gross and Frank Wilczek. For their understanding of counter-intuitive aspects of the strong force, which governs quarks inside protons and neutrons, on 5 October three American physicists were awarded the 2004 Nobel Prize in Physics. David J. Gross (Kavli Institute of Theoretical Physics, University of California, Santa Barbara), H. David Politzer (California Institute of Technology), and Frank Wilczek (Massachusetts Institute of Technology) made a key theoretical discovery with a surprising result: the closer quarks are together, the weaker the force - opposite to what is seen with electromagnetism and gravity. Rather, the strong force is analogous to a rubber band stretching, where the force increases as the quarks get farther apart. These physicists discovered this property of quarks, known as asymptotic freedom, in 1976. It later became a key part of the theory of quantum chromodynamics (QCD) and the Standard Model, the current best theory to describe the interac...

Large magnetoresistance effect in nitrogen-doped silicon

Directory of Open Access Journals (Sweden)

Tao Wang

2017-05-01

Full Text Available In this work, we reported a large magnetoresistance effect in silicon by ion implantation of nitrogen atoms. At room temperature, the magnetoresistance of silicon reaches 125 % under magnetic field 1.7 T and voltage bias -80 V. By applying an alternating magnetic field with a frequency (f of 0.008 Hz, we find that the magnetoresistance of silicon is divided into f and 2f two signal components, which represent the linear and quadratic magnetoresistance effects, respectively. The analysis based on tuning the magnetic field and the voltage bias reveals that electric-field-induced space-charge effect plays an important role to enhance both the linear and quadratic magnetoresistance effects. Observation as well as a comprehensive explanation of large MR in silicon, especially based on semiconductor CMOS implantation technology, will be an important progress towards magnetoelectronic applications.

Finite size effects of a pion matrix element

International Nuclear Information System (INIS)

Guagnelli, M.; Jansen, K.; Palombi, F.; Petronzio, R.; Shindler, A.; Wetzorke, I.

2004-01-01

We investigate finite size effects of the pion matrix element of the non-singlet, twist-2 operator corresponding to the average momentum of non-singlet quark densities. Using the quenched approximation, they come out to be surprisingly large when compared to the finite size effects of the pion mass. As a consequence, simulations of corresponding nucleon matrix elements could be affected by finite size effects even stronger which could lead to serious systematic uncertainties in their evaluation

Surprising judgments about robot drivers: Experiments on rising expectations and blaming humans

Directory of Open Access Journals (Sweden)

Peter Danielson

2015-05-01

Full Text Available N-Reasons is an experimental Internet survey platform designed to enhance public participation in applied ethics and policy. N-Reasons encourages individuals to generate reasons to support their judgments, and groups to converge on a common set of reasons pro and con various issues.  In the Robot Ethics Survey some of the reasons contributed surprising judgments about autonomous machines. Presented with a version of the trolley problem with an autonomous train as the agent, participants gave unexpected answers, revealing high expectations for the autonomous machine and shifting blame from the automated device to the humans in the scenario. Further experiments with a standard pair of human-only trolley problems refine these results. While showing the high expectations even when no autonomous machine is involved, human bystanders are only blamed in the machine case. A third experiment explicitly aimed at responsibility for driverless cars confirms our findings about shifting blame in the case of autonomous machine agents. We conclude methodologically that both results point to the power of an experimental survey based approach to public participation to explore surprising assumptions and judgments in applied ethics. However, both results also support using caution when interpreting survey results in ethics, demonstrating the importance of qualitative data to provide further context for evaluating judgments revealed by surveys. On the ethics side, the result about shifting blame to humans interacting with autonomous machines suggests caution about the unintended consequences of intuitive principles requiring human responsibility.http://dx.doi.org/10.5324/eip.v9i1.1727

Surprises from a Deep ASCA Spectrum of the Broad Absorption Line Quasar PHL 5200

Science.gov (United States)

Mathur, Smita; Matt, G.; Green, P. J.; Elvis, M.; Singh, K. P.

2002-01-01

We present a deep (approx. 85 ks) ASCA observation of the prototype broad absorption line quasar (BALQSO) PHL 5200. This is the best X-ray spectrum of a BALQSO yet. We find the following: (1) The source is not intrinsically X-ray weak. (2) The line-of-sight absorption is very strong, with N(sub H) = 5 x 10(exp 23)/sq cm. (3) The absorber does not cover the source completely; the covering fraction is approx. 90%. This is consistent with the large optical polarization observed in this source, implying multiple lines of sight. The most surprising result of this observation is that (4) the spectrum of this BALQSO is not exactly similar to other radio-quiet quasars. The hard X-ray spectrum of PHL 5200 is steep, with the power-law spectral index alpha approx. 1.5. This is similar to the steepest hard X-ray slopes observed so far. At low redshifts, such steep slopes are observed in narrow-line Seyfert 1 (NLS1) galaxies, believed to be accreting at a high Eddington rate. This observation strengthens the analogy between BALQSOs and NLS1 galaxies and supports the hypothesis that BALQSOs represent an early evolutionary state of quasars. It is well accepted that the orientation to the line of sight determines the appearance of a quasar: age seems to play a significant role as well.

Economic valuation of the downstream hydrological effects of land use change: Large hydroelectric reservoirs

Science.gov (United States)

Aylward, Bruce Allan

1998-12-01

Land use change that accompanies economic development and population growth is intended to raise the economic productivity of land. An inevitable by product of this process is the alteration of natural vegetation and downstream hydrological function. This dissertation explores hydrological externalities of land use change in detail, particularly with regard to their economic impact on large hydroelectric reservoirs (LHRs). A review of the linkages between land use, hydrological function and downstream economic activity suggests that on theoretical grounds the net welfare effect of land use change on hydrological function will be indeterminate. Review of the literature suggests that, though the effects of downstream sedimentation will typically be negative, they may often be of little practical significance. The literature on water quantity impacts is sparse at best. This is most surprising in the case of the literature on LHRs where the potentially important and positive effects of increased water yield are typically ignored in favor of simplistic efforts to document the negative effects of reservoir sedimentation. In order to improve the methodological basis for the economic valuation of hydrological externalities, the dissertation considers existing techniques for the evaluation of non-marketed goods and services, clarifying the manner in which they have been and, in the future, may be applied to the topic at hand. A deterministic simulation model is then constructed for the case of LHRs. The model incorporates the effect of changes in water yield, the seasonal pattern of water yield and sedimentation of live and dead storage volumes as they affect reservoir operation and the production of hydroelectricity. The welfare effects of changes in the productivity of the LHR in the short run and changes to the power system expansion plan in the long run are evaluated using the marginal opportunity costs of alternative power sources and power plants, respectively. A case

Arctic skate Amblyraja hyperborea preys on remarkably large glacial eelpouts Lycodes frigidus.

Science.gov (United States)

Byrkjedal, I; Christiansen, J S; Karamushko, O V; Langhelle, G; Lynghammar, A

2015-01-01

During scientific surveys on the continental slopes north-west of Spitsbergen and off north-east Greenland (c. 600 and 1000 m depths), two female Arctic skates Amblyraja hyperborea were caught while swallowing extraordinary large individuals of glacial eelpout Lycodes frigidus. The total length (LT) of the prey constituted 50 and 80% of the LT of the skates, which reveal that A. hyperborea are capable predators of fishes of surprisingly large relative size. © 2014 The Fisheries Society of the British Isles.

Effects of large herbivores on grassland arthropod diversity.

Science.gov (United States)

van Klink, R; van der Plas, F; van Noordwijk, C G E Toos; WallisDeVries, M F; Olff, H

2015-05-01

Both arthropods and large grazing herbivores are important components and drivers of biodiversity in grassland ecosystems, but a synthesis of how arthropod diversity is affected by large herbivores has been largely missing. To fill this gap, we conducted a literature search, which yielded 141 studies on this topic of which 24 simultaneously investigated plant and arthropod diversity. Using the data from these 24 studies, we compared the responses of plant and arthropod diversity to an increase in grazing intensity. This quantitative assessment showed no overall significant effect of increasing grazing intensity on plant diversity, while arthropod diversity was generally negatively affected. To understand these negative effects, we explored the mechanisms by which large herbivores affect arthropod communities: direct effects, changes in vegetation structure, changes in plant community composition, changes in soil conditions, and cascading effects within the arthropod interaction web. We identify three main factors determining the effects of large herbivores on arthropod diversity: (i) unintentional predation and increased disturbance, (ii) decreases in total resource abundance for arthropods (biomass) and (iii) changes in plant diversity, vegetation structure and abiotic conditions. In general, heterogeneity in vegetation structure and abiotic conditions increases at intermediate grazing intensity, but declines at both low and high grazing intensity. We conclude that large herbivores can only increase arthropod diversity if they cause an increase in (a)biotic heterogeneity, and then only if this increase is large enough to compensate for the loss of total resource abundance and the increased mortality rate. This is expected to occur only at low herbivore densities or with spatio-temporal variation in herbivore densities. As we demonstrate that arthropod diversity is often more negatively affected by grazing than plant diversity, we strongly recommend considering the

Cloud Surprises Discovered in Moving NASA EOSDIS Applications into Amazon Web Services… and #6 Will Shock You!

Science.gov (United States)

McLaughlin, B. D.; Pawloski, A. W.

2017-12-01

NASA ESDIS has been moving a variety of data ingest, distribution, and science data processing applications into a cloud environment over the last 2 years. As expected, there have been a number of challenges in migrating primarily on-premises applications into a cloud-based environment, related to architecture and taking advantage of cloud-based services. What was not expected is a number of issues that were beyond purely technical application re-architectures. From surprising network policy limitations, billing challenges in a government-based cost model, and obtaining certificates in an NASA security-compliant manner to working with multiple applications in a shared and resource-constrained AWS account, these have been the relevant challenges in taking advantage of a cloud model. And most surprising of all… well, you'll just have to wait and see the "gotcha" that caught our entire team off guard!

Surprising Ripple Effects: How Changing the SAT Score-Sending Policy for Low-Income Students Impacts College Access and Success

Science.gov (United States)

Hurwitz, Michael; Mbekeani, Preeya P.; Nipson, Margaret M.; Page, Lindsay C.

2017-01-01

Subtle policy adjustments can induce relatively large "ripple effects." We evaluate a College Board initiative that increased the number of free SAT score reports available to low-income students and changed the time horizon for using these score reports. Using a difference-in-differences analytic strategy, we estimate that targeted…

THE RECENCY EFFECT OF ACCOUNTING INFORMATION

Directory of Open Access Journals (Sweden)

Jogiyanto Hartono

2012-01-01

Full Text Available This study tests the joint effects of dividend and earnings information. A study of joint effects is justified for the following reasons. First, dividends and earnings are considered two of the most important signaling devices (Aharony and Swary 1980 that investors use in evaluating stock prices. Second, dividends and earnings are 'garbled' information (Ohlson 1989. Dividends and earnings may contain corroborating or disconfirming news. Third, investors may be have with memory, revising beliefs in complex ways in evaluating a sequence of information. Prior dividend studies that controlling for earnings announcement effects do not address these possibilities. Using Hogarth and Einhorn's (1992 belief-adjustment theory, this study models the behavior of investor reactions to joint dividend and earnings surprises. The theory predicts that order and timing of dividend and earnings surprises have different effects on stock returns. When dividend and earnings surprises have opposite signs (mixedevidence, the theory predicts that later surprises have a larger impact on stock returns than do earlier surprises (the recency effect hypothesis. The evidence for the recency  effect hypotheses is relatively strong. In three out of four cases of mixed evidence (positive earnings, negative earnings and positive dividend surprises, the recency effect hypotheses are supported.

A surprisingly simple correlation between the classical and quantum structural networks in liquid water

Science.gov (United States)

Hamm, Peter; Fanourgakis, George S.; Xantheas, Sotiris S.

2017-08-01

Nuclear quantum effects in liquid water have profound implications for several of its macroscopic properties related to the structure, dynamics, spectroscopy, and transport. Although several of water's macroscopic properties can be reproduced by classical descriptions of the nuclei using interaction potentials effectively parameterized for a narrow range of its phase diagram, a proper account of the nuclear quantum effects is required to ensure that the underlying molecular interactions are transferable across a wide temperature range covering different regions of that diagram. When performing an analysis of the hydrogen-bonded structural networks in liquid water resulting from the classical (class) and quantum (qm) descriptions of the nuclei with two interaction potentials that are at the two opposite ends of the range in describing quantum effects, namely the flexible, pair-wise additive q-TIP4P/F, and the flexible, polarizable TTM3-F, we found that the (class) and (qm) results can be superimposed over the temperature range T = 250-350 K using a surprisingly simple, linear scaling of the two temperatures according to T(qm) = α T(class) + ΔT, where α = 0.99 and ΔT = -6 K for q-TIP4P/F and α = 1.24 and ΔT = -64 K for TTM3-F. This simple relationship suggests that the structural networks resulting from the quantum and classical treatment of the nuclei with those two very different interaction potentials are essentially similar to each other over this extended temperature range once a model-dependent linear temperature scaling law is applied.

Virtual Volatility, an Elementary New Concept with Surprising Stock Market Consequences

Science.gov (United States)

Prange, Richard; Silva, A. Christian

2006-03-01

Textbook investors start by predicting the future price distribution, PDF, of a candidate stock (or portfolio) at horizon T, e.g. a year hence. A (log)normal PDF with center (=drift =expected return) μT and width (=volatility) σT is often assumed on Central Limit Theorem grounds, i.e. by a random walk of daily (log)price increments δs. The standard deviation, stdev, of historical (ex post) δs `s is usually a fair predictor of the coming year's (ex ante) stdev(δs) = σdaily, but the historical mean E(δs) at best roughly limits the true, to be predicted, drift by μtrueT˜ μhistT ± σhistT. Textbooks take a PDF with σ ˜ σdaily and μ as somehow known, as if accurate predictions of μ were possible. It is elementary and presumably new to argue that an average of PDF's over a range of μ values should be taken, e.g. an average over forecasts by different analysts. We estimate that this leads to a PDF with a `virtual' volatility σ ˜ 1.3σdaily. It is indeed clear that uncertainty in the value of the expected gain parameter increases the risk of investment in that security by most measures, e. g. Sharpe's ratio μT/σT will be 30% smaller because of this effect. It is significant and surprising that there are investments which benefit from this 30% virtual increase in the volatility

The Surprising Impact of Seat Location on Student Performance

Science.gov (United States)

Perkins, Katherine K.; Wieman, Carl E.

2005-01-01

Every physics instructor knows that the most engaged and successful students tend to sit at the front of the class and the weakest students tend to sit at the back. However, it is normally assumed that this is merely an indication of the respective seat location preferences of weaker and stronger students. Here we present evidence suggesting that in fact this may be mixing up the cause and effect. It may be that the seat selection itself contributes to whether the student does well or poorly, rather than the other way around. While a number of studies have looked at the effect of seat location on students, the results are often inconclusive, and few, if any, have studied the effects in college classrooms with randomly assigned seats. In this paper, we report on our observations of a large introductory physics course in which we randomly assigned students to particular seat locations at the beginning of the semester. Seat location during the first half of the semester had a noticeable impact on student success in the course, particularly in the top and bottom parts of the grade distribution. Students sitting in the back of the room for the first half of the term were nearly six times as likely to receive an F as students who started in the front of the room. A corresponding but less dramatic reversal was evident in the fractions of students receiving As. These effects were in spite of many unusual efforts to engage students at the back of the class and a front-to-back reversal of seat location halfway through the term. These results suggest there may be inherent detrimental effects of large physics lecture halls that need to be further explored.

X rays and radioactivity: a complete surprise

International Nuclear Information System (INIS)

Radvanyi, P.; Bordry, M.

1995-01-01

The discoveries of X rays and of radioactivity came as complete experimental surprises; the physicists, at that time, had no previous hint of a possible structure of atoms. It is difficult now, knowing what we know, to replace ourselves in the spirit, astonishment and questioning of these years, between 1895 and 1903. The nature of X rays was soon hypothesized, but the nature of the rays emitted by uranium, polonium and radium was much more difficult to disentangle, as they were a mixture of different types of radiations. The origin of the energy continuously released in radioactivity remained a complete mystery for a few years. The multiplicity of the radioactive substances became soon a difficult matter: what was real and what was induced ? Isotopy was still far ahead. It appeared that some radioactive substances had ''half-lifes'': were they genuine radioactive elements or was it just a transitory phenomenon ? Henri Becquerel (in 1900) and Pierre and Marie Curie (in 1902) hesitated on the correct answer. Only after Ernest Rutherford and Frederick Soddy established that radioactivity was the transmutation of one element into another, could one understand that a solid element transformed into a gaseous element, which in turn transformed itself into a succession of solid radioactive elements. It was only in 1913 - after the discovery of the atomic nucleus -, through precise measurements of X ray spectra, that Henry Moseley showed that the number of electrons of a given atom - and the charge of its nucleus - was equal to its atomic number in the periodic table. (authors)

X rays and radioactivity: a complete surprise

Energy Technology Data Exchange (ETDEWEB)

Radvanyi, P. [Laboratoire National Saturne, Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France); Bordry, M. [Institut du Radium, 75 - Paris (France)

1995-12-31

The discoveries of X rays and of radioactivity came as complete experimental surprises; the physicists, at that time, had no previous hint of a possible structure of atoms. It is difficult now, knowing what we know, to replace ourselves in the spirit, astonishment and questioning of these years, between 1895 and 1903. The nature of X rays was soon hypothesized, but the nature of the rays emitted by uranium, polonium and radium was much more difficult to disentangle, as they were a mixture of different types of radiations. The origin of the energy continuously released in radioactivity remained a complete mystery for a few years. The multiplicity of the radioactive substances became soon a difficult matter: what was real and what was induced ? Isotopy was still far ahead. It appeared that some radioactive substances had ``half-lifes``: were they genuine radioactive elements or was it just a transitory phenomenon ? Henri Becquerel (in 1900) and Pierre and Marie Curie (in 1902) hesitated on the correct answer. Only after Ernest Rutherford and Frederick Soddy established that radioactivity was the transmutation of one element into another, could one understand that a solid element transformed into a gaseous element, which in turn transformed itself into a succession of solid radioactive elements. It was only in 1913 - after the discovery of the atomic nucleus -, through precise measurements of X ray spectra, that Henry Moseley showed that the number of electrons of a given atom - and the charge of its nucleus - was equal to its atomic number in the periodic table. (authors).

The effects of active labour market policies for immigrants receiving social assistance in Denmark

DEFF Research Database (Denmark)

Heinesen, Eskil; Leif, Husted,; Rosholm, Michael

2013-01-01

We estimate the effect of active labour-market programmes on the exit rate to regular employment for non-western immigrants in Denmark who receive social assistance. We use the timing-of-events duration model and rich administrative data. We find large positive post-programme effects, and......, surprisingly, even most in-programme effects are positive. The effects are largest for subsidized employment programmes, but effects are also large and significant for direct employment programmes and other programmes. Effects are larger if programmes begin after six months of unemployment. Implications of our...... estimates are illustrated by calculating effects on the duration to regular employment over a five-year period....

Prediction, Expectation, and Surprise: Methods, Designs, and Study of a Deployed Traffic Forecasting Service

OpenAIRE

Horvitz, Eric J.; Apacible, Johnson; Sarin, Raman; Liao, Lin

2012-01-01

We present research on developing models that forecast traffic flow and congestion in the Greater Seattle area. The research has led to the deployment of a service named JamBayes, that is being actively used by over 2,500 users via smartphones and desktop versions of the system. We review the modeling effort and describe experiments probing the predictive accuracy of the models. Finally, we present research on building models that can identify current and future surprises, via efforts on mode...

Collaborative Resilience to Episodic Shocks and Surprises: A Very Long-Term Case Study of Zanjera Irrigation in the Philippines 1979–2010

Directory of Open Access Journals (Sweden)

Ruth Yabes

2015-07-01

Full Text Available This thirty-year case study uses surveys, semi-structured interviews, and content analysis to examine the adaptive capacity of Zanjera San Marcelino, an indigenous irrigation management system in the northern Philippines. This common pool resource (CPR system exists within a turbulent social-ecological system (SES characterized by episodic shocks such as large typhoons as well as novel surprises, such as national political regime change and the construction of large dams. The Zanjera nimbly responded to these challenges, although sometimes in ways that left its structure and function substantially altered. While a partial integration with the Philippine National Irrigation Agency was critical to the Zanjera’s success, this relationship required on-going improvisation and renegotiation. Over time, the Zanjera showed an increasing capacity to learn and adapt. A core contribution of this analysis is the integration of a CPR study within an SES framework to examine resilience, made possible the occurrence of a wide range of challenges to the Zanjera’s function and survival over the long period of study. Long-term analyses like this one, however rare, are particularly useful for understanding the adaptive and transformative dimensions of resilience.

Stars Form Surprisingly Close to Milky Way's Black Hole

Science.gov (United States)

2005-10-01

million low mass, sun-like stars in and around the ring, whereas in the disk model, the number of low mass stars could be much less. Nayakshin and his coauthor, Rashid Sunyaev of the Max Plank Institute for Physics in Garching, Germany, used Chandra observations to compare the X-ray glow from the region around Sgr A* to the X-ray emission from thousands of young stars in the Orion Nebula star cluster. They found that the Sgr A* star cluster contains only about 10,000 low mass stars, thereby ruling out the migration model. "We can now say that the stars around Sgr A* were not deposited there by some passing star cluster, rather they were born there," said Sunyaev . "There have been theories that this was possible, but this is the first real evidence. Many scientists are going to be very surprised by these results." Because the Galactic Center is shrouded in dust and gas, it has not been possible to look for the low-mass stars in optical observations. In contrast, X-ray data have allowed astronomers to penetrate the veil of gas and dust and look for these low mass stars. Scenario Dismissed by Chandra Results Scenario Dismissed by Chandra Results "In one of the most inhospitable places in our Galaxy, stars have prevailed," said Nayakshin. "It appears that star formation is much more tenacious than we previously believed." The results suggest that the "rules" of star formation change when stars form in the disk of a giant black hole. Because this environment is very different from typical star formation regions, there is a change in the proportion of stars that form. For example, there is a much higher percentage of massive stars in the disks around black holes. And, when these massive stars explode as supernovae, they will "fertilize" the region with heavy elements such as oxygen. This may explain the large amounts of such elements observed in the disks of young supermassive black holes. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for

A Numeric Scorecard Assessing the Mental Health Preparedness for Large-Scale Crises at College and University Campuses: A Delphi Study

Science.gov (United States)

Burgin, Rick A.

2012-01-01

Large-scale crises continue to surprise, overwhelm, and shatter college and university campuses. While the devastation to physical plants and persons is often evident and is addressed with crisis management plans, the number of emotional casualties left in the wake of these large-scale crises may not be apparent and are often not addressed with…

Positive interactions between large herbivores and grasshoppers, and their consequences for grassland plant diversity.

Science.gov (United States)

Zhong, Zhiwei; Wang, Deli; Zhu, Hui; Wang, Ling; Feng, Chao; Wang, Zhongnan

2014-04-01

Although the influence of positive interactions on plant and sessile communities has been well documented, surprisingly little is known about their role in structuring terrestrial animal communities. We evaluated beneficial interactions between two distantly related herbivore taxa, large vertebrate grazers (sheep) and smaller insect grazers (grasshoppers), using a set of field experiments in eastern Eurasian steppe of China. Grazing by large herbivores caused significantly higher grasshopper density, and this pattern persisted until the end of the experiment. Grasshoppers, in turn, increased the foraging time of larger herbivores, but such response occurred only during the peak of growing season (August). These reciprocal interactions were driven by differential herbivore foraging preferences for plant resources; namely, large herbivores preferred Artemisia forbs, whereas grasshoppers preferred Leymus grass. The enhancement of grasshopper density in areas grazed by large herbivores likely resulted from the selective consumption of Artemisia forbs by vertebrate grazers, which may potentially improve the host finding of grasshoppers. Likewise, grasshoppers appeared to benefit large herbivores by decreasing the cover and density of the dominant grass Leymus chinensis, which hampers large herbivores' access to palatable forbs. Moreover, we found that large herbivores grazing alone may significantly decrease plant diversity, yet grasshoppers appeared to mediate such negative effects when they grazed with large herbivores. Our results suggest that the positive, reciprocal interactions in terrestrial herbivore communities may be more prevalent and complex than previously thought.

Quantitative Missense Variant Effect Prediction Using Large-Scale Mutagenesis Data.

Science.gov (United States)

Gray, Vanessa E; Hause, Ronald J; Luebeck, Jens; Shendure, Jay; Fowler, Douglas M

2018-01-24

Large datasets describing the quantitative effects of mutations on protein function are becoming increasingly available. Here, we leverage these datasets to develop Envision, which predicts the magnitude of a missense variant's molecular effect. Envision combines 21,026 variant effect measurements from nine large-scale experimental mutagenesis datasets, a hitherto untapped training resource, with a supervised, stochastic gradient boosting learning algorithm. Envision outperforms other missense variant effect predictors both on large-scale mutagenesis data and on an independent test dataset comprising 2,312 TP53 variants whose effects were measured using a low-throughput approach. This dataset was never used for hyperparameter tuning or model training and thus serves as an independent validation set. Envision prediction accuracy is also more consistent across amino acids than other predictors. Finally, we demonstrate that Envision's performance improves as more large-scale mutagenesis data are incorporated. We precompute Envision predictions for every possible single amino acid variant in human, mouse, frog, zebrafish, fruit fly, worm, and yeast proteomes (https://envision.gs.washington.edu/). Copyright © 2017 Elsevier Inc. All rights reserved.

Macroscopic quantum phenomena from the large N perspective

International Nuclear Information System (INIS)

Chou, C H; Hu, B L; Subasi, Y

2011-01-01

Macroscopic quantum phenomena (MQP) is a relatively new research venue, with exciting ongoing experiments and bright prospects, yet with surprisingly little theoretical activity. What makes MQP intellectually stimulating is because it is counterpoised against the traditional view that macroscopic means classical. This simplistic and hitherto rarely challenged view need be scrutinized anew, perhaps with much of the conventional wisdoms repealed. In this series of papers we report on a systematic investigation into some key foundational issues of MQP, with the hope of constructing a viable theoretical framework for this new endeavour. The three major themes discussed in these three essays are the large N expansion, the correlation hierarchy and quantum entanglement for systems of 'large' sizes, with many components or degrees of freedom. In this paper we use different theories in a variety of contexts to examine the conditions or criteria whereby a macroscopic quantum system may take on classical attributes, and, more interestingly, that it keeps some of its quantum features. The theories we consider here are, the O(N) quantum mechanical model, semiclassical stochastic gravity and gauge / string theories; the contexts include that of a 'quantum roll' in inflationary cosmology, entropy generation in quantum Vlasov equation for plasmas, the leading order and next-to-leading order large N behaviour, and hydrodynamic / thermodynamic limits. The criteria for classicality in our consideration include the use of uncertainty relations, the correlation between classical canonical variables, randomization of quantum phase, environment-induced decoherence, decoherent history of hydrodynamic variables, etc. All this exercise is to ask only one simple question: Is it really so surprising that quantum features can appear in macroscopic objects? By examining different representative systems where detailed theoretical analysis has been carried out, we find that there is no a priori

Effects of combustible stacking in large compartments

DEFF Research Database (Denmark)

Gentili, Filippo; Giuliani, Luisa; Bontempi, Franco

2013-01-01

This paper focuses on the modelling of fire in case of various distributions of combustible materials in a large compartment. Large compartments often represent a challenge for structural fire safety, because of lack of prescriptive rules to follow and difficulties of taking into account the effect...... of non uniform distribution of the combustible materials and fire propagation. These aspects are discussed in this paper with reference to an industrial steel building, taken as case study. Fires triggered by the burning of wooden pallets stored in the premises have been investigated with respect...

Phenomenology of future neutrino experiments with large θ13

International Nuclear Information System (INIS)

Minakata, Hisakazu

2013-01-01

The question “how small is the lepton mixing angle θ 13 ?” had a convincing answer in a surprisingly short time, θ 13 ≃9 ° , a large value comparable to the Chooz limit. It defines a new epoch in the program of determining the lepton mixing parameters, opening the door to search for lepton CP violation of the Kobayashi-Maskawa-type. I discuss influences of the large value of θ 13 to search for CP violation and determination of the neutrino mass hierarchy, the remaining unknowns in the standard three-flavor mixing scheme of neutrinos. I emphasize the following two points: (1) Large θ 13 makes determination of the mass hierarchy easier. It stimulates to invent new ideas and necessitates quantitative reexamination of practical ways to explore it. (2) However, large θ 13 does not quite make CP measurement easier so that we do need a “guaranteeing machine” to measure CP phase δ

Vascular legacy: HOPE ADVANCEs to EMPA-REG and LEADER: A Surprising similarity

Directory of Open Access Journals (Sweden)

Sanjay Kalra

2017-01-01

Full Text Available Recently reported cardiovascular outcome studies on empagliflozin (EMPA-REG and liraglutide (LEADER have spurred interest in this field of diabetology. This commentary compares and contrasts these studies with two equally important outcome trials conducted using blood pressure lowering agents. A comparison with MICROHOPE (using ramipril and ADVANCE (using perindopril + indapamide blood pressure arms throws up interesting facts. The degree of blood pressure lowering, dissociation between cardiovascular and cerebrovascular benefits, and discordance between renal and retinal outcomes are surprisingly similar in these trials, conducted using disparate molecules. The time taken to achieve such benefits is similar for all drugs except empagliflozin. Such discussion helps inform rational and evidence-based choice of therapy and forms the framework for future research.

Tune-shift with amplitude due to nonlinear kinematic effect

CERN Document Server

Wan, W

1999-01-01

Tracking studies of the Muon Collider 50 on 50 GeV collider ring show that the on-momentum dynamic aperture is limited to around 10 sigma even with the chromaticity sextupoles turned off. Numerical results from the normal form algorithm show that the tune-shift with amplitude is surprisingly large. Both analytical and numerical results are presented to show that nonlinear kinematic effect originated from the large angles of particles in the interaction region is responsible for the large tune-shift which in turn limits the dynamic aperture. A comparative study of the LHC collider ring is also presented to demonstrate the difference between the two machines. (14 refs).

Large Differences in the Optical Spectrum Associated with the Same Complex: The Effect of the Anisotropy of the Embedding Lattice

DEFF Research Database (Denmark)

Aramburu, José Antonio; García-Fernández, Pablo; García Lastra, Juan Maria

2017-01-01

of the electric field created by the rest of lattice ions over the complex. To illustrate this concept we analyze the origin of the surprisingly large differences in the d–d optical transitions of two systems containing square-planar CuF42– complexes, CaCuF4, and center II in Cu2+-doped Ba2ZnF6, even though...... the Cu2+–F–distance difference is just found to be 1%. Using a minimalist first-principles model we show that the different morphology of the host lattices creates an anisotropic field that red-shifts the in vacuo complex transitions to the 1.25–1.70 eV range in CaCuF4, while it blue-shifts them to the 1...

Surprise: Dwarf Galaxy Harbors Supermassive Black Hole

Science.gov (United States)

2011-01-01

The surprising discovery of a supermassive black hole in a small nearby galaxy has given astronomers a tantalizing look at how black holes and galaxies may have grown in the early history of the Universe. Finding a black hole a million times more massive than the Sun in a star-forming dwarf galaxy is a strong indication that supermassive black holes formed before the buildup of galaxies, the astronomers said. The galaxy, called Henize 2-10, 30 million light-years from Earth, has been studied for years, and is forming stars very rapidly. Irregularly shaped and about 3,000 light-years across (compared to 100,000 for our own Milky Way), it resembles what scientists think were some of the first galaxies to form in the early Universe. "This galaxy gives us important clues about a very early phase of galaxy evolution that has not been observed before," said Amy Reines, a Ph.D. candidate at the University of Virginia. Supermassive black holes lie at the cores of all "full-sized" galaxies. In the nearby Universe, there is a direct relationship -- a constant ratio -- between the masses of the black holes and that of the central "bulges" of the galaxies, leading them to conclude that the black holes and bulges affected each others' growth. Two years ago, an international team of astronomers found that black holes in young galaxies in the early Universe were more massive than this ratio would indicate. This, they said, was strong evidence that black holes developed before their surrounding galaxies. "Now, we have found a dwarf galaxy with no bulge at all, yet it has a supermassive black hole. This greatly strengthens the case for the black holes developing first, before the galaxy's bulge is formed," Reines said. Reines, along with Gregory Sivakoff and Kelsey Johnson of the University of Virginia and the National Radio Astronomy Observatory (NRAO), and Crystal Brogan of the NRAO, observed Henize 2-10 with the National Science Foundation's Very Large Array radio telescope and

Large-Angle CMB Suppression and Polarisation Predictions

CERN Document Server

Copi, C.J.; Schwarz, D.J.; Starkman, G.D.

2013-01-01

The anomalous lack of large angle temperature correlations has been a surprising feature of the CMB since first observed by COBE-DMR and subsequently confirmed and strengthened by WMAP. This anomaly may point to the need for modifications of the standard model of cosmology or may show that our Universe is a rare statistical fluctuation within that model. Further observations of the temperature auto-correlation function will not elucidate the issue; sufficiently high precision statistical observations already exist. Instead, alternative probes are required. In this work we explore the expectations for forthcoming polarisation observations. We define a prescription to test the hypothesis that the large-angle CMB temperature perturbations in our Universe represent a rare statistical fluctuation within the standard cosmological model. These tests are based on the temperature-Q Stokes parameter correlation. Unfortunately these tests cannot be expected to be definitive. However, we do show that if this TQ-correlati...

Importance of regional species pools and functional traits in colonization processes: predicting re-colonization after large-scale destruction of ecosystems

NARCIS (Netherlands)

Kirmer, A.; Tischew, S.; Ozinga, W.A.; Lampe, von M.; Baasch, A.; Groenendael, van J.M.

2008-01-01

Large-scale destruction of ecosystems caused by surface mining provides an opportunity for the study of colonization processes starting with primary succession. Surprisingly, over several decades and without any restoration measures, most of these sites spontaneously developed into valuable biotope

Surprising quantum bounces

CERN Document Server

Nesvizhevsky, Valery

2015-01-01

This unique book demonstrates the undivided unity and infinite diversity of quantum mechanics using a single phenomenon: quantum bounces of ultra-cold particles. Various examples of such "quantum bounces" are: gravitational quantum states of ultra-cold neutrons (the first observed quantum states of matter in a gravitational field), the neutron whispering gallery (an observed matter-wave analog of the whispering gallery effect well known in acoustics and for electromagnetic waves), and gravitational and whispering gallery states for anti-matter atoms that remain to be observed. These quantum states are an invaluable tool in the search for additional fundamental short-range forces, for exploring the gravitational interaction and quantum effects of gravity, for probing physics beyond the standard model, and for furthering studies into the foundations of quantum mechanics, quantum optics, and surface science.

A 32-bit NMOS microprocessor with a large register file

Science.gov (United States)

Sherburne, R. W., Jr.; Katevenis, M. G. H.; Patterson, D. A.; Sequin, C. H.

1984-10-01

Two scaled versions of a 32-bit NMOS reduced instruction set computer CPU, called RISC II, have been implemented on two different processing lines using the simple Mead and Conway layout rules with lambda values of 2 and 1.5 microns (corresponding to drawn gate lengths of 4 and 3 microns), respectively. The design utilizes a small set of simple instructions in conjunction with a large register file in order to provide high performance. This approach has resulted in two surprisingly powerful single-chip processors.

From Lithium-Ion to Sodium-Ion Batteries: Advantages, Challenges, and Surprises.

Science.gov (United States)

Nayak, Prasant Kumar; Yang, Liangtao; Brehm, Wolfgang; Adelhelm, Philipp

2018-01-02

Mobile and stationary energy storage by rechargeable batteries is a topic of broad societal and economical relevance. Lithium-ion battery (LIB) technology is at the forefront of the development, but a massively growing market will likely put severe pressure on resources and supply chains. Recently, sodium-ion batteries (SIBs) have been reconsidered with the aim of providing a lower-cost alternative that is less susceptible to resource and supply risks. On paper, the replacement of lithium by sodium in a battery seems straightforward at first, but unpredictable surprises are often found in practice. What happens when replacing lithium by sodium in electrode reactions? This review provides a state-of-the art overview on the redox behavior of materials when used as electrodes in lithium-ion and sodium-ion batteries, respectively. Advantages and challenges related to the use of sodium instead of lithium are discussed. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Large Aperture "Photon Bucket" Optical Receiver Performance in High Background Environments

Science.gov (United States)

Vilnrotter, Victor A.; Hoppe, D.

2011-01-01

The potential development of large aperture groundbased "photon bucket" optical receivers for deep space communications, with acceptable performance even when pointing close to the sun, is receiving considerable attention. Sunlight scattered by the atmosphere becomes significant at micron wavelengths when pointing to a few degrees from the sun, even with the narrowest bandwidth optical filters. In addition, high quality optical apertures in the 10-30 meter range are costly and difficult to build with accurate surfaces to ensure narrow fields-of-view (FOV). One approach currently under consideration is to polish the aluminum reflector panels of large 34-meter microwave antennas to high reflectance, and accept the relatively large FOV generated by state-of-the-art polished aluminum panels with rms surface accuracies on the order of a few microns, corresponding to several-hundred micro-radian FOV, hence generating centimeter-diameter focused spots at the Cassegrain focus of 34-meter antennas. Assuming pulse-position modulation (PPM) and Poisson-distributed photon-counting detection, a "polished panel" photon-bucket receiver with large FOV will collect hundreds of background photons per PPM slot, along with comparable signal photons due to its large aperture. It is demonstrated that communications performance in terms of PPM symbol-error probability in high-background high-signal environments depends more strongly on signal than on background photons, implying that large increases in background energy can be compensated by a disproportionally small increase in signal energy. This surprising result suggests that large optical apertures with relatively poor surface quality may nevertheless provide acceptable performance for deep-space optical communications, potentially enabling the construction of cost-effective hybrid RF/optical receivers in the future.

Old Star's "Rebirth" Gives Astronomers Surprises

Science.gov (United States)

2005-04-01

Astronomers using the National Science Foundation's Very Large Array (VLA) radio telescope are taking advantage of a once-in-a-lifetime opportunity to watch an old star suddenly stir back into new activity after coming to the end of its normal life. Their surprising results have forced them to change their ideas of how such an old, white dwarf star can re-ignite its nuclear furnace for one final blast of energy. Sakurai's Object Radio/Optical Images of Sakurai's Object: Color image shows nebula ejected thousands of years ago. Contours indicate radio emission. Inset is Hubble Space Telescope image, with contours indicating radio emission; this inset shows just the central part of the region. CREDIT: Hajduk et al., NRAO/AUI/NSF, ESO, StSci, NASA Computer simulations had predicted a series of events that would follow such a re-ignition of fusion reactions, but the star didn't follow the script -- events moved 100 times more quickly than the simulations predicted. "We've now produced a new theoretical model of how this process works, and the VLA observations have provided the first evidence supporting our new model," said Albert Zijlstra, of the University of Manchester in the United Kingdom. Zijlstra and his colleagues presented their findings in the April 8 issue of the journal Science. The astronomers studied a star known as V4334 Sgr, in the constellation Sagittarius. It is better known as "Sakurai's Object," after Japanese amateur astronomer Yukio Sakurai, who discovered it on February 20, 1996, when it suddenly burst into new brightness. At first, astronomers thought the outburst was a common nova explosion, but further study showed that Sakurai's Object was anything but common. The star is an old white dwarf that had run out of hydrogen fuel for nuclear fusion reactions in its core. Astronomers believe that some such stars can undergo a final burst of fusion in a shell of helium that surrounds a core of heavier nuclei such as carbon and oxygen. However, the

Optimal counterterrorism and the recruitment effect of large terrorist attacks

DEFF Research Database (Denmark)

Jensen, Thomas

2011-01-01

We analyze a simple dynamic model of the interaction between terrorists and authorities. Our primary aim is to study optimal counterterrorism and its consequences when large terrorist attacks lead to a temporary increase in terrorist recruitment. First, we show that an increase in counterterrorism...... makes it more likely that terrorist cells plan small rather than large attacks and therefore may increase the probability of a successful attack. Analyzing optimal counterterrorism we see that the recruitment effect makes authorities increase the level of counterterrorism after large attacks. Therefore......, in periods following large attacks a new attack is more likely to be small compared to other periods. Finally, we analyze the long-run consequences of the recruitment effect. We show that it leads to more counterterrorism, more small attacks, and a higher sum of terrorism damage and counterterrorism costs...

A large, benign prostatic cyst presented with an extremely high serum prostate-specific antigen level.

Science.gov (United States)

Chen, Han-Kuang; Pemberton, Richard

2016-01-08

We report a case of a patient who presented with an extremely high serum prostate specific antigen (PSA) level and underwent radical prostatectomy for presumed prostate cancer. Surprisingly, the whole mount prostatectomy specimen showed only small volume, organ-confined prostate adenocarcinoma and a large, benign intraprostatic cyst, which was thought to be responsible for the PSA elevation. 2016 BMJ Publishing Group Ltd.

The Influence of Company Size on Accounting Information: Evidence in Large Caps and Small Caps Companies Listed on BM&FBovespa

Directory of Open Access Journals (Sweden)

Karen Yukari Yokoyama

2015-09-01

Full Text Available In this study, the relation between accounting information aspects and the capitalization level o companies listed on the São Paulo Stock Exchange was investigated, classified as Large Caps or Small Caps, companies with larger and smaller capitalization, respectively, between 2010 and 2012. Three accounting information measures were addressed: informativeness, conservatism and relevance, through the application of Easton and Harris’ (1991 models of earnings informativeness, Basu’s (1997 model of conditional conservatism and the value relevance model, based on Ohlson (1995. The results appointed that, although the Large Caps present a higher level of conservatism, their accounting figures were less informative and more relevant when compared to the Large Caps companies. Due to the greater production of private information (predisclosure surrounding larger companies, the market would tend to respond less strongly or surprised to the publication of these companies’ accounting information, while the lack of anticipated information would make the effect of disclosing these figures more preponderant for the Small Caps companies.

The Most Distant Mature Galaxy Cluster - Young, but surprisingly grown-up

Science.gov (United States)

2011-03-01

Astronomers have used an armada of telescopes on the ground and in space, including the Very Large Telescope at ESO's Paranal Observatory in Chile to discover and measure the distance to the most remote mature cluster of galaxies yet found. Although this cluster is seen when the Universe was less than one quarter of its current age it looks surprisingly similar to galaxy clusters in the current Universe. "We have measured the distance to the most distant mature cluster of galaxies ever found", says the lead author of the study in which the observations from ESO's VLT have been used, Raphael Gobat (CEA, Paris). "The surprising thing is that when we look closely at this galaxy cluster it doesn't look young - many of the galaxies have settled down and don't resemble the usual star-forming galaxies seen in the early Universe." Clusters of galaxies are the largest structures in the Universe that are held together by gravity. Astronomers expect these clusters to grow through time and hence that massive clusters would be rare in the early Universe. Although even more distant clusters have been seen, they appear to be young clusters in the process of formation and are not settled mature systems. The international team of astronomers used the powerful VIMOS and FORS2 instruments on ESO's Very Large Telescope (VLT) to measure the distances to some of the blobs in a curious patch of very faint red objects first observed with the Spitzer space telescope. This grouping, named CL J1449+0856 [1], had all the hallmarks of being a very remote cluster of galaxies [2]. The results showed that we are indeed seeing a galaxy cluster as it was when the Universe was about three billion years old - less than one quarter of its current age [3]. Once the team knew the distance to this very rare object they looked carefully at the component galaxies using both the NASA/ESA Hubble Space Telescope and ground-based telescopes, including the VLT. They found evidence suggesting that most of the

The effects of large beach debris on nesting sea turtles

Science.gov (United States)

Fujisaki, Ikuko; Lamont, Margaret M.

2016-01-01

A field experiment was conducted to understand the effects of large beach debris on sea turtle nesting behavior as well as the effectiveness of large debris removal for habitat restoration. Large natural and anthropogenic debris were removed from one of three sections of a sea turtle nesting beach and distributions of nests and false crawls (non-nesting crawls) in pre- (2011–2012) and post- (2013–2014) removal years in the three sections were compared. The number of nests increased 200% and the number of false crawls increased 55% in the experimental section, whereas a corresponding increase in number of nests and false crawls was not observed in the other two sections where debris removal was not conducted. The proportion of nest and false crawl abundance in all three beach sections was significantly different between pre- and post-removal years. The nesting success, the percent of successful nests in total nesting attempts (number of nests + false crawls), also increased from 24% to 38%; however the magnitude of the increase was comparably small because both the number of nests and false crawls increased, and thus the proportion of the nesting success in the experimental beach in pre- and post-removal years was not significantly different. The substantial increase in sea turtle nesting activities after the removal of large debris indicates that large debris may have an adverse impact on sea turtle nesting behavior. Removal of large debris could be an effective restoration strategy to improve sea turtle nesting.

Functionalization and large scale assembly of carbon nanotubes

OpenAIRE

Majumder, Anindya

2016-01-01

Assembly of nanoparticles provides effective building blocks for physical, chemical and biological systems which have surprisingly collective intrinsic physical properties. One-dimensional nanomaterials are one of the most spectacular and promising candidates for technological application in the field of nanotechnology. Single-walled carbon nanotubes represent an anisotropic and perfectly one-dimensional group of nanomaterials with extraordinary electronic, mechanical, chemical and thermal pr...

The effective field theory of cosmological large scale structures

Energy Technology Data Exchange (ETDEWEB)

Carrasco, John Joseph M. [Stanford Univ., Stanford, CA (United States); Hertzberg, Mark P. [Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States); Senatore, Leonardo [Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)

2012-09-20

Large scale structure surveys will likely become the next leading cosmological probe. In our universe, matter perturbations are large on short distances and small at long scales, i.e. strongly coupled in the UV and weakly coupled in the IR. To make precise analytical predictions on large scales, we develop an effective field theory formulated in terms of an IR effective fluid characterized by several parameters, such as speed of sound and viscosity. These parameters, determined by the UV physics described by the Boltzmann equation, are measured from N-body simulations. We find that the speed of sound of the effective fluid is c²_s ≈ 10^–6c² and that the viscosity contributions are of the same order. The fluid describes all the relevant physics at long scales k and permits a manifestly convergent perturbative expansion in the size of the matter perturbations δ(k) for all the observables. As an example, we calculate the correction to the power spectrum at order δ(k)⁴. As a result, the predictions of the effective field theory are found to be in much better agreement with observation than standard cosmological perturbation theory, already reaching percent precision at this order up to a relatively short scale k ≃ 0.24h Mpc^–1.

Would you be surprised if this patient died?: Preliminary exploration of first and second year residents' approach to care decisions in critically ill patients

Directory of Open Access Journals (Sweden)

Armstrong John D

2003-01-01

Full Text Available Abstract Background How physicians approach decision-making when caring for critically ill patients is poorly understood. This study aims to explore how residents think about prognosis and approach care decisions when caring for seriously ill, hospitalized patients. Methods Qualitative study where we conducted structured discussions with first and second year internal medicine residents (n = 8 caring for critically ill patients during Medical Intensive Care Unit Ethics and Discharge Planning Rounds. Residents were asked to respond to questions beginning with "Would you be surprised if this patient died?" Results An equal number of residents responded that they would (n = 4 or would not (n = 4 be surprised if their patient died. Reasons for being surprised included the rapid onset of an acute illness, reversible disease, improving clinical course and the patient's prior survival under similar circumstances. Residents reported no surprise with worsening clinical course. Based on the realization that their patient might die, residents cited potential changes in management that included clarifying treatment goals, improving communication with families, spending more time with patients and ordering fewer laboratory tests. Perceived or implied barriers to changes in management included limited time, competing clinical priorities, "not knowing" a patient, limited knowledge and experience, presence of diagnostic or prognostic uncertainty and unclear treatment goals. Conclusions These junior-level residents appear to rely on clinical course, among other factors, when assessing prognosis and the possibility for death in severely ill patients. Further investigation is needed to understand how these factors impact decision-making and whether perceived barriers to changes in patient management influence approaches to care.

Effects of large-scale deforestation on precipitation in the monsoon regions: remote versus local effects.

Science.gov (United States)

Devaraju, N; Bala, Govindasamy; Modak, Angshuman

2015-03-17

In this paper, using idealized climate model simulations, we investigate the biogeophysical effects of large-scale deforestation on monsoon regions. We find that the remote forcing from large-scale deforestation in the northern middle and high latitudes shifts the Intertropical Convergence Zone southward. This results in a significant decrease in precipitation in the Northern Hemisphere monsoon regions (East Asia, North America, North Africa, and South Asia) and moderate precipitation increases in the Southern Hemisphere monsoon regions (South Africa, South America, and Australia). The magnitude of the monsoonal precipitation changes depends on the location of deforestation, with remote effects showing a larger influence than local effects. The South Asian Monsoon region is affected the most, with 18% decline in precipitation over India. Our results indicate that any comprehensive assessment of afforestation/reforestation as climate change mitigation strategies should carefully evaluate the remote effects on monsoonal precipitation alongside the large local impacts on temperatures.

Do large mergers increase or decrease the productivity of pharmaceutical R&D?

Science.gov (United States)

Ringel, Michael S; Choy, Michael K

2017-12-01

There is current uncertainty regarding the effects of mergers on pharmaceutical R&D productivity, with various mechanisms reported by which mergers could either help or harm R&D, and mixed empirical findings in prior analyses. Here, we present an analysis that is novel in several ways: we use downstream measures of R&D productivity, account for both inputs and outputs in our calculations, and use a self-controlled design. We find that recent large pharmaceutical mergers are associated with statistically significant increases in R&D productivity. These results are perhaps not surprising in light of the broader literature on R&D productivity that points to two factors as instrumental in driving higher R&D productivity (depth of scientific information, and objectivity of decision-making based on that information), both of which could be expected to increase because of a merger. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effective string dynamics in large N QCD

Energy Technology Data Exchange (ETDEWEB)

Iroshnikov, G.S. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)]|[Moskow Inst. of Physics and Technology, Moscow (Russian Federation)

1995-05-01

The semiclassical 1/N expansion in the strong coupling regime for spinor quarks was developed and the form of effective action was obtained. An extremum of the effective action that arises in the calculation of the hadronic correlation functions in the large N limit corresponds to a topologically non-trivial configuration of the gauge field. This configuration forms a chromoelectric Nambu string with additional spinor terms that contain in particular the Polyakov spinor factor. In the case when real quarks forming hadrons are replaced by scalar particles the above correlators yield the standard dual resonance amplitudes. (author). 10 refs, 1 fig.

Disentangling the effects of evolutionary, demographic, and environmental factors influencing genetic structure of natural populations: Atlantic herring as a case study

DEFF Research Database (Denmark)

Gaggiotti, Oscar E.; Bekkevold, Dorte; Jørgensen, Hanne B.H.

2009-01-01

, on the other hand, seems to have been largely eroded, which is not surprising given the large reproductive potential and presumed enormous local effective population sizes of pelagic fish that constrain the effect of stochastic processes. The approach we used can in principle be applied to any abundant...... carried out separate analyses of neutral and selected genetic variation, which allowed us to establish that the two most important factors affecting population structure were selection due to salinity at spawning sites and feeding migrations. The genetic signal left by the demographic history of herring...

Isolating relativistic effects in large-scale structure

Science.gov (United States)

Bonvin, Camille

2014-12-01

We present a fully relativistic calculation of the observed galaxy number counts in the linear regime. We show that besides the density fluctuations and redshift-space distortions, various relativistic effects contribute to observations at large scales. These effects all have the same physical origin: they result from the fact that our coordinate system, namely the galaxy redshift and the incoming photons’ direction, is distorted by inhomogeneities in our Universe. We then discuss the impact of the relativistic effects on the angular power spectrum and on the two-point correlation function in configuration space. We show that the latter is very well adapted to isolate the relativistic effects since it naturally makes use of the symmetries of the different contributions. In particular, we discuss how the Doppler effect and the gravitational redshift distortions can be isolated by looking for a dipole in the cross-correlation function between a bright and a faint population of galaxies.

Effects of large bending deflections on blade flutter limits

Energy Technology Data Exchange (ETDEWEB)

Kallesoee, Bjarne Skovmose; Hartvig Hansen, Morten

2008-04-15

The coupling of bending and torsion due to large blade bending are assumed to have some effects of the flutter limits of wind turbines. In the present report, the aeroelastic blade model suggested by Kallesoee, which is similar to a second order model, is used to investigate the aeroelastic stability limits of the RWT blade with and without the effects of the large blade deflection. The investigation shows no significant change of the flutter limit on the rotor speed due to the blade deflection,whereas the first edgewise bending mode becomes negatively damped due to the coupling with blade torsion which causes a change of the effective direction of blade vibration. These observations are confirmed by nonlinear aeroelastic simulations using HAWC2. This work is part of the UpWind project funded by the European Commission under the contract number SES6-CT-2005-019945 which is gratefully acknowledged. This report is the deliverable D2.3 of the UpWind project. (au)

More statistics, less surprise

CERN Multimedia

Antonella Del Rosso & the LHCb collaboration

2013-01-01

The LHCb collaboration has recently announced new results for a parameter that measures the CP violation effect in particles containing charm quarks. The new values obtained with a larger data set and with a new independent method are showing that the effect is smaller than previous measurements had  suggested. The parameter is back into the Standard Model picture.   CP violation signals – in particles containing charm quarks, such as the D0 particle, is a powerful probe of new physics. Indeed, such effects could result in unexpected values of parameters whose expectation values in the Standard Model are known. Although less precise than similar approaches used in particles made of b quarks, the investigation of the charm system has proven  to be intriguing. The LHCb collaboration has reported new measurements of ΔACP, the difference in CP violation between the D0→K+K– and D0→π+π– decays. The results are ob...

A large mixing effect on eta,eta' and iota

International Nuclear Information System (INIS)

Kawai, E.

1983-01-01

We quantitatively investigate a possible large mixing effect on eta(549), eta'(958) and iota(1440) in a phenomenological way, taking both SU(3) symmetry breaking and gluon intervention into due account. (orig.)

Experiences with Text Mining Large Collections of Unstructured Systems Development Artifacts at JPL

Science.gov (United States)

Port, Dan; Nikora, Allen; Hihn, Jairus; Huang, LiGuo

2011-01-01

Often repositories of systems engineering artifacts at NASA's Jet Propulsion Laboratory (JPL) are so large and poorly structured that they have outgrown our capability to effectively manually process their contents to extract useful information. Sophisticated text mining methods and tools seem a quick, low-effort approach to automating our limited manual efforts. Our experiences of exploring such methods mainly in three areas including historical risk analysis, defect identification based on requirements analysis, and over-time analysis of system anomalies at JPL, have shown that obtaining useful results requires substantial unanticipated efforts - from preprocessing the data to transforming the output for practical applications. We have not observed any quick 'wins' or realized benefit from short-term effort avoidance through automation in this area. Surprisingly we have realized a number of unexpected long-term benefits from the process of applying text mining to our repositories. This paper elaborates some of these benefits and our important lessons learned from the process of preparing and applying text mining to large unstructured system artifacts at JPL aiming to benefit future TM applications in similar problem domains and also in hope for being extended to broader areas of applications.

Using lanthanoid complexes to phase large macromolecular assemblies

International Nuclear Information System (INIS)

Talon, Romain; Kahn, Richard; Durá, M. Asunción; Maury, Olivier; Vellieux, Frédéric M. D.; Franzetti, Bruno; Girard, Eric

2011-01-01

A lanthanoid complex, [Eu(DPA) 3 ] 3− , was used to obtain experimental phases at 4.0 Å resolution of PhTET1-12s, a large self-compartmentalized homo-dodecameric protease complex of 444 kDa. Lanthanoid ions exhibit extremely large anomalous X-ray scattering at their L III absorption edge. They are thus well suited for anomalous diffraction experiments. A novel class of lanthanoid complexes has been developed that combines the physical properties of lanthanoid atoms with functional chemical groups that allow non-covalent binding to proteins. Two structures of large multimeric proteins have already been determined by using such complexes. Here the use of the luminescent europium tris-dipicolinate complex [Eu(DPA) 3 ] 3− to solve the low-resolution structure of a 444 kDa homododecameric aminopeptidase, called PhTET1-12s from the archaea Pyrococcus horikoshii, is reported. Surprisingly, considering the low resolution of the data, the experimental electron density map is very well defined. Experimental phases obtained by using the lanthanoid complex lead to maps displaying particular structural features usually observed in higher-resolution maps. Such complexes open a new way for solving the structure of large molecular assemblies, even with low-resolution data

Gluon bremstrahlung effects in large P/sub perpendicular/ hadron-hadron scattering

International Nuclear Information System (INIS)

Fox, G.C.; Kelly, R.L.

1982-02-01

We consider effects of parton (primarily gluon) bremstrahlung in the initial and final states of high transverse momentum hadron-hadron scattering. Monte Carlo calculations based on conventional QCD parton branching and scattering processes are presented. The calculations are carried only to the parton level in the final state. We apply the model to the Drell-Yan process and to high transverse momentum hadron-hadron scattering triggered with a large aperture calorimeter. We show that the latter triggers are biased in that they select events with unusually large bremstrahlung effects. We suggest that this trigger bias explains the large cross section and non-coplanar events observed in the NA5 experiment at the SPS

Surprises from the resolution of operator mixing in N=4 SYM

International Nuclear Information System (INIS)

Bianchi, Massimo; Rossi, Giancarlo; Stanev, Yassen S.

2004-01-01

We reexamine the problem of operator mixing in N=4 SYM. Particular attention is paid to the correct definition of composite gauge invariant local operators, which is necessary for the computation of their anomalous dimensions beyond lowest order. As an application we reconsider the case of operators with naive dimension Δ 0 =4, already studied in the literature. Stringent constraints from the resummation of logarithms in power behaviours are exploited and the role of the generalized N=4 Konishi anomaly in the mixing with operators involving fermions is discussed. A general method for the explicit (numerical) resolution of the operator mixing and the computation of anomalous dimensions is proposed. We then resolve the order g 2 mixing for the 15 (purely scalar) singlet operators of naive dimension Δ 0 =6. Rather surprisingly we find one isolated operator which has a vanishing anomalous dimension up to order g 4 , belonging to an apparently long multiplet. We also solve the order g 2 mixing for the 26 operators belonging to the representation 20' of SU(4). We find an operator with the same one-loop anomalous dimension as the Konishi multiplet

Effects of Aromatic Ammoniums on Methyl Ammonium Lead Iodide Hybrid Perovskite Materials

Directory of Open Access Journals (Sweden)

Jianli Yang

2017-01-01

Full Text Available The introduction of bulky ammoniums into methyl ammonium lead iodide hybrid perovskites (MAPbI3 has emerged as a promising strategy to improve the properties of these materials. In the present work, we studied the effects of several aromatic ammoniums onto the structural, electronic, and optical properties of MAPbI3. Although powder XRD data suggest that the bulky cations are not involved in the bulk phase of the MAPbI3, a surprisingly large effect of the bulky cations onto the photoluminescence properties was observed.

Interactive effects of fire and large herbivores on web-building spiders.

Science.gov (United States)

Foster, C N; Barton, P S; Wood, J T; Lindenmayer, D B

2015-09-01

Altered disturbance regimes are a major driver of biodiversity loss worldwide. Maintaining or re-creating natural disturbance regimes is therefore the focus of many conservation programmes. A key challenge, however, is to understand how co-occurring disturbances interact to affect biodiversity. We experimentally tested for the interactive effects of prescribed fire and large macropod herbivores on the web-building spider assemblage of a eucalypt forest understorey and investigated the role of vegetation in mediating these effects using path analysis. Fire had strong negative effects on the density of web-building spiders, which were partly mediated by effects on vegetation structure, while negative effects of large herbivores on web density were not related to changes in vegetation. Fire amplified the effects of large herbivores on spiders, both via vegetation-mediated pathways and by increasing herbivore activity. The importance of vegetation-mediated pathways and fire-herbivore interactions differed for web density and richness and also differed between web types. Our results demonstrate that for some groups of web-building spiders, the effects of co-occurring disturbance drivers may be mostly additive, whereas for other groups, interactions between drivers can amplify disturbance effects. In our study system, the use of prescribed fire in the presence of high densities of herbivores could lead to reduced densities and altered composition of web-building spiders, with potential cascading effects through the arthropod food web. Our study highlights the importance of considering both the independent and interactive effects of disturbances, as well as the mechanisms driving their effects, in the management of disturbance regimes.

Life Satisfaction Effects of Unemployment in Europe: The Moderating Influence of Labour Market Policy

DEFF Research Database (Denmark)

Wulfgramm, Melike

2014-01-01

Public policy shapes the lives of individuals, and even more so if they depend on state support. In the case of unemployment, the financial situation is largely determined by cash transfers and daily routines depend on the involvement in active labour market policy measures. To what extent, however......, can subjective well-being differences of European unemployed be traced back to the national design and generosity of labour market policy? This article applies multilevel and panel estimation techniques to identify the moderating effect of unemployment benefit generosity and active labour market...... policy on life satisfaction of the unemployed. While unemployment has strong negative life satisfaction effects in all 21 European countries under study, the generosity of passive labour market policy moderates this effect to a surprisingly large extent: the adverse effect of unemployment is almost...

Surprise responses in the human brain demonstrate statistical learning under high concurrent cognitive demand

Science.gov (United States)

Garrido, Marta Isabel; Teng, Chee Leong James; Taylor, Jeremy Alexander; Rowe, Elise Genevieve; Mattingley, Jason Brett

2016-06-01

The ability to learn about regularities in the environment and to make predictions about future events is fundamental for adaptive behaviour. We have previously shown that people can implicitly encode statistical regularities and detect violations therein, as reflected in neuronal responses to unpredictable events that carry a unique prediction error signature. In the real world, however, learning about regularities will often occur in the context of competing cognitive demands. Here we asked whether learning of statistical regularities is modulated by concurrent cognitive load. We compared electroencephalographic metrics associated with responses to pure-tone sounds with frequencies sampled from narrow or wide Gaussian distributions. We showed that outliers evoked a larger response than those in the centre of the stimulus distribution (i.e., an effect of surprise) and that this difference was greater for physically identical outliers in the narrow than in the broad distribution. These results demonstrate an early neurophysiological marker of the brain's ability to implicitly encode complex statistical structure in the environment. Moreover, we manipulated concurrent cognitive load by having participants perform a visual working memory task while listening to these streams of sounds. We again observed greater prediction error responses in the narrower distribution under both low and high cognitive load. Furthermore, there was no reliable reduction in prediction error magnitude under high-relative to low-cognitive load. Our findings suggest that statistical learning is not a capacity limited process, and that it proceeds automatically even when cognitive resources are taxed by concurrent demands.

Identifying demand effects in a large network of product categories

NARCIS (Netherlands)

Gelper, S.E.C.; Wilms, I.; Croux, C.

2016-01-01

Planning marketing mix strategies requires retailers to understand within- as well as cross-category demand effects. Most retailers carry products in a large variety of categories, leading to a high number of such demand effects to be estimated. At the same time, we do not expect cross-category

Estimating the Effectiveness of Special Education Using Large-Scale Assessment Data

Science.gov (United States)

Ewing, Katherine Anne

2009-01-01

The inclusion of students with disabilities in large scale assessment and accountability programs has provided new opportunities to examine the impact of special education services on student achievement. Hanushek, Kain, and Rivkin (1998, 2002) evaluated the effectiveness of special education programs by examining students' gains on a large-scale…

Estimation and Inference for Very Large Linear Mixed Effects Models

OpenAIRE

Gao, K.; Owen, A. B.

2016-01-01

Linear mixed models with large imbalanced crossed random effects structures pose severe computational problems for maximum likelihood estimation and for Bayesian analysis. The costs can grow as fast as $N^{3/2}$ when there are N observations. Such problems arise in any setting where the underlying factors satisfy a many to many relationship (instead of a nested one) and in electronic commerce applications, the N can be quite large. Methods that do not account for the correlation structure can...

Large Scale Obscuration and Related Climate Effects Workshop: Proceedings

Energy Technology Data Exchange (ETDEWEB)

Zak, B.D.; Russell, N.A.; Church, H.W.; Einfeld, W.; Yoon, D.; Behl, Y.K. [eds.

1994-05-01

A Workshop on Large Scale Obsurcation and Related Climate Effects was held 29--31 January, 1992, in Albuquerque, New Mexico. The objectives of the workshop were: to determine through the use of expert judgement the current state of understanding of regional and global obscuration and related climate effects associated with nuclear weapons detonations; to estimate how large the uncertainties are in the parameters associated with these phenomena (given specific scenarios); to evaluate the impact of these uncertainties on obscuration predictions; and to develop an approach for the prioritization of further work on newly-available data sets to reduce the uncertainties. The workshop consisted of formal presentations by the 35 participants, and subsequent topical working sessions on: the source term; aerosol optical properties; atmospheric processes; and electro-optical systems performance and climatic impacts. Summaries of the conclusions reached in the working sessions are presented in the body of the report. Copies of the transparencies shown as part of each formal presentation are contained in the appendices (microfiche).

EFFECTS OF LARGE-SCALE POULTRY FARMS ON AQUATIC MICROBIAL COMMUNITIES: A MOLECULAR INVESTIGATION.

Science.gov (United States)

The effects of large-scale poultry production operations on water quality and human health are largely unknown. Poultry litter is frequently applied as fertilizer to agricultural lands adjacent to large poultry farms. Run-off from the land introduces a variety of stressors into t...

Projection Effects of Large-scale Structures on Weak-lensing Peak Abundances

Science.gov (United States)

Yuan, Shuo; Liu, Xiangkun; Pan, Chuzhong; Wang, Qiao; Fan, Zuhui

2018-04-01

High peaks in weak lensing (WL) maps originate dominantly from the lensing effects of single massive halos. Their abundance is therefore closely related to the halo mass function and thus a powerful cosmological probe. However, besides individual massive halos, large-scale structures (LSS) along lines of sight also contribute to the peak signals. In this paper, with ray-tracing simulations, we investigate the LSS projection effects. We show that for current surveys with a large shape noise, the stochastic LSS effects are subdominant. For future WL surveys with source galaxies having a median redshift z med ∼ 1 or higher, however, they are significant. For the cosmological constraints derived from observed WL high-peak counts, severe biases can occur if the LSS effects are not taken into account properly. We extend the model of Fan et al. by incorporating the LSS projection effects into the theoretical considerations. By comparing with simulation results, we demonstrate the good performance of the improved model and its applicability in cosmological studies.

Hillslope, river, and Mountain: some surprises in Landscape evolution (Ralph Alger Bagnold Medal Lecture)

Science.gov (United States)

Tucker, G. E.

2012-04-01

Geomorphology, like the rest of geoscience, has always had two major themes: a quest to understand the earth's history and 'products' - its landscapes and seascapes - and, in parallel, a quest to understand its formative processes. This dualism is manifest in the remarkable career of R. A. Bagnold, who was inspired by landforms such as dunes, and dedicated to understanding the physical processes that shaped them. His legacy inspires us to emulate two principles at the heart of his contributions: the benefits of rooting geomorphic theory in basic physics, and the importance of understanding geomorphic systems in terms of simple equations framed around energy or force. Today, following Bagnold's footsteps, the earth-surface process community is engaged in a quest to build, test, and refine an ever-improving body of theory to describe our planet's surface and its evolution. In this lecture, I review a small sample of some of the fruits of that quest, emphasizing the value of surprises encountered along the way. The first example involves models of long-term river incision into bedrock. When the community began to grapple with how to represent this process mathematically, several different ideas emerged. Some were based on the assumption that sediment transport is the limiting factor; others assumed that hydraulic stress on rock is the key, while still others treated rivers as first-order 'reactors.' Thanks in part to advances in digital topography and numerical computing, the predictions of these models can be tested using natural-experiment case studies. Examples from the King Range, USA, the Central Apennines, Italy, and the fold-thrust belt of Taiwan, illustrate that independent knowledge of history and/or tectonics makes it possible to quantify how the rivers have responded to external forcing. Some interesting surprises emerge, such as: that the relief-uplift relationship can be highly nonlinear in a steady-state landscape because of grain-entrainment thresholds

Non-intuitive bubble effects in reactor and containment technology

International Nuclear Information System (INIS)

Moody, F.J.

1991-01-01

Most people know a lot about bubbles, including how they rise in liquids and the way they appear when the cap is removed from a bottle of carbonated beverage. A lot of bubble knowledge is obtained from bubbling air through water in aquariums to keep the fish alive and happy, or watching scuba divers feed the sharks in large glass tanks at the local zoo. But innocent bubbles can be sources of structural loadings and sometimes destructive fluid behavior. In fact, there are many non-intuitive effects associated with bubbles which have been discovered by experiments and analyses. It has been necessary to design various reactor and containment components in the nuclear energy industry to accommodate the fact that bubbles can expand like compressed springs, or oscillate, or collapse abruptly, and create structural loads. This paper describes several important phenomena associated with bubble action in nuclear reactor and containment systems and the associated loads exerted. An awareness of these effects can help to avoid unwelcome surprises in general thermal-hydraulic applications when a system is disturbed by bubble behavior. Major topics discussed include expanding and collapsing submerged bubbles, steam chugging and ringout, bubble shattering, surprising hot bubble action in a saturated pool, bubble effects on fluid-structure-interaction, waterhammer from collapsing bubble in pipes, and vapor bubble effects on sound speed in saturated mixtures

Imprint of non-linear effects on HI intensity mapping on large scales

Energy Technology Data Exchange (ETDEWEB)

Umeh, Obinna, E-mail: umeobinna@gmail.com [Department of Physics and Astronomy, University of the Western Cape, Cape Town 7535 (South Africa)

2017-06-01

Intensity mapping of the HI brightness temperature provides a unique way of tracing large-scale structures of the Universe up to the largest possible scales. This is achieved by using a low angular resolution radio telescopes to detect emission line from cosmic neutral Hydrogen in the post-reionization Universe. We use general relativistic perturbation theory techniques to derive for the first time the full expression for the HI brightness temperature up to third order in perturbation theory without making any plane-parallel approximation. We use this result and the renormalization prescription for biased tracers to study the impact of nonlinear effects on the power spectrum of HI brightness temperature both in real and redshift space. We show how mode coupling at nonlinear order due to nonlinear bias parameters and redshift space distortion terms modulate the power spectrum on large scales. The large scale modulation may be understood to be due to the effective bias parameter and effective shot noise.

Large-scale diversity patterns in spore communities of Arbuscular mycorrhizal fungi [Chapter 2

Science.gov (United States)

Javier Alvarez-Sanchez; Nancy C. Johnson; Anita Antoninka; V. Bala Chaudhary; Matthew K. Lau; Suzanne M. Owen; Patricia Gauadarrama; Silvia. Castillo

2010-01-01

Surprising little is known about the factors controlling Arbuscular Mycorrhizal (AM) fungal diversity and distribution patterns. A better understanding of these factors is necessary before mycorrhizas can be effectively managed for their benefits in ecosystem restoration and agriculture. The goal of this chapter is to examine the relationships between AM fungal...

Hypersingular integral equations, waveguiding effects in Cantorian Universe and genesis of large scale structures

International Nuclear Information System (INIS)

Iovane, G.; Giordano, P.

2005-01-01

In this work we introduce the hypersingular integral equations and analyze a realistic model of gravitational waveguides on a cantorian space-time. A waveguiding effect is considered with respect to the large scale structure of the Universe, where the structure formation appears as if it were a classically self-similar random process at all astrophysical scales. The result is that it seems we live in an El Naschie's o (∞) Cantorian space-time, where gravitational lensing and waveguiding effects can explain the appearing Universe. In particular, we consider filamentary and planar large scale structures as possible refraction channels for electromagnetic radiation coming from cosmological structures. From this vision the Universe appears like a large self-similar adaptive mirrors set, thanks to three numerical simulations. Consequently, an infinite Universe is just an optical illusion that is produced by mirroring effects connected with the large scale structure of a finite and not a large Universe

Renormalization in Large Momentum Effective Theory of Parton Physics.

Science.gov (United States)

Ji, Xiangdong; Zhang, Jian-Hui; Zhao, Yong

2018-03-16

In the large-momentum effective field theory approach to parton physics, the matrix elements of nonlocal operators of quark and gluon fields, linked by straight Wilson lines in a spatial direction, are calculated in lattice quantum chromodynamics as a function of hadron momentum. Using the heavy-quark effective theory formalism, we show a multiplicative renormalization of these operators at all orders in perturbation theory, both in dimensional and lattice regularizations. The result provides a theoretical basis for extracting parton properties through properly renormalized observables in Monte Carlo simulations.

Large scale obscuration and related climate effects open literature bibliography

Energy Technology Data Exchange (ETDEWEB)

Russell, N.A.; Geitgey, J.; Behl, Y.K.; Zak, B.D.

1994-05-01

Large scale obscuration and related climate effects of nuclear detonations first became a matter of concern in connection with the so-called ``Nuclear Winter Controversy`` in the early 1980`s. Since then, the world has changed. Nevertheless, concern remains about the atmospheric effects of nuclear detonations, but the source of concern has shifted. Now it focuses less on global, and more on regional effects and their resulting impacts on the performance of electro-optical and other defense-related systems. This bibliography reflects the modified interest.

Large scale obscuration and related climate effects open literature bibliography

International Nuclear Information System (INIS)

Russell, N.A.; Geitgey, J.; Behl, Y.K.; Zak, B.D.

1994-05-01

Large scale obscuration and related climate effects of nuclear detonations first became a matter of concern in connection with the so-called ''Nuclear Winter Controversy'' in the early 1980's. Since then, the world has changed. Nevertheless, concern remains about the atmospheric effects of nuclear detonations, but the source of concern has shifted. Now it focuses less on global, and more on regional effects and their resulting impacts on the performance of electro-optical and other defense-related systems. This bibliography reflects the modified interest

Large magnetoresistance in non-magnetic silver chalcogenides and new class of magnetoresistive compounds

Science.gov (United States)

Saboungi, Marie-Louis; Price, David C. L.; Rosenbaum, Thomas F.; Xu, Rong; Husmann, Anke

2001-01-01

The heavily-doped silver chalcogenides, Ag.sub.2+.delta. Se and Ag.sub.2+.delta. Te, show magnetoresistance effects on a scale comparable to the "colossal" magnetoresistance (CMR) compounds. Hall coefficient, magnetoconductivity, and hydrostatic pressure experiments establish that elements of narrow-gap semiconductor physics apply, but both the size of the effects at room temperature and the linear field dependence down to fields of a few Oersteds are surprising new features.

Different goods, different effects: Exploring the effects of generalized social trust in large-N collective action

DEFF Research Database (Denmark)

Sønderskov, Kim Mannemar

2009-01-01

Does generalized social trust help solve large-N collective action problems? This paper argues so, offering a novel explanation for the relationship: People tend to cooperate if they expect others to be cooperating, which implies that people holding generalized social trust more readily cooperate...... in large-N dilemmas because they expect that most people will cooperate. The paper tests the explanation in a rigorous design. The analyses show a positive, robust effect of generalized social trust on public good provision, but no effect is found in a joint product situation. This supports the hypothesis......, indicating that trust specifically enhances cooperation in collective action dilemmas....

Effective field theories in the large-N limit

International Nuclear Information System (INIS)

Weinberg, S.

1997-01-01

Various effective field theories in four dimensions are shown to have exact nontrivial solutions in the limit as the number N of fields of some type becomes large. These include extended versions of the U (N) Gross-Neveu model, the nonlinear O(N) σ model, and the CP N-1 model. Although these models are not renormalizable in the usual sense, the infinite number of coupling types allows a complete cancellation of infinities. These models provide qualitative predictions of the form of scattering amplitudes for arbitrary momenta, but because of the infinite number of free parameters, it is possible to derive quantitative predictions only in the limit of small momenta. For small momenta the large-N limit provides only a modest simplification, removing at most a finite number of diagrams to each order in momenta, except near phase transitions, where it reduces the infinite number of diagrams that contribute for low momenta to a finite number. copyright 1997 The American Physical Society

Electromagnetic and structural coupled analysis with the effect of large deflection

International Nuclear Information System (INIS)

Horie, Tomoyoshi; Niho, Tomoya

1997-01-01

In the designs of future fusion reactors and magnetic levitated vehicles, thin shell conducting structures are located in a high electromagnetic field. The transient magnetic field induces the eddy current on the conductive structure. While the Lorentz force by the eddy current and the magnetic field is loaded to the thin shell structure, the electromotive force by the deflection velocity and magnetic field reduces the eddy current. Therefore, the electromagnetic and structural coupled analysis is required for the design of these components. This paper describes a coupled finite element analysis for the eddy current and the structure. A formulation is presented considering the effect of the large deflection of shell structures by the total Lagrangian formulation. Both matrix equations for the eddy current and the structure are solved simultaneously using coupling sub-matrices. A coupled problem of a cantilever bending plate is analyzed. Based on the analysis results, the influence of the large deflection on the coupling effect is discussed. The condition that the large deflection analysis is required is examined through some parametric analyses

Probing Critical Point Energies of Transition Metal Dichalcogenides: Surprising Indirect Gap of Single Layer WSe 2

KAUST Repository

Zhang, Chendong; Chen, Yuxuan; Johnson, Amber; Li, Ming-yang; Li, Lain-Jong; Mende, Patrick C.; Feenstra, Randall M.; Shih, Chih Kang

2015-01-01

By using a comprehensive form of scanning tunneling spectroscopy, we have revealed detailed quasi-particle electronic structures in transition metal dichalcogenides, including the quasi-particle gaps, critical point energy locations, and their origins in the Brillouin zones. We show that single layer WSe surprisingly has an indirect quasi-particle gap with the conduction band minimum located at the Q-point (instead of K), albeit the two states are nearly degenerate. We have further observed rich quasi-particle electronic structures of transition metal dichalcogenides as a function of atomic structures and spin-orbit couplings. Such a local probe for detailed electronic structures in conduction and valence bands will be ideal to investigate how electronic structures of transition metal dichalcogenides are influenced by variations of local environment.

Probing Critical Point Energies of Transition Metal Dichalcogenides: Surprising Indirect Gap of Single Layer WSe 2

KAUST Repository

Zhang, Chendong

2015-09-21

By using a comprehensive form of scanning tunneling spectroscopy, we have revealed detailed quasi-particle electronic structures in transition metal dichalcogenides, including the quasi-particle gaps, critical point energy locations, and their origins in the Brillouin zones. We show that single layer WSe surprisingly has an indirect quasi-particle gap with the conduction band minimum located at the Q-point (instead of K), albeit the two states are nearly degenerate. We have further observed rich quasi-particle electronic structures of transition metal dichalcogenides as a function of atomic structures and spin-orbit couplings. Such a local probe for detailed electronic structures in conduction and valence bands will be ideal to investigate how electronic structures of transition metal dichalcogenides are influenced by variations of local environment.

A simple biosynthetic pathway for large product generation from small substrate amounts

Science.gov (United States)

Djordjevic, Marko; Djordjevic, Magdalena

2012-10-01

A recently emerging discipline of synthetic biology has the aim of constructing new biosynthetic pathways with useful biological functions. A major application of these pathways is generating a large amount of the desired product. However, toxicity due to the possible presence of toxic precursors is one of the main problems for such production. We consider here the problem of generating a large amount of product from a potentially toxic substrate. To address this, we propose a simple biosynthetic pathway, which can be induced in order to produce a large number of the product molecules, by keeping the substrate amount at low levels. Surprisingly, we show that the large product generation crucially depends on fast non-specific degradation of the substrate molecules. We derive an optimal induction strategy, which allows as much as three orders of magnitude increase in the product amount through biologically realistic parameter values. We point to a recently discovered bacterial immune system (CRISPR/Cas in E. coli) as a putative example of the pathway analysed here. We also argue that the scheme proposed here can be used not only as a stand-alone pathway, but also as a strategy to produce a large amount of the desired molecules with small perturbations of endogenous biosynthetic pathways.

A simple biosynthetic pathway for large product generation from small substrate amounts

Energy Technology Data Exchange (ETDEWEB)

Djordjevic, Marko [Institute of Physiology and Biochemistry, Faculty of Biology, University of Belgrade (Serbia); Djordjevic, Magdalena [Institute of Physics Belgrade, University of Belgrade (Serbia)

2012-10-01

A recently emerging discipline of synthetic biology has the aim of constructing new biosynthetic pathways with useful biological functions. A major application of these pathways is generating a large amount of the desired product. However, toxicity due to the possible presence of toxic precursors is one of the main problems for such production. We consider here the problem of generating a large amount of product from a potentially toxic substrate. To address this, we propose a simple biosynthetic pathway, which can be induced in order to produce a large number of the product molecules, by keeping the substrate amount at low levels. Surprisingly, we show that the large product generation crucially depends on fast non-specific degradation of the substrate molecules. We derive an optimal induction strategy, which allows as much as three orders of magnitude increase in the product amount through biologically realistic parameter values. We point to a recently discovered bacterial immune system (CRISPR/Cas in E. coli) as a putative example of the pathway analysed here. We also argue that the scheme proposed here can be used not only as a stand-alone pathway, but also as a strategy to produce a large amount of the desired molecules with small perturbations of endogenous biosynthetic pathways. (paper)

A simple biosynthetic pathway for large product generation from small substrate amounts

International Nuclear Information System (INIS)

Djordjevic, Marko; Djordjevic, Magdalena

2012-01-01

A recently emerging discipline of synthetic biology has the aim of constructing new biosynthetic pathways with useful biological functions. A major application of these pathways is generating a large amount of the desired product. However, toxicity due to the possible presence of toxic precursors is one of the main problems for such production. We consider here the problem of generating a large amount of product from a potentially toxic substrate. To address this, we propose a simple biosynthetic pathway, which can be induced in order to produce a large number of the product molecules, by keeping the substrate amount at low levels. Surprisingly, we show that the large product generation crucially depends on fast non-specific degradation of the substrate molecules. We derive an optimal induction strategy, which allows as much as three orders of magnitude increase in the product amount through biologically realistic parameter values. We point to a recently discovered bacterial immune system (CRISPR/Cas in E. coli) as a putative example of the pathway analysed here. We also argue that the scheme proposed here can be used not only as a stand-alone pathway, but also as a strategy to produce a large amount of the desired molecules with small perturbations of endogenous biosynthetic pathways. (paper)

Fundamental surprise in the application of airpower

Science.gov (United States)

2017-05-25

explain transformations in scientific research proposed by Thomas Kuhn in his book “The Structure of Scientific Revolutions." Kuhn proposed the idea...that the accepted traditions of scientific research within a particular community, known as a paradigm, provide the tools to perform "normal science...the large-scale attacks on Lebanese infrastructure would have on the regime, this concept was a non- starter . The order issued to the IDF on 12 July

Extremely Large Magnetoresistance at Low Magnetic Field by Coupling the Nonlinear Transport Effect and the Anomalous Hall Effect.

Science.gov (United States)

Luo, Zhaochu; Xiong, Chengyue; Zhang, Xu; Guo, Zhen-Gang; Cai, Jianwang; Zhang, Xiaozhong

2016-04-13

The anomalous Hall effect of a magnetic material is coupled to the nonlinear transport effect of a semiconductor material in a simple structure to achieve a large geometric magnetoresistance (MR) based on a diode-assisted mechanism. An extremely large MR (>10(4) %) at low magnetic fields (1 mT) is observed at room temperature. This MR device shows potential for use as a logic gate for the four basic Boolean logic operations. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A conceptual geochemical model of the geothermal system at Surprise Valley, CA

Science.gov (United States)

Fowler, Andrew P. G.; Ferguson, Colin; Cantwell, Carolyn A.; Zierenberg, Robert A.; McClain, James; Spycher, Nicolas; Dobson, Patrick

2018-03-01

Characterizing the geothermal system at Surprise Valley (SV), northeastern California, is important for determining the sustainability of the energy resource, and mitigating hazards associated with hydrothermal eruptions that last occurred in 1951. Previous geochemical studies of the area attempted to reconcile different hot spring compositions on the western and eastern sides of the valley using scenarios of dilution, equilibration at low temperatures, surface evaporation, and differences in rock type along flow paths. These models were primarily supported using classical geothermometry methods, and generally assumed that fluids in the Lake City mud volcano area on the western side of the valley best reflect the composition of a deep geothermal fluid. In this contribution, we address controls on hot spring compositions using a different suite of geochemical tools, including optimized multicomponent geochemistry (GeoT) models, hot spring fluid major and trace element measurements, mineralogical observations, and stable isotope measurements of hot spring fluids and precipitated carbonates. We synthesize the results into a conceptual geochemical model of the Surprise Valley geothermal system, and show that high-temperature (quartz, Na/K, Na/K/Ca) classical geothermometers fail to predict maximum subsurface temperatures because fluids re-equilibrated at progressively lower temperatures during outflow, including in the Lake City area. We propose a model where hot spring fluids originate as a mixture between a deep thermal brine and modern meteoric fluids, with a seasonally variable mixing ratio. The deep brine has deuterium values at least 3 to 4‰ lighter than any known groundwater or high-elevation snow previously measured in and adjacent to SV, suggesting it was recharged during the Pleistocene when meteoric fluids had lower deuterium values. The deuterium values and compositional characteristics of the deep brine have only been identified in thermal springs and

Deciphering the clinical effect of drugs through large-scale data integration

DEFF Research Database (Denmark)

Kjærulff, Sonny Kim

. This work demonstrates the power of a strategy that uses clinical data mining in association with chemical biology in order to reduce the search space and aid identification of novel drug actions. The second article described in chapter 3 outlines a high confidence side-effect-drug interaction dataset. We...... demonstrates the importance of using high-confidence drug-side-effect data in deciphering the effect of small molecules in humans. In summary, this thesis presents computational systems chemical biology approaches that can help identify clinical effects of small molecules through large-scale data integration...

Large-D gravity and low-D strings.

Science.gov (United States)

Emparan, Roberto; Grumiller, Daniel; Tanabe, Kentaro

2013-06-21

We show that in the limit of a large number of dimensions a wide class of nonextremal neutral black holes has a universal near-horizon limit. The limiting geometry is the two-dimensional black hole of string theory with a two-dimensional target space. Its conformal symmetry explains the properties of massless scalars found recently in the large-D limit. For black branes with string charges, the near-horizon geometry is that of the three-dimensional black strings of Horne and Horowitz. The analogies between the α' expansion in string theory and the large-D expansion in gravity suggest a possible effective string description of the large-D limit of black holes. We comment on applications to several subjects, in particular to the problem of critical collapse.

Large eddy simulation study of the kinetic energy entrainment by energetic turbulent flow structures in large wind farms

Science.gov (United States)

VerHulst, Claire; Meneveau, Charles

2014-02-01

In this study, we address the question of how kinetic energy is entrained into large wind turbine arrays and, in particular, how large-scale flow structures contribute to such entrainment. Previous research has shown this entrainment to be an important limiting factor in the performance of very large arrays where the flow becomes fully developed and there is a balance between the forcing of the atmospheric boundary layer and the resistance of the wind turbines. Given the high Reynolds numbers and domain sizes on the order of kilometers, we rely on wall-modeled large eddy simulation (LES) to simulate turbulent flow within the wind farm. Three-dimensional proper orthogonal decomposition (POD) analysis is then used to identify the most energetic flow structures present in the LES data. We quantify the contribution of each POD mode to the kinetic energy entrainment and its dependence on the layout of the wind turbine array. The primary large-scale structures are found to be streamwise, counter-rotating vortices located above the height of the wind turbines. While the flow is periodic, the geometry is not invariant to all horizontal translations due to the presence of the wind turbines and thus POD modes need not be Fourier modes. Differences of the obtained modes with Fourier modes are documented. Some of the modes are responsible for a large fraction of the kinetic energy flux to the wind turbine region. Surprisingly, more flow structures (POD modes) are needed to capture at least 40% of the turbulent kinetic energy, for which the POD analysis is optimal, than are needed to capture at least 40% of the kinetic energy flux to the turbines. For comparison, we consider the cases of aligned and staggered wind turbine arrays in a neutral atmospheric boundary layer as well as a reference case without wind turbines. While the general characteristics of the flow structures are robust, the net kinetic energy entrainment to the turbines depends on the presence and relative

Cerebral metastasis masquerading as cerebritis: A case of misguiding history and radiological surprise!

Directory of Open Access Journals (Sweden)

Ashish Kumar

2013-01-01

Full Text Available Cerebral metastases usually have a characteristic radiological appearance. They can be differentiated rather easily from any infective etiology. Similarly, positive medical history also guides the neurosurgeon towards the possible diagnosis and adds to the diagnostic armamentarium. However, occasionally, similarities on imaging may be encountered where even history could lead us in the wrong direction and tends to bias the clinician. We report a case of a 40-year-old female with a history of mastoidectomy for otitis media presenting to us with a space occupying lesion in the right parietal region, which was thought pre-operatively as an abscess along with the cerebritis. Surprisingly, the histopathology proved it to be a metastatic adenocarcinoma. Hence, a ring enhancing lesion may be a high grade neoplasm/metastasis/abscess, significant gyral enhancement; a feature of cerebritis is not linked with a neoplastic etiology more often. This may lead to delayed diagnosis, incorrect prognostication and treatment in patients having coincidental suggestive history of infection. We review the literature and highlight the key points helping to differentiate an infective from a neoplastic pathology which may look similar at times.

ESB application for effective synchronization of large volume measurements data

CERN Document Server

Wyszkowski, Przemysław Michał

2011-01-01

The TOTEM experiment at CERN aims at measurement of total cross section, elastic scattering and diffractive processes of colliding protons in the Large Hadron Collider. In order for the research to be possible, it is necessary to process huge amounts of data coming from variety of sources: TOTEM detectors, CMS detectors, measurement devices around the Large Hadron Collider tunnel and many other external systems. Preparing final results involves also calculating plenty of intermediate figures, which also need to be stored. In order for the work of the scientist to be effective and convenient it is crucial to provide central point for the data storage, where all raw and intermediate figures will be stored. This thesis aims at presenting the usage of Enterprise Service Bus concept in building software infrastructure for transferring large volume of measurements data. Topics discussed here include technologies and mechanisms realizing the concept of integration bus, model of data transferring system based on ...

Segmentation, Diarization and Speech Transcription: Surprise Data Unraveled

NARCIS (Netherlands)

Huijbregts, M.A.H.

2008-01-01

In this thesis, research on large vocabulary continuous speech recognition for unknown audio conditions is presented. For automatic speech recognition systems based on statistical methods, it is important that the conditions of the audio used for training the statistical models match the conditions

Neutron flux shape effects in large fast reactor safety calculations

International Nuclear Information System (INIS)

Galati, A.; Loizzo, P.; Musco, A.

1978-01-01

Three classes of accidents in a large fast reactor were studied by the two-dimensional core dynamics code NADYP-2. A Modified version of the code, including a point kinetics module, allowed comparison between 2D and 0D power, reactivity and temperature histories. A strong shape effect was evidenced by these calculations in the boiling phase of LOF accidents as well as in the accident generated by control rod removal. Some future possibilities of by passing the consequences of this effect are indicated

Investor Reaction to Market Surprises on the Istanbul Stock Exchange Investor Reaction to Market Surprises on the Istanbul Stock Exchange = İstanbul Menkul Kıymetler Borsasında Piyasa Sürprizlerine Yatırımcı Tepkisi

Directory of Open Access Journals (Sweden)

Yaman Ömer ERZURUMLU

2011-08-01

Full Text Available This paper examines the reaction of investors to the arrival of unexpected information on the Istanbul Stock Exchange. The empirical results suggest that the investor reaction following unexpected news on the ISE100 is consistent with Overreaction Hypothesis especially after unfavorable market surprises. Interestingly such pattern does not exist for ISE30 index which includes more liquid and informationally efficient securities. A possible implication of this study for investors is that employing a semi contrarian investment strategy of buying losers in ISE100 may generate superior returns. Moreover, results are supportive of the last regulation change of Capital Market Board of Turkey which mandates more disclosure regarding the trading of less liquid stocks with lower market capitalization.

Revisiting the Effectiveness of Large Optical Telescopes

Directory of Open Access Journals (Sweden)

V. V. Sychev

2015-01-01

back action of design elements and propagation medium on the transmitted radiation wave-front;- lack of a basic source of radiation on the laser radiation wavelength, which is necessary for the adaptive correction methods to be applied to distorted wave-front;- inherent only in laser systems additional distorting factors available in transmitting systems.Such distorting factors are as follows:• length of optical path because of spacing necessary for a high-power laser source with a large number of the consistent optical elements;• thermal self-influence of powerful laser radiation in the channel of radiation transportation before its input in the forming optical system;• instability of spatiotemporal characteristics of laser radiation source itself, which worsens passing radiation conditions both in an optical path and in the free atmosphere;• thermal heterogeneity and thermal deformations.It is shown that adaptive systems are distinguished from active optics by the fact that correction of the radiation wave-front distortions occurs in real time on the entire set of the distorting factors (not only on influence of the atmosphere with the speed much exceeding action of distortions. Thus, the quality correction is assessed according to criterion of quality of primary image.Thus, correction continuously considers information on the current spatial, temperature, temporary, and justified parameters of the optical system, providing quality maintenance of the image under conditions of distorting factors.The main postulates of adaptive correction are formulated and offered.Postulates represent the set of statements and provisions allowing us to realize effective remedies of adaptive correction of distortions.It is also shown what real opportunities are open by using methods and means of adaptive optics in effective application of laser radiation power and what ways allow us to solve these tasks. First of all, it is:- forming a system of assumptions and minimizing the

Surface roughness effect on ultracold neutron interaction with a wall and implications for computer simulations

International Nuclear Information System (INIS)

Steyerl, A.; Malik, S. S.; Desai, A. M.; Kaufman, C.

2010-01-01

We review the diffuse scattering and the loss coefficient in ultracold neutron reflection from slightly rough surfaces, report a surprising reduction in loss coefficient due to roughness, and discuss the possibility of transition from quantum treatment to ray optics. The results are used in a computer simulation of neutron storage in a recent neutron lifetime experiment that reported a large discrepancy of neutron lifetime with the current particle data value. Our partial reanalysis suggests the possibility of systematic effects that were not included in this publication.

The effects and consequences of very large explosive volcanic eruptions.

Science.gov (United States)

Self, S

2006-08-15

Every now and again Earth experiences tremendous explosive volcanic eruptions, considerably bigger than the largest witnessed in historic times. Those yielding more than 450km3 of magma have been called super-eruptions. The record of such eruptions is incomplete; the most recent known example occurred 26000 years ago. It is more likely that the Earth will next experience a super-eruption than an impact from a large meteorite greater than 1km in diameter. Depending on where the volcano is located, the effects will be felt globally or at least by a whole hemisphere. Large areas will be devastated by pyroclastic flow deposits, and the more widely dispersed ash falls will be laid down over continent-sized areas. The most widespread effects will be derived from volcanic gases, sulphur gases being particularly important. This gas is converted into sulphuric acid aerosols in the stratosphere and layers of aerosol can cover the global atmosphere within a few weeks to months. These remain for several years and affect atmospheric circulation causing surface temperature to fall in many regions. Effects include temporary reductions in light levels and severe and unseasonable weather (including cool summers and colder-than-normal winters). Some aspects of the understanding and prediction of super-eruptions are problematic because they are well outside modern experience. Our global society is now very different to that affected by past, modest-sized volcanic activity and is highly vulnerable to catastrophic damage of infrastructure by natural disasters. Major disruption of services that society depends upon can be expected for periods of months to, perhaps, years after the next very large explosive eruption and the cost to global financial markets will be high and sustained.

A hard-to-read font reduces the framing effect in a large sample.

Science.gov (United States)

Korn, Christoph W; Ries, Juliane; Schalk, Lennart; Oganian, Yulia; Saalbach, Henrik

2018-04-01

How can apparent decision biases, such as the framing effect, be reduced? Intriguing findings within recent years indicate that foreign language settings reduce framing effects, which has been explained in terms of deeper cognitive processing. Because hard-to-read fonts have been argued to trigger deeper cognitive processing, so-called cognitive disfluency, we tested whether hard-to-read fonts reduce framing effects. We found no reliable evidence for an effect of hard-to-read fonts on four framing scenarios in a laboratory (final N = 158) and an online study (N = 271). However, in a preregistered online study with a rather large sample (N = 732), a hard-to-read font reduced the framing effect in the classic "Asian disease" scenario (in a one-sided test). This suggests that hard-read-fonts can modulate decision biases-albeit with rather small effect sizes. Overall, our findings stress the importance of large samples for the reliability and replicability of modulations of decision biases.

Large-order behavior of nondecoupling effects in the standard model and triviality

International Nuclear Information System (INIS)

Aoki, K.

1994-01-01

We compute some nondecoupling effects in the standard model, such as the ρ parameter, to all orders in the coupling constant expansion. We analyze their large order behavior and explicitly show how they are related to the nonperturbative cutoff dependence of these nondecoupling effects due to the triviality of the theory

Large enhancements of thermopower and carrier mobility in quantum dot engineered bulk semiconductors.

Science.gov (United States)

Liu, Yuanfeng; Sahoo, Pranati; Makongo, Julien P A; Zhou, Xiaoyuan; Kim, Sung-Joo; Chi, Hang; Uher, Ctirad; Pan, Xiaoqing; Poudeu, Pierre F P

2013-05-22

The thermopower (S) and electrical conductivity (σ) in conventional semiconductors are coupled adversely through the carriers' density (n) making it difficult to achieve meaningful simultaneous improvements in both electronic properties through doping and/or substitutional chemistry. Here, we demonstrate the effectiveness of coherently embedded full-Heusler (FH) quantum dots (QDs) in tailoring the density, mobility, and effective mass of charge carriers in the n-type Ti(0.1)Zr(0.9)NiSn half-Heusler matrix. We propose that the embedded FH QD forms a potential barrier at the interface with the matrix due to the offset of their conduction band minima. This potential barrier discriminates existing charge carriers from the conduction band of the matrix with respect to their relative energy leading to simultaneous large enhancements of the thermopower (up to 200%) and carrier mobility (up to 43%) of the resulting Ti(0.1)Zr(0.9)Ni(1+x)Sn nanocomposites. The improvement in S with increasing mole fraction of the FH-QDs arises from a drastic reduction (up to 250%) in the effective carrier density coupled with an increase in the carrier's effective mass (m*), whereas the surprising enhancement in the mobility (μ) is attributed to an increase in the carrier's relaxation time (τ). This strategy to manipulate the transport behavior of existing ensembles of charge carriers within a bulk semiconductor using QDs is very promising and could pave the way to a new generation of high figure of merit thermoelectric materials.

Quantum tunneling observed without its characteristic large kinetic isotope effects.

Science.gov (United States)

Hama, Tetsuya; Ueta, Hirokazu; Kouchi, Akira; Watanabe, Naoki

2015-06-16

Classical transition-state theory is fundamental to describing chemical kinetics; however, quantum tunneling is also important in explaining the unexpectedly large reaction efficiencies observed in many chemical systems. Tunneling is often indicated by anomalously large kinetic isotope effects (KIEs), because a particle's ability to tunnel decreases significantly with its increasing mass. Here we experimentally demonstrate that cold hydrogen (H) and deuterium (D) atoms can add to solid benzene by tunneling; however, the observed H/D KIE was very small (1-1.5) despite the large intrinsic H/D KIE of tunneling (≳ 100). This strong reduction is due to the chemical kinetics being controlled not by tunneling but by the surface diffusion of the H/D atoms, a process not greatly affected by the isotope type. Because tunneling need not be accompanied by a large KIE in surface and interfacial chemical systems, it might be overlooked in other systems such as aerosols or enzymes. Our results suggest that surface tunneling reactions on interstellar dust may contribute to the deuteration of interstellar aromatic and aliphatic hydrocarbons, which could represent a major source of the deuterium enrichment observed in carbonaceous meteorites and interplanetary dust particles. These findings could improve our understanding of interstellar physicochemical processes, including those during the formation of the solar system.

Analogies and surprising differences between recombinant nitric oxide synthase-like proteins from Staphylococcus aureus and Bacillus anthracis in their interactions with l-arginine analogs and iron ligands.

Science.gov (United States)

Salard, Isabelle; Mercey, Emilie; Rekka, Eleni; Boucher, Jean-Luc; Nioche, Pierre; Mikula, Ivan; Martasek, Pavel; Raman, C S; Mansuy, Daniel

2006-12-01

Genome sequencing has recently shown the presence of genes coding for NO-synthase (NOS)-like proteins in bacteria. The roles of these proteins remain unclear. The interactions of a series of l-arginine (l-arg) analogs and iron ligands with two recombinant NOS-like proteins from Staphylococcus aureus (saNOS) and Bacillus anthracis (baNOS) have been studied by UV-visible spectroscopy. SaNOS and baNOS in their ferric native state, as well as their complexes with l-arg analogs and with various ligands, exhibit spectral characteristics highly similar to the corresponding complexes of heme-thiolate proteins such as cytochromes P450 and NOSs. However, saNOS greatly differs from baNOS at the level of three main properties: (i) native saNOS mainly exists under an hexacoordinated low-spin ferric state whereas native baNOS is mainly high-spin, (ii) the addition of tetrahydrobiopterin (H4B) or H4B analogs leads to an increase of the affinity of l-arg for saNOS but not for baNOS, and (iii) saNOS Fe(II), contrary to baNOS, binds relatively bulky ligands such as nitrosoalkanes and tert-butylisocyanide. Thus, saNOS exhibits properties very similar to those of the oxygenase domain of inducible NOS (iNOS(oxy)) not containing H4B, as expected for a NOSoxy-like protein that does not contain H4B. By contrast, the properties of baNOS which look like those of H4B-containing iNOS(oxy) are unexpected for a NOS-like protein not containing H4B. The origin of these surprising properties of baNOS remains to be determined.

On the Renormalization of the Effective Field Theory of Large Scale Structures

OpenAIRE

Pajer, Enrico; Zaldarriaga, Matias

2013-01-01

Standard perturbation theory (SPT) for large-scale matter inhomogeneities is unsatisfactory for at least three reasons: there is no clear expansion parameter since the density contrast is not small on all scales; it does not fully account for deviations at large scales from a perfect pressureless fluid induced by short-scale non-linearities; for generic initial conditions, loop corrections are UV-divergent, making predictions cutoff dependent and hence unphysical. The Effective Field Theory o...

Corn Ethanol: The Surprisingly Effective Route for Natural Gas Consumption in the Transportation Sector

Energy Technology Data Exchange (ETDEWEB)

Szybist, James P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Curran, Scott [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-05-01

Proven reserves and production of natural gas (NG) in the United States have increased dramatically in the last decade, due largely to the commercialization of hydraulic fracturing. This has led to a plentiful supply of NG, resulting in a significantly lower cost on a gallon of gasoline-equivalent (GGE) basis. Additionally, NG is a domestic, non-petroleum source of energy that is less carbon-intensive than coal or petroleum products, and thus can lead to lower greenhouse gas emissions. Because of these factors, there is a desire to increase the use of NG in the transportation sector in the United States (U.S.). However, using NG directly in the transportation sector requires that several non-trivial challenges be overcome. One of these issues is the fueling infrastructure. There are currently only 1,375 NG fueling stations in the U.S. compared to 152,995 fueling stations for gasoline in 2014. Additionally, there are very few light-duty vehicles that can consume this fuel directly as dedicated or bi-fuel options. For example, in model year 2013Honda was the only OEM to offer a dedicated CNG sedan while a number of others offered CNG options as a preparation package for LD trucks and vans. In total, there were a total of 11 vehicle models in 2013 that could be purchased that could use natural gas directly. There are additional potential issues associated with NG vehicles as well. Compared to commercial refueling stations, the at-home refueling time for NG vehicles is substantial – a result of the small compressors used for home refilling. Additionally, the methane emissions from both refueling (leakage) and from tailpipe emissions (slip) from these vehicles can add to their GHG footprint, and while these emissions are not currently regulated it could be a barrier in the future, especially in scenarios with broad scale adoption of CNG vehicles. However, NG consumption already plays a large role in other sectors of the economy, including some that are important to

Analytic expressions for polarimetry in plasma with large Cotton endash Mouton or Faraday effects

International Nuclear Information System (INIS)

Segre, S.E.

1996-01-01

Analytic expressions for plasma polarimetry are derived for the case when either the Cotton endash Mouton effect or the Faraday effect is large while the other effect is small. copyright 1996 American Institute of Physics

The Large Scale Distribution of Water Ice in the Polar Regions of the Moon

Science.gov (United States)

Jordan, A.; Wilson, J. K.; Schwadron, N.; Spence, H. E.

2017-12-01

For in situ resource utilization, one must know where water ice is on the Moon. Many datasets have revealed both surface deposits of water ice and subsurface deposits of hydrogen near the lunar poles, but it has proved difficult to resolve the differences among the locations of these deposits. Despite these datasets disagreeing on how deposits are distributed on small scales, we show that most of these datasets do agree on the large scale distribution of water ice. We present data from the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on the Lunar Reconnaissance Orbiter (LRO), LRO's Lunar Exploration Neutron Detector (LEND), the Neutron Spectrometer on Lunar Prospector (LPNS), LRO's Lyman Alpha Mapping Project (LAMP), LRO's Lunar Orbiter Laser Altimeter (LOLA), and Chandrayaan-1's Moon Mineralogy Mapper (M3). All, including those that show clear evidence for water ice, reveal surprisingly similar trends with latitude, suggesting that both surface and subsurface datasets are measuring ice. All show that water ice increases towards the poles, and most demonstrate that its signature appears at about ±70° latitude and increases poleward. This is consistent with simulations of how surface and subsurface cold traps are distributed with latitude. This large scale agreement constrains the origin of the ice, suggesting that an ancient cometary impact (or impacts) created a large scale deposit that has been rendered locally heterogeneous by subsequent impacts. Furthermore, it also shows that water ice may be available down to ±70°—latitudes that are more accessible than the poles for landing.

Effects of electrolyte gating on photoluminescence spectra of large-area WSe2monolayer films

KAUST Repository

Matsuki, Keiichiro; Pu, Jiang; Kozawa, Daichi; Matsuda, Kazunari; Li, Lain-Jong; Takenobu, Taishi

2016-01-01

We fabricated electric double-layer transistors comprising large-area WSe2 monolayers and investigated the effects of electrolyte gating on their photoluminescence (PL) spectra. Using the efficient gating effects of electric double layers, we succeeded in the application of a large electric field (>107Vcm%1) and the accumulation of high carrier density (>1013cm%2). As a result, we observed PL spectra based on both positively and negatively charged excitons and their gate-voltage-dependent redshifts, suggesting the effects of both an electric field and charge accumulation. © 2016 The Japan Society of Applied Physics.

Effects of electrolyte gating on photoluminescence spectra of large-area WSe2monolayer films

KAUST Repository

Matsuki, Keiichiro

2016-05-24

We fabricated electric double-layer transistors comprising large-area WSe2 monolayers and investigated the effects of electrolyte gating on their photoluminescence (PL) spectra. Using the efficient gating effects of electric double layers, we succeeded in the application of a large electric field (>107Vcm%1) and the accumulation of high carrier density (>1013cm%2). As a result, we observed PL spectra based on both positively and negatively charged excitons and their gate-voltage-dependent redshifts, suggesting the effects of both an electric field and charge accumulation. © 2016 The Japan Society of Applied Physics.

Modeling thermo-optic effect in large mode area double cladding photonic crystal fibers

Science.gov (United States)

Coscelli, Enrico; Cucinotta, Annamaria

2014-02-01

The impact of thermally-induced refractive index changes on the single-mode (SM) properties of large mode area (LMA) photonic crystal fibers are thoroughly investigated by means of a full-vector modal solver with integrated thermal model. Three photonic crystal fiber designs are taken into account, namely the 19-cell core fiber, the large-pitch fiber (LPF) and the distributed modal filtering (DMF) fiber, to assess the effects of the interplay between thermal effects and the high-order mode (HOM) suppression mechanisms exploited in order to obtain effectively SM guiding. The results have shown significant differences in the way the SM regime is changed by the increase of heat load, providing useful hints for the design of LMA fibers for high power lasers.

Large-current-controllable carbon nanotube field-effect transistor in electrolyte solution

Science.gov (United States)

Myodo, Miho; Inaba, Masafumi; Ohara, Kazuyoshi; Kato, Ryogo; Kobayashi, Mikinori; Hirano, Yu; Suzuki, Kazuma; Kawarada, Hiroshi

2015-05-01

Large-current-controllable carbon nanotube field-effect transistors (CNT-FETs) were fabricated with mm-long CNT sheets. The sheets, synthesized by remote-plasma-enhanced CVD, contained both single- and double-walled CNTs. Titanium was deposited on the sheet as source and drain electrodes, and an electrolyte solution was used as a gate electrode (solution gate) to apply a gate voltage to the CNTs through electric double layers formed around the CNTs. The drain current came to be well modulated as electrolyte solution penetrated into the sheets, and one of the solution gate CNT-FETs was able to control a large current of over 2.5 A. In addition, we determined the transconductance parameter per tube and compared it with values for other CNT-FETs. The potential of CNT sheets for applications requiring the control of large current is exhibited in this study.

An innovative large scale integration of silicon nanowire-based field effect transistors

Science.gov (United States)

Legallais, M.; Nguyen, T. T. T.; Mouis, M.; Salem, B.; Robin, E.; Chenevier, P.; Ternon, C.

2018-05-01

Since the early 2000s, silicon nanowire field effect transistors are emerging as ultrasensitive biosensors while offering label-free, portable and rapid detection. Nevertheless, their large scale production remains an ongoing challenge due to time consuming, complex and costly technology. In order to bypass these issues, we report here on the first integration of silicon nanowire networks, called nanonet, into long channel field effect transistors using standard microelectronic process. A special attention is paid to the silicidation of the contacts which involved a large number of SiNWs. The electrical characteristics of these FETs constituted by randomly oriented silicon nanowires are also studied. Compatible integration on the back-end of CMOS readout and promising electrical performances open new opportunities for sensing applications.

Fringe field effects in small rings of large acceptance

Directory of Open Access Journals (Sweden)

Martin Berz

2000-12-01

Full Text Available Recently there has been renewed interest in the influence of fringe fields on particle dynamics, due to studies that revealed their importance in some cases, as, for example, the proposed Neutrino Factory and muon colliders. In this paper, we present a systematic study of generic fringe field effects. Using as an example a lattice of the proposed Neutrino Factory, we show that fringe fields influence the dynamics of particles at all orders, starting with the linear motion. It is found that the widely used sharp cutoff approximation leads to divergences regardless of the specific fall-off shape of the fields. The results suggest that a careful consideration of fringe field effects in the design stage of small machines for large emittances is always recommended.

Large picture archiving and communication systems of the world--Part 2.

Science.gov (United States)

Bauman, R A; Gell, G; Dwyer, S J

1996-11-01

A survey of 82 institutions worldwide was done in 1995 to identify large picture archiving and communication systems (PACS) in clinical operation. A continuing strong trend toward the creation and operation of large PACS was identified. In the 15 months since the first such survey the number of clinical large PACS went from 13 to 23, almost a doubling in that short interval. New systems were added in Asia, Europe, and North America. A strong move to primary interpretation from soft copy was identified, and filmless radiology has become a reality. Workstations for interpretation reside mainly within radiology, but one-third of reporting PACS have more than 20 workstations outside of radiology. Fiber distributed data interface networks were the most numerous, but a variety of networks was reported to be in use. Replies on various display times showed surprisingly good, albeit diverse, speeds. The planned archive length of many systems was 60 months, with usually more than 1 year of data on-line. The main large archive and off-line storage media for these systems were optical disks and magneto-optical disks. Compression was not used before interpretation in most cases, but many systems used 2.5:1 compression for on-line, interpreted cases and 10:1 compression for longer-term archiving. A move to digital imaging and communication in medicine interface usage was identified.

Effectiveness of Acupuncture Therapy on Stress in a Large Urban College Population.

Science.gov (United States)

Schroeder, Stefanie; Burnis, James; Denton, Antony; Krasnow, Aaron; Raghu, T S; Mathis, Kimberly

2017-06-01

This study is a randomized controlled clinical trial to study the effectiveness of acupuncture on the perception of stress in patients who study or work on a large, urban college campus. The hypothesis was that verum acupuncture would demonstrate a significant positive impact on perceived stress as compared to sham acupuncture. This study included 111 participants with high self-reported stress levels who either studied or worked at a large, urban public university in the southwestern United States. However, only 62 participants completed the study. The participants were randomized into a verum acupuncture or sham acupuncture group. Both the groups received treatment once a week for 12 weeks. The Cohen's global measure of perceived stress scale (PSS-14) was completed by each participant prior to treatment, at 6 weeks, at 12 weeks, and 6 weeks and 12 weeks post-treatment completion. While participants of both the groups showed a substantial initial decrease in perceived stress scores, at 12 weeks post treatment, the verum acupuncture group showed a significantly greater treatment effect than the sham acupuncture group. This study indicates that acupuncture may be successful in decreasing the perception of stress in students and staff at a large urban university, and this effect persists for at least 3 months after the completion of treatment. Copyright © 2017. Published by Elsevier B.V.

‘Surprise’: Outbreak of Campylobacter infection associated with chicken liver pâté at a surprise birthday party, Adelaide, Australia, 2012

OpenAIRE

Emma Denehy; Amy Parry; Emily Fearnley

2012-01-01

Objective: In July 2012, an outbreak of Campylobacter infection was investigated by the South Australian Communicable Disease Control Branch and Food Policy and Programs Branch. The initial notification identified illness at a surprise birthday party held at a restaurant on 14 July 2012. The objective of the investigation was to identify the potential source of infection and institute appropriate intervention strategies to prevent further illness.Methods: A guest list was obtained and a retro...

The effects of an invasive alien plant (Chromolaena odorata on large African mammals

Directory of Open Access Journals (Sweden)

Lihle Dumalisile

2017-11-01

Full Text Available Alien plants have invaded most ecosystem types (terrestrial, fresh water and marine and are responsible for the loss of irreplaceable natural services on which humankind relies. They alter food quantity, quality and accessibility, and may result in declines in native species richness, which may ultimately result in extinction. For an effective management of invasive alien plants, it is important to understand the effects that such plants have on all levels of biodiversity. However, the effects that invasive alien plants, such as the Triffid weed (Chromolaena odorata, have on mammalian biodiversity, especially large mammalian species, are not well-known, although they play major ecological roles in areas such as nutrient cycling. Also, little is known about the recovery of the ecosystem following alien plant removal. This study investigated the effects of C. odorata invasion on large mammalian herbivores in Hluhluwe-iMfolozi Park and whether clearing of this plant helped in rehabilitating the habitat. We used track counts to estimate and compare species richness, diversity and abundance indices for large mammalian species between areas with differing C. odorata invasion durations (ca 2 years, ca 10 years, ca 20 years, areas with differing clearing times (cl < 2 years, cl 3–5 years and an area without any history of C. odorata invasion as a control. The results from this study show that large mammalian species utilised the uninvaded and the cleared areas more than the invaded areas. Species richness, abundance and diversity decreased with increasing invasion duration and cleared areas showed an increasing species richness and abundance. We conclude that this invasive alien plant modifies habitats and their removal does aid in the restoration of the ecosystem.

Effectiveness of feeding large kibbles with mechanical cleaning properties in cats with gingivitis

NARCIS (Netherlands)

Vrieling, HE; Theyse, LFH; van Winkelhoff, AJ; Dijkshoorn, NA; Logan, EI; Picovet, P

2005-01-01

Effectiveness of feeding large kibbles with mechanical cleaning properties in cats with gingivitis periodontal disease is the most common acquired oral disease in cats. it starts with plaque accumulation and gingivitis. The aim of this study was to evaluate the effectiveness of different types of

Large radiative corrections to the effective potential and the gauge hierarchy problem

International Nuclear Information System (INIS)

Sachrajda, C.T.C.

1982-01-01

We study the higher order corrections to the effective potential in a simple toy model and in the SU(5) grand unified theory, with a view to seeing what their effects are on the stability equations, and hence on the gauge hierarchy problem for these theories. These corrections contain powers of log (v 2 /h 2 ), where v and h are the large and small vacuum expectation values respectively, and hence cannot a priori be neglected. Nevertheless, after summing these large logarithms we find that the stability equations always contain two equations for v (i.e. these equations are independent of h) and hence can only be satisfied by a special (and hence unnatural) choice of parameters. This we claim is the precise statement of the gauge hierarchy problem. (orig.)

Non-Dirac Chern insulators with large band gaps and spin-polarized edge states.

Science.gov (United States)

Xue, Y; Zhang, J Y; Zhao, B; Wei, X Y; Yang, Z Q

2018-05-10

Based on first-principles calculations and k·p models, we demonstrate that PbC/MnSe heterostructures are a non-Dirac type of Chern insulator with very large band gaps (244 meV) and exotically half-metallic edge states, providing the possibilities of realizing very robust, completely spin polarized, and dissipationless spintronic devices from the heterostructures. The achieved extraordinarily large nontrivial band gap can be ascribed to the contribution of the non-Dirac type electrons (composed of px and py) and the very strong atomic spin-orbit coupling (SOC) interaction of the heavy Pb element in the system. Surprisingly, the band structures are found to be sensitive to the different exchange and correlation functionals adopted in the first-principles calculations. Chern insulators with various mechanisms are acquired from them. These discoveries show that the predicted nontrivial topology in PbC/MnSe heterostructures is robust and can be observed in experiments at high temperatures. The system has great potential to have attractive applications in future spintronics.

Large N Scalars

DEFF Research Database (Denmark)

Sannino, Francesco

2016-01-01

We construct effective Lagrangians, and corresponding counting schemes, valid to describe the dynamics of the lowest lying large N stable massive composite state emerging in strongly coupled theories. The large N counting rules can now be employed when computing quantum corrections via an effective...

Derivation of the pure Faraday and Cotton-Mouton effects when polarimetric effects in a tokamak are large

International Nuclear Information System (INIS)

Segre, S E; Zanza, V

2006-01-01

When polarimetric effects are large the Cotton-Mouton and Faraday effects do not combine linearly and it is not possible to separate exactly the pure Cotton-Mouton effect W 1 and the pure Faraday effect, W 3 . Four alternative approximate expressions for W 1 and W 3 in terms of measurable quantities are examined for tokamak configurations. Two of these approximations proposed recently are found to be preferable, some previous statements concerning them are corrected and the errors incurred by their use are evaluated

Using Java to visualize and manipulate large arrays of neutron scattering data

International Nuclear Information System (INIS)

Mikkelson, D.; Worlton, T.; Chatterjee, A.; Hammonds, J.; Chen, D.

2000-01-01

The Intense Pulsed Neutron Source at Argonne National Laboratory is a world class pulsed neutron source with thirteen instruments designed to characterize materials using time-of-flight neutron scattering techniques. For each instrument, a collimated pulse of neutrons is directed to a material sample. The neutrons are scattered by the sample and detected by arrays of detectors. The type, number and arrangement of detectors vary widely from instrument to instrument, depending on which properties of materials are being studied. In all cases, the faster, higher energy neutrons reach the detectors sooner than the lower energy neutrons. This produces a time-of-flight spectrum at each detector element. The time-of-flight spectrum produced by each detector element records the scattering intensity at hundreds to thousands of discrete time intervals. Since there are typically between two hundred and ten thousand distinct detector elements, a single set of raw data can include millions of points. Often many such datasets are collected for a single sample to determine the effect of different conditions on the microscopic structure and dynamics of the sample. In this project, Java was used to construct a portable highly interactive system for viewing and operating on large collections of time-of-flight spectra. Java performed surprisingly well in handling large amounts of data quickly was fast enough even with standard PC hardware. Although Java may not be the choice at this time for applications where computational efficiency is the primary refinement, any disadvantages in this case were outweighed by the advantages of a clean object oriented language with a portable set of GUI components. The authors anticipate that Java will prove useful for scientific computing and data visualization in situations where portability, case of use and effective use of software development manpower are critical

Characterizing Android apps’ behavior for effective detection of malapps at large scale

KAUST Repository

Wang, Xing

2017-05-06

Android malicious applications (malapps) have surged and been sophisticated, posing a great threat to users. How to characterize, understand and detect Android malapps at a large scale is thus a big challenge. In this work, we are motivated to discover the discriminatory and persistent features extracted from Android APK files for automated malapp detection at a large scale. To achieve this goal, firstly we extract a very large number of features from each app and categorize the features into two groups, namely, app-specific features as well as platform-defined features. These feature sets will then be fed into four classifiers (i.e., Logistic Regression, linear SVM, Decision Tree and Random Forest) for the detection of malapps. Secondly, we evaluate the persistence of app-specific and platform-defined features on classification performance with two data sets collected in different time periods. Thirdly, we comprehensively analyze the relevant features selected by Logistic Regression classifier to identify the contributions of each feature set. We conduct extensive experiments on large real-world app sets consisting of 213,256 benign apps collected from six app markets, 4,363 benign apps from Google Play market, and 18,363 malapps. The experimental results and our analysis give insights regarding what discriminatory features are most effective to characterize malapps for building an effective and efficient malapp detection system. With the selected discriminatory features, the Logistic Regression classifier yields the best true positive rate as 96% with a false positive rate as 0.06%.

Cluster galaxy dynamics and the effects of large-scale environment

Science.gov (United States)

White, Martin; Cohn, J. D.; Smit, Renske

2010-11-01

Advances in observational capabilities have ushered in a new era of multi-wavelength, multi-physics probes of galaxy clusters and ambitious surveys are compiling large samples of cluster candidates selected in different ways. We use a high-resolution N-body simulation to study how the influence of large-scale structure in and around clusters causes correlated signals in different physical probes and discuss some implications this has for multi-physics probes of clusters (e.g. richness, lensing, Compton distortion and velocity dispersion). We pay particular attention to velocity dispersions, matching galaxies to subhaloes which are explicitly tracked in the simulation. We find that not only do haloes persist as subhaloes when they fall into a larger host, but groups of subhaloes retain their identity for long periods within larger host haloes. The highly anisotropic nature of infall into massive clusters, and their triaxiality, translates into an anisotropic velocity ellipsoid: line-of-sight galaxy velocity dispersions for any individual halo show large variance depending on viewing angle. The orientation of the velocity ellipsoid is correlated with the large-scale structure, and thus velocity outliers correlate with outliers caused by projection in other probes. We quantify this orientation uncertainty and give illustrative examples. Such a large variance suggests that velocity dispersion estimators will work better in an ensemble sense than for any individual cluster, which may inform strategies for obtaining redshifts of cluster members. We similarly find that the ability of substructure indicators to find kinematic substructures is highly viewing angle dependent. While groups of subhaloes which merge with a larger host halo can retain their identity for many Gyr, they are only sporadically picked up by substructure indicators. We discuss the effects of correlated scatter on scaling relations estimated through stacking, both analytically and in the simulations

Relationship of fish indices with sampling effort and land use change in a large Mediterranean river.

Science.gov (United States)

Almeida, David; Alcaraz-Hernández, Juan Diego; Merciai, Roberto; Benejam, Lluís; García-Berthou, Emili

2017-12-15

Fish are invaluable ecological indicators in freshwater ecosystems but have been less used for ecological assessments in large Mediterranean rivers. We evaluated the effects of sampling effort (transect length) on fish metrics, such as species richness and two fish indices (the new European Fish Index EFI+ and a regional index, IBICAT2b), in the mainstem of a large Mediterranean river. For this purpose, we sampled by boat electrofishing five sites each with 10 consecutive transects corresponding to a total length of 20 times the river width (European standard required by the Water Framework Directive) and we also analysed the effect of sampling area on previous surveys. Species accumulation curves and richness extrapolation estimates in general suggested that species richness was reasonably estimated with transect lengths of 10 times the river width or less. The EFI+ index was significantly affected by sampling area, both for our samplings and previous data. Surprisingly, EFI+ values in general decreased with increasing sampling area, despite the higher observed richness, likely because the expected values of metrics were higher. By contrast, the regional fish index was not dependent on sampling area, likely because it does not use a predictive model. Both fish indices, but particularly the EFI+, decreased with less forest cover percentage, even within the smaller disturbance gradient in the river type studied (mainstem of a large Mediterranean river, where environmental pressures are more general). Although the two fish-based indices are very different in terms of their development, methodology, and metrics used, they were significantly correlated and provided a similar assessment of ecological status. Our results reinforce the importance of standardization of sampling methods for bioassessment and suggest that predictive models that use sampling area as a predictor might be more affected by differences in sampling effort than simpler biotic indices. Copyright �

[Fall from height--surprising autopsy diagnosis in primarily unclear initial situations].

Science.gov (United States)

Schyma, Christian; Doberentz, Elke; Madea, Burkhard

2012-01-01

External post-mortem examination and first police assessments are often not consistent with subsequent autopsy results. This is all the more surprising the more serious the injuries found at autopsy are. Such discrepancies result especially from an absence of gross external injuries, as demonstrated by four examples. A 42-year-old, externally uninjured male was found at night time in a helpless condition in the street and died in spite of resuscitation. Autopsy showed severe polytrauma with traumatic brain injury and lesions of the thoracic and abdominal organs. A jump from the third floor was identified as the cause. At dawn, a twenty-year-old male was found dead on the grounds of the adjacent house. Because of the blood-covered head the police assumed a traumatic head injury by strike impact. The external examination revealed only abrasions on the forehead and to a minor extent on the back. At autopsy a midfacial fracture, a trauma of the thorax and abdomen and fractures of the spine and pelvis were detected. Afterwards investigations showed that the man, intoxicated by alcohol, had fallen from the flat roof of a multistoried house. A 77-year-old man was found unconscious on his terrace at day time; a cerebral seizure was assumed. He was transferred to emergency care where he died. The corpse was externally inconspicuous. Autopsy revealed serious traumatic injuries of the brain, thorax, abdomen and pelvis, which could be explained by a fall from the balcony. A 47-year-old homeless person without any external injuries was found dead in a barn. An alcohol intoxication was assumed. At autopsy severe injuries of the brain and cervical spine were found which were the result of a fall from a height of 5 m. On the basis of an external post-mortem examination alone gross blunt force trauma cannot be reliably excluded.

Influence of the large-small split effect on strategy choice in complex subtraction.

Science.gov (United States)

Xiang, Yan Hui; Wu, Hao; Shang, Rui Hong; Chao, Xiaomei; Ren, Ting Ting; Zheng, Li Ling; Mo, Lei

2018-04-01

Two main theories have been used to explain the arithmetic split effect: decision-making process theory and strategy choice theory. Using the inequality paradigm, previous studies have confirmed that individuals tend to adopt a plausibility-checking strategy and a whole-calculation strategy to solve large and small split problems in complex addition arithmetic, respectively. This supports strategy choice theory, but it is unknown whether this theory also explains performance in solving different split problems in complex subtraction arithmetic. This study used small, intermediate and large split sizes, with each split condition being further divided into problems requiring and not requiring borrowing. The reaction times (RTs) for large and intermediate splits were significantly shorter than those for small splits, while accuracy was significantly higher for large and middle splits than for small splits, reflecting no speed-accuracy trade-off. Further, RTs and accuracy differed significantly between the borrow and no-borrow conditions only for small splits. This study indicates that strategy choice theory is suitable to explain the split effect in complex subtraction arithmetic. That is, individuals tend to choose the plausibility-checking strategy or the whole-calculation strategy according to the split size. © 2016 International Union of Psychological Science.

Large eddy simulation of a buoyancy-aided flow in a non-uniform channel – Buoyancy effects on large flow structures

Energy Technology Data Exchange (ETDEWEB)

Duan, Y. [Department of Mechanical Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom); School of Mechanical, Aerospace and Civil Engineering, University of Manchester, Manchester M13 9PL (United Kingdom); He, S., E-mail: s.he@sheffield.ac.uk [Department of Mechanical Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom)

2017-02-15

Highlights: • Buoyancy may greatly redistribute the flow in a non-uniform channel. • Flow structures in the narrow gap are greatly changed when buoyancy is strong. • Large flow structures exist in wider gap, which is enhanced when heat is strong. • Buoyancy reduces mixing factor caused by large flow structures in narrow gap. - Abstract: It has been a long time since the ‘abnormal’ turbulent intensity distribution and high inter-sub-channel mixing rates were observed in the vicinity of the narrow gaps formed by the fuel rods in nuclear reactors. The extraordinary flow behaviour was first described as periodic flow structures by Hooper and Rehme (1984). Since then, the existences of large flow structures were demonstrated by many researchers in various non-uniform flow channels. It has been proved by many authors that the Strouhal number of the flow structure in the isothermal flow is dependent on the size of the narrow gap, not the Reynolds number once it is sufficiently large. This paper reports a numerical investigation on the effect of buoyancy on the large flow structures. A buoyancy-aided flow in a tightly-packed rod-bundle-like channel is modelled using large eddy simulation (LES) together with the Boussinesq approximation. The behaviour of the large flow structures in the gaps of the flow passage are studied using instantaneous flow fields, spectrum analysis and correlation analysis. It is found that the non-uniform buoyancy force in the cross section of the flow channel may greatly redistribute the velocity field once the overall buoyancy force is sufficiently strong, and consequently modify the large flow structures. The temporal and axial spatial scales of the large flow structures are influenced by buoyancy in a way similar to that turbulence is influenced. These scales reduce when the flow is laminarised, but start increasing in the turbulence regeneration region. The spanwise scale of the flow structures in the narrow gap remains more or

SPIN EFFECTS IN THE FRAGMENTATION OF TRANSVERSELY POLARIZED AND UNPOLARIZED QUARKS

International Nuclear Information System (INIS)

ANSELMINO, M.; BOER, D.; DALESIO, U.; MURGIA, F.

2001-01-01

We study the fragmentation of a transversely polarized quark into a non-collinear (kperpendicular ≠ 0) spinless hadron and the fragmentation of an unpolarized quark into a non collinear transversely polarized spin 1/2 baryon. These nonperturbative properties are described by spin and kperpendicular dependent fragmentation functions and are revealed in the observation of single spin asymmetries. Recent data on the production of pions in polarized semi-inclusive DIS and long known data on A polarization in unpolarized p-N processes are considered: these new fragmentation functions can describe the experimental results and the single spin effects in the quark fragmentation turn out to be surprisingly large

Effects of large herbivores on grassland arthropod diversity

NARCIS (Netherlands)

van Klink, R.; van der Plas, F.; van Noordwijk, C. G. E. (Toos); WallisDeVries, M. F.; Olff, H.

Both arthropods and large grazing herbivores are important components and drivers of biodiversity in grassland ecosystems, but a synthesis of how arthropod diversity is affected by large herbivores has been largely missing. To fill this gap, we conducted a literature search, which yielded 141

The morphodynamics and sedimentology of large river confluences

Science.gov (United States)

Nicholas, Andrew; Sambrook Smith, Greg; Best, James; Bull, Jon; Dixon, Simon; Goodbred, Steven; Sarker, Mamin; Vardy, Mark

2017-04-01

Confluences are key locations within large river networks, yet surprisingly little is known about how they migrate and evolve through time. Moreover, because confluence sites are associated with scour pools that are typically several times the mean channel depth, the deposits associated with such scours should have a high potential for preservation within the rock record. However, paradoxically, such scours are rarely observed, and the sedimentological characteristics of such deposits are poorly understood. This study reports results from a physically-based morphodynamic model, which is applied to simulate the evolution and resulting alluvial architecture associated with large river junctions. Boundary conditions within the model simulation are defined to approximate the junction of the Ganges and Jamuna rivers, in Bangladesh. Model results are supplemented by geophysical datasets collected during boat-based surveys at this junction. Simulated deposit characteristics and geophysical datasets are compared with three existing and contrasting conceptual models that have been proposed to represent the sedimentary architecture of confluence scours. Results illustrate that existing conceptual models may be overly simplistic, although elements of each of the three conceptual models are evident in the deposits generated by the numerical simulation. The latter are characterised by several distinct styles of sedimentary fill, which can be linked to particular morphodynamic behaviours. However, the preserved characteristics of simulated confluence deposits vary substantial according to the degree of reworking by channel migration. This may go some way towards explaining the confluence scour paradox; while abundant large scours might be expected in the rock record, they are rarely reported.

Reconstructing Information in Large-Scale Structure via Logarithmic Mapping

Science.gov (United States)

Szapudi, Istvan

We propose to develop a new method to extract information from large-scale structure data combining two-point statistics and non-linear transformations; before, this information was available only with substantially more complex higher-order statistical methods. Initially, most of the cosmological information in large-scale structure lies in two-point statistics. With non- linear evolution, some of that useful information leaks into higher-order statistics. The PI and group has shown in a series of theoretical investigations how that leakage occurs, and explained the Fisher information plateau at smaller scales. This plateau means that even as more modes are added to the measurement of the power spectrum, the total cumulative information (loosely speaking the inverse errorbar) is not increasing. Recently we have shown in Neyrinck et al. (2009, 2010) that a logarithmic (and a related Gaussianization or Box-Cox) transformation on the non-linear Dark Matter or galaxy field reconstructs a surprisingly large fraction of this missing Fisher information of the initial conditions. This was predicted by the earlier wave mechanical formulation of gravitational dynamics by Szapudi & Kaiser (2003). The present proposal is focused on working out the theoretical underpinning of the method to a point that it can be used in practice to analyze data. In particular, one needs to deal with the usual real-life issues of galaxy surveys, such as complex geometry, discrete sam- pling (Poisson or sub-Poisson noise), bias (linear, or non-linear, deterministic, or stochastic), redshift distortions, pro jection effects for 2D samples, and the effects of photometric redshift errors. We will develop methods for weak lensing and Sunyaev-Zeldovich power spectra as well, the latter specifically targetting Planck. In addition, we plan to investigate the question of residual higher- order information after the non-linear mapping, and possible applications for cosmology. Our aim will be to work out

The genome of Pelobacter carbinolicus reveals surprising metabolic capabilities and physiological features

Energy Technology Data Exchange (ETDEWEB)

Aklujkar, Muktak [University of Massachusetts, Amherst; Haveman, Shelley [University of Massachusetts, Amherst; DiDonatoJr, Raymond [University of Massachusetts, Amherst; Chertkov, Olga [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Land, Miriam L [ORNL; Brown, Peter [University of Massachusetts, Amherst; Lovley, Derek [University of Massachusetts, Amherst

2012-01-01

Background: The bacterium Pelobacter carbinolicus is able to grow by fermentation, syntrophic hydrogen/formate transfer, or electron transfer to sulfur from short-chain alcohols, hydrogen or formate; it does not oxidize acetate and is not known to ferment any sugars or grow autotrophically. The genome of P. carbinolicus was sequenced in order to understand its metabolic capabilities and physiological features in comparison with its relatives, acetate-oxidizing Geobacter species. Results: Pathways were predicted for catabolism of known substrates: 2,3-butanediol, acetoin, glycerol, 1,2-ethanediol, ethanolamine, choline and ethanol. Multiple isozymes of 2,3-butanediol dehydrogenase, ATP synthase and [FeFe]-hydrogenase were differentiated and assigned roles according to their structural properties and genomic contexts. The absence of asparagine synthetase and the presence of a mutant tRNA for asparagine encoded among RNA-active enzymes suggest that P. carbinolicus may make asparaginyl-tRNA in a novel way. Catabolic glutamate dehydrogenases were discovered, implying that the tricarboxylic acid (TCA) cycle can function catabolically. A phosphotransferase system for uptake of sugars was discovered, along with enzymes that function in 2,3-butanediol production. Pyruvate: ferredoxin/flavodoxin oxidoreductase was identified as a potential bottleneck in both the supply of oxaloacetate for oxidation of acetate by the TCA cycle and the connection of glycolysis to production of ethanol. The P. carbinolicus genome was found to encode autotransporters and various appendages, including three proteins with similarity to the geopilin of electroconductive nanowires. Conclusions: Several surprising metabolic capabilities and physiological features were predicted from the genome of P. carbinolicus, suggesting that it is more versatile than anticipated.

Effect of thermal contact resistances on fast charging of large format lithium ion batteries

International Nuclear Information System (INIS)

Ye, Yonghuang; Saw, Lip Huat; Shi, Yixiang; Somasundaram, Karthik; Tay, Andrew A.O.

2014-01-01

Highlights: • The effect of thermal contact resistance on thermal performance of large format lithium ion batteries. • The effect of temperature gradient on electrochemical performance of large format batteries during fast charging. • The thermal performance of lithium ion battery utilizing pulse charging protocol. • Suggestions on battery geometry design optimization to improve thermal performance. - Abstract: A two dimensional electrochemical thermal model is developed on the cross-plane of a laminate stack plate pouch lithium ion battery to study the thermal performance of large format batteries. The effect of thermal contact resistance is taken into consideration, and is found to greatly increase the maximum temperature and temperature gradient of the battery. The resulting large temperature gradient would induce in-cell non-uniformity of charging-discharging current and state of health. Simply increasing the cooling intensity is inadequate to reduce the maximum temperature and narrow down the temperature difference due to the poor cross-plane thermal conductivity. Pulse charging protocol does not help to mitigate the temperature difference on the bias of same total charging time, because of larger time-averaged heat generation rate than constant current charging. Suggestions on battery geometry optimizations for both prismatic/pouch battery and cylindrical battery are proposed to reduce the maximum temperature and mitigate the temperature gradient within the lithium ion battery

How to reach clients of female sex workers: a survey by surprise in brothels in Dakar, Senegal.

Science.gov (United States)

Espirito Santo, M. E. Gomes do; Etheredge, G. D.

2002-01-01

OBJECTIVE: To describe the sampling techniques and survey procedures used in identifying male clients who frequent brothels to buy sexual services from female sex workers in Dakar, Senegal, with the aim of measuring the prevalence of human immunodeficiency virus (HIV) infection and investigating related risk behaviours. METHODS: Surveys were conducted in seven brothels in Dakar, Senegal. Clients were identified "by surprise" and interviewed and requested to donate saliva for HIV testing. RESULTS: Of the 1450 clients of prostitutes who were solicited to enter the study, 1140 (79.8%) agreed to be interviewed; 1083 (95%) of these clients provided saliva samples for testing. Of the samples tested, 47 were positive for HIV-1 or HIV-2, giving an HIV prevalence of 4.4%. CONCLUSION: The procedures adopted were successful in reaching the target population. Men present in the brothels could not deny being there, and it proved possible to explain the purpose of the study and to gain their confidence. Collection of saliva samples was shown to be an excellent method for performing HIV testing in difficult field conditions where it is hard to gain access to the population under study. The surveying of prostitution sites is recommended as a means of identifying core groups for HIV infection with a view to targeting education programmes more effectively. In countries such as Senegal, where the prevalence of HIV infection is still low, interventions among commercial sex workers and their clients may substantially delay the onset of a larger epidemic in the general population. PMID:12378288

QUAL-NET, a high temporal-resolution eutrophication model for large hydrographic networks

Science.gov (United States)

Minaudo, Camille; Curie, Florence; Jullian, Yann; Gassama, Nathalie; Moatar, Florentina

2018-04-01

To allow climate change impact assessment of water quality in river systems, the scientific community lacks efficient deterministic models able to simulate hydrological and biogeochemical processes in drainage networks at the regional scale, with high temporal resolution and water temperature explicitly determined. The model QUALity-NETwork (QUAL-NET) was developed and tested on the Middle Loire River Corridor, a sub-catchment of the Loire River in France, prone to eutrophication. Hourly variations computed efficiently by the model helped disentangle the complex interactions existing between hydrological and biological processes across different timescales. Phosphorus (P) availability was the most constraining factor for phytoplankton development in the Loire River, but simulating bacterial dynamics in QUAL-NET surprisingly evidenced large amounts of organic matter recycled within the water column through the microbial loop, which delivered significant fluxes of available P and enhanced phytoplankton growth. This explained why severe blooms still occur in the Loire River despite large P input reductions since 1990. QUAL-NET could be used to study past evolutions or predict future trajectories under climate change and land use scenarios.

QUAL-NET, a high temporal-resolution eutrophication model for large hydrographic networks

Directory of Open Access Journals (Sweden)

C. Minaudo

2018-04-01

Full Text Available To allow climate change impact assessment of water quality in river systems, the scientific community lacks efficient deterministic models able to simulate hydrological and biogeochemical processes in drainage networks at the regional scale, with high temporal resolution and water temperature explicitly determined. The model QUALity-NETwork (QUAL-NET was developed and tested on the Middle Loire River Corridor, a sub-catchment of the Loire River in France, prone to eutrophication. Hourly variations computed efficiently by the model helped disentangle the complex interactions existing between hydrological and biological processes across different timescales. Phosphorus (P availability was the most constraining factor for phytoplankton development in the Loire River, but simulating bacterial dynamics in QUAL-NET surprisingly evidenced large amounts of organic matter recycled within the water column through the microbial loop, which delivered significant fluxes of available P and enhanced phytoplankton growth. This explained why severe blooms still occur in the Loire River despite large P input reductions since 1990. QUAL-NET could be used to study past evolutions or predict future trajectories under climate change and land use scenarios.

Vlasov simulation of the relativistic effect on the breaking of large amplitude plasma waves

International Nuclear Information System (INIS)

Xu Hui; Sheng Zhengming; Zhang Jie

2007-01-01

The influence of relativistic and thermal effects on plasma wave breaking has been studied by solving the coupled Vlasov-Poisson equations. When the relativistic effect is not considered, the wave breaking will not occur, provided the initial perturbation is less than certain value as predicted previously, and the largest amplitude of the plasma wave will decrease with the increase of the initial temperature. When the relativistic effect is considered, wave breaking always occurs during the time evolution, irrespective of the initial perturbation amplitude. Yet the smaller the initial perturbation amplitude is, the longer is the time for wave breaking to occur. With large initial perturbations, wave breaking can always occur with the without the relativistic effect. However, the results are significantly different in the two cases. The thermal effects of electrons decrease the threshold value to initial amplitude for wave breaking and large phase velocity makes the nonlinear phenomenon occur more easily. (authors)

Large reversible magnetostrictive effect of MnCoSi-based compounds prepared by high-magnetic-field solidification

Science.gov (United States)

Hu, Q. B.; Hu, Y.; Zhang, S.; Tang, W.; He, X. J.; Li, Z.; Cao, Q. Q.; Wang, D. H.; Du, Y. W.

2018-01-01

The MnCoSi compound is a potential magnetostriction material since the magnetic field can drive a metamagnetic transition from an antiferromagnetic phase to a high magnetization phase in it, which accompanies a large lattice distortion. However, a large driving magnetic field, magnetic hysteresis, and poor mechanical properties seriously hinder its application for magnetostriction. By substituting Fe for Mn and introducing vacancies of the Mn element, textured and dense Mn0.97Fe0.03CoSi and Mn0.88CoSi compounds are prepared through a high-magnetic-field solidification approach. As a result, large room-temperature and reversible magnetostriction effects are observed in these compounds at a low magnetic field. The origin of this large magnetostriction effect and potential applications are discussed.

Effects of cell asymmetry on the performance of a large heterogeneous critical assembly

International Nuclear Information System (INIS)

Scholtyssek, W.; Humbert, G.; Martini, M.; Norvez, G.

1981-09-01

Calculations were performed to investigate asymmetry effects observed in the RACINE reference configuration. The perturbation sources -material shifts in fissile rodlet cells- were identified and influences on various experimental parameters were estimated. Improvements of the relatively simple methods used in this work could lead to applications, considering similar effects, in project calculations for large power reactor cores

String effects on Fermi-Dirac correlation measurements

International Nuclear Information System (INIS)

Duran Delgado, R.M.; Gustafson, G.; Loennblad, L.

2007-01-01

We investigate some recent measurements of Fermi-Dirac correlations by the LEP collaborations indicating surprisingly small source radii for the production of baryons in e + e - annihilation at the Z 0 peak. In hadronization models there is besides the Fermi-Dirac correlation effect also a strong dynamical (anti-) correlation. We demonstrate that the extraction of the pure FD effect is highly dependent on a realistic Monte Carlo event generator, both for separation of those dynamical correlations that are not related to Fermi-Dirac statistics, and for corrections of the data and background subtractions. Although the model can be tuned to well reproduce single particle distributions, there are large model uncertainties when it comes to correlations between identical baryons. We therefore, unfortunately, have to conclude that it is at present not possible to draw any firm conclusion about the source radii relevant for baryon production at LEP. (orig.)

Stability of car following with human memory effects and automatic headway compensation.

Science.gov (United States)

Sipahi, Rifat; Niculescu, Silviu-Iulian

2010-10-13

This paper addresses the study of some appropriate control strategies in order to guarantee the exponential stability of a class of deterministic microscopic car-following models including human drivers' memory effects and automated headway controllers. More precisely, the delayed action/decision of human drivers is represented using distributed delays with a gap and the considered automated controller is of proportional derivative type. The analysis is performed in both delay parameter and controller gain parameter spaces, and appropriate algorithms are proposed. Surprisingly, large delays and/or gains improve stability for the corresponding closed-loop schemes. Finally, some illustrative examples as well as various interpretations of the results complete the presentation.

Experimental Study of the Effect of Language (English and Spanish on Advertisement Effectiveness with Puerto Rican Hispanic University Students

Directory of Open Access Journals (Sweden)

Carlos Lebrón

2002-09-01

Full Text Available Even though the population of Puerto Rico includes a large percent of residents with some knowledge of the English language (bilinguals, the vast majority communicates using Spanish, which is their native language. Not surprisingly, the majority of advertisements in Puerto Rican media use the Spanish language. The common sense assumption that Spanish advertising is significantly superior to English advertising when targeting Puerto Rican Hispanics living in Puerto Rico is tested experimentally in this study. The Social Value component of the Theory of Consumption Values was used to generate several Hypotheses that would favor the use of English language. The experiment used magazine-like printed illustrated advertisements to test the hypotheses, all of them dealing with relative effectiveness of Spanish versus English language advertisements. The results show that Spanish advertisements and English advertisements were about the same in terms of their persuasion effectiveness.

D-brane black holes: Large-N limit and the effective string description

Energy Technology Data Exchange (ETDEWEB)

Hassan, S F [International Centre for Theoretical Physics, Trieste (Italy); Wadia, S R [Theoretical Physics Div., CERN, Geneva (Switzerland)

1997-03-01

We address the derivation of the effective conformal field theory description of the 5-dimensional black hole, modelled by a collection of D1-and D5-branes, from the corresponding low energy U(Q{sub 1}) x U(Q{sub 5}) gauge theory. Finite horizon size at weak coupling requires both Q{sub 1} and Q{sub 5} to be large. We derive the results in the moduli space approximation (say for Q{sub 1} > Q{sub 5}) and appeal to supersymmetry to argue its validity beyond weak coupling. As a result of a combination of quenched Z{sub Q1} Wilson lines and a residual Weyl symmetry, the low-lying excitations of the U(Q{sub 1}) x U(Q{sub 5}) gauge theory are described by an effective N = 4 superconformal field theory with c = 6 in 1 + 1 dimensions, where the space is a circle of radius RQ{sub 1}Q{sub 5}. We also discuss the appearance of a marginal perturbation of the effective conformal field theory for large but finite values of Q{sub 5}. (author). 42 refs.

The costs and effectiveness of large Phase III pre-licensure vaccine clinical trials.

Science.gov (United States)

Black, Steven

2015-01-01

Prior to the 1980s, most vaccines were licensed based upon safety and effectiveness studies in several hundred individuals. Beginning with the evaluation of Haemophilus influenzae type b conjugate vaccines, much larger pre-licensure trials became common. The pre-licensure trial for Haemophilus influenzae oligosaccharide conjugate vaccine had more than 60,000 children and that of the seven-valent pneumococcal conjugate vaccine included almost 38,000 children. Although trial sizes for both of these studies were driven by the sample size required to demonstrate efficacy, the sample size requirements for safety evaluations of other vaccines have subsequently increased. With the demonstration of an increased risk of intussusception following the Rotashield brand rotavirus vaccine, this trend has continued. However, routinely requiring safety studies of 20,000-50,000 or more participants has two major downsides. First, the cost of performing large safety trials routinely prior to licensure of a vaccine is very large, with some estimates as high at US$200 million euros for one vaccine. This high financial cost engenders an opportunity cost whereby the number of vaccines that a company is willing or able to develop to meet public health needs becomes limited by this financial barrier. The second downside is that in the pre-licensure setting, such studies are very time consuming and delay the availability of a beneficial vaccine substantially. One might argue that in some situations, this financial commitment is warranted such as for evaluations of the risk of intussusception following newer rotavirus vaccines. However, it must be noted that while an increased risk of intussusception was not identified in large pre-licensure studies, in post marketing evaluations an increased risk of this outcome has been identified. Thus, even the extensive pre-licensure evaluations conducted did not identify an associated risk. The limitations of large Phase III trials have also been

Centrifugal force: a few surprises

International Nuclear Information System (INIS)

Abramowicz, M.A.; Max-Planck-Institut fuer Physik und Astrophysik, Garching

1990-01-01

The need for a rather fundamental revision in understanding of the nature of the centrifugal force is discussed. It is shown that in general relativity (and contrary to the situation in Newtonian theory) rotation of a reference frame is a necessary but not sufficient condition for the centrifugal force to appear. A sufficient condition for its appearance, in the instantaneously corotating reference frame of a particle, is that the particle motion in space (observed in the global rest frame) differs from a photon trajectory. The direction of the force is the same as that of the gradient of the effective potential for photon motion. In some cases, the centrifugal force will attract towards the axis of rotation. (author)

Large-scale behaviour of local and entanglement entropy of the free Fermi gas at any temperature

Science.gov (United States)

Leschke, Hajo; Sobolev, Alexander V.; Spitzer, Wolfgang

2016-07-01

The leading asymptotic large-scale behaviour of the spatially bipartite entanglement entropy (EE) of the free Fermi gas infinitely extended in multidimensional Euclidean space at zero absolute temperature, T = 0, is by now well understood. Here, we present and discuss the first rigorous results for the corresponding EE of thermal equilibrium states at T> 0. The leading large-scale term of this thermal EE turns out to be twice the first-order finite-size correction to the infinite-volume thermal entropy (density). Not surprisingly, this correction is just the thermal entropy on the interface of the bipartition. However, it is given by a rather complicated integral derived from a semiclassical trace formula for a certain operator on the underlying one-particle Hilbert space. But in the zero-temperature limit T\\downarrow 0, the leading large-scale term of the thermal EE considerably simplifies and displays a {ln}(1/T)-singularity which one may identify with the known logarithmic enhancement at T = 0 of the so-called area-law scaling. birthday of the ideal Fermi gas.

Performance of informative priors skeptical of large treatment effects in clinical trials: A simulation study.

Science.gov (United States)

Pedroza, Claudia; Han, Weilu; Thanh Truong, Van Thi; Green, Charles; Tyson, Jon E

2018-01-01

One of the main advantages of Bayesian analyses of clinical trials is their ability to formally incorporate skepticism about large treatment effects through the use of informative priors. We conducted a simulation study to assess the performance of informative normal, Student- t, and beta distributions in estimating relative risk (RR) or odds ratio (OR) for binary outcomes. Simulation scenarios varied the prior standard deviation (SD; level of skepticism of large treatment effects), outcome rate in the control group, true treatment effect, and sample size. We compared the priors with regards to bias, mean squared error (MSE), and coverage of 95% credible intervals. Simulation results show that the prior SD influenced the posterior to a greater degree than the particular distributional form of the prior. For RR, priors with a 95% interval of 0.50-2.0 performed well in terms of bias, MSE, and coverage under most scenarios. For OR, priors with a wider 95% interval of 0.23-4.35 had good performance. We recommend the use of informative priors that exclude implausibly large treatment effects in analyses of clinical trials, particularly for major outcomes such as mortality.

Relativistic effects on large amplitude nonlinear Langmuir waves in a two-fluid plasma

International Nuclear Information System (INIS)

Nejoh, Yasunori

1994-07-01

Large amplitude relativistic nonlinear Langmuir waves are analyzed by the pseudo-potential method. The existence conditions for nonlinear Langmuir waves are confirmed by considering relativistic high-speed electrons in a two-fluid plasma. The significant feature of this investigation is that the propagation of nonlinear Langmuir waves depends on the ratio of the electron streaming velocity to the velocity of light, the normalized potential and the ion mass to electron mass ratio. The constant energy is determined by the specific range of the relativistic effect. In the non-relativistic limit, large amplitude relativistic Langmuir waves do not exist. The present investigation predicts new findings of large amplitude nonlinear Langmuir waves in space plasma phenomena in which relativistic electrons are important. (author)

Large anomalous Nernst and spin Nernst effects in the noncollinear antiferromagnets Mn3X (X =Sn ,Ge ,Ga )

Science.gov (United States)

Guo, Guang-Yu; Wang, Tzu-Cheng

2017-12-01

Noncollinear antiferromagnets have recently been attracting considerable interest partly due to recent surprising discoveries of the anomalous Hall effect (AHE) in them and partly because they have promising applications in antiferromagnetic spintronics. Here we study the anomalous Nernst effect (ANE), a phenomenon having the same origin as the AHE, and also the spin Nernst effect (SNE) as well as AHE and the spin Hall effect (SHE) in noncollinear antiferromagnetic Mn3X (X =Sn , Ge, Ga) within the Berry phase formalism based on ab initio relativistic band structure calculations. For comparison, we also calculate the anomalous Nernst conductivity (ANC) and anomalous Hall conductivity (AHC) of ferromagnetic iron as well as the spin Nernst conductivity (SNC) of platinum metal. Remarkably, the calculated ANC at room temperature (300 K) for all three alloys is huge, being 10-40 times larger than that of iron. Moreover, the calculated SNC for Mn3Sn and Mn3Ga is also larger, being about five times larger than that of platinum. This suggests that these antiferromagnets would be useful materials for thermoelectronic devices and spin caloritronic devices. The calculated ANC of Mn3Sn and iron are in reasonably good agreement with the very recent experiments. The calculated SNC of platinum also agrees with the very recent experiments in both sign and magnitude. The calculated thermoelectric and thermomagnetic properties are analyzed in terms of the band structures as well as the energy-dependent AHC, ANC, SNC, and spin Hall conductivity via the Mott relations.

Fabrication of large-scale one-dimensional Au nanochain and nanowire networks by interfacial self-assembly

International Nuclear Information System (INIS)

Wang Minhua; Li Yongjun; Xie Zhaoxiong; Liu Cai; Yeung, Edward S.

2010-01-01

By utilizing the strong capillary attraction between interfacial nanoparticles, large-scale one-dimensional Au nanochain networks were fabricated at the n-butanol/water interface, and could be conveniently transferred onto hydrophilic substrates. Furthermore, the length of the nanochains could be adjusted simply by controlling the density of Au nanoparticles (AuNPs) at the n-butanol/water interface. Surprisingly, the resultant Au nanochains could further transform into smooth nanowires by increasing the aging time, forming a nanowire network. Combined characterization by HRTEM and UV-vis spectroscopy indicates that the formation of Au nanochains stemmed from a stochastic assembly of interfacial AuNPs due to strong capillary attraction, and the evolution of nanochains to nanowires follows an Ostwald ripening mechanism rather than an oriented attachment. This method could be utilized to fabricate large-area nanochain or nanowire networks more uniformly on solid substrates than that of evaporating a solution of nanochain colloid, since it eliminates the three-dimensional aggregation behavior.

‘Surprise’: Outbreak of Campylobacter infection associated with chicken liver pâté at a surprise birthday party, Adelaide, Australia, 2012

Directory of Open Access Journals (Sweden)

Emma Denehy

2012-11-01

Full Text Available Objective: In July 2012, an outbreak of Campylobacter infection was investigated by the South Australian Communicable Disease Control Branch and Food Policy and Programs Branch. The initial notification identified illness at a surprise birthday party held at a restaurant on 14 July 2012. The objective of the investigation was to identify the potential source of infection and institute appropriate intervention strategies to prevent further illness.Methods: A guest list was obtained and a retrospective cohort study undertaken. A combination of paper-based and telephone questionnaires were used to collect exposure and outcome information. An environmental investigation was conducted by Food Policy and Programs Branch at the implicated premises.Results: All 57 guests completed the questionnaire (100% response rate, and 15 met the case definition. Analysis showed a significant association between illness and consumption of chicken liver pâté (relative risk: 16.7, 95% confidence interval: 2.4–118.6. No other food or beverage served at the party was associated with illness. Three guests submitted stool samples; all were positive for Campylobacter. The environmental investigation identified that the cooking process used in the preparation of chicken liver pâté may have been inconsistent, resulting in some portions not cooked adequately to inactivate potential Campylobacter contamination.Discussion: Chicken liver products are a known source of Campylobacter infection; therefore, education of food handlers remains a high priority. To better identify outbreaks among the large number of Campylobacter notifications, routine typing of Campylobacter isolates is recommended.

‘Surprise’: Outbreak of Campylobacter infection associated with chicken liver pâté at a surprise birthday party, Adelaide, Australia, 2012

Science.gov (United States)

Fearnley, Emily; Denehy, Emma

2012-01-01

Objective In July 2012, an outbreak of Campylobacter infection was investigated by the South Australian Communicable Disease Control Branch and Food Policy and Programs Branch. The initial notification identified illness at a surprise birthday party held at a restaurant on 14 July 2012. The objective of the investigation was to identify the potential source of infection and institute appropriate intervention strategies to prevent further illness. Methods A guest list was obtained and a retrospective cohort study undertaken. A combination of paper-based and telephone questionnaires were used to collect exposure and outcome information. An environmental investigation was conducted by Food Policy and Programs Branch at the implicated premises. Results All 57 guests completed the questionnaire (100% response rate), and 15 met the case definition. Analysis showed a significant association between illness and consumption of chicken liver pâté (relative risk: 16.7, 95% confidence interval: 2.4–118.6). No other food or beverage served at the party was associated with illness. Three guests submitted stool samples; all were positive for Campylobacter. The environmental investigation identified that the cooking process used in the preparation of chicken liver pâté may have been inconsistent, resulting in some portions not cooked adequately to inactivate potential Campylobacter contamination. Discussion Chicken liver products are a known source of Campylobacter infection; therefore, education of food handlers remains a high priority. To better identify outbreaks among the large number of Campylobacter notifications, routine typing of Campylobacter isolates is recommended. PMID:23908933

THE TURN OF THE MONTH EFFECT CONTINUED: A COMPARISON OF SMALL CAP STOCKS AND LARGE CAP STOCKS

OpenAIRE

Ramsundhar, Shamman

2010-01-01

The purpose of this paper is to investigate whether the turn of the month effect occurs in small cap and large cap stocks and if it occurs in both categories, to determine whether there is a difference in the magnitude. My research, for the period of 1963-2008, based on the CRSP value weighted index, shows that there is a significant turn of the month effect in small and large cap stocks, however the effect is larger in small cap stocks. Furthermore, this effect is not limited to a short time...

Moduli dynamics as a predictive tool for thermal maximally supersymmetric Yang-Mills at large N

Energy Technology Data Exchange (ETDEWEB)

Morita, Takeshi [Department of Physics, Shizuoka University,836 Ohya, Suruga-ku, Shizuoka 422-8529 (Japan); Department of Physics and Astronomy, University of Kentucky,Lexington, KY 40506 (United States); Shiba, Shotaro [Maskawa Institute for Science and Culture, Kyoto Sangyo University,Kamigamo-Motoyama, Kita-ku, Kyoto 603-8555 (Japan); Wiseman, Toby [Theoretical Physics Group, Blackett Laboratory, Imperial College,Exhibition Road, London SW7 2AZ (United Kingdom); Withers, Benjamin [Mathematical Sciences and STAG Research Centre, University of Southampton,Highfield, Southampton SO17 1BJ (United Kingdom)

2015-07-09

Maximally supersymmetric (p+1)-dimensional Yang-Mills theory at large N and finite temperature, with possibly compact spatial directions, has a rich phase structure. Strongly coupled phases may have holographic descriptions as black branes in various string duality frames, or there may be no gravity dual. In this paper we provide tools in the gauge theory which give a simple and unified picture of the various strongly coupled phases, and transitions between them. Building on our previous work we consider the effective theory describing the moduli of the gauge theory, which can be computed precisely when it is weakly coupled far out on the Coulomb branch. Whilst for perturbation theory naive extrapolation from weak coupling to strong gives little information, for this moduli theory naive extrapolation from its weakly to its strongly coupled regime appears to encode a surprising amount of information about the various strongly coupled phases. We argue it encodes not only the parametric form of thermodynamic quantities for these strongly coupled phases, but also certain transcendental factors with a geometric origin, and allows one to deduce transitions between the phases. We emphasise it also gives predictions for the behaviour of other observables in these phases.

Moduli dynamics as a predictive tool for thermal maximally supersymmetric Yang-Mills at large N

International Nuclear Information System (INIS)

Morita, Takeshi; Shiba, Shotaro; Wiseman, Toby; Withers, Benjamin

2015-01-01

Maximally supersymmetric (p+1)-dimensional Yang-Mills theory at large N and finite temperature, with possibly compact spatial directions, has a rich phase structure. Strongly coupled phases may have holographic descriptions as black branes in various string duality frames, or there may be no gravity dual. In this paper we provide tools in the gauge theory which give a simple and unified picture of the various strongly coupled phases, and transitions between them. Building on our previous work we consider the effective theory describing the moduli of the gauge theory, which can be computed precisely when it is weakly coupled far out on the Coulomb branch. Whilst for perturbation theory naive extrapolation from weak coupling to strong gives little information, for this moduli theory naive extrapolation from its weakly to its strongly coupled regime appears to encode a surprising amount of information about the various strongly coupled phases. We argue it encodes not only the parametric form of thermodynamic quantities for these strongly coupled phases, but also certain transcendental factors with a geometric origin, and allows one to deduce transitions between the phases. We emphasise it also gives predictions for the behaviour of other observables in these phases.

Large-scale monitoring of effects of clothianidin-dressed OSR seeds on pollinating insects in Northern Germany: effects on large earth bumble bees (Bombus terrestris).

Science.gov (United States)

Sterk, Guido; Peters, Britta; Gao, Zhenglei; Zumkier, Ulrich

2016-11-01

The aim of this study was to investigate the effects of Elado ® -dressed winter oilseed rape (OSR, 10 g clothianidin & 2 g beta-cyfluthrin/kg seed) on the development, reproduction and behaviour of large earth bumble bees (Bombus terrestris) as part of a large-scale monitoring field study in Northern Germany, where OSR is usually cultivated at 25-33 % of the arable land. Both reference and test sites comprised 65 km 2 in which no other crops attractive to pollinating insects were present. Six study locations were selected per site and 10 bumble bee hives were placed at each location. At each site, three locations were directly adjacent to OSR fields and three locations were situated 400 m distant from the nearest OSR field. The development of colonies was monitored from the beginning of OSR flowering in April until June 2014. Pollen from returning foragers was analysed for its composition. An average of 44 % of OSR pollen was found in pollen loads of bumble bees indicating that OSR was a major resource for the colonies. At the end of OSR flowering, hives were transferred to a nature reserve until the end of the study. Colony development in terms of hive weight and the number of workers showed a typical course with no statistically significant differences between the sites. Reproductive output was comparatively high and not negatively affected by the exposure to treated OSR. In summary, Elado ® -dressed OSR did not cause any detrimental effects on the development or reproduction of bumble bee colonies.

COMBINED EFFECTS OF GALAXY INTERACTIONS AND LARGE-SCALE ENVIRONMENT ON GALAXY PROPERTIES

International Nuclear Information System (INIS)

Park, Changbom; Choi, Yun-Young

2009-01-01

We inspect the coupled dependence of physical parameters of the Sloan Digital Sky Survey galaxies on the small-scale (distance to and morphology of the nearest neighbor galaxy) and the large-scale (background density smoothed over 20 nearby galaxies) environments. The impacts of interaction on galaxy properties are detected at least out to the neighbor separation corresponding to the virial radius of galaxies, which is typically between 200 and 400 h -1 kpc for the galaxies in our sample. To detect these long-range interaction effects, it is crucial to divide galaxy interactions into four cases dividing the morphology of target and neighbor galaxies into early and late types. We show that there are two characteristic neighbor-separation scales where the galaxy interactions cause abrupt changes in the properties of galaxies. The first scale is the virial radius of the nearest neighbor galaxy r vir,nei . Many physical parameters start to deviate from those of extremely isolated galaxies at the projected neighbor separation r p of about r vir,nei . The second scale is at r p ∼ 0.05r vir,nei = 10-20 h -1 kpc, and is the scale at which the galaxies in pairs start to merge. We find that late-type neighbors enhance the star formation activity of galaxies while early-type neighbors reduce it, and that these effects occur within r vir,nei . The hot halo gas and cold disk gas must be participating in the interactions at separations less than the virial radius of the galaxy plus dark halo system. Our results also show that the role of the large-scale density in determining galaxy properties is minimal once luminosity and morphology are fixed. We propose that the weak residual dependence of galaxy properties on the large-scale density is due to the dependence of the halo gas property on the large-scale density.

Effects of uncertainty in model predictions of individual tree volume on large area volume estimates

Science.gov (United States)

Ronald E. McRoberts; James A. Westfall

2014-01-01

Forest inventory estimates of tree volume for large areas are typically calculated by adding model predictions of volumes for individual trees. However, the uncertainty in the model predictions is generally ignored with the result that the precision of the large area volume estimates is overestimated. The primary study objective was to estimate the effects of model...

Plasma polarimetry for large Cotton--Mouton and Faraday effects

International Nuclear Information System (INIS)

Segre, S.E.

1995-01-01

A formalism is presented for treating plasma polarimetry when both the Cotton--Mouton and the Faraday effects are large. For this general case it is shown that, for each measuring chord, up to nine parameters related to the plasma can be determined, instead of the usual single Faraday rotation. These parameters can be measured by a convenient modulation of the polarization state of the input radiation, and they can be used in the reconstruction of the magnetohydrodynamic equilibrium. Thus, the potential of the polarimetric diagnostic can be significantly increased, and the range of plasma conditions where the latter can be used, is extended. The importance of refraction is discussed. copyright 1995 American Institute of Physics

Surprising transformation of a block copolymer into a high performance polystyrene ultrafiltration membrane with a hierarchically organized pore structure

KAUST Repository

Shevate, Rahul

2018-02-08

We describe the preparation of hierarchical polystyrene nanoporous membranes with a very narrow pore size distribution and an extremely high porosity. The nanoporous structure is formed as a result of unusual degradation of the poly(4-vinyl pyridine) block from self-assembled poly(styrene)-b-poly(4-vinyl pyridine) (PS-b-P4VP) membranes through the formation of an unstable pyridinium intermediate in an alkaline medium. During this process, the confined swelling and controlled degradation produced a tunable pore size. We unequivocally confirmed the successful elimination of the P4VP block from a PS-b-P4VPVP membrane using 1D/2D NMR spectroscopy and other characterization techniques. Surprisingly, the long range ordered surface porosity was preserved even after degradation of the P4VP block from the main chain of the diblock copolymer, as revealed by SEM. Aside from a drastically improved water flux (∼67% increase) compared to the PS-b-P4VP membrane, the hydraulic permeability measurements validated pH independent behaviour of the isoporous PS membrane over a wide pH range from 3 to 10. The effect of the pore size on protein transport rate and selectivity (a) was investigated for lysozyme (Lys), bovine serum albumin (BSA) and globulin-γ (IgG). A high selectivity of 42 (Lys/IgG) and 30 (BSA/IgG) was attained, making the membranes attractive for size selective separation of biomolecules from their synthetic model mixture solutions.

Summit surprises.

Science.gov (United States)

Myers, N

1994-01-01

A New Delhi Population Summit, organized by the Royal Society, the US National Academy of Sciences, the Royal Swedish Academy of Sciences, and the Indian National Science Academy, was convened with representation of 120 (only 10% women) scientists from 50 countries and about 12 disciplines and 43 national scientific academies. Despite the common assumption that scientists never agree, a 3000 word statement was signed by 50 prominent national figures and supported by 25 professional papers on diverse subjects. The statement proclaimed that stable world population and "prodigious planning efforts" are required for dealing with global social, economic, and environmental problems. The target should be zero population growth by the next generation. The statement, although containing many uncompromising assertions, was not as strong as a statement by the Royal Society and the US National Academy of Sciences released last year: that, in the future, science and technology may not be able to prevent "irreversible degradation of the environment and continued poverty," and that the capacity to sustain life on the planet may be permanently jeopardized. The Delhi statement was backed by professional papers highlighting several important issues. Dr Mahmoud Fathalla of the Rockefeller Foundation claimed that the 500,000 annual maternal deaths worldwide, of which perhaps 33% are due to "coathanger" abortions, are given far less attention than a one-day political event of 500 deaths would receive. Although biologically women have been given a greater survival advantage, which is associated with their reproductive capacity, socially disadvantaged females are relegated to low status. There is poorer nutrition and overall health care for females, female infanticide, and female fetuses are increasingly aborted in China, India, and other countries. The sex ratio in developed countries is 95-97 males to every 100 females, but in developing Asian countries the ratio is 105 males to 100 females. There are reports of 60-100 million missing females. The human species 12,000 years ago had a population of 6 million, a life expectancy of 20 years, and a doubling time of 8000 years; high birth rates were important for preservation of the species. Profertility attitudes are still prevalent today. Insufficient funds go to contraceptive research.

An Audit of the Effectiveness of Large Group Neurology Tutorials for Irish Undergraduate Medical Students

LENUS (Irish Health Repository)

Kearney, H

2016-07-01

The aim of this audit was to determine the effectiveness of large group tutorials for teaching neurology to medical students. Students were asked to complete a questionnaire rating their confidence on a ten point Likert scale in a number of domains in the undergraduate education guidelines from the Association of British Neurologists (ABN). We then arranged a series of interactive large group tutorials for the class and repeated the questionnaire one month after teaching. In the three core domains of neurological: history taking, examination and differential diagnosis, none of the students rated their confidence as nine or ten out of ten prior to teaching. This increased to 6% for history taking, 12 % in examination and 25% for differential diagnosis after eight weeks of tutorials. This audit demonstrates that in our centre, large group tutorials were an effective means of teaching, as measured by the ABN guidelines in undergraduate neurology.

Metaproteomics of cellulose methanisation under thermophilic conditions reveals a surprisingly high proteolytic activity.

Science.gov (United States)

Lü, Fan; Bize, Ariane; Guillot, Alain; Monnet, Véronique; Madigou, Céline; Chapleur, Olivier; Mazéas, Laurent; He, Pinjing; Bouchez, Théodore

2014-01-01

Cellulose is the most abundant biopolymer on Earth. Optimising energy recovery from this renewable but recalcitrant material is a key issue. The metaproteome expressed by thermophilic communities during cellulose anaerobic digestion was investigated in microcosms. By multiplying the analytical replicates (65 protein fractions analysed by MS/MS) and relying solely on public protein databases, more than 500 non-redundant protein functions were identified. The taxonomic community structure as inferred from the metaproteomic data set was in good overall agreement with 16S rRNA gene tag pyrosequencing and fluorescent in situ hybridisation analyses. Numerous functions related to cellulose and hemicellulose hydrolysis and fermentation catalysed by bacteria related to Caldicellulosiruptor spp. and Clostridium thermocellum were retrieved, indicating their key role in the cellulose-degradation process and also suggesting their complementary action. Despite the abundance of acetate as a major fermentation product, key methanogenesis enzymes from the acetoclastic pathway were not detected. In contrast, enzymes from the hydrogenotrophic pathway affiliated to Methanothermobacter were almost exclusively identified for methanogenesis, suggesting a syntrophic acetate oxidation process coupled to hydrogenotrophic methanogenesis. Isotopic analyses confirmed the high dominance of the hydrogenotrophic methanogenesis. Very surprising was the identification of an abundant proteolytic activity from Coprothermobacter proteolyticus strains, probably acting as scavenger and/or predator performing proteolysis and fermentation. Metaproteomics thus appeared as an efficient tool to unravel and characterise metabolic networks as well as ecological interactions during methanisation bioprocesses. More generally, metaproteomics provides direct functional insights at a limited cost, and its attractiveness should increase in the future as sequence databases are growing exponentially.

Effect of Coulomb scattering from trapped charges on the mobility in an organic field-effect transistor

NARCIS (Netherlands)

Sharma, A.; Janssen, N.M.A.; Matthijssen, S.J.G.; de Leeuw, D.M.; Kemerink, M.; Bobbert, P.A.

2011-01-01

We investigate the effect of Coulomb scattering from trapped charges on the mobility in the two-dimensional channel of an organic field-effect transistor. The number of trapped charges can be tuned by applying a prolonged gate bias. Surprisingly, after increasing the number of trapped charges to a

Latin America: how a region surprised the experts.

Science.gov (United States)

De Sherbinin, A

1993-02-01

In 1960-1970, family planning specialists and demographers worried that poverty, limited education, Latin machismo, and strong catholic ideals would obstruct family planning efforts to reduce high fertility in Latin America. It had the highest annual population growth rate in the world (2.8%), which would increase the population 2-fold in 25 years. Yet, the UN's 1992 population projection for Latin America and the Caribbean in the year 2000 was about 20% lower than its 1963 projection (just over 500 vs. 638 million). Since life expectancy increased simultaneously from 57 to 68 years, this reduced projection was caused directly by a large decline in fertility from 5.9 to 3. A regression analysis of 11 Latin American and Caribbean countries revealed that differences in the contraceptive prevalence rates accounted for 90% of the variation in the total fertility rate between countries. Thus, contraception played a key role in the fertility decline. The second most significant determinant of fertility decline was an increase in the average age at first marriage from about 20 to 23 years. Induced abortion and breast feeding did not contribute significantly to fertility decline. The major socioeconomic factors responsible for the decline included economic development and urbanization, resulting in improvements in health care, reduced infant and child mortality, and increases in female literacy, education, and labor force participation. Public and private family planning programs also contributed significantly to the decline. They expanded from cities to remote rural areas, thereby increasing access to contraception. By the early 1990s, Brazil, Mexico, and Colombia had among the lowest levels of unmet need (13-24%) in developing countries. Other key factors of fertility decline were political commitment, strong communication efforts, and stress on quality services. Latin America provides hope to other regions where religion and culture promote a large family size.

Antioxidant effects of carotenoids

NARCIS (Netherlands)

Bast, A.; Haenen, G.R.M.M.; Berg, R. van den; Berg, H. van den

1998-01-01

Surprisingly, neither the precise pharmacological effect nor the toxicological profile is usually established for food components. Carotenoids are no exception in this regard. Only limited insight into the pharmacology and toxicology of carotenoids exists. It is known that the antioxidant action of

Absolute activity determinations on large volume geological samples independent of self-absorption effects

International Nuclear Information System (INIS)

Wilson, W.E.

1980-01-01

This paper describes a method for measuring the absolute activity of large volume samples by γ-spectroscopy independent of self-absorption effects using Ge detectors. The method yields accurate matrix independent results at the expense of replicative counting of the unknown sample. (orig./HP)

Electric field confinement effect on charge transport in organic field-effect transistors

NARCIS (Netherlands)

Li, X.; Kadashchuk, A.; Fishchuk, I.I.; Smaal, W.T.T.; Gelinck, G.H.; Broer, D.J.; Genoe, J.; Heremans, P.; Bässler, H.

2012-01-01

While it is known that the charge-carrier mobility in organic semiconductors is only weakly dependent on the electric field at low fields, the experimental mobility in organic field-effect transistors using silylethynyl-substituted pentacene is found to be surprisingly field dependent at low

HIFU procedures at moderate intensities-effect of large blood vessels

International Nuclear Information System (INIS)

Hariharan, P; Myers, M R; Banerjee, R K

2007-01-01

A three-dimensional computational model is presented for studying the efficacy of high-intensity focused ultrasound (HIFU) procedures targeted near large blood vessels. The analysis applies to procedures performed at intensities below the threshold for cavitation, boiling and highly nonlinear propagation, but high enough to increase tissue temperature a few degrees per second. The model is based upon the linearized KZK equation and the bioheat equation in tissue. In the blood vessel the momentum and energy equations are satisfied. The model is first validated in a tissue phantom, to verify the absence of bubble formation and nonlinear effects. Temperature rise and lesion-volume calculations are then shown for different beam locations and orientations relative to a large vessel. Both single and multiple ablations are considered. Results show that when the vessel is located within about a beam width (few mm) of the ultrasound beam, significant reduction in lesion volume is observed due to blood flow. However, for gaps larger than a beam width, blood flow has no major effect on the lesion formation. Under the clinically representative conditions considered, the lesion volume is reduced about 40% (relative to the no-flow case) when the beam is parallel to the blood vessel, compared to about 20% for a perpendicular orientation. Procedures involving multiple ablation sites are affected less by blood flow than single ablations. The model also suggests that optimally focused transducers can generate lesions that are significantly larger (>2 times) than the ones produced by highly focused beams

HIFU procedures at moderate intensities-effect of large blood vessels

Energy Technology Data Exchange (ETDEWEB)

Hariharan, P [Mechanical, Industrial, and Nuclear Engineering Department, University of Cincinnati, Cincinnati, OH (United States); Myers, M R [Division of Solid and Fluid Mechanics, Center for Devices and Radiological Health, US Food and Drug Administration, 10903 New Hampshire Avenue, Building 62, Silver Spring, MD 20993-0002 (United States); Banerjee, R K [Mechanical, Industrial, and Nuclear Engineering Department, University of Cincinnati, Cincinnati, OH (United States)

2007-07-21

A three-dimensional computational model is presented for studying the efficacy of high-intensity focused ultrasound (HIFU) procedures targeted near large blood vessels. The analysis applies to procedures performed at intensities below the threshold for cavitation, boiling and highly nonlinear propagation, but high enough to increase tissue temperature a few degrees per second. The model is based upon the linearized KZK equation and the bioheat equation in tissue. In the blood vessel the momentum and energy equations are satisfied. The model is first validated in a tissue phantom, to verify the absence of bubble formation and nonlinear effects. Temperature rise and lesion-volume calculations are then shown for different beam locations and orientations relative to a large vessel. Both single and multiple ablations are considered. Results show that when the vessel is located within about a beam width (few mm) of the ultrasound beam, significant reduction in lesion volume is observed due to blood flow. However, for gaps larger than a beam width, blood flow has no major effect on the lesion formation. Under the clinically representative conditions considered, the lesion volume is reduced about 40% (relative to the no-flow case) when the beam is parallel to the blood vessel, compared to about 20% for a perpendicular orientation. Procedures involving multiple ablation sites are affected less by blood flow than single ablations. The model also suggests that optimally focused transducers can generate lesions that are significantly larger (>2 times) than the ones produced by highly focused beams.

SUSY Higgs at the LHC large stop mixing effects and associated production

CERN Document Server

Bélanger, G; Sridhar, K

2000-01-01

We revisit the effect of the large stop mixing on the decay and production of the lightest SUSY Higgs at the LHC. We stress that whenever the inclusive 2-photon signature is substantially reduced, associated production, $Wh$ and $t\\bar t h$, with the subsequent decay of the Higgs into photons is enhanced and becomes an even more important discovery channel. We also point out that these reductions in the inclusive channel do not occur for the smallest Higgs mass where the significance is known to be lowest. We show that in such scenarios the Higgs can be produced in the decay of the heaviest stop. For not too heavy masses of the pseudo-scalar Higgs where the inclusive channel is even further reduced, we show that large stop mixing also allows the production of the pseudo-scalar Higgs through stop decays. These large mixing scenarios therefore offer much better prospects than previously thought. As a by-product we have recalculated stop1-stop1-h production at the LHC and give a first evaluation of stop1-stop1-Z...

Beyond interests and institutions: US health policy reform and the surprising silence of big business.

Science.gov (United States)

Smyrl, Marc E

2014-02-01

Interest-based arguments do not provide satisfying explanations for the surprising reticence of major US employers to take a more active role in the debate surrounding the 2010 Patient Protection and Affordable Care Act (ACA). Through focused comparison with the Bismarckian systems of France and Germany, on the one hand, and with the 1950s and 1960s in the United States, on the other, this article concludes that while institutional elements do account for some of the observed behavior of big business, a necessary complement to this is a fuller understanding of the historically determined legitimating ideology of US firms. From the era of the "corporate commonwealth," US business inherited the principles of private welfare provision and of resistance to any expansion of government control. Once complementary, these principles are now mutually exclusive: employer-provided health insurance increasingly is possible only at the cost of ever-increasing government subsidy and regulation. Paralyzed by the uncertainty that followed from this clash of legitimate ideas, major employers found themselves unable to take a coherent and unified stand for or against the law. As a consequence, they failed either to oppose it successfully or to secure modifications to it that would have been useful to them.

Effects of experimental fuel additions on fire intensity and severity: unexpected carbon resilience of a neotropical forest.

Science.gov (United States)

Brando, Paulo M; Oliveria-Santos, Claudinei; Rocha, Wanderley; Cury, Roberta; Coe, Michael T

2016-07-01

Global changes and associated droughts, heat waves, logging activities, and forest fragmentation may intensify fires in Amazonia by altering forest microclimate and fuel dynamics. To isolate the effects of fuel loads on fire behavior and fire-induced changes in forest carbon cycling, we manipulated fine fuel loads in a fire experiment located in southeast Amazonia. We predicted that a 50% increase in fine fuel loads would disproportionally increase fire intensity and severity (i.e., tree mortality and losses in carbon stocks) due to multiplicative effects of fine fuel loads on the rate of fire spread, fuel consumption, and burned area. The experiment followed a fully replicated randomized block design (N = 6) comprised of unburned control plots and burned plots that were treated with and without fine fuel additions. The fuel addition treatment significantly increased burned area (+22%) and consequently canopy openness (+10%), fine fuel combustion (+5%), and mortality of individuals ≥5 cm in diameter at breast height (dbh; +37%). Surprisingly, we observed nonsignificant effects of the fuel addition treatment on fireline intensity, and no significant differences among the three treatments for (i) mortality of large trees (≥30 cm dbh), (ii) aboveground forest carbon stocks, and (iii) soil respiration. It was also surprising that postfire tree growth and wood increment were higher in the burned plots treated with fuels than in the unburned control. These results suggest that (i) fine fuel load accumulation increases the likelihood of larger understory fires and (ii) single, low-intensity fires weakly influence carbon cycling of this primary neotropical forest, although delayed postfire mortality of large trees may lower carbon stocks over the long term. Overall, our findings indicate that increased fine fuel loads alone are unlikely to create threshold conditions for high-intensity, catastrophic fires during nondrought years. © 2016 John Wiley & Sons Ltd.

A surprise case of colonic interposition

International Nuclear Information System (INIS)

Law, Robert

2006-01-01

Blind nasogastric intubation failure as a result of changes to the normal anatomical pathway is not uncommon. This case report is of fluoroscopically guided intubation in a patient in whom blind intubation failed as a result of what was subsequently found to be a colonic interposition with associated late complications. Fluroscopically guided nasogastric intubation is a safe and effective procedure that should always be considered when blind intubation has failed

Renormalization-group flow of the effective action of cosmological large-scale structures

CERN Document Server

Floerchinger, Stefan

2017-01-01

Following an approach of Matarrese and Pietroni, we derive the functional renormalization group (RG) flow of the effective action of cosmological large-scale structures. Perturbative solutions of this RG flow equation are shown to be consistent with standard cosmological perturbation theory. Non-perturbative approximate solutions can be obtained by truncating the a priori infinite set of possible effective actions to a finite subspace. Using for the truncated effective action a form dictated by dissipative fluid dynamics, we derive RG flow equations for the scale dependence of the effective viscosity and sound velocity of non-interacting dark matter, and we solve them numerically. Physically, the effective viscosity and sound velocity account for the interactions of long-wavelength fluctuations with the spectrum of smaller-scale perturbations. We find that the RG flow exhibits an attractor behaviour in the IR that significantly reduces the dependence of the effective viscosity and sound velocity on the input ...

Instantons and Large N

Science.gov (United States)

Mariño, Marcos

2015-09-01

Preface; Part I. Instantons: 1. Instantons in quantum mechanics; 2. Unstable vacua in quantum field theory; 3. Large order behavior and Borel summability; 4. Non-perturbative aspects of Yang-Mills theories; 5. Instantons and fermions; Part II. Large N: 6. Sigma models at large N; 7. The 1=N expansion in QCD; 8. Matrix models and matrix quantum mechanics at large N; 9. Large N QCD in two dimensions; 10. Instantons at large N; Appendix A. Harmonic analysis on S3; Appendix B. Heat kernel and zeta functions; Appendix C. Effective action for large N sigma models; References; Author index; Subject index.

Effects of large-angle Coulomb collisions on inertial confinement fusion plasmas.

Science.gov (United States)

Turrell, A E; Sherlock, M; Rose, S J

2014-06-20

Large-angle Coulomb collisions affect the rates of energy and momentum exchange in a plasma, and it is expected that their effects will be important in many plasmas of current research interest, including in inertial confinement fusion. Their inclusion is a long-standing problem, and the first fully self-consistent method for calculating their effects is presented. This method is applied to "burn" in the hot fuel in inertial confinement fusion capsules and finds that the yield increases due to an increase in the rate of temperature equilibration between electrons and ions which is not predicted by small-angle collision theories. The equilibration rate increases are 50%-100% for number densities of 10(30)  m(-3) and temperatures around 1 keV.

Herbivore grazing—or trampling? Trampling effects by a large ungulate in cold high- latitude ecosystems

OpenAIRE

Heggenes, Jan; Odland, Arvid; Chevalier, Tomas; Ahlberg, Jörgen; Berg, Amanda; Larsson, Håkan; Bjerketvedt, Dag Kjartan

2017-01-01

Mammalian herbivores have important top-down effects on ecological processes and landscapes by generating vegetation changes through grazing and trampling. For free-ranging herbivores on large landscapes, trampling is an important ecological factor. However, whereas grazing is widely studied, low-intensity trampling is rarely studied and quantified. The cold-adapted northern tundra reindeer (Rangifer tarandus) is a wide-ranging keystone herbivore in large open alpine and Arctic ecosystems. Re...

Herbivore grazing?or trampling? Trampling effects by a large ungulate in cold high?latitude ecosystems

OpenAIRE

Heggenes, Jan; Odland, Arvid; Chevalier, Tomas; Ahlberg, J?rgen; Berg, Amanda; Larsson, H?kan; Bjerketvedt, Dag K.

2017-01-01

Mammalian herbivores have important top-down effects on ecological processes and landscapes by generating vegetation changes through grazing and trampling. For free-ranging herbivores on large landscapes, trampling is an important ecological factor. However, whereas grazing is widely studied, low-intensity trampling is rarely studied and quantified. The cold-adapted northern tundra reindeer (Rangifer tarandus) is a wide-ranging keystone herbivore in large open alpine and Arctic ecosystems. Re...

[Adverse Effect Predictions Based on Computational Toxicology Techniques and Large-scale Databases].

Science.gov (United States)

Uesawa, Yoshihiro

2018-01-01

　Understanding the features of chemical structures related to the adverse effects of drugs is useful for identifying potential adverse effects of new drugs. This can be based on the limited information available from post-marketing surveillance, assessment of the potential toxicities of metabolites and illegal drugs with unclear characteristics, screening of lead compounds at the drug discovery stage, and identification of leads for the discovery of new pharmacological mechanisms. This present paper describes techniques used in computational toxicology to investigate the content of large-scale spontaneous report databases of adverse effects, and it is illustrated with examples. Furthermore, volcano plotting, a new visualization method for clarifying the relationships between drugs and adverse effects via comprehensive analyses, will be introduced. These analyses may produce a great amount of data that can be applied to drug repositioning.

Large Quantum Probability Backflow and the Azimuthal Angle-Angular Momentum Uncertainty Relation for an Electron in a Constant Magnetic Field

Science.gov (United States)

Strange, P.

2012-01-01

In this paper we demonstrate a surprising aspect of quantum mechanics that is accessible to an undergraduate student. We discuss probability backflow for an electron in a constant magnetic field. It is shown that even for a wavepacket composed entirely of states with negative angular momentum the effective angular momentum can take on positive…

Are seismic hazard assessment errors and earthquake surprises unavoidable?

Science.gov (United States)

Kossobokov, Vladimir

2013-04-01

Why earthquake occurrences bring us so many surprises? The answer seems evident if we review the relationships that are commonly used to assess seismic hazard. The time-span of physically reliable Seismic History is yet a small portion of a rupture recurrence cycle at an earthquake-prone site, which makes premature any kind of reliable probabilistic statements about narrowly localized seismic hazard. Moreover, seismic evidences accumulated to-date demonstrate clearly that most of the empirical relations commonly accepted in the early history of instrumental seismology can be proved erroneous when testing statistical significance is applied. Seismic events, including mega-earthquakes, cluster displaying behaviors that are far from independent or periodic. Their distribution in space is possibly fractal, definitely, far from uniform even in a single segment of a fault zone. Such a situation contradicts generally accepted assumptions used for analytically tractable or computer simulations and complicates design of reliable methodologies for realistic earthquake hazard assessment, as well as search and definition of precursory behaviors to be used for forecast/prediction purposes. As a result, the conclusions drawn from such simulations and analyses can MISLEAD TO SCIENTIFICALLY GROUNDLESS APPLICATION, which is unwise and extremely dangerous in assessing expected societal risks and losses. For example, a systematic comparison of the GSHAP peak ground acceleration estimates with those related to actual strong earthquakes, unfortunately, discloses gross inadequacy of this "probabilistic" product, which appears UNACCEPTABLE FOR ANY KIND OF RESPONSIBLE SEISMIC RISK EVALUATION AND KNOWLEDGEABLE DISASTER PREVENTION. The self-evident shortcomings and failures of GSHAP appeals to all earthquake scientists and engineers for an urgent revision of the global seismic hazard maps from the first principles including background methodologies involved, such that there becomes: (a) a

Planetary Structures And Simulations Of Large-scale Impacts On Mars

Science.gov (United States)

Swift, Damian; El-Dasher, B.

2009-09-01

The impact of large meteroids is a possible cause for isolated orogeny on bodies devoid of tectonic activity. On Mars, there is a significant, but not perfect, correlation between large, isolated volcanoes and antipodal impact craters. On Mercury and the Moon, brecciated terrain and other unusual surface features can be found at the antipodes of large impact sites. On Earth, there is a moderate correlation between long-lived mantle hotspots at opposite sides of the planet, with meteoroid impact suggested as a possible cause. If induced by impacts, the mechanisms of orogeny and volcanism thus appear to vary between these bodies, presumably because of differences in internal structure. Continuum mechanics (hydrocode) simulations have been used to investigate the response of planetary bodies to impacts, requiring assumptions about the structure of the body: its composition and temperature profile, and the constitutive properties (equation of state, strength, viscosity) of the components. We are able to predict theoretically and test experimentally the constitutive properties of matter under planetary conditions, with reasonable accuracy. To provide a reference series of simulations, we have constructed self-consistent planetary structures using simplified compositions (Fe core and basalt-like mantle), which turn out to agree surprisingly well with the moments of inertia. We have performed simulations of large-scale impacts, studying the transmission of energy to the antipodes. For Mars, significant antipodal heating to depths of a few tens of kilometers was predicted from compression waves transmitted through the mantle. Such heating is a mechanism for volcanism on Mars, possibly in conjunction with crustal cracking induced by surface waves. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

The roles of large top predators in coastal ecosystems: new insights from long term ecological research

Science.gov (United States)

Rosenblatt, Adam E.; Heithaus, Michael R.; Mather, Martha E.; Matich, Philip; Nifong, James C.; Ripple, William J.; Silliman, Brian R.

2013-01-01

During recent human history, human activities such as overhunting and habitat destruction have severely impacted many large top predator populations around the world. Studies from a variety of ecosystems show that loss or diminishment of top predator populations can have serious consequences for population and community dynamics and ecosystem stability. However, there are relatively few studies of the roles of large top predators in coastal ecosystems, so that we do not yet completely understand what could happen to coastal areas if large top predators are extirpated or significantly reduced in number. This lack of knowledge is surprising given that coastal areas around the globe are highly valued and densely populated by humans, and thus coastal large top predator populations frequently come into conflict with coastal human populations. This paper reviews what is known about the ecological roles of large top predators in coastal systems and presents a synthesis of recent work from three coastal eastern US Long Term Ecological Research (LTER) sites where long-term studies reveal what appear to be common themes relating to the roles of large top predators in coastal systems. We discuss three specific themes: (1) large top predators acting as mobile links between disparate habitats, (2) large top predators potentially affecting nutrient and biogeochemical dynamics through localized behaviors, and (3) individual specialization of large top predator behaviors. We also discuss how research within the LTER network has led to enhanced understanding of the ecological roles of coastal large top predators. Highlighting this work is intended to encourage further investigation of the roles of large top predators across diverse coastal aquatic habitats and to better inform researchers and ecosystem managers about the importance of large top predators for coastal ecosystem health and stability.

Large signal S-parameters: modeling and radiation effects in microwave power transistors

International Nuclear Information System (INIS)

Graham, E.D. Jr.; Chaffin, R.J.; Gwyn, C.W.

1973-01-01

Microwave power transistors are usually characterized by measuring the source and load impedances, efficiency, and power output at a specified frequency and bias condition in a tuned circuit. These measurements provide limited data for circuit design and yield essentially no information concerning broadbanding possibilities. Recently, a method using large signal S-parameters has been developed which provides a rapid and repeatable means for measuring microwave power transistor parameters. These large signal S-parameters have been successfully used to design rf power amplifiers. Attempts at modeling rf power transistors have in the past been restricted to a modified Ebers-Moll procedure with numerous adjustable model parameters. The modified Ebers-Moll model is further complicated by inclusion of package parasitics. In the present paper an exact one-dimensional device analysis code has been used to model the performance of the transistor chip. This code has been integrated into the SCEPTRE circuit analysis code such that chip, package and circuit performance can be coupled together in the analysis. Using []his computational tool, rf transistor performance has been examined with particular attention given to the theoretical validity of large-signal S-parameters and the effects of nuclear radiation on device parameters. (auth)

How Gamification Affects Physical Activity: Large-scale Analysis of Walking Challenges in a Mobile Application.

Science.gov (United States)

Shameli, Ali; Althoff, Tim; Saberi, Amin; Leskovec, Jure

2017-04-01

Gamification represents an effective way to incentivize user behavior across a number of computing applications. However, despite the fact that physical activity is essential for a healthy lifestyle, surprisingly little is known about how gamification and in particular competitions shape human physical activity. Here we study how competitions affect physical activity. We focus on walking challenges in a mobile activity tracking application where multiple users compete over who takes the most steps over a predefined number of days. We synthesize our findings in a series of game and app design implications. In particular, we analyze nearly 2,500 physical activity competitions over a period of one year capturing more than 800,000 person days of activity tracking. We observe that during walking competitions, the average user increases physical activity by 23%. Furthermore, there are large increases in activity for both men and women across all ages, and weight status, and even for users that were previously fairly inactive. We also find that the composition of participants greatly affects the dynamics of the game. In particular, if highly unequal participants get matched to each other, then competition suffers and the overall effect on the physical activity drops significantly. Furthermore, competitions with an equal mix of both men and women are more effective in increasing the level of activities. We leverage these insights to develop a statistical model to predict whether or not a competition will be particularly engaging with significant accuracy. Our models can serve as a guideline to help design more engaging competitions that lead to most beneficial behavioral changes.

Statistical Analysis of Large Simulated Yield Datasets for Studying Climate Effects

Science.gov (United States)

Makowski, David; Asseng, Senthold; Ewert, Frank; Bassu, Simona; Durand, Jean-Louis; Martre, Pierre; Adam, Myriam; Aggarwal, Pramod K.; Angulo, Carlos; Baron, Chritian;

Catharanthine C16 substituent effects on the biomimetic coupling with vindoline: preparation and evaluation of a key series of vinblastine analogues

Science.gov (United States)

Tam, Annie; Gotoh, Hiroaki; Robertson, William M.; Boger, Dale L.

2010-01-01

The examination of the catharanthine C16 substituent effects on the Fe(III)-promoted biomimetic coupling reaction with vindoline is detailed, confirming the importance of the presence of a C16 electron-withdrawing substituent, and establishing an unanticipated unique role (>10-fold) that the C16 methyl ester plays in the expression of the natural product properties. Thus, replacement of the vinblastine C16′ methyl ester with an ethyl ester (10-fold), a cyano group (100-fold), an aldehyde (100-fold), a hydroxymethyl group (1000-fold), or a primary carboxamide (>1000-fold) led to surprisingly large reductions in cytotoxic activity. PMID:20932748

Effects of a large wildfire on vegetation structure in a variable fire mosaic.

Science.gov (United States)

Foster, C N; Barton, P S; Robinson, N M; MacGregor, C I; Lindenmayer, D B

2017-12-01

Management guidelines for many fire-prone ecosystems highlight the importance of maintaining a variable mosaic of fire histories for biodiversity conservation. Managers are encouraged to aim for fire mosaics that are temporally and spatially dynamic, include all successional states of vegetation, and also include variation in the underlying "invisible mosaic" of past fire frequencies, severities, and fire return intervals. However, establishing and maintaining variable mosaics in contemporary landscapes is subject to many challenges, one of which is deciding how the fire mosaic should be managed following the occurrence of large, unplanned wildfires. A key consideration for this decision is the extent to which the effects of previous fire history on vegetation and habitats persist after major wildfires, but this topic has rarely been investigated empirically. In this study, we tested to what extent a large wildfire interacted with previous fire history to affect the structure of forest, woodland, and heath vegetation in Booderee National Park in southeastern Australia. In 2003, a summer wildfire burned 49.5% of the park, increasing the extent of recently burned vegetation (post-fire) to more than 72% of the park area. We tracked the recovery of vegetation structure for nine years following the wildfire and found that the strength and persistence of fire effects differed substantially between vegetation types. Vegetation structure was modified by wildfire in forest, woodland, and heath vegetation, but among-site variability in vegetation structure was reduced only by severe fire in woodland vegetation. There also were persistent legacy effects of the previous fire regime on some attributes of vegetation structure including forest ground and understorey cover, and woodland midstorey and overstorey cover. For example, woodland midstorey cover was greater on sites with higher fire frequency, irrespective of the severity of the 2003 wildfire. Our results show that even

Observation of large magnetocaloric effect in equiatomic binary compound ErZn

Directory of Open Access Journals (Sweden)

Lingwei Li

2017-05-01

Full Text Available The magnetism, magnetocaloric effect and universal behaviour in rare earth Zinc binary compound of ErZn have been studied. The ErZn compound undergoes a second order paramagnetic (PM to ferromagnetic (FM transition at Curie temperature of TC ∼ 20 K. The ErZn compound exhibits a large reversible magnetocaloric effect (MCE around its own TC. The rescaled magnetic entropy change curves overlap with each other under various magnetic field changes, further confirming the ErZn with the second order phase transition. For the magnetic field change of 0-7 T, the maximum values of the magnetic entropy change (−ΔSMmax, relative cooling power (RCP and refrigerant capacity (RC for ErZn are 23.3 J/kg K, 581 J/kg and 437 J/kg, respectively.

Climatological changing effects on wind, precipitation and erosion: Large, meso and small scale analysis

International Nuclear Information System (INIS)

Aslan, Z.

2004-01-01

The Fourier transformation analysis for monthly average values of meteorological parameters has been considered, and amplitudes, phase angles have been calculated by using ground measurements in Turkey. The first order harmonics of meteorological parameters show large scale effects, while higher order harmonics show the effects of small scale fluctuations. The variations of first through sixth order harmonic amplitudes and phases provide a useful means of understanding the large and local scale effects on meteorological parameters. The phase angle can be used to determine the time of year the maximum or minimum of a given harmonic occurs. The analysis helps us to distinguish different pressure, relative humidity, temperature, precipitation and wind speed regimes and transition regions. Local and large scale phenomenon and some unusual seasonal patterns are also defined near Keban Dam and the irrigation area. Analysis of precipitation based on long term data shows that semi-annual fluctuations are predominant in the study area. Similarly, pressure variations are mostly influenced by semi-annual fluctuations. Temperature and humidity variations are mostly influenced by meso and micro scale fluctuations. Many large and meso scale climate change simulations for the 21st century are based on concentration of green house gases. A better understanding of these effects on soil erosion is necessary to determine social, economic and other impacts of erosion. The second part of this study covers the time series analysis of precipitation, rainfall erosivity and wind erosion at the Marmara Region. Rainfall and runoff erosivity factors are defined by considering the results of field measurements at 10 stations. Climatological changing effects on rainfall erosion have been determined by monitoring meteorological variables. In the previous studies, Fournier Index is defined to estimate the rainfall erosivity for the study area. The Fournier Index or in other words a climatic index

Comment exploiter les 'corpus-surprise' ?

Directory of Open Access Journals (Sweden)

Rittaud-Hutinet, Chantal

2009-01-01

Full Text Available To what extent non-recorded oral corpora may constitute objects of analysis of pragmatic meaning?These corpora are heard by chance: on the radio, on television, in the street, a shop, a means of transport or generally in any conversational interaction in which the linguist participates, but had not previously planned to record for his research. The problem of the use of these corpora in linguistics is all the more crucial since the aim, in phonopragmatics, is to discover the functions and significations of their phonic part. I shall attempt to answer the following questions:–The accuracy of the transcription with respect to the original. To what extent can we ignore our own phonological code, our regional variants, mastered/partly known styles of speech?–The reliability of the oral reproduction carried out by the linguist – for example, during a talk at a conference. What is his capacity for deferred mimicry?–The relation between a significant discrepancy and the elocutionary habits of the speaker.–The relation between the comprehension of the external auditors and the effect produced on the 'real' person addressed.Considering that transparency is (sometimes? often? an illusion, I shall also examine what precautions should be taken so that these corpora offer guarantees as to the veracity.

Effect of Diuretics on Renal Tubular Transport of Calcium and Magnesium

DEFF Research Database (Denmark)

Alexander, R Todd; Dimke, Henrik

2017-01-01

are important for both forming divalent cation permeable pores and channels, but also for generating the necessary driving forces for Ca2+ and Mg2+ transport. Alterations in these molecular constituents lead to profound effects on tubular Ca2+ and Mg2+ handling. Diuretics are used to treat a large range...... of clinical conditions, but most commonly for the management of blood pressure and fluid balance. The pharmacological targets of diuretics generally directly facilitate sodium (Na+) transport, but also indirectly affect renal Ca2+ and Mg2+ handling, i.e. by establishing a prerequisite electrochemical gradient....... It is therefore not surprising that substantial alterations in divalent cation handling can be observed following diuretic treatment. The effects of diuretics on renal Ca2+ and Mg2+ handling are reviewed in the context of the current understanding of basal molecular mechanisms of Ca2+ and Mg2+ transport...

Large Spatial and Temporal Separations of Cause and Effect in Policy Making - Dealing with Non-linear Effects

Science.gov (United States)

McCaskill, John

There can be large spatial and temporal separation of cause and effect in policy making. Determining the correct linkage between policy inputs and outcomes can be highly impractical in the complex environments faced by policy makers. In attempting to see and plan for the probable outcomes, standard linear models often overlook, ignore, or are unable to predict catastrophic events that only seem improbable due to the issue of multiple feedback loops. There are several issues with the makeup and behaviors of complex systems that explain the difficulty many mathematical models (factor analysis/structural equation modeling) have in dealing with non-linear effects in complex systems. This chapter highlights those problem issues and offers insights to the usefulness of ABM in dealing with non-linear effects in complex policy making environments.

Exotic B=2 states in the SU(2) Skyrme model and other recent results in the B=1 sector

International Nuclear Information System (INIS)

Schwesinger, B.

1986-01-01

Effective theories with surprising phenomenological success immediatly prompt the suspicion that they are intimately connected to a more fundamental theory. In the case of the Skyrme model things have gone the other way round: first there was the finding that the large N c -limit of QCD results in an effective theory of free mesons where baryons emerge as solitons from meson fields. Subsequently the long forgotten Skyrme model was unearthed by Witten as a possible candidate for such a theory. Examined in the light of its phenomenological capabilities the Skyrme model lead to the surprising success it enjoys till now. (orig./BBOE)

Test methods of total dose effects in very large scale integrated circuits

International Nuclear Information System (INIS)

He Chaohui; Geng Bin; He Baoping; Yao Yujuan; Li Yonghong; Peng Honglun; Lin Dongsheng; Zhou Hui; Chen Yusheng

2004-01-01

A kind of test method of total dose effects (TDE) is presented for very large scale integrated circuits (VLSI). The consumption current of devices is measured while function parameters of devices (or circuits) are measured. Then the relation between data errors and consumption current can be analyzed and mechanism of TDE in VLSI can be proposed. Experimental results of 60 Co γ TDEs are given for SRAMs, EEPROMs, FLASH ROMs and a kind of CPU

Examining the effectiveness of experiential teaching in small and large OM modules

OpenAIRE

Piercy, N.; Brandon-Jones, A.; Brandon-Jones, E.; Campbell, C.

2012-01-01

Purpose – This paper aims to examine the preferences of students towards different teaching methods and the perceived effectiveness of experiential teaching methods in different operations management (OM) modules.Design/methodology/approach – Student perceptions of different teaching methods and various aspects of an experiential teaching method, in the form of a business simulation game, are examined using survey data from 274 respondents in four small post-experience and two large pre-exper...

A Simple Method to Estimate Large Fixed Effects Models Applied to Wage Determinants and Matching

OpenAIRE

Mittag, Nikolas

2016-01-01

Models with high dimensional sets of fixed effects are frequently used to examine, among others, linked employer-employee data, student outcomes and migration. Estimating these models is computationally difficult, so simplifying assumptions that are likely to cause bias are often invoked to make computation feasible and specification tests are rarely conducted. I present a simple method to estimate large two-way fixed effects (TWFE) and worker-firm match effect models without additional assum...

Chandra Finds Surprising Black Hole Activity In Galaxy Cluster

Science.gov (United States)

2002-09-01

Scientists at the Carnegie Observatories in Pasadena, California, have uncovered six times the expected number of active, supermassive black holes in a single viewing of a cluster of galaxies, a finding that has profound implications for theories as to how old galaxies fuel the growth of their central black holes. The finding suggests that voracious, central black holes might be as common in old, red galaxies as they are in younger, blue galaxies, a surprise to many astronomers. The team made this discovery with NASA'S Chandra X-ray Observatory. They also used Carnegie's 6.5-meter Walter Baade Telescope at the Las Campanas Observatory in Chile for follow-up optical observations. "This changes our view of galaxy clusters as the retirement homes for old and quiet black holes," said Dr. Paul Martini, lead author on a paper describing the results that appears in the September 10 issue of The Astrophysical Journal Letters. "The question now is, how do these black holes produce bright X-ray sources, similar to what we see from much younger galaxies?" Typical of the black hole phenomenon, the cores of these active galaxies are luminous in X-ray radiation. Yet, they are obscured, and thus essentially undetectable in the radio, infrared and optical wavebands. "X rays can penetrate obscuring gas and dust as easily as they penetrate the soft tissue of the human body to look for broken bones," said co-author Dr. Dan Kelson. "So, with Chandra, we can peer through the dust and we have found that even ancient galaxies with 10-billion-year-old stars can have central black holes still actively pulling in copious amounts of interstellar gas. This activity has simply been hidden from us all this time. This means these galaxies aren't over the hill after all and our theories need to be revised." Scientists say that supermassive black holes -- having the mass of millions to billions of suns squeezed into a region about the size of our Solar System -- are the engines in the cores of

Strong effects of ionizing radiation from Chernobyl on mutation rates.

Science.gov (United States)

Møller, Anders Pape; Mousseau, Timothy A

2015-02-10

In this paper we use a meta-analysis to examine the relationship between radiation and mutation rates in Chernobyl across 45 published studies, covering 30 species. Overall effect size of radiation on mutation rates estimated as Pearson's product-moment correlation coefficient was very large (E = 0.67; 95% confidence intervals (CI) 0.59 to 0.73), accounting for 44.3% of the total variance in an unstructured random-effects model. Fail-safe calculations reflecting the number of unpublished null results needed to eliminate this average effect size showed the extreme robustness of this finding (Rosenberg's method: 4135 at p = 0.05). Indirect tests did not provide any evidence of publication bias. The effect of radiation on mutations varied among taxa, with plants showing a larger effect than animals. Humans were shown to have intermediate sensitivity of mutations to radiation compared to other species. Effect size did not decrease over time, providing no evidence for an improvement in environmental conditions. The surprisingly high mean effect size suggests a strong impact of radioactive contamination on individual fitness in current and future generations, with potentially significant population-level consequences, even beyond the area contaminated with radioactive material.

Initial condition effects on large scale structure in numerical simulations of plane mixing layers

Science.gov (United States)

McMullan, W. A.; Garrett, S. J.

2016-01-01

In this paper, Large Eddy Simulations are performed on the spatially developing plane turbulent mixing layer. The simulated mixing layers originate from initially laminar conditions. The focus of this research is on the effect of the nature of the imposed fluctuations on the large-scale spanwise and streamwise structures in the flow. Two simulations are performed; one with low-level three-dimensional inflow fluctuations obtained from pseudo-random numbers, the other with physically correlated fluctuations of the same magnitude obtained from an inflow generation technique. Where white-noise fluctuations provide the inflow disturbances, no spatially stationary streamwise vortex structure is observed, and the large-scale spanwise turbulent vortical structures grow continuously and linearly. These structures are observed to have a three-dimensional internal geometry with branches and dislocations. Where physically correlated provide the inflow disturbances a "streaky" streamwise structure that is spatially stationary is observed, with the large-scale turbulent vortical structures growing with the square-root of time. These large-scale structures are quasi-two-dimensional, on top of which the secondary structure rides. The simulation results are discussed in the context of the varying interpretations of mixing layer growth that have been postulated. Recommendations are made concerning the data required from experiments in order to produce accurate numerical simulation recreations of real flows.

Explanatory models of health and disease: surprises from within the former Soviet Union

Directory of Open Access Journals (Sweden)

Tatiana I Andreeva

2013-06-01

Full Text Available Extract The review of anthropological theories as applied to public health by Jennifer J. Carroll (Carroll, 2013 published in this issue of TCPHEE made me recollect my first and most surprising discoveries of how differently same things can be understood in different parts of the world. Probably less unexpectedly, these impressions concern substance abuse and addiction behaviors, similarly to many examples deployed by Jennifer J. Carroll. The first of these events happened soon after the break-up of the Soviet Union when some of the most active people from the West rushed to discover what was going on behind the opening iron curtain. A director of an addiction clinic, who had just come into contact with a Dutch counterpart, invited me to join the collaboration and the innovation process he planned to launch. Being a participant of the exchange program started within this collaboration, I had an opportunity to discover how addictive behaviors were understood and explained in books (English, 1961; Kooyman, 1992; Viorst, 1986 recommended by the colleagues in the Netherlands and, as I could observe with my own eyes, addressed in everyday practice. This was a jaw-dropping contrast to what I learnt at the soviet medical university and some post-graduate courses, where all the diseases related to alcohol, tobacco, or drug abuse were considered predominantly a result of the substance intake. In the Soviet discourse, the intake itself was understood as 'willful and deliberate' or immoral behavior which, in some cases, was to be rectified in prison-like treatment facilities. In the West, quite oppositely, substance abuse was seen rather as a consequence of a constellation of life-course adversities thoroughly considered by developmental psychology. This approach was obviously deeply ingrained in how practitioners diagnosed and treated their patients.

Modeling the Hydrologic Effects of Large-Scale Green Infrastructure Projects with GIS

Science.gov (United States)

Bado, R. A.; Fekete, B. M.; Khanbilvardi, R.

2015-12-01

Impervious surfaces in urban areas generate excess runoff, which in turn causes flooding, combined sewer overflows, and degradation of adjacent surface waters. Municipal environmental protection agencies have shown a growing interest in mitigating these effects with 'green' infrastructure practices that partially restore the perviousness and water holding capacity of urban centers. Assessment of the performance of current and future green infrastructure projects is hindered by the lack of adequate hydrological modeling tools; conventional techniques fail to account for the complex flow pathways of urban environments, and detailed analyses are difficult to prepare for the very large domains in which green infrastructure projects are implemented. Currently, no standard toolset exists that can rapidly and conveniently predict runoff, consequent inundations, and sewer overflows at a city-wide scale. We demonstrate how streamlined modeling techniques can be used with open-source GIS software to efficiently model runoff in large urban catchments. Hydraulic parameters and flow paths through city blocks, roadways, and sewer drains are automatically generated from GIS layers, and ultimately urban flow simulations can be executed for a variety of rainfall conditions. With this methodology, users can understand the implications of large-scale land use changes and green/gray storm water retention systems on hydraulic loading, peak flow rates, and runoff volumes.

On the renormalization of the effective field theory of large scale structures

International Nuclear Information System (INIS)

Pajer, Enrico; Zaldarriaga, Matias

2013-01-01

Standard perturbation theory (SPT) for large-scale matter inhomogeneities is unsatisfactory for at least three reasons: there is no clear expansion parameter since the density contrast is not small on all scales; it does not fully account for deviations at large scales from a perfect pressureless fluid induced by short-scale non-linearities; for generic initial conditions, loop corrections are UV-divergent, making predictions cutoff dependent and hence unphysical. The Effective Field Theory of Large Scale Structures successfully addresses all three issues. Here we focus on the third one and show explicitly that the terms induced by integrating out short scales, neglected in SPT, have exactly the right scale dependence to cancel all UV-divergences at one loop, and this should hold at all loops. A particularly clear example is an Einstein deSitter universe with no-scale initial conditions P in ∼ k n . After renormalizing the theory, we use self-similarity to derive a very simple result for the final power spectrum for any n, excluding two-loop corrections and higher. We show how the relative importance of different corrections depends on n. For n ∼ −1.5, relevant for our universe, pressure and dissipative corrections are more important than the two-loop corrections

On the renormalization of the effective field theory of large scale structures

Energy Technology Data Exchange (ETDEWEB)

Pajer, Enrico [Department of Physics, Princeton University, Princeton, NJ 08544 (United States); Zaldarriaga, Matias, E-mail: enrico.pajer@gmail.com, E-mail: matiasz@ias.edu [Institute for Advanced Study, Princeton, NJ 08544 (United States)

2013-08-01

Standard perturbation theory (SPT) for large-scale matter inhomogeneities is unsatisfactory for at least three reasons: there is no clear expansion parameter since the density contrast is not small on all scales; it does not fully account for deviations at large scales from a perfect pressureless fluid induced by short-scale non-linearities; for generic initial conditions, loop corrections are UV-divergent, making predictions cutoff dependent and hence unphysical. The Effective Field Theory of Large Scale Structures successfully addresses all three issues. Here we focus on the third one and show explicitly that the terms induced by integrating out short scales, neglected in SPT, have exactly the right scale dependence to cancel all UV-divergences at one loop, and this should hold at all loops. A particularly clear example is an Einstein deSitter universe with no-scale initial conditions P{sub in} ∼ k{sup n}. After renormalizing the theory, we use self-similarity to derive a very simple result for the final power spectrum for any n, excluding two-loop corrections and higher. We show how the relative importance of different corrections depends on n. For n ∼ −1.5, relevant for our universe, pressure and dissipative corrections are more important than the two-loop corrections.

A Methodology of Estimation on Air Pollution and Its Health Effects in Large Japanese Cities

OpenAIRE

Hirota, Keiko; Shibuya, Satoshi; Sakamoto, Shogo; Kashima, Shigeru

2012-01-01

The correlation between air pollution and health effects in large Japanese cities presents a great challenge owing to the limited availability of data on the exposure to pollution, health effects and the uncertainty of mixed causes. A methodology for quantitative relationships (between the emission volume and air quality, and the air quality and health effects) is analysed with a statistical method in this article; the correlation of air pollution reduction policy in Japan from 1974 to 2007. ...

Do Large Companies Have Lower Effective Corporate Tax Rates? A European Survey

OpenAIRE

Gaëtan Nicodème

2007-01-01

The current debate in corporate taxation is focusing on leveling the tax playing field within the European Union for companies operating across-countries. However, tax burdens could also vary with the size of companies within the same country, raising the question whether large companies pay their share of the burden. This paper uses firm-level data for 21 European countries between 1992 and 2004. The paper finds a robust negative correlation between the number of employees and the effective ...

A re-examination of the effects of biased lineup instructions in eyewitness identification.

Science.gov (United States)

Clark, Steven E

2005-10-01

A meta-analytic review of research comparing biased and unbiased instructions in eyewitness identification experiments showed an asymmetry; specifically, that biased instructions led to a large and consistent decrease in accuracy in target-absent lineups, but produced inconsistent results for target-present lineups, with an average effect size near zero (Steblay, 1997). The results for target-present lineups are surprising, and are inconsistent with statistical decision theories (i.e., Green & Swets, 1966). A re-examination of the relevant studies and the meta-analysis of those studies shows clear evidence that correct identification rates do increase with biased lineup instructions, and that biased witnesses make correct identifications at a rate considerably above chance. Implications for theory, as well as police procedure and policy, are discussed.

Time delay effects on large-scale MR damper based semi-active control strategies

International Nuclear Information System (INIS)

Cha, Y-J; Agrawal, A K; Dyke, S J

2013-01-01

This paper presents a detailed investigation on the robustness of large-scale 200 kN MR damper based semi-active control strategies in the presence of time delays in the control system. Although the effects of time delay on stability and performance degradation of an actively controlled system have been investigated extensively by many researchers, degradation in the performance of semi-active systems due to time delay has yet to be investigated. Since semi-active systems are inherently stable, instability problems due to time delay are unlikely to arise. This paper investigates the effects of time delay on the performance of a building with a large-scale MR damper, using numerical simulations of near- and far-field earthquakes. The MR damper is considered to be controlled by four different semi-active control algorithms, namely (i) clipped-optimal control (COC), (ii) decentralized output feedback polynomial control (DOFPC), (iii) Lyapunov control, and (iv) simple-passive control (SPC). It is observed that all controllers except for the COC are significantly robust with respect to time delay. On the other hand, the clipped-optimal controller should be integrated with a compensator to improve the performance in the presence of time delay. (paper)

Large-scale assessment of flood risk and the effects of mitigation measures along the Elbe River

NARCIS (Netherlands)

de Kok, Jean-Luc; Grossmann, M.

2010-01-01

The downstream effects of flood risk mitigation measures and the necessity to develop flood risk management strategies that are effective on a basin scale call for a flood risk assessment methodology that can be applied at the scale of a large river. We present an example of a rapid flood risk

Shellfish Fishery Severely Reduces Condition and Survival of Oystercatchers Despite Creation of Large Marine Protected Areas

Directory of Open Access Journals (Sweden)

Simon Verhulst

2004-06-01

Full Text Available Fisheries and other human activities pose a global threat to the marine environment. Marine protected areas (MPAs are an emerging tool to cope with such threats. In the Dutch Wadden Sea, large MPAs (covering 31% of all intertidal flats have been created to protect shellfish-eating birds and allow recovery of important habitats. Even though shellfish fishing is prohibited in these areas, populations of shellfish-eating birds in the Wadden Sea have declined sharply. The role of shellfish fisheries in these declines is hotly debated, therefore, we investigated the effectiveness of MPAs for protecting oystercatcher (Haematopus ostralegus populations. Shellfish stocks (cockles, Cerastoderma edule were substantially higher in the MPAs, but surprisingly this has not resulted in a redistribution of wintering oystercatchers. Oystercatchers in unprotected areas had less shellfish in their diet and lower condition (a combined measure of mass and haematological parameters, and their estimated mortality was 43% higher. It is likely, therefore, that shellfish fishing explains at least part of the 40% decline in oystercatcher numbers in recent years. Condition and mortality effects were strongest in males, and the population sex ratio was female biased, in agreement with the fact that males rely more on shellfish. The unprotected areas apparently function as an "ecological trap," because oystercatchers did not respond as anticipated to the artificial spatial heterogeneity in food supply. Consequently, the MPAs are effective on a local scale, but not on a global scale. Similar problems are likely to exist in terrestrial ecosystems, and distribution strategies of target species need to be considered when designing terrestrial and marine protected areas if they are to be effective.

Large Fizeau's light-dragging effect in a moving electromagnetically induced transparent medium.

Science.gov (United States)

Kuan, Pei-Chen; Huang, Chang; Chan, Wei Sheng; Kosen, Sandoko; Lan, Shau-Yu

2016-10-03

As one of the most influential experiments on the development of modern macroscopic theory from Newtonian mechanics to Einstein's special theory of relativity, the phenomenon of light dragging in a moving medium has been discussed and observed extensively in different types of systems. To have a significant dragging effect, the long duration of light travelling in the medium is preferred. Here we demonstrate a light-dragging experiment in an electromagnetically induced transparent cold atomic ensemble and enhance the dragging effect by at least three orders of magnitude compared with the previous experiments. With a large enhancement of the dragging effect, we realize an atom-based velocimeter that has a sensitivity two orders of magnitude higher than the velocity width of the atomic medium used. Such a demonstration could pave the way for motional sensing using the collective state of atoms in a room temperature vapour cell or solid state material.

Large photon drag effect of intrinsic graphene induced by plasmonic evanescent field

Science.gov (United States)

Luo, Ma; Li, Zhibing

2016-12-01

A large photon drag effect of the massless Dirac fermions in intrinsic graphene is predicted for a graphene-on-plasmonic-layer system. The surface plasmons in the plasmonic layer enlarge the wave number of the photon hundreds times more than in vacuum. The evanescent field of the surface plasmons generates a directional motion of carriers in the intrinsic graphene because of the large momentum transfer from the surface plasmon to the excited carriers. A model Hamiltonian is developed on the assumption that the in-plane wavelength of the surface plasmons is much smaller than the mean free path of the carriers. The time evolution of the density matrix is solved by perturbation method as well as numerical integration. The nondiagonal density matrix elements with momentum transfer lead to a gauge current, which is an optically driven macroscopic direct current. The dependence of the macroscopic direct current on the incident direction and intensity of the laser field is studied.

Auxiliary basis expansions for large-scale electronic structure calculations.

Science.gov (United States)

Jung, Yousung; Sodt, Alex; Gill, Peter M W; Head-Gordon, Martin

2005-05-10

One way to reduce the computational cost of electronic structure calculations is to use auxiliary basis expansions to approximate four-center integrals in terms of two- and three-center integrals, usually by using the variationally optimum Coulomb metric to determine the expansion coefficients. However, the long-range decay behavior of the auxiliary basis expansion coefficients has not been characterized. We find that this decay can be surprisingly slow. Numerical experiments on linear alkanes and a toy model both show that the decay can be as slow as 1/r in the distance between the auxiliary function and the fitted charge distribution. The Coulomb metric fitting equations also involve divergent matrix elements for extended systems treated with periodic boundary conditions. An attenuated Coulomb metric that is short-range can eliminate these oddities without substantially degrading calculated relative energies. The sparsity of the fit coefficients is assessed on simple hydrocarbon molecules and shows quite early onset of linear growth in the number of significant coefficients with system size using the attenuated Coulomb metric. Hence it is possible to design linear scaling auxiliary basis methods without additional approximations to treat large systems.

Surpresa refrativa pós-facoemulsificação em distrofia corneana posterior amorfa Post-phacoemulsification refractive surprise in a posterior amorphous corneal dystrophy patient

Directory of Open Access Journals (Sweden)

Giuliano de Oliveira Freitas

2010-02-01

Full Text Available Relato de um caso de surpresa refracional pós-operatória não pretendida em paciente portador de distrofia corneana posterior amorfa submetida à facoemulsificação. A provável causa do erro, bem como a conduta tomada a partir do reconhecimento da mesma, são discutidas neste relato.One case of post-phacoemulsification refractive surprise in a posterior amorphous corneal dystrophy patient is reported herein. Its likely causative factor, as well as our approach once it was recognized are discussed in this report.

Side effects of problem-solving strategies in large-scale nutrition science: towards a diversification of health.

Science.gov (United States)

Penders, Bart; Vos, Rein; Horstman, Klasien

2009-11-01

Solving complex problems in large-scale research programmes requires cooperation and division of labour. Simultaneously, large-scale problem solving also gives rise to unintended side effects. Based upon 5 years of researching two large-scale nutrigenomic research programmes, we argue that problems are fragmented in order to be solved. These sub-problems are given priority for practical reasons and in the process of solving them, various changes are introduced in each sub-problem. Combined with additional diversity as a result of interdisciplinarity, this makes reassembling the original and overall goal of the research programme less likely. In the case of nutrigenomics and health, this produces a diversification of health. As a result, the public health goal of contemporary nutrition science is not reached in the large-scale research programmes we studied. Large-scale research programmes are very successful in producing scientific publications and new knowledge; however, in reaching their political goals they often are less successful.

Quantitation of the late effects of x radiation on the large intestine

International Nuclear Information System (INIS)

Black, W.C.; Gomez, L.S.; Yuhas, J.M.; Kligerman, M.M.

1980-01-01

A model for quantitating late effects of x radiation on the large intestine utilizing the rectum of the Sprague-Dawley rat is reported. This model was constructed prefatory to establishing relative biological effectiveness for negative pions as a component of preclinical trials at the Clinton P. Anderson Meson Physics Facility. The endpoint involves microscopic evaluation of the severity of the experimental lesion, compared with surgically resected bowel lesions we have studied following clinical radiation exposure of the bowel. Individual components of the overall lesion include mucosal ulceration, a typical epithelial regeneration, colitis cystica profunda, fibrosis, and vascular sclerosis. Dose response curves were established for animals receiving 1, 2, 5 and 10 fractions with groups sacrificed at both four and 12 months after completion of radiation exposures

Postulated weather modification effects of large energy releases

Energy Technology Data Exchange (ETDEWEB)

Ramsdell, J.V.; Scott, B.C.; Orgill, M.M.; Renne, D.S.; Hubbard, J.E.; McGinnis, K.A.

1977-02-01

Postulated impacts of large energy releases were examined in the light of existing technical information. The magnitudes of direct atmospheric modifications were estimated, and the ecological and economic implications of the modifications were explored. Energy releases from energy centers (10 to 40 power plants at a single site) and individual power plant clusters (1 to 4 power plants) were considered. In the atmosphere the energy will exist initially as increased temperature (sensible heat), moisture (latent heat), and air motion (kinetic energy). Addition of energy could result in increased cloudiness and fog, and changed precipitation patterns. A framework for economic analysis of the impacts of the postulated atmospheric modifications was established on the basis of costs and benefits. Willingness-to-pay was selected as the appropriate measure for valuing each impact. The primary and secondary atmospheric modifications may affect recreation, transportation, and aesthetics as well as agriculture and forestry. Economic values can be placed on some of the effects. However, the willingness of people to pay to gain benefits and avoid damages in many cases can only be determined through extensive surveys. The economic consequences of a given energy release would be highly site specific.

Postulated weather modification effects of large energy releases

International Nuclear Information System (INIS)

Ramsdell, J.V.; Scott, B.C.; Orgill, M.M.; Renne, D.S.; Hubbard, J.E.; McGinnis, K.A.

1977-02-01

Postulated impacts of large energy releases were examined in the light of existing technical information. The magnitudes of direct atmospheric modifications were estimated, and the ecological and economic implications of the modifications were explored. Energy releases from energy centers (10 to 40 power plants at a single site) and individual power plant clusters (1 to 4 power plants) were considered. In the atmosphere the energy will exist initially as increased temperature (sensible heat), moisture (latent heat), and air motion (kinetic energy). Addition of energy could result in increased cloudiness and fog, and changed precipitation patterns. A framework for economic analysis of the impacts of the postulated atmospheric modifications was established on the basis of costs and benefits. Willingness-to-pay was selected as the appropriate measure for valuing each impact. The primary and secondary atmospheric modifications may affect recreation, transportation, and aesthetics as well as agriculture and forestry. Economic values can be placed on some of the effects. However, the willingness of people to pay to gain benefits and avoid damages in many cases can only be determined through extensive surveys. The economic consequences of a given energy release would be highly site specific

Mitigating Aviation Communication and Satellite Orbit Operations Surprises from Adverse Space Weather

Science.gov (United States)

Tobiska, W. Kent

2008-01-01

Adverse space weather affects operational activities in aviation and satellite systems. For example, large solar flares create highly variable enhanced neutral atmosphere and ionosphere electron density regions. These regions impact aviation communication frequencies as well as precision orbit determination. The natural space environment, with its dynamic space weather variability, is additionally changed by human activity. The increase in orbital debris in low Earth orbit (LEO), combined with lower atmosphere CO2 that rises into the lower thermosphere and causes increased cooling that results in increased debris lifetime, adds to the environmental hazards of navigating in near-Earth space. This is at a time when commercial space endeavors are posed to begin more missions to LEO during the rise of the solar activity cycle toward the next maximum (2012). For satellite and aviation operators, adverse space weather results in greater expenses for orbit management, more communication outages or aviation and ground-based high frequency radio used, and an inability to effectively plan missions or service customers with space-based communication, imagery, and data transferal during time-critical activities. Examples of some revenue-impacting conditions and solutions for mitigating adverse space weather are offered.

Disruption of circumstellar discs by large-scale stellar magnetic fields

Science.gov (United States)

ud-Doula, Asif; Owocki, Stanley P.; Kee, Nathaniel Dylan

2018-05-01

Spectropolarimetric surveys reveal that 8-10% of OBA stars harbor large-scale magnetic fields, but thus far no such fields have been detected in any classical Be stars. Motivated by this, we present here MHD simulations for how a pre-existing Keplerian disc - like that inferred to form from decretion of material from rapidly rotating Be stars - can be disrupted by a rotation-aligned stellar dipole field. For characteristic stellar and disc parameters of a near-critically rotating B2e star, we find that a polar surface field strength of just 10 G can significantly disrupt the disc, while a field of 100 G, near the observational upper limit inferred for most Be stars, completely destroys the disc over just a few days. Our parameter study shows that the efficacy of this magnetic disruption of a disc scales with the characteristic plasma beta (defined as the ratio between thermal and magnetic pressure) in the disc, but is surprisingly insensitive to other variations, e.g. in stellar rotation speed, or the mass loss rate of the star's radiatively driven wind. The disc disruption seen here for even a modest field strength suggests that the presumed formation of such Be discs by decretion of material from the star would likely be strongly inhibited by such fields; this provides an attractive explanation for why no large-scale fields are detected from such Be stars.

Mitigating Surprise Through Enhanced Operational Design: Civilian Conceptual Planning Models

Science.gov (United States)

2007-01-01

political, historical, cultural , and economic contexts. If we are going to fight among the people, we must understand them.1 When evaluating US military...represents both the Christian and Yoruba minorities as well as the military, continues to compete against rival elites representing disparate elements...undeniably have to learn a new culture , the physical battlespace would not be alien since MS-13 maintains a large presence in areas that are home to

Ampullary Mixed Adenoneuroendocrine Carcinoma: Surprise Histology, Familiar Management.

Science.gov (United States)

Mahansaria, Shyam Sunder; Agrawal, Nikhil; Arora, Asit; Bihari, Chhagan; Appukuttan, Murali; Chattopadhyay, Tushar Kanti

2017-10-01

Mixed adenoneuroendocrine carcinoma (MANEC) has recently been defined by the World Health Organization in 2010. These are rare tumors and MANECs of ampullary region are even rarer. Only 19 cases have been reported in literature. We present 3 cases; the largest series, second case of amphicrine tumor and first case associated with chronic pancreatitis. Retrospective review of 3 patients who were diagnosed to have ampullary MANEC. All 3 patients were diagnosed preoperatively as neuroendocrine carcinoma and underwent margin negative pancreaticoduodenectomy. The histopathology revealed MANECs of small cell, mixed type in 2 patients and large cell, amphicrine type in 1 patient. The neuroendocrine component was grade 3 in all, the tumor was T3 in 2 and T2 in 1 and all had nodal metastases. Two patients received adjuvant chemotherapy and 2 of them had recurrence at 13 and 16 months. The median survival was 15 months. Ampullary MANECs are rare tumors. They are diagnosed on histopathologic examination of the resected specimen. Clinical presentation, management, and prognosis is similar to ampullary adenocarcinoma in literature.

Aeolian comminution experiments revealing surprising sandball mineral aggregates

Science.gov (United States)

Nørnberg, P.; Bak, E.; Finster, K.; Gunnlaugsson, H. P.; Iversen, J. J.; Jensen, S. Knak; Merrison, J. P.

2014-06-01

We have undertaken a set of wind erosion experiments on a simple and well defined mineral, quartz. In these experiments wind action is simulated by end over end tumbling of quartz grains in a sealed quartz flask. The tumbling induces collisions among the quartz grains and the walls of the flask. This process simulates wind action impact speed of ∼1.2 m/s. After several months of tumbling we observed the formation of a large number of spherical sand aggregates, which resemble small snowballs under optical microscopy. Upon mechanical load the aggregates are seen to be more elastic than quartz and their mechanical strength is comparable, though slightly lower than that of sintered silica aerogels. Aggregates of this kind have not been reported from field sites or from closed circulation systems. However, sparse occurrence might explain this, or in nature the concentration of the aggregate building particles is so low that they never meet and just appear as the most fine grained tail of the sediment particle size distribution.

Solar-terrestrial effect controls seismic activity to a large extent (Invited)

Science.gov (United States)

Duma, G.

2010-12-01

, too, and the number of events during Kp maxima is about twice that observed for N-America. For the whole of Eurasia the same becomes evident. In all three regions, the strongest earthquakes with magnitude 7 and even 8 occur during the Kp maxima. In the recent decade, several geophysical models have been tested to interpret the coupling between the solar induced geomagnetic variations and disturbances and its mechanic implications in the Earth’s lithosphere, i.e. in rupture zones. The main questions in that regard are, of course, how mechanic forces are generated by the magnetic variations and whether they are strong enough to influence the tectonic process, that is, to act as a powerful trigger mechanism, as observed. Two such models are demonstrated, which fit well the observations, and which both indicate a surprisingly high energy and mechanic stress involved in the process. They build on Lorentz forces and on the effect of magnetostriction, respectively. The effect applies in particular to strong earthquake activity as outlined above. Moreover, it is a general geodynamic process which acts in nearly all main seismic regions on the globe. Thus, the results add very novel and important aspects to the research on seismic performance, temporal trends of strong earthquake occurrence and hazard assessment.

Technological monitoring radar: a weak signals interpretation tool for the identification of strategic surprises

Directory of Open Access Journals (Sweden)

Adalton Ozaki

2011-07-01

Full Text Available In the current competitive scenario, marked by rapid and constant changes, it is vital that companies actively monitor the business environment, in search of signs which might anticipate changes. This study poses to propose and discuss a tool called Technological Monitoring Radar, which endeavours to address the following query: “How can a company systematically monitor the environment and capture signs that anticipate opportunities and threats concerning a particular technology?”. The literature review covers Competitive Intelligence, Technological Intelligence, Environmental Analysis and Anticipative Monitoring. Based on the critical analysis of the literature, a tool called Technological Monitoring Radar is proposed comprising five environments to be monitored (political, economical, technological, social and competition each of which with key topics for analysis. To exemplify the use of the tool, it is applied to the smartphone segment in an exclusively reflexive manner, and without the participation of a specific company. One of the suggestions for future research is precisely the application of the proposed methodology in an actual company. Despite the limitation of this being a theoretical study, the example demonstrated the tool´s applicability. The radar prove to be very useful for a company that needs to monitor the environment in search of signs of change. This study´s main contribution is to relate different fields of study (technological intelligence, environmental analysis and anticipative monitoring and different approaches to provide a practical tool that allows a manager to identify and better visualize opportunities and threats, thus avoiding strategic surprises in the technological arena.Key words: Technological monitoring. Technological intelligence. Competitive intelligence. Weak signals.

Affordable Electro-Magnetic Interference (EMI) Testing on Large Space Vehicles

Science.gov (United States)

Aldridge, Edward; Curry, Bruce; Scully, Robert

2015-01-01

Objective: Perform System-Level EMI testing of the Orion Exploration Flight Test-1 (EFT-1) spacecraft in situ in the Kennedy Space Center's Neil Armstrong Operations & Checkout (O&C) Facility in 6 days. The only way to execute the system-level EMI testing and meet this schedule challenge was to perform the EMI testing in situ in the Final Assembly & System Test (FAST) Cell in a reverberant mode, not the direct illumination mode originally planned. This required the unplanned construction of a Faraday Cage around the vehicle and FAST Cell structure. The presence of massive steel platforms created many challenges to developing an efficient screen room to contain the RF energy and yield an effective reverberant chamber. An initial effectiveness test showed marginal performance, but improvements implemented afterward resulted in the final test performing surprisingly well! The paper will explain the design, the challenges, and the changes that made the difference in performance!

Effect of cobratoxin binding on the normal mode vibration within acetylcholine binding protein.

Science.gov (United States)

Bertaccini, Edward J; Lindahl, Erik; Sixma, Titia; Trudell, James R

2008-04-01

Recent crystal structures of the acetylcholine binding protein (AChBP) have revealed surprisingly small structural alterations upon ligand binding. Here we investigate the extent to which ligand binding may affect receptor dynamics. AChBP is a homologue of the extracellular component of ligand-gated ion channels (LGICs). We have previously used an elastic network normal-mode analysis to propose a gating mechanism for the LGICs and to suggest the effects of various ligands on such motions. However, the difficulties with elastic network methods lie in their inability to account for the modest effects of a small ligand or mutation on ion channel motion. Here, we report the successful application of an elastic network normal mode technique to measure the effects of large ligand binding on receptor dynamics. The present calculations demonstrate a clear alteration in the native symmetric motions of a protein due to the presence of large protein cobratoxin ligands. In particular, normal-mode analysis revealed that cobratoxin binding to this protein significantly dampened the axially symmetric motion of the AChBP that may be associated with channel gating in the full nAChR. The results suggest that alterations in receptor dynamics could be a general feature of ligand binding.

The large sample size fallacy.

Science.gov (United States)

Lantz, Björn

2013-06-01

Significance in the statistical sense has little to do with significance in the common practical sense. Statistical significance is a necessary but not a sufficient condition for practical significance. Hence, results that are extremely statistically significant may be highly nonsignificant in practice. The degree of practical significance is generally determined by the size of the observed effect, not the p-value. The results of studies based on large samples are often characterized by extreme statistical significance despite small or even trivial effect sizes. Interpreting such results as significant in practice without further analysis is referred to as the large sample size fallacy in this article. The aim of this article is to explore the relevance of the large sample size fallacy in contemporary nursing research. Relatively few nursing articles display explicit measures of observed effect sizes or include a qualitative discussion of observed effect sizes. Statistical significance is often treated as an end in itself. Effect sizes should generally be calculated and presented along with p-values for statistically significant results, and observed effect sizes should be discussed qualitatively through direct and explicit comparisons with the effects in related literature. © 2012 Nordic College of Caring Science.

Modern Sedimentation along the SE Bangladesh Coast Reveal Surprisingly Low Accumulation Rates

Science.gov (United States)

McHugh, C.; Mustaque, S.; Mondal, D. R.; Akhter, S. H.; Iqbal, M.

2016-12-01

Recent sediments recovered along the SE coast of Bangladesh, from Teknaf to Cox's Bazar and drainage basin analyses reveal sediment sources and very low sedimentation rates of 1mm/year. These low rates are surprisingly low given that this coast is adjacent to the Ganges-Brahmaputra Delta with a yearly discharge of 1GT. The Teknaf anticline (elevation 200 m), part of the western Burma fold-thrust belt dominates the topography extending across and along the Teknaf peninsula. It is thought to have begun evolving since the Miocene (Alam et al. 2003 & Allen et al. 2008). Presently the anticline foothills on the west are flanked by uplifted terraces, the youngest linked to coseismic displacement during the 1762 earthquake (Mondal et al. 2015), and a narrow beach 60-200 m in width. Petrography, semi-quantitative bulk mineralogy and SEM/EDX analyses were conducted on sediments recovered along the west coast from 1-4 m deep trenches and three 4-8 m deep drill holes. GIS mapping of drainage basins and quartz-feldspar-lithic (QFL) ternary plots based on grain counting show mixing of sediments from multiple sources: Himalayan provenance of metamorphic and igneous origin (garnet-mostly almandine, tourmaline, rutile, kyanite, zircon, sillimanite and clinopyroxene) similar to Uddin et al. (2007); Brahmaputra provenance of igneous and metamorphic origin (amphibole, epidote, plagioclase 40% Na and 60% Ca, apatite, ilmenite, magnetite, Cr-spinel and garnet-mostly grossular,) as indicated by Garzanti et al. (2010) & Rahman et al. (2016) and Burmese sources (cassiterite and wolframite) (Zaw 1990 & Searle et al. 2007). Low sedimentation rates are the result of two main factors: 1. Strong longshore currents from the south-east that interact with high tidal ranges as evidenced by the morphology of sand waves and ridge and runnel landforms along the beach. 2. Streams draining the Teknaf anticline are dry during the winter and during summer monsoon rains, the sediments bypass the narrow

Largely Improved Near-Infrared Silicon-Photosensing by the Piezo-Phototronic Effect.

Science.gov (United States)

Dai, Yejing; Wang, Xingfu; Peng, Wenbo; Zou, Haiyang; Yu, Ruomeng; Ding, Yong; Wu, Changsheng; Wang, Zhong Lin

2017-07-25

Although silicon (Si) devices are the backbone of modern (opto-)electronics, infrared Si-photosensing suffers from low-efficiency due to its limitation in light-absorption. Here, we demonstrate a large improvement in the performance, equivalent to a 366-fold enhancement in photoresponsivity, of a Si-based near-infrared (NIR) photodetector (PD) by introducing the piezo-phototronic effect via a deposited CdS layer. By externally applying a -0.15‰ compressive strain to the heterojunction, carrier-dynamics modulation at the local junction can be induced by the piezoelectric polarization, and the photoresponsivity and detectivity of the PD exhibit an enhancement of two orders of magnitude, with the peak values up to 19.4 A/W and 1.8 × 10 12 cm Hz 1/2 /W, respectively. The obtained maximum responsivity is considerably larger than those of commercial Si and InGaAs PDs in the NIR waveband. Meanwhile, the rise time and fall time are reduced by 84.6% and 76.1% under the external compressive strain. This work provides a cost-effective approach to achieve high-performance NIR photosensing by the piezo-phototronic effect for high-integration Si-based optoelectronic systems.

Large-area, lightweight and thick biomimetic composites with superior material properties via fast, economic, and green pathways.

Science.gov (United States)

Walther, Andreas; Bjurhager, Ingela; Malho, Jani-Markus; Pere, Jaakko; Ruokolainen, Janne; Berglund, Lars A; Ikkala, Olli

2010-08-11

Although remarkable success has been achieved to mimic the mechanically excellent structure of nacre in laboratory-scale models, it remains difficult to foresee mainstream applications due to time-consuming sequential depositions or energy-intensive processes. Here, we introduce a surprisingly simple and rapid methodology for large-area, lightweight, and thick nacre-mimetic films and laminates with superior material properties. Nanoclay sheets with soft polymer coatings are used as ideal building blocks with intrinsic hard/soft character. They are forced to rapidly self-assemble into aligned nacre-mimetic films via paper-making, doctor-blading or simple painting, giving rise to strong and thick films with tensile modulus of 45 GPa and strength of 250 MPa, that is, partly exceeding nacre. The concepts are environmentally friendly, energy-efficient, and economic and are ready for scale-up via continuous roll-to-roll processes. Excellent gas barrier properties, optical translucency, and extraordinary shape-persistent fire-resistance are demonstrated. We foresee advanced large-scale biomimetic materials, relevant for lightweight sustainable construction and energy-efficient transportation.

The importance of temperature in the effective sanitization of aqueous effluents: A review of the case for a thermal treatment that is environmentally and economically credible

International Nuclear Information System (INIS)

Burtun, C.

2009-01-01

The survival time of pathogens in the environment is normally longest in cold conditions. A large number of published studies have demonstrated a fall in this period from months or years down to a matter of weeks as the ambient temperature rises into the twenties. The effect of temperature is thus not surprisingly a key actor in the sanitizing efficiency of any biological treatment process as conditions move through the mesophilic range (30 to 45 degree centigrade) towards thermophilic conditions (over 50 degree centigrade) again, many publications report a substantial positive impact of such elevated temperatures on many harmful organisms. (Author)

Large-scale automatic extraction of side effects associated with targeted anticancer drugs from full-text oncological articles.

Science.gov (United States)

Xu, Rong; Wang, QuanQiu

2015-06-01

Targeted anticancer drugs such as imatinib, trastuzumab and erlotinib dramatically improved treatment outcomes in cancer patients, however, these innovative agents are often associated with unexpected side effects. The pathophysiological mechanisms underlying these side effects are not well understood. The availability of a comprehensive knowledge base of side effects associated with targeted anticancer drugs has the potential to illuminate complex pathways underlying toxicities induced by these innovative drugs. While side effect association knowledge for targeted drugs exists in multiple heterogeneous data sources, published full-text oncological articles represent an important source of pivotal, investigational, and even failed trials in a variety of patient populations. In this study, we present an automatic process to extract targeted anticancer drug-associated side effects (drug-SE pairs) from a large number of high profile full-text oncological articles. We downloaded 13,855 full-text articles from the Journal of Oncology (JCO) published between 1983 and 2013. We developed text classification, relationship extraction, signaling filtering, and signal prioritization algorithms to extract drug-SE pairs from downloaded articles. We extracted a total of 26,264 drug-SE pairs with an average precision of 0.405, a recall of 0.899, and an F1 score of 0.465. We show that side effect knowledge from JCO articles is largely complementary to that from the US Food and Drug Administration (FDA) drug labels. Through integrative correlation analysis, we show that targeted drug-associated side effects positively correlate with their gene targets and disease indications. In conclusion, this unique database that we built from a large number of high-profile oncological articles could facilitate the development of computational models to understand toxic effects associated with targeted anticancer drugs. Copyright © 2015 Elsevier Inc. All rights reserved.

Older Galaxy Pair Has Surprisingly Youthful Glow

Science.gov (United States)

2007-01-01

[figure removed for brevity, see original site] Poster Version A pair of interacting galaxies might be experiencing the galactic equivalent of a mid-life crisis. For some reason, the pair, called Arp 82, didn't make their stars early on as is typical of most galaxies. Instead, they got a second wind later in life -- about 2 billion years ago -- and started pumping out waves of new stars as if they were young again. Arp 82 is an interacting pair of galaxies with a strong bridge and a long tail. NGC 2535 is the big galaxy and NGC 2536 is its smaller companion. The disk of the main galaxy looks like an eye, with a bright 'pupil' in the center and oval-shaped 'eyelids.' Dramatic 'beads on a string' features are visible as chains of evenly spaced star-formation complexes along the eyelids. These are presumably the result of large-scale gaseous shocks from a grazing encounter. The colors of this galaxy indicate that the observed stars are young to intermediate in age, around 2 million to 2 billion years old, much less than the age of the universe (13.7 billion years). The puzzle is: why didn't Arp 82 form many stars earlier, like most galaxies of that mass range? Scientifically, it is an oddball and provides a relatively nearby lab for studying the age of intermediate-mass galaxies. This picture is a composite captured by Spitzer's infrared array camera with light at wavelength 8 microns shown in red, NASA's Galaxy Evolution Explorer combined 1530 and 2310 Angstroms shown in blue, and the Southeastern Association for Research in Astronomy Observatory light at 6940 Angstroms shown in green.

Romantic refractions : light effects in Ruskin's poetry.

OpenAIRE

Garratt, Peter

2016-01-01

The poetry of John Ruskin – which amounts to a surprisingly large body of work, mostly written in the 1830s and 1840s – reveals the stirrings of the moral perceptual attitude that would emerge with such distinctive force in Modern Painters, yet one guided by the influences of Keats, Shelley and Byron as much as the natural theology of Wordsworth (despite Modern Painters taking its epigraph from The Excursion). Although in some respects a poetry of post-Romantic transition, Ruskin's work also ...

Effects of large deep-seated landslides on hillslope morphology, western Southern Alps, New Zealand

Science.gov (United States)

Korup, Oliver

2006-03-01

Morphometric analysis and air photo interpretation highlight geomorphic imprints of large landslides (i.e., affecting ≥1 km2) on hillslopes in the western Southern Alps (WSA), New Zealand. Large landslides attain kilometer-scale runout, affect >50% of total basin relief, and in 70% are slope clearing, and thus relief limiting. Landslide terrain shows lower mean local relief, relief variability, slope angles, steepness, and concavity than surrounding terrain. Measuring mean slope angle smoothes out local landslide morphology, masking any relationship between large landslides and possible threshold hillslopes. Large failures also occurred on low-gradient slopes, indicating persistent low-frequency/high-magnitude hillslope adjustment independent of fluvial bedrock incision. At the basin and hillslope scale, slope-area plots partly constrain the effects of landslides on geomorphic process regimes. Landslide imprints gradually blend with relief characteristics at orogen scale (102 km), while being sensitive to length scales of slope failure, topography, sampling, and digital elevation model resolution. This limits means of automated detection, and underlines the importance of local morphologic contrasts for detecting large landslides in the WSA. Landslide controls on low-order drainage include divide lowering and shifting, formation of headwater basins and hanging valleys, and stream piracy. Volumes typically mobilized, yet still stored in numerous deposits despite high denudation rates, are >107 m3, and theoretically equal to 102 years of basin-wide debris production from historic shallow landslides; lack of absolute ages precludes further estimates. Deposit size and mature forest cover indicate residence times of 101-104 years. On these timescales, large landslides require further attention in landscape evolution models of tectonically active orogens.

Towards a Spiderman suit: large invisible cables and self-cleaning releasable superadhesive materials

International Nuclear Information System (INIS)

Pugno, Nicola M

2007-01-01

Spiders can produce cobwebs with high strength to density ratio and surprisingly display self-cleaning, strong and releasable adhesion (like geckos). Nanointerlocking, capillary and van der Waals forces, all potential adhesive mechanisms, are thus discussed, demonstrating the key role played by hierarchy in the design of superhydrophobic, i.e. self-cleaning (dry or wet and enhanced by activating Fakir drops as in lotus leaves) and superadhesive materials. The reversibility of the strong attachment is quantified thanks to an improved nonlinear peeling model including friction, for which the solution in closed form is provided. Thus, mimicking nature, thanks to carbon-nanotube-based technology, we suggest the feasibility of large invisible cables, as well as of self-cleaning, superadhesive and releasable hierarchical smart materials. We found that a man can theoretically be supported by a transparent cable with cross-section of 1 cm 2 and feasibly, with spider material gloves and boots, could remain attached even to a ceiling: a preliminary step towards a Spiderman suit

Towards a Spiderman suit: large invisible cables and self-cleaning releasable superadhesive materials

Science.gov (United States)

Pugno, Nicola M.

2007-10-01

Spiders can produce cobwebs with high strength to density ratio and surprisingly display self-cleaning, strong and releasable adhesion (like geckos). Nanointerlocking, capillary and van der Waals forces, all potential adhesive mechanisms, are thus discussed, demonstrating the key role played by hierarchy in the design of superhydrophobic, i.e. self-cleaning (dry or wet and enhanced by activating Fakir drops as in lotus leaves) and superadhesive materials. The reversibility of the strong attachment is quantified thanks to an improved nonlinear peeling model including friction, for which the solution in closed form is provided. Thus, mimicking nature, thanks to carbon-nanotube-based technology, we suggest the feasibility of large invisible cables, as well as of self-cleaning, superadhesive and releasable hierarchical smart materials. We found that a man can theoretically be supported by a transparent cable with cross-section of 1 cm2 and feasibly, with spider material gloves and boots, could remain attached even to a ceiling: a preliminary step towards a Spiderman suit.

Towards a Spiderman suit: large invisible cables and self-cleaning releasable superadhesive materials

Energy Technology Data Exchange (ETDEWEB)

Pugno, Nicola M [Department of Structural Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin (Italy)

2007-10-03

Spiders can produce cobwebs with high strength to density ratio and surprisingly display self-cleaning, strong and releasable adhesion (like geckos). Nanointerlocking, capillary and van der Waals forces, all potential adhesive mechanisms, are thus discussed, demonstrating the key role played by hierarchy in the design of superhydrophobic, i.e. self-cleaning (dry or wet and enhanced by activating Fakir drops as in lotus leaves) and superadhesive materials. The reversibility of the strong attachment is quantified thanks to an improved nonlinear peeling model including friction, for which the solution in closed form is provided. Thus, mimicking nature, thanks to carbon-nanotube-based technology, we suggest the feasibility of large invisible cables, as well as of self-cleaning, superadhesive and releasable hierarchical smart materials. We found that a man can theoretically be supported by a transparent cable with cross-section of 1 cm{sup 2} and feasibly, with spider material gloves and boots, could remain attached even to a ceiling: a preliminary step towards a Spiderman suit.

Large differences in the diabatic heat budget of the tropical UTLS in reanalyses

Science.gov (United States)

Wright, J. S.; Fueglistaler, S.

2013-04-01

We present the time mean heat budgets of the tropical upper troposphere (UT) and lower stratosphere (LS) as simulated by five reanalysis models: MERRA, ERA-Interim, CFSR, JRA-25/JCDAS, and NCEP/NCAR. The simulated diabatic heat budget in the tropical UTLS differs significantly from model to model, with substantial implications for representations of transport and mixing. Large differences are apparent both in the net heat budget and in all comparable individual components, including latent heating, heating due to radiative transfer, and heating due to parameterised vertical mixing. We describe and discuss the most pronounced differences. Although they may be expected given difficulties in representing moist convection in models, the discrepancies in latent heating are still disturbing. We pay particular attention to discrepancies in radiative heating (which may be surprising given the strength of observational constraints on temperature and tropospheric water vapour) and discrepancies in heating due to turbulent mixing (which have received comparatively little attention).

Large-angle theory for pion-nucleus scattering at high energies

International Nuclear Information System (INIS)

Hoock, D.W. Jr.

1978-01-01

An approximate solution for high-energy, projectile-nucleus, multiple scattering is developed from the exact Watson series and applied to pion scattering for 12 C and 4 He. Agreement with measured differential cross sections available from the literature for the range 150 to 260 MeV pion laboratory energies is surprisingly good. The approximation method expands the propagators of the Watson series about the transverse component of the momentum transfer. Contributions of each of the first two terms to double scattering from a Gaussian potential are compared to the exact solution. The purely plane-wave propagation produces a scattering amplitude that agrees to order (k 0 a) -1 with the exact solution at the forward and backward directions at high energies. The second (off-axis) propagation term produces an amplitude that is one order smaller at forward angles and two orders smaller at 180 0 than the exact amplitude. At intermediate angles it is of the same order. The general multiple-scattering series is approximated with selection of plane-wave propagation as the fundamental process at large and small angles. This model suggests that a single nucleon accepts most of the momentum transfer for backward scattering. The resulting multiple-scattering formula agrees with the well-known high-energy eikonal theory at small angles and the backward-angle scattering formula of Chen at exactly 180 0 . A lowest-order formula that includes off-axis propagation is also derived. Predicted differential cross sections are found to be sensitive to nucleon motion and binding. For 4 He the effect of the nuclear potential on the pion kinetic energy is also examined and found to produce significant changes in the predicted cross sections

Effects of air pollution on infant and children respiratory mortality in four large Latin-American cities.

Science.gov (United States)

Gouveia, Nelson; Junger, Washington Leite

2018-01-01

Air pollution is an important public health concern especially for children who are particularly susceptible. Latin America has a large children population, is highly urbanized and levels of pollution are substantially high, making the potential health impact of air pollution quite large. We evaluated the effect of air pollution on children respiratory mortality in four large urban centers: Mexico City, Santiago, Chile, and Sao Paulo and Rio de Janeiro in Brazil. Generalized Additive Models in Poisson regression was used to fit daily time-series of mortality due to respiratory diseases in infants and children, and levels of PM 10 and O 3 . Single lag and constrained polynomial distributed lag models were explored. Analyses were carried out per cause for each age group and each city. Fixed- and random-effects meta-analysis was conducted in order to combine the city-specific results in a single summary estimate. These cities host nearly 43 million people and pollution levels were above the WHO guidelines. For PM 10 the percentage increase in risk of death due to respiratory diseases in infants in a fixed effect model was 0.47% (0.09-0.85). For respiratory deaths in children 1-5 years old, the increase in risk was 0.58% (0.08-1.08) while a higher effect was observed for lower respiratory infections (LRI) in children 1-14 years old [1.38% (0.91-1.85)]. For O 3 , the only summarized estimate statistically significant was for LRI in infants. Analysis by season showed effects of O 3 in the warm season for respiratory diseases in infants, while negative effects were observed for respiratory and LRI deaths in children. We provided comparable mortality impact estimates of air pollutants across these cities and age groups. This information is important because many public policies aimed at preventing the adverse effects of pollution on health consider children as the population group that deserves the highest protection. Copyright © 2017 Elsevier Ltd. All rights reserved.

An undiagnosed pleural effusion with surprising consequences

Directory of Open Access Journals (Sweden)

A.G. Casalini

2017-01-01

With this case report, we would like to underline the importance of making a correct diagnosis of any pleural effusion as soon as possible by at least a thoracocentesis. If untreated, tuberculosis may easily disseminate to other organs. Some considerations and suggestions for antibiotic treatment of pleural effusion will also be given, since many antibiotics have some anti-tuberculosis effect and may delay the diagnosis of this infectious disease.

Survival of migrating salmon smolts in large rivers with and without dams.

Directory of Open Access Journals (Sweden)

David W Welch

2008-10-01

Full Text Available The mortality of salmon smolts during their migration out of freshwater and into the ocean has been difficult to measure. In the Columbia River, which has an extensive network of hydroelectric dams, the decline in abundance of adult salmon returning from the ocean since the late 1970s has been ascribed in large measure to the presence of the dams, although the completion of the hydropower system occurred at the same time as large-scale shifts in ocean climate, as measured by climate indices such as the Pacific Decadal Oscillation. We measured the survival of salmon smolts during their migration to sea using elements of the large-scale acoustic telemetry system, the Pacific Ocean Shelf Tracking (POST array. Survival measurements using acoustic tags were comparable to those obtained independently using the Passive Integrated Transponder (PIT tag system, which is operational at Columbia and Snake River dams. Because the technology underlying the POST array works in both freshwater and the ocean, it is therefore possible to extend the measurement of survival to large rivers lacking dams, such as the Fraser, and to also extend the measurement of survival to the lower Columbia River and estuary, where there are no dams. Of particular note, survival during the downstream migration of at least some endangered Columbia and Snake River Chinook and steelhead stocks appears to be as high or higher than that of the same species migrating out of the Fraser River in Canada, which lacks dams. Equally surprising, smolt survival during migration through the hydrosystem, when scaled by either the time or distance migrated, is higher than in the lower Columbia River and estuary where dams are absent. Our results raise important questions regarding the factors that are preventing the recovery of salmon stocks in the Columbia and the future health of stocks in the Fraser River.

Very large refrigerant capacity at room temperature with reproducible magnetocaloric effect in Fe0.975Ni0.025Rh

International Nuclear Information System (INIS)

Manekar, Meghmalhar; Roy, S B

2011-01-01

We present the results of magnetocaloric effect (MCE) measurements on Fe 0.975 Ni 0.025 Rh. The MCE is estimated using both the isothermal field-dependent magnetization and the temperature-dependent magnetization in constant magnetic fields. We find a very large effective refrigerant capacity of nearly 492.8 J kg -1 , with the hot end at about 307 K, which is reproducible over many field cycles. We compare this refrigerant capacity with those of two well known systems, namely Gd 5 Ge 1.9 Si 2 Fe 0.1 and MnFeP 0.45 As 0.55 , which show a large MCE near room temperature, and also with our earlier results on the parent Fe-Rh alloy. The large effective refrigerant capacity in our sample is one of the largest achieved yet at room temperature with a significant improvement over the parent Fe-Rh system. (fast track communication)

Comparing the Effectiveness of Self-Paced and Collaborative Frame-of-Reference Training on Rater Accuracy in a Large-Scale Writing Assessment

Science.gov (United States)

Raczynski, Kevin R.; Cohen, Allan S.; Engelhard, George, Jr.; Lu, Zhenqiu

2015-01-01

There is a large body of research on the effectiveness of rater training methods in the industrial and organizational psychology literature. Less has been reported in the measurement literature on large-scale writing assessments. This study compared the effectiveness of two widely used rater training methods--self-paced and collaborative…

Poor housing quality: Prevalence and health effects.

Science.gov (United States)

Baker, Emma; Lester, Laurence H; Bentley, Rebecca; Beer, Andrew

2016-01-01

Housing is a central component of productive, healthy, and meaningful lives, and a principle social determinant of health and well-being. Surprisingly, though, evidence on the ways that housing influences health in Australia is poorly developed. This stems largely from the fact that the majority of the population are accommodated in good quality housing. The dominance of a "good housing paradigm" means that households living in poor quality and unhealthy housing are doubly disadvantaged-by the quality of their housing and because policy makers in Australia do not acknowledge the health effects of housing. In this article, we examine the relationship between health outcomes and quality of housing. We base our analysis on data from the Household Income and Labour Dynamics in Australia (HILDA) survey, a panel dataset that is representative across Australia. We find a sizeable, policy-important, and to date under-acknowledged cohort of Australians whose health is influenced by poor-condition dwellings.

Comparison of cardioprotective effects of salvianolic acid B and benazepril on large myocardial infarction in rats.

Science.gov (United States)

He, Hai-Bo; Yang, Xian-Zhe; Shi, Meng-Qiong; Zeng, Xiao-Wei; Wu, Li-Mao; Li, Lian-Da

2008-01-01

In the present study, we compared cardioprotective effects of salvianolic acid B (Sal B) and the angiotension-converting enzyme inhibitor, benazepril, in rats with large myocardial infarction (MI). The large MI was produced by coronary artery ligation for 4 weeks in rats. The rats were divided into the following groups: sham operation; MI; MI + Sal B (100 mg/kg by a gavage, once a day for 4 weeks) and MI + benazepril (1 mg/kg by a gavage, once a day for 4 weeks). Echocardiogram, hemodynamic and hemorheological changes, angiogenesis, infarct size and cardiac remodeling, as well as messenger ribonucleic acid (mRNA) of vascular endothelium growth factor (VEGF) were measured. The following similar effects were observed in MI rats treated with Sal B and benazepril: (1) a marked improvement of echocardiographic, hemodynamic and hemorheological parameters, (2) significant reduction of infarct size, (3) significantly attenuated heart hypertrophy, left ventricular (LV) dilatation and fibrosis. The unique effects of Sal B were: angiogenesis and augmented VEGF expression in the border and remote noninfarcted LV area. These results suggest that Sal B and benazepril exerted beneficial cardioprotective effects. However, Sal B enforced some different modality than benazepril, which might improve myocardial microcirculation by augmenting VEGF expression and promoting angiogenesis besides similar effects to benazepril.

Effectiveness of a large mimic panel in an existing nuclear power plant central control board

International Nuclear Information System (INIS)

Kubota, Ryuji; Satoh, Hiroyuki; Sasajima, Katsuhiro; Kawano, Ryutaro; Shibuya Shinya

1999-01-01

We conducted the analysis of the nuclear power plant (NPP) operators' behaviors under emergency conditions by using training simulators as a joint research project by Japanese BWR groups for twelve years. In the phase-IV of this project we executed two kinds of experiments to evaluate the effectiveness of the interfaces. One was for evaluations of the interfaces such as CRTs with touch screen, a large mimic panel, and a hierarchical annunciator system introduced in the newly developed ABWR type central control board. The other was that we analyzed the operators' behaviors in emergency conditions by using the first generation BWR type central control board which was added new interfaces such as a large display screen and demarcation on the board to help operators to understand the plant. The demarcation is one of the visual interface improvements and its technique is that a line enclosing several components causes them to be perceived as a group.The result showed that both the large display panel Introduced in ABWR central control board and the large display screen in the existing BWR type central control board improved the performance of the NPP operators in the experiments. It was expected that introduction of the large mimic panel into the existing BWR type central control boards would improve operators' performance. However, in the case of actual installation of the large display board into the existing central control boards, there are spatial and hardware constraints. Therefore the size of lamps, lines connecting from symbols of the pumps or valves to the others' will have to be modified under these constraints. It is important to evaluate the displayed information on the large display board before actual installation. We made experiments to solve these problems by using TEPCO's research simulator which is added a large mimic panel. (author)

Stochastic Effects in Microstructure

Directory of Open Access Journals (Sweden)

Glicksman M.E.

2002-01-01

Full Text Available We are currently studying microstructural responses to diffusion-limited coarsening in two-phase materials. A mathematical solution to late-stage multiparticle diffusion in finite systems is formulated with account taken of particle-particle interactions and their microstructural correlations, or "locales". The transition from finite system behavior to that for an infinite microstructure is established analytically. Large-scale simulations of late-stage phase coarsening dynamics show increased fluctuations with increasing volume fraction, Vv, of the mean flux entering or leaving particles of a given size class. Fluctuations about the mean flux were found to depend on the scaled particle size, R/, where R is the radius of a particle and is the radius of the dispersoid averaged over the population within the microstructure. Specifically, small (shrinking particles tend to display weak fluctuations about their mean flux, whereas particles of average, or above average size, exhibit strong fluctuations. Remarkably, even in cases of microstructures with a relatively small volume fraction (Vv ~ 10-4, the particle size distribution is broader than that for the well-known Lifshitz-Slyozov limit predicted at zero volume fraction. The simulation results reported here provide some additional surprising insights into the effect of diffusion interactions and stochastic effects during evolution of a microstructure, as it approaches its thermodynamic end-state.

A post-genomic surprise. The molecular reinscription of race in science, law and medicine.

Science.gov (United States)

Duster, Troy

2015-03-01

The completion of the first draft of the Human Genome Map in 2000 was widely heralded as the promise and future of genetics-based medicines and therapies - so much so that pundits began referring to the new century as 'The Century of Genetics'. Moreover, definitive assertions about the overwhelming similarities of all humans' DNA (99.9 per cent) by the leaders of the Human Genome Project were trumpeted as the end of racial thinking about racial taxonomies of human genetic differences. But the first decade of the new century brought unwelcomed surprises. First, gene therapies turned out to be far more complicated than any had anticipated - and instead the pharmaceutical industry turned to a focus on drugs that might be 'related' to population differences based upon genetic markers. While the language of 'personalized medicine' dominated this frame, research on racially and ethnically designated populations differential responsiveness to drugs dominated the empirical work in the field. Ancestry testing and 'admixture research' would play an important role in a new kind of molecular reification of racial categories. Moreover, the capacity of the super-computer to map differences reverberated into personal identification that would affect both the criminal justice system and forensic science, and generate new levels of concern about personal privacy. Social scientists in general, and sociologists in particular, have been caught short by these developments - relying mainly on assertions that racial categories are socially constructed, regionally and historically contingent, and politically arbitrary. While these assertions are true, the imprimatur of scientific legitimacy has shifted the burden, since now 'admixture research' can claim that its results get at the 'reality' of human differentiation, not the admittedly flawed social constructions of racial categories. Yet what was missing from this framing of the problem: 'admixture research' is itself based upon socially

When and where does preferential flow matter - from observation to large scale modelling

Science.gov (United States)

Weiler, Markus; Leistert, Hannes; Steinbrich, Andreas

2017-04-01

Preferential flow can be of relevance in a wide range of soils and the interaction of different processes and factors are still difficult to assess. As most studies (including our own studies) focusing on the effect of preferential flow are based on relatively high precipitation rates, there is always the question how relevant preferential flow is under natural conditions, considering the site specific precipitation characteristics, the effect of the drying and wetting cycle on the initial soil water condition and shrinkage cracks, the site specific soil properties, soil structure and rock fragments, and the effect of plant roots and soil fauna (e.g. earthworm channels). In order to assess this question, we developed the distributed, process-based model RoGeR (Runoff Generation Research) to include a large number relevant features and processes of preferential flow in soils. The model was developed from a large number of process based research and experiments and includes preferential flow in roots, earthworm channels, along rock fragments and shrinkage cracks. We parameterized the uncalibrated model at a high spatial resolution of 5x5m for the whole state of Baden-Württemberg in Germany using LiDAR data, degree of sealing, landuse, soil properties and geology. As the model is an event based model, we derived typical event based precipitation characteristics based on rainfall duration, mean intensity and amount. Using the site-specific variability of initial soil moisture derived from a water balance model based on the same dataset, we simulated the infiltration and recharge amounts of all event classes derived from the event precipitation characteristics and initial soil moisture conditions. The analysis of the simulation results allowed us to extracts the relevance of preferential flow for infiltration and recharge considering all factors above. We could clearly see a strong effect of the soil properties and land-use, but also, particular for clay rich soils a

More Supernova Surprises

Science.gov (United States)

2010-09-24

originated in South America. E veryone appreciates the beauty of dai- sies, chrysanthemums, and sunfl ow- ers, and many of us enjoy eating lettuce ...few fossils. On page 1621 of this issue, Barreda et al. ( 1) describe an unusually well-preserved new fossil that sheds light on the history of

Surprising radiation detectors

CERN Document Server

Fleischer, Robert

2003-01-01

Radiation doses received by the human body can be measured indirectly and retrospectively by counting the tracks left by particles in ordinary objects like pair of spectacles, glassware, compact disks...This method has been successfully applied to determine neutron radiation doses received 50 years ago on the Hiroshima site. Neutrons themselves do not leave tracks in bulk matter but glass contains atoms of uranium that may fission when hurt by a neutron, the recoil of the fission fragments generates a track that is detectable. The most difficult is to find adequate glass items and to evaluate the radiation shield they benefited at their initial place. The same method has been used to determine the radiation dose due to the pile-up of radon in houses. In that case the tracks left by alpha particles due to the radioactive decay of polonium-210 have been counted on the superficial layer of the window panes. Other materials like polycarbonate plastics have been used to determine the radiation dose due to heavy io...

Large carnivores, moose, and humans: A changing paradigm of predator management in the 21st century

Science.gov (United States)

Schwartz, Charles C.; Swenson, J.E.; Miller, Sterling D.

2003-01-01

We compare and contrast the evolution of human attitudes toward large carnivores between Europe and North America. In general, persecution of large carnivores began much earlier in Europe than North America. Likewise, conservation programs directed at restoration and recovery appeared in European history well before they did in North America. Together, the pattern suggests there has been an evolution in how humans perceive large predators. Our early ancestors were physically vulnerable to large carnivores and developed corresponding attitudes of respect, avoidance, and acceptance. As civilization evolved and man developed weapons, the balance shifted. Early civilizations, in particular those with pastoral ways, attempted to eliminate large carnivores as threats to life and property. Brown bears (Ursus arctos) and wolves (Canis lupus) were consequently extirpated from much of their range in Europe and in North America south of Canada. Efforts to protect brown bears began in the late 1880s in some European countries and population reintroductions and augmentations are ongoing. They are less controversial than in North America. On the other hand, there are no wolf introductions, as has occurred in North America, and Europeans have a more negative attitude towards wolves. Control of predators to enhance ungulate harvest varies. In Western Europe, landowners own the hunting rights to ungulates. In the formerly communistic Eastern European countries and North America, hunting rights are held in common, although this is changing in some Eastern European countries. Wolf control to increase harvests of moose (Alces alces) occurs in parts of North America and Russia; bear control for similar reasons only occurs in parts of North America. Surprisingly, bears and wolves are not controlled to increase ungulates where private landowners have the hunting rights in Europe, although wolves were originally exterminated from these areas. Both the inability of scientific research to

Thermal effect-resilient design of large mode area double-cladding Yb-doped photonic crystal fibers

DEFF Research Database (Denmark)

Coscelli, Enrico; Poli, Federica; Johansen, Mette Marie

2013-01-01

The effects of thermally-induced refractive index change on the guiding properties of different large mode area fibers have been numerically analyzed. A simple but accurate model has been applied to obtain the refractive index change in the fiber cross-section, and a full-vector modal solver base...

Orthographic effects in spoken word recognition: Evidence from Chinese.

Science.gov (United States)

Qu, Qingqing; Damian, Markus F

2017-06-01

Extensive evidence from alphabetic languages demonstrates a role of orthography in the processing of spoken words. Because alphabetic systems explicitly code speech sounds, such effects are perhaps not surprising. However, it is less clear whether orthographic codes are involuntarily accessed from spoken words in languages with non-alphabetic systems, in which the sound-spelling correspondence is largely arbitrary. We investigated the role of orthography via a semantic relatedness judgment task: native Mandarin speakers judged whether or not spoken word pairs were related in meaning. Word pairs were either semantically related, orthographically related, or unrelated. Results showed that relatedness judgments were made faster for word pairs that were semantically related than for unrelated word pairs. Critically, orthographic overlap on semantically unrelated word pairs induced a significant increase in response latencies. These findings indicate that orthographic information is involuntarily accessed in spoken-word recognition, even in a non-alphabetic language such as Chinese.

Effects of fluid flow on heat transfer in large rotating electrical machines

International Nuclear Information System (INIS)

Lancial, Nicolas

2014-01-01

EDF operates a large number of electrical rotating machines in its electricity generation capacity. Thermal stresses which affect them can cause local heating, sufficient to damage their integrity. The present work contributes to provide methodologies for detecting hot spots in these machines, better understanding the topology of rotating flows and identifying their effects on heat transfer. Several experimental scale model were used by increasing their complexity to understand and validate the numerical simulations. A first study on a turbulent wall jet over a non-confined backward-facing step (half-pole hydro-generator) notes significant differences compared to results from confined case: both of them are present in an hydro-generator. A second study was done on a small confined rotating scale model to determinate the effects of a Taylor-Couette-Poiseuille on temperature distribution and position of hot spots on the heated rotor, by studying the overall flow regimes flow. These studies have helped to obtain a reliable method based on conjugate heat transfer (CHT) simulations. Another method, based on FEM coupled with the use of an inverse method, has been studied on a large model of hydraulic generator so as to solve the computation time issue of the first methodology. It numerically calculates the convective heat transfer from temperature measurements, but depends on the availability of experimental data. This work has also developed new no-contact measurement techniques as the use of a high-frequency pyrometer which can be applied on rotating machines for monitoring temperature. (author)

What are the Effects of Fiscal Policy Shocks?

NARCIS (Netherlands)

Mountford, A.W.; Uhlig, H.F.H.V.S.

2002-01-01

We investigate the effects of fiscal policy surprises for US data, using vector autoregressions.We overcome the difficulties that changes in fiscal policy may manifest themselves in variables other than fiscal variables first and that fiscal variables may respond 'automatically' to business cycle

Design of an amplifier model accounting for thermal effect in fully aperiodic large pitch fibers

Science.gov (United States)

Tragni, K.; Molardi, C.; Poli, F.; Dauliat, R.; Leconte, B.; Darwich, D.; du Jeu, R.; Malleville, M. A.; Jamier, R.; Selleri, S.; Roy, P.; Cucinotta, A.

2018-02-01

Yb-doped Photonic Crystal Fibers (PCFs) have triggered a significant power scaling into fiber-based lasers. However thermally-induced effects, like mode instability, can compromise the output beam quality. PCF design with improved Higher Order Mode (HOM) delocalization and effective thermal resilience can contain the problem. In particular, Fully- Aperiodic Large-Pitch Fibers (FA-LPFs) have shown interesting properties in terms of resilience to thermal effects. In this paper the performances of a Yb-doped FA-LPF amplifier are experimentally and numerically investigated. Modal properties and gain competition between Fundamental Mode (FM) and first HOM have been calculated, in presence of thermal effects. The main doped fiber characteristics have been derived by comparison between experimental and numerical results.

You Should Be the Specialist! Weak Mental Rotation Performance in Aviation Security Screeners - Reduced Performance Level in Aviation Security with No Gender Effect.

Science.gov (United States)

Krüger, Jenny K; Suchan, Boris

2016-01-01

Aviation security screeners analyze a large number of X-ray images per day and seem to be experts in mentally rotating diverse kinds of visual objects. A robust gender-effect that men outperform women in the Vandenberg & Kuse mental rotation task has been well documented over the last years. In addition it has been shown that training can positively influence the overall task-performance. Considering this, the aim of the present study was to investigate whether security screeners show better performance in the Mental Rotation Test (MRT) independently of gender. Forty-seven security screeners of both sexes from two German airports were examined with a computer based MRT. Their performance was compared to a large sample of control subjects. The well-known gender-effect favoring men on mental rotation was significant within the control group. However, the security screeners did not show any sex differences suggesting an effect of training and professional performance. Surprisingly this specialized group showed a lower level of overall MRT performance than the control participants. Possible aviation related influences such as secondary effects of work-shift or expertise which can cumulatively cause this result are discussed.

Large lateral photovoltaic effect with ultrafast relaxation time in SnSe/Si junction

Energy Technology Data Exchange (ETDEWEB)

Wang, Xianjie; Zhao, Xiaofeng; Hu, Chang; Zhang, Yang; Song, Bingqian; Zhang, Lingli; Liu, Weilong; Lv, Zhe; Zhang, Yu; Sui, Yu, E-mail: suiyu@hit.edu.cn [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China); Tang, Jinke [Department of Physics and Astronomy, University of Wyoming, Laramie, Wyoming 82071 (United States); Song, Bo, E-mail: songbo@hit.edu.cn [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China); Academy of Fundamental and Interdisciplinary Sciences, Harbin Institute of Technology, Harbin 150001 (China)

2016-07-11

In this paper, we report a large lateral photovoltaic effect (LPE) with ultrafast relaxation time in SnSe/p-Si junctions. The LPE shows a linear dependence on the position of the laser spot, and the position sensitivity is as high as 250 mV mm{sup −1}. The optical response time and the relaxation time of the LPE are about 100 ns and 2 μs, respectively. The current-voltage curve on the surface of the SnSe film indicates the formation of an inversion layer at the SnSe/p-Si interface. Our results clearly suggest that most of the excited-electrons diffuse laterally in the inversion layer at the SnSe/p-Si interface, which results in a large LPE with ultrafast relaxation time. The high positional sensitivity and ultrafast relaxation time of the LPE make the SnSe/p-Si junction a promising candidate for a wide range of optoelectronic applications.

Unusually large magnetic moments in the normal state and superconducting state of Sn nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Hung, Chi-Hang; Lee, Chi-Hung; Hsu, Chien-Kang; Li, Chi-Yen; Karna, Sunil K.; Wang, Chin-Wei; Wu, Chun-Ming; Li, Wen-Hsien, E-mail: whli@phy.ncu.edu.tw [National Central University, Department of Physics and Center for Neutron Beam Applications (China)

2013-09-15

We report on the observations of spontaneous magnetic moments in the normal as well as in the superconducting states of a 9 nm Sn nanoparticle assembly, through X-ray diffraction, magnetization, ac magnetic susceptibility, and neutron diffraction measurements. The saturation magnetization reaches an unexpectedly large value of 1.04 emu/g at 5 K, with a temperature profile that can be described by Bloch's law with an exponent of b = 1.8. A magnetic moment of Left-Pointing-Angle-Bracket {mu}{sub Z} Right-Pointing-Angle-Bracket = 0.38 {mu}{sub B} develops after cooling from 260 to 4 K. Superconductivity develops below T{sub C} = 3.98 K, which is 7 % higher than the T{sub C} = 3.72 K of bulk Sn. Surprisingly, an addition magnetic moment of Left-Pointing-Angle-Bracket {mu}{sub Z} Right-Pointing-Angle-Bracket = 0.05 {mu}{sub B} develops upon entering the superconducting state.

Reionization on large scales. IV. Predictions for the 21 cm signal incorporating the light cone effect

Energy Technology Data Exchange (ETDEWEB)

La Plante, P.; Battaglia, N.; Natarajan, A.; Peterson, J. B.; Trac, H. [McWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Cen, R. [Department of Astrophysical Science, Princeton University, Princeton, NJ 08544 (United States); Loeb, A., E-mail: plaplant@andrew.cmu.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

2014-07-01

We present predictions for the 21 cm brightness temperature power spectrum during the Epoch of Reionization (EoR). We discuss the implications of the 'light cone' effect, which incorporates evolution of the neutral hydrogen fraction and 21 cm brightness temperature along the line of sight. Using a novel method calibrated against radiation-hydrodynamic simulations, we model the neutral hydrogen density field and 21 cm signal in large volumes (L = 2 Gpc h {sup –1}). The inclusion of the light cone effect leads to a relative decrease of about 50% in the 21 cm power spectrum on all scales. We also find that the effect is more prominent at the midpoint of reionization and later. The light cone effect can also introduce an anisotropy along the line of sight. By decomposing the 3D power spectrum into components perpendicular to and along the line of sight, we find that in our fiducial reionization model, there is no significant anisotropy. However, parallel modes can contribute up to 40% more power for shorter reionization scenarios. The scales on which the light cone effect is relevant are comparable to scales where one measures the baryon acoustic oscillation. We argue that due to its large comoving scale and introduction of anisotropy, the light cone effect is important when considering redshift space distortions and future application to the Alcock-Paczyński test for the determination of cosmological parameters.

Implementation of effective alcohol control strategies is needed at large sports and entertainment events.

Science.gov (United States)

Lyne, Mark; Galloway, Andrew

2012-02-01

To assess the implementation and effectiveness of strategies and actions to eliminate and/or reduce alcohol-related problems at large sports and entertainment events in New Zealand. We conducted site visits and monitoring observations at venues before, during and after a variety of large events between March 2009 and November 2010. Thirteen events were attended at nine different venues. Events included rugby, rugby league and cricket matches, motor racing, rowing, horse racing, an outdoor music festival, and food and wine festivals. Most large events appeared to pass with few or no alcohol-related problems. The exceptions were one of the horse-race meetings, a rugby league match and one food and wine festival. Common contexts at events where alcohol-related problems were seen included: inadequate alcohol control and management by security staff; the ability to purchase four alcoholic drinks (rather than two) at a time; inexperienced bar staff untrained in responsible alcohol service; no or little promotion of low and non-alcoholic drinks; and a lack of monitoring and enforcement of the law on intoxication. An important approach to prevent and reduce alcohol-related problems at large spots and entertainment events is the use of specific alcohol-control strategies. The management of alcohol consumption is a major part of event management that must be planned with harm-minimisation strategies well in advance of the event itself. If strategies and actions are not properly implemented to manage the sale and supply of alcohol at large events, there is significant risk of alcohol-related problems and harm resulting from them. © 2012 The Authors. ANZJPH © 2012 Public Health Association of Australia.

A Methodology of Health Effects Estimation from Air Pollution in Large Asian Cities

Directory of Open Access Journals (Sweden)

Keiko Hirota

2017-09-01

Full Text Available The increase of health effects caused by air pollution seems to be a growing concern in Asian cities with increasing motorization. This paper discusses methods of estimating the health effects of air pollution in large Asian cities. Due to the absence of statistical data in Asia, this paper carefully chooses the methodology using data of the Japanese compensation system. A basic idea of health effects will be captured from simple indicators, such as population and air quality, in a correlation model. This correlation model enables more estimation results of respiratory mortality caused by air pollution to be yielded than by using the relative model. The correlation model could be an alternative method to estimate mortality besides the relative risk model since the results of the correlation model are comparable with those of the relative model by city and by time series. The classification of respiratory diseases is not known from the statistical yearbooks in many countries. Estimation results could support policy decision-making with respect to public health in a cost-effective way.

But you should be the specialist! Weak Mental Rotation Performance in Aviation Security Screeners.Reduced performance level in aviation security with no gender effect.

Directory of Open Access Journals (Sweden)

Jenny Kathinka Krüger

2016-03-01

Full Text Available Aviation security screeners analyze a large number of X-ray images per day and seem to be experts in mentally rotating diverse kinds of visual objects. A robust gender-effect that men outperform women in the Vandenberg & Kuse mental rotation task has been well documented over the last years. In addition it has been shown that training can positively influence the overall task-performance. Considering this, the aim of the present study was to investigate whether security screeners show better performance in the Mental Rotation Test (MRT independently of gender. Forty-seven security screeners of both sexes from two German airports were examined with a computer based MRT. Their performance was compared to a large sample of control subjects. The well-known gender-effect favoring men on mental rotation was significant within the control group. However, the security screeners did not show any sex differences suggesting an effect of training and professional performance. Surprisingly this specialized group showed a lower level of overall MRT performance than the control participants. Possible aviation related influences such as secondary effects of work-shift or expertise which can cumulatively cause this result are discussed.

Surprisingly low frequency attenuation effects in long tubes when measuring turbulent fluxes at tall towers

DEFF Research Database (Denmark)

Ibrom, Andreas; Brændholt, Andreas; Pilegaard, Kim

2016-01-01

The eddy covariance technique relies on the fast and accurate measurement of gas concentration fluctuations. While for some gasses robust and compact sensors are available, measurement of, e.g., non CO2 greenhouse gas fluxes is often performed with sensitive equipment that cannot be run on a tower...... without massively disturbing the wind field. To measure CO and N2O fluxes, we installed an eddy covariance system at a 125 m mast, where the gas analyser was kept in a laboratory close to the tower and the sampling was performed using a 150 m long tube with a gas intake at 96 m height. We investigated...... by reducing both the water vapour dilution correction and the cross sensitivity effects on the N2O and CO flux measurements. Here we present the set-up of the concentration step change experiment and its results and compare them with recently developed theories for the behaviour of gases in turbulent tube...

Investigating Coastal Processes Responsible for Large-Scale Shoreline Responses to Human Shoreline Stabilization

Science.gov (United States)

Slott, J. M.; Murray, A. B.; Ashton, A. D.

2006-12-01

Human shoreline stabilization practices, such as beach nourishment (i.e. placing sand on an eroding beach), have become more prevalent as erosion threatens coastal communities. On sandy shorelines, recent experiments with a numerical model of shoreline change (Slott, et al., in press) indicate that moderate shifts in storminess patterns, one possible outcome of global warming, may accelerate the rate at which shorelines erode or accrete, by altering the angular distribution of approaching waves (the `wave climate'). Accelerated erosion would undoubtedly place greater demands on stabilization. Scientists and coastal engineers have typically only considered the site-specific consequences of shoreline stabilization; here we explore the coastal processes responsible for large-scale (10's kms) and long-term (decades) effects using a numerical model developed by Ashton, et al. (2001). In this numerical model, waves breaking at oblique angles drive a flux of sediment along the shoreline, where gradients in this flux can shape the coastline into surprisingly complex forms (e.g. cuspate-capes found on the Carolina coast). Wave "shadowing" plays a major role in shoreline evolution, whereby coastline features may block incoming waves from reaching distant parts. In this work, we include beach nourishment in the Ashton, et al. (2001) model. Using a cuspate-cape shoreline as our initial model condition, we conducted pairs of experiments and varied the wave-climate forcing across each pair, each representing different storminess scenarios. Here we report on one scenario featuring increased extra-tropical storm influence. For each experiment-pair we ran a control experiment with no shoreline stabilization and a second where a beach nourishment project stabilized a cape tip. By comparing the results of these two parallel runs, we isolate the tendency of the shoreline to migrate landward or seaward along the domain due solely to beach nourishment. Significant effects from beach

A large-scale deforestation experiment: Effects of patch area and isolation on Amazon birds

Science.gov (United States)

Ferraz, G.; Nichols, J.D.; Hines, J.E.; Stouffer, P.C.; Bierregaard, R.O.; Lovejoy, T.E.

2007-01-01

As compared with extensive contiguous areas, small isolated habitat patches lack many species. Some species disappear after isolation; others are rarely found in any small patch, regardless of isolation. We used a 13-year data set of bird captures from a large landscape-manipulation experiment in a Brazilian Amazon forest to model the extinction-colonization dynamics of 55 species and tested basic predictions of island biogeography and metapopulation theory. From our models, we derived two metrics of species vulnerability to changes in isolation and patch area. We found a strong effect of area and a variable effect of isolation on the predicted patch occupancy by birds.

Some remarks about large p/sub perpendicular/ spin effects

International Nuclear Information System (INIS)

Field, R.D.

1977-01-01

A discussion of the ingredients necessary to make predictions concerning single and double spin measurements in large p/sub perpendicular to/ inclusive processes is presented. Remarks are made as to what might be expected and what might be learned from such measurements. Various models for the production of large p/sub perpendicular to/ mesons have quite different spin structure and hence can be expected to give differing predictions. However, it is not possible at this time to make quantitative calculations, and it is possible (not probable) that the interesting spin observables will be negligibly small

Decrease of the tunneling time and violation of the Hartman effect for large barriers

International Nuclear Information System (INIS)

Olkhovsky, V.S.; Zaichenko, A.K.; Petrillo, V.

2004-01-01

The explicit formulation of the initial conditions of the definition of the wave-packet tunneling time is proposed. This formulation takes adequately into account the irreversibility of the wave-packet space-time spreading. Moreover, it explains the violations of the Hartman effect, leading to a strong decrease of the tunneling times up to negative values for wave packets with large momentum spreads due to strong wave-packet time spreading

Dark energy and modified gravity in the Effective Field Theory of Large-Scale Structure

Science.gov (United States)

Cusin, Giulia; Lewandowski, Matthew; Vernizzi, Filippo

2018-04-01

We develop an approach to compute observables beyond the linear regime of dark matter perturbations for general dark energy and modified gravity models. We do so by combining the Effective Field Theory of Dark Energy and Effective Field Theory of Large-Scale Structure approaches. In particular, we parametrize the linear and nonlinear effects of dark energy on dark matter clustering in terms of the Lagrangian terms introduced in a companion paper [1], focusing on Horndeski theories and assuming the quasi-static approximation. The Euler equation for dark matter is sourced, via the Newtonian potential, by new nonlinear vertices due to modified gravity and, as in the pure dark matter case, by the effects of short-scale physics in the form of the divergence of an effective stress tensor. The effective fluid introduces a counterterm in the solution to the matter continuity and Euler equations, which allows a controlled expansion of clustering statistics on mildly nonlinear scales. We use this setup to compute the one-loop dark-matter power spectrum.

Vacuum-thermal-evaporation: the route for roll-to-roll production of large-area organic electronic circuits

International Nuclear Information System (INIS)

Taylor, D M

2015-01-01

Surprisingly little consideration is apparently being given to vacuum-evaporation as the route for the roll-to-roll (R2R) production of large-area organic electronic circuits. While considerable progress has been made by combining silicon lithographic approaches with solution processing, it is not obvious that these will be compatible with a low-cost, high-speed R2R process. Most efforts at achieving this ambition are directed at conventional solution printing approaches such as inkjet and gravure. This is surprising considering that vacuum-evaporation of organic semiconductors (OSCs) is already used commercially in the production of organic light emitting diode displays. Beginning from a discussion of the materials and geometrical parameters determining transistor performance and drawing on results from numerous publications, this review makes a case for vacuum-evaporation as an enabler of R2R organic circuit production. The potential of the vacuum route is benchmarked against solution approaches and found to be highly competitive. For example, evaporated small molecules tend to have higher mobility than printed OSCs. High resolution metal patterning on plastic films is already a low-cost commercial process for high-volume packaging applications. Similarly, solvent-free flash-evaporation and polymerization of thin films on plastic substrates is also a high-volume commercial process and has been shown capable of producing robust gate dielectrics. Reports of basic logic circuit elements produced in a vacuum R2R environment are reviewed and shown to be superior to all-solution printing approaches. Finally, the main issues that need to be resolved in order to fully develop the vacuum route to R2R circuit production are highlighted. (paper)

Large magnetocaloric effect of GdNiAl2 compound

International Nuclear Information System (INIS)

Dembele, S.N.; Ma, Z.; Shang, Y.F.; Fu, H.; Balfour, E.A.; Hadimani, R.L.; Jiles, D.C.; Teng, B.H.; Luo, Y.

2015-01-01

This paper presents the structure, magnetic properties, and magnetocaloric effect of the polycrystalline compound GdNiAl 2 . Powder X-ray diffraction (XRD) measurement and Rietveld refinement revealed that GdNiAl 2 alloy is CuMgAl 2 -type phase structure with about 1 wt% GdNi 2 Al 3 secondary phase. Magnetic measurements suggest that the compound is ferromagnetic and undergoes a second-order phase transition near 28 K. The maximum value of magnetic entropy change reaches 16.0 J/kg K for an applied magnetic field change of 0–50 kOe and the relative cooling power was 6.4×10 2 J/kg. It is a promising candidate as a magnetocaloric material working near liquid hydrogen temperature (~20 K) exhibiting large relative cooling power. - Highlights: • Preferred orientation with axis of [010] was found in the GdNiAl 2 compound. • The ΔS Mmax and the RCP are 16.0 J/kg K and 640 J/kg, respectively, for ΔH=50 kOe. • Relative low rare earth content in GdNiAl 2 comparing with other candidates

Large N non-perturbative effects in N=4 superconformal Chern-Simons theories

International Nuclear Information System (INIS)

Hatsuda, Yasuyuki; Honda, Masazumi; Okuyama, Kazumi

2015-07-01

We investigate the large N instanton effects of partition functions in a class of N = 4 circular quiver Chern-Simons theories on a three-sphere. Our analysis is based on the supersymmetry localization and the Fermi-gas formalism. The resulting matrix model can be regarded as a two-parameter deformation of the ABJM matrix model, and has richer non-perturbative structures. Based on a systematic semi-classical analysis, we find analytic expressions of membrane instanton corrections. We also exactly compute the partition function for various cases and find some exact forms of worldsheet instanton corrections, which appear as quantum mechanical non-perturbative corrections in the Fermi-gas system.

Safety Effect Analysis of the Large-Scale Design Changes in a Nuclear Power Plant

Energy Technology Data Exchange (ETDEWEB)

Lee, Eun-Chan; Lee, Hyun-Gyo [Korea Hydro and Nuclear Power Co. Ltd., Daejeon (Korea, Republic of)

2015-05-15

These activities were predominantly focused on replacing obsolete systems with new systems, and these efforts were not only to prolong the plant life, but also to guarantee the safe operation of the units. This review demonstrates the safety effect evaluation using the probabilistic safety assessment (PSA) of the design changes, system improvements, and Fukushima accident action items for Kori unit 1 (K1). For the large scale of system design changes for K1, the safety effects from the PSA perspective were reviewed using the risk quantification results before and after the system improvements. This evaluation considered the seven significant design changes including the replacement of the control building air conditioning system and the performance improvement of the containment sump using a new filtering system as well as above five system design changes. The analysis results demonstrated that the CDF was reduced by 12% overall from 1.62E-5/y to 1.43E-5/y. The CDF reduction was larger in the transient group than in the loss of coolant accident (LOCA) group. In conclusion, the analysis using the K1 PSA model supports that the plant safety has been appropriately maintained after the large-scale design changes in consideration of the changed operation factors and failure modes due to the system improvements.

Taking the pulse of a continent: Expanding site-based research infrastructure for regional- to continental-scale ecology

Science.gov (United States)

Many of the most dramatic and surprising effects of global change on ecological systems will occur across large spatial extents, from regions to continents. Multiple ecosystem types will be impacted across a range of interacting spatial and temporal scales. The ability of ecologists to understand an...

Large Mines and the Community : Socioeconomic and ...

International Development Research Centre (IDRC) Digital Library (Canada)

1 janv. 2001 ... Large Mines and the Community : Socioeconomic and Environmental Effects in Latin America, Canada, and Spain. Couverture du livre Large Mines and the Community : Socioeconomic and Environmental Effects in Latin America. Directeur(s):. Gary McMahon et Felix Remy. Maison(s) d'édition: Banque ...

Charge-collection efficiency of GaAs field effect transistors fabricated with a low temperature grown buffer layer: dependence on charge deposition profile

International Nuclear Information System (INIS)

McMorrow, D.; Knudson, A.R.; Melinger, J.S.; Buchner, S.

1999-01-01

The results presented here reveal a surprising dependence of the charge-collection efficiency of LT GaAs FETs (field effect transistors) on the depth profile of the deposited charge. Investigation of the temporal dependence of the signal amplitude, carrier density contours, and potential contours reveals different mechanisms for charge collection arising from carriers deposited above and below the LT GaAs buffer layer, respectively. In particular, carriers deposited below the LT GaAs buffer layer dissipate slowly and give rise to a persistent charge collection that is associated with a bipolar-like gain process. These results may be of significance in understanding the occurrence of single-event upsets from protons, neutrons, and large-angle, glancing heavy-ion strikes. (authors)

Natural selection shaped the rise and fall of passenger pigeon genomic diversity.

Science.gov (United States)

Murray, Gemma G R; Soares, André E R; Novak, Ben J; Schaefer, Nathan K; Cahill, James A; Baker, Allan J; Demboski, John R; Doll, Andrew; Da Fonseca, Rute R; Fulton, Tara L; Gilbert, M Thomas P; Heintzman, Peter D; Letts, Brandon; McIntosh, George; O'Connell, Brendan L; Peck, Mark; Pipes, Marie-Lorraine; Rice, Edward S; Santos, Kathryn M; Sohrweide, A Gregory; Vohr, Samuel H; Corbett-Detig, Russell B; Green, Richard E; Shapiro, Beth

2017-11-17

The extinct passenger pigeon was once the most abundant bird in North America, and possibly the world. Although theory predicts that large populations will be more genetically diverse, passenger pigeon genetic diversity was surprisingly low. To investigate this disconnect, we analyzed 41 mitochondrial and 4 nuclear genomes from passenger pigeons and 2 genomes from band-tailed pigeons, which are passenger pigeons' closest living relatives. Passenger pigeons' large population size appears to have allowed for faster adaptive evolution and removal of harmful mutations, driving a huge loss in their neutral genetic diversity. These results demonstrate the effect that selection can have on a vertebrate genome and contradict results that suggested that population instability contributed to this species's surprisingly rapid extinction. Copyright © 2017, American Association for the Advancement of Science.

Large CO2 and CH4 release from a flooded formerly drained fen

Science.gov (United States)

Sachs, T.; Franz, D.; Koebsch, F.; Larmanou, E.; Augustin, J.

2016-12-01

Drained peatlands are usually strong carbon dioxide (CO2) sources. In Germany, up to 4.5 % of the national CO2 emissions are estimated to be released from agriculturally used peatlands and for some peatland-rich northern states, such as Mecklenburg-Western Pomerania, this share increases to about 20%. Reducing this CO2 source and restoring the peatlands' natural carbon sink is one objective of large-scale nature protection and restoration measures, in which 37.000 ha of drained and degraded peatlands in Mecklenburg-Western Pomerania are slated for rewetting. It is well known, however, that in the initial phase of rewetting, a reduction of the CO2 source strength is usually accompanied by an increase in CH4 emissions. Thus, whether and when the intended effects of rewetting with regard to greenhouse gases are achieved, depends on the balance of CO2 and CH4 fluxes and on the duration of the initial CH4 emission phase. In 2013, a new Fluxnet site went online at a flooded formerly drained river valley fen site near Zarnekow, NE Germany (DE-Zrk), to investigate the combined CO2 and CH4 dynamics at such a heavily degraded and rewetted peatland. The site is dominated by open water with submerged and floating vegetation and surrounding Typha latifolia.Nine year after rewetting, we found large CH4 emissions of 53 g CH4 m-2 a-1 from the open water area, which are 4-fold higher than from the surrounding vegetation zone (13 g CH4 m-2 a-1). Surprisingly, both the open water and the vegetated area were net CO2 sources of 158 and 750 g CO2 m-2 a-1, respectively. Unusual meteorological conditions with a warm and dry summer and a mild winter might have facilitated high respiration rates, particularly from temporally non-inundated organic mud in the vegetation zone.

Threats and surprises behind IPv6 extension headers

NARCIS (Netherlands)

Hendriks, Luuk; Velan, Petr; de Oliveira Schmidt, Ricardo; De Boer, Pieter Tjerk; Pras, Aiko

2017-01-01

The concept of Extension Headers, newly introduced with IPv6, is elusive and enables new types of threats in the Internet. Simply dropping all traffic containing any Extension Header - a current practice by operators-seemingly is an effective solution, but at the cost of possibly dropping legitimate

HotpathVM: An Effective JIT for Resource-constrained Devices

DEFF Research Database (Denmark)

Gal, Andreas; Franz, Michael; Probst, Christian

2006-01-01

We present a just-in-time compiler for a Java VM that is small enough to fit on resource-constrained devices, yet surprisingly effective. Our system dynamically identifies traces of frequently executed bytecode instructions (which may span several basic blocks across several methods) and compiles...

Large persistent photochromic effect due to DX centers in AlSb doped with selenium

International Nuclear Information System (INIS)

Becla, P.; Witt, A.G.

1995-04-01

A large photochromic effect has been observed in bulk AlSb crystals doped with Se. Illumination with light of energy higher than 1 eV leads to an increase of the absorption coefficient in the spectral range 0.1 to 1.6 eV. The enhanced absorption is persistent at temperatures below about K. The effect is a manifestation of a DX-like bistability of Se donors. The illumination transfers the from the DX center to a metastable hydrogenic level. The increased absorption with peaks around 0.2 eV and 0.5 is due to photoionization from the donor level to X l and X 3 minima of the conduction band

The effects of black-tailed prairie dogs on plant communities within a complex urban landscape: an ecological surprise?

Science.gov (United States)

Beals, Stower C; Hartley, Laurel M; Prevéy, Janet S; Seastedt, Timothy R

2014-05-01

Historically, prairie dogs (Cynomys spp.) have been considered essential keystone species of western United States grassland ecosystems because they provide unique services and increase vegetation community richness, evenness, and diversity. However, the effects of black-tailed prairie dogs (Cynomys ludovicianus) on lands adjacent to or surrounded by urban areas may not result in the same ecosystem benefits historically associated with their presence. An urban landscape presents prairie dogs with movement challenges unparalleled in natural landscapes, as well as suites of nonnative plant species that are more common in disturbed areas. This study examined a complex ecosystem where vegetation communities are being influenced by directional environmental change, and quantified the synergistic effects resulting from the protective management of a native keystone species. The data set for this analysis was comprised of 71 paired (occupied by prairie dogs vs. unoccupied) vegetation surveys and 156 additional unpaired surveys collected from around the city of Boulder, Colorado, USA for 14 yr. Linear mixed models were used to compare data from transects occupied and unoccupied by prairie dogs, as well as to evaluate the effect of prairie dog occupation duration. In the absence of prairie dogs, vegetation in this region exhibited declines in native grasses, no changes in introduced grasses, and increases in native and nonnative forbs and bare soil over the study interval. In the presence of prairie dogs, these observed directional changes were nearly all amplified at rates four to 10 times greater than when prairie dogs were absent. Areas in Boulder occupied by prairie dogs also had significantly lower richness, evenness, and diversity of plant species, compared to unoccupied areas. Analysis of plant functional groups revealed the significant reduction of perennial native grasses, as well as a significantly higher cover of introduced forbs in occupied areas. Prairie dogs

Simultaneous effect of modified gravity and primordial non-Gaussianity in large scale structure observations

International Nuclear Information System (INIS)

Mirzatuny, Nareg; Khosravi, Shahram; Baghram, Shant; Moshafi, Hossein

2014-01-01

In this work we study the simultaneous effect of primordial non-Gaussianity and the modification of the gravity in f(R) framework on large scale structure observations. We show that non-Gaussianity and modified gravity introduce a scale dependent bias and growth rate functions. The deviation from ΛCDM in the case of primordial non-Gaussian models is in large scales, while the growth rate deviates from ΛCDM in small scales for modified gravity theories. We show that the redshift space distortion can be used to distinguish positive and negative f NL in standard background, while in f(R) theories they are not easily distinguishable. The galaxy power spectrum is generally enhanced in presence of non-Gaussianity and modified gravity. We also obtain the scale dependence of this enhancement. Finally we define galaxy growth rate and galaxy growth rate bias as new observational parameters to constrain cosmology

Evidence from Impact Crater Observations for Few Large Impacts on the Moon 0.8-1.7 Ga

Science.gov (United States)

Kirchoff, M. R.; Bottke, W. F.; Marchi, S.; Chapman, C. R.; Enke, B.

2012-12-01

Our Moon is a keystone for understanding the inner solar system impact flux through time, because it is the only body for which we have crater size-frequency distributions (SFDs) through most of bombardment history and radiometric ages of probable associated terrains. Even so, the bombardment rate over the last 3.5 Gyr is poorly understood. According to the spatial density of sub-km craters on dated lunar terrains, the lunar impact flux has been roughly constant over this interval [e.g., 1 and references therein]. If so, one may expect that craters with diameter (D) > 50 km should also be equally dispersed in time over the last 3.5 Gyr. Surprisingly, our new work indicates this may not be so. We have compiled SFDs for small, superposed craters with D~0.6-15 km on the original floors of several previously designated Copernican and Eratothenian craters (USGS Geological Atlas of the Moon and [2]) with D > 50 km using JMARS. Using these data we compute the large craters' formation model ages with the Model Production Function chronology developed by Marchi et al. [3]. Many of these craters, especially on the farside (e.g., Sharnov, Birkeland), can now be suitably examined only because of the excellent LROC imaging (we use the Wide Angle Camera mosaic). As a test of our methods, we calculated the model age of the 55 km crater Aristillus (34°N, 1°E), a relatively young crater thought to have showered the Apollo 15 landing site with ejecta. Interestingly, our model age of 2.2 ± 0.6 Ga is surprisingly consistent with a 2.1 Ga-old impact-derived clast (radiometric age) returned by the Apollo 15 astronauts [4]. We find that nearly all of our computed ages for the large craters are older than indicated by previous work, with very few having ages younger than 3 Ga. Reasons for these discrepancies include (i) use of poor resolution Lunar Orbiter images (especially away from the near side) and (ii) application of the unreliable "DL" method, which involves simplified

Colleges Leverage Large Endowments to Benefit Some Donors and Employees

Science.gov (United States)

Hermes, J. J.

2008-01-01

College endowments have beaten the market so consistently in recent years, it is not surprising that individuals would like to take advantage of that institutional wisdom to invest their own money. Increasingly, many are. A small but growing number of universities are trying to entice donors to invest their trusts alongside college endowments,…

Effective models of new physics at the Large Hadron Collider

International Nuclear Information System (INIS)

Llodra-Perez, J.

2011-07-01

With the start of the Large Hadron Collider runs, in 2010, particle physicists will be soon able to have a better understanding of the electroweak symmetry breaking. They might also answer to many experimental and theoretical open questions raised by the Standard Model. Surfing on this really favorable situation, we will first present in this thesis a highly model-independent parametrization in order to characterize the new physics effects on mechanisms of production and decay of the Higgs boson. This original tool will be easily and directly usable in data analysis of CMS and ATLAS, the huge generalist experiments of LHC. It will help indeed to exclude or validate significantly some new theories beyond the Standard Model. In another approach, based on model-building, we considered a scenario of new physics, where the Standard Model fields can propagate in a flat six-dimensional space. The new spatial extra-dimensions will be compactified on a Real Projective Plane. This orbifold is the unique six-dimensional geometry which possesses chiral fermions and a natural Dark Matter candidate. The scalar photon, which is the lightest particle of the first Kaluza-Klein tier, is stabilized by a symmetry relic of the six dimension Lorentz invariance. Using the current constraints from cosmological observations and our first analytical calculation, we derived a characteristic mass range around few hundred GeV for the Kaluza-Klein scalar photon. Therefore the new states of our Universal Extra-Dimension model are light enough to be produced through clear signatures at the Large Hadron Collider. So we used a more sophisticated analysis of particle mass spectrum and couplings, including radiative corrections at one-loop, in order to establish our first predictions and constraints on the expected LHC phenomenology. (author)

Bifurcation of equilibria between with and without a large island in the large helical device

Energy Technology Data Exchange (ETDEWEB)

Ohyabu, N; Narushima, Y; Nagayama, Y; Narihara, K; Morisaki, T; Komori, A [National Institute for Fusion Science, Toki, Gifu, 509-5292 (Japan)

2005-09-01

A rapid bifurcation of the equilibria with and without a large island (n/m = 1/1) has been observed in the medium to high beta large helical device discharges. A large island imposed by an external resonant field is suddenly suppressed nearly perfectly by the plasma effects when the beta at the {iota}/2{pi} = 1 surface exceeds a critical value. The critical beta value is nearly proportional to the externally imposed resonant field normalized by the main field strength.

Comparative Performance in Single-Port Versus Multiport Minimally Invasive Surgery, and Small Versus Large Operative Working Spaces: A Preclinical Randomized Crossover Trial.

Science.gov (United States)

Marcus, Hani J; Seneci, Carlo A; Hughes-Hallett, Archie; Cundy, Thomas P; Nandi, Dipankar; Yang, Guang-Zhong; Darzi, Ara

2016-04-01

Surgical approaches such as transanal endoscopic microsurgery, which utilize small operative working spaces, and are necessarily single-port, are particularly demanding with standard instruments and have not been widely adopted. The aim of this study was to compare simultaneously surgical performance in single-port versus multiport approaches, and small versus large working spaces. Ten novice, 4 intermediate, and 1 expert surgeons were recruited from a university hospital. A preclinical randomized crossover study design was implemented, comparing performance under the following conditions: (1) multiport approach and large working space, (2) multiport approach and intermediate working space, (3) single-port approach and large working space, (4) single-port approach and intermediate working space, and (5) single-port approach and small working space. In each case, participants performed a peg transfer and pattern cutting tasks, and each task repetition was scored. Intermediate and expert surgeons performed significantly better than novices in all conditions (P Performance in single-port surgery was significantly worse than multiport surgery (P performance in the intermediate versus large working space. In single-port surgery, there was a converse trend; performances in the intermediate and small working spaces were significantly better than in the large working space. Single-port approaches were significantly more technically challenging than multiport approaches, possibly reflecting loss of instrument triangulation. Surprisingly, in single-port approaches, in which triangulation was no longer a factor, performance in large working spaces was worse than in intermediate and small working spaces. © The Author(s) 2015.

Effect of air gap on uniformity of large-scale surface-wave plasma

International Nuclear Information System (INIS)

Lan Chaohui; Hu Xiwei; Jiang Zhonghe; Liu Minghai

2009-01-01

The effect of air gap on the uniformity of large-scale surface-wave plasma (SWP) in a rectangular chamber device is studied by using three-dimensional numerical analyses based on the finite difference time-domain (FDTD) approximation to Maxwell's equations and plasma fluid model. The spatial distributions of surface wave excited by slot-antenna array and the plasma parameters such as electron density and temperature are presented. For different air gap thicknesses, the results show that the existence of air gap would severely weaken the excitations of the surface wave and thereby the SWP. Thus the air gap should be eliminated completely in the design of the SWP source, which is opposite to the former research results. (authors)

Understanding long-term impacts of R&D funding: The EU framework programme

NARCIS (Netherlands)

Arnold, Erik

2012-01-01

Despite a large and growing effort in the evaluation of public R&D funding programmes, we know surprisingly little about their long-term effects. This is a pity, because the conventional justifications for state intervention in research depend upon phenomena such as the production and use of public

Thermal motion in proteins: Large effects on the time-averaged interaction energies

International Nuclear Information System (INIS)

Goethe, Martin; Rubi, J. Miguel; Fita, Ignacio

2016-01-01

As a consequence of thermal motion, inter-atomic distances in proteins fluctuate strongly around their average values, and hence, also interaction energies (i.e. the pair-potentials evaluated at the fluctuating distances) are not constant in time but exhibit pronounced fluctuations. These fluctuations cause that time-averaged interaction energies do generally not coincide with the energy values obtained by evaluating the pair-potentials at the average distances. More precisely, time-averaged interaction energies behave typically smoother in terms of the average distance than the corresponding pair-potentials. This averaging effect is referred to as the thermal smoothing effect. Here, we estimate the strength of the thermal smoothing effect on the Lennard-Jones pair-potential for globular proteins at ambient conditions using x-ray diffraction and simulation data of a representative set of proteins. For specific atom species, we find a significant smoothing effect where the time-averaged interaction energy of a single atom pair can differ by various tens of cal/mol from the Lennard-Jones potential at the average distance. Importantly, we observe a dependency of the effect on the local environment of the involved atoms. The effect is typically weaker for bulky backbone atoms in beta sheets than for side-chain atoms belonging to other secondary structure on the surface of the protein. The results of this work have important practical implications for protein software relying on free energy expressions. We show that the accuracy of free energy expressions can largely be increased by introducing environment specific Lennard-Jones parameters accounting for the fact that the typical thermal motion of protein atoms depends strongly on their local environment.

Thermal motion in proteins: Large effects on the time-averaged interaction energies

Energy Technology Data Exchange (ETDEWEB)

Goethe, Martin, E-mail: martingoethe@ub.edu; Rubi, J. Miguel [Departament de Física Fonamental, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona (Spain); Fita, Ignacio [Institut de Biologia Molecular de Barcelona, Baldiri Reixac 10, 08028 Barcelona (Spain)

2016-03-15

As a consequence of thermal motion, inter-atomic distances in proteins fluctuate strongly around their average values, and hence, also interaction energies (i.e. the pair-potentials evaluated at the fluctuating distances) are not constant in time but exhibit pronounced fluctuations. These fluctuations cause that time-averaged interaction energies do generally not coincide with the energy values obtained by evaluating the pair-potentials at the average distances. More precisely, time-averaged interaction energies behave typically smoother in terms of the average distance than the corresponding pair-potentials. This averaging effect is referred to as the thermal smoothing effect. Here, we estimate the strength of the thermal smoothing effect on the Lennard-Jones pair-potential for globular proteins at ambient conditions using x-ray diffraction and simulation data of a representative set of proteins. For specific atom species, we find a significant smoothing effect where the time-averaged interaction energy of a single atom pair can differ by various tens of cal/mol from the Lennard-Jones potential at the average distance. Importantly, we observe a dependency of the effect on the local environment of the involved atoms. The effect is typically weaker for bulky backbone atoms in beta sheets than for side-chain atoms belonging to other secondary structure on the surface of the protein. The results of this work have important practical implications for protein software relying on free energy expressions. We show that the accuracy of free energy expressions can largely be increased by introducing environment specific Lennard-Jones parameters accounting for the fact that the typical thermal motion of protein atoms depends strongly on their local environment.

Interactive effects of large- and small-scale sources of feral honey-bees for sunflower in the Argentine Pampas.

Directory of Open Access Journals (Sweden)

Agustín Sáez

Full Text Available Pollinators for animal pollinated crops can be provided by natural and semi-natural habitats, ranging from large vegetation remnants to small areas of non-crop land in an otherwise highly modified landscape. It is unknown, however, how different small- and large-scale habitat patches interact as pollinator sources. In the intensively managed Argentine Pampas, we studied the additive and interactive effects of large expanses (up to 2200 ha of natural habitat, represented by untilled isolated "sierras", and narrow (3-7 m wide strips of semi-natural habitat, represented by field margins, as pollinator sources for sunflower (Helianthus annus. We estimated visitation rates by feral honey-bees, Apis mellifera, and native flower visitors (as a group at 1, 5, 25, 50 and 100 m from a field margin in 17 sunflower fields 0-10 km distant from the nearest sierra. Honey-bees dominated the pollinator assemblage accounting for >90% of all visits to sunflower inflorescences. Honey-bee visitation was strongly affected by proximity to the sierras decreasing by about 70% in the most isolated fields. There was also a decline in honey-bee visitation with distance from the field margin, which was apparent with increasing field isolation, but undetected in fields nearby large expanses of natural habitat. The probability of observing a native visitor decreased with isolation from the sierras, but in other respects visitation by flower visitors other than honey-bees was mostly unaffected by the habitat factors assessed in this study. Overall, we found strong hierarchical and interactive effects between the study large and small-scale pollinator sources. These results emphasize the importance of preserving natural habitats and managing actively field verges in the absence of large remnants of natural habitat for improving pollinator services.

Interactive effects of large- and small-scale sources of feral honey-bees for sunflower in the Argentine Pampas.

Science.gov (United States)

Sáez, Agustín; Sabatino, Malena; Aizen, Marcelo A

2012-01-01

Pollinators for animal pollinated crops can be provided by natural and semi-natural habitats, ranging from large vegetation remnants to small areas of non-crop land in an otherwise highly modified landscape. It is unknown, however, how different small- and large-scale habitat patches interact as pollinator sources. In the intensively managed Argentine Pampas, we studied the additive and interactive effects of large expanses (up to 2200 ha) of natural habitat, represented by untilled isolated "sierras", and narrow (3-7 m wide) strips of semi-natural habitat, represented by field margins, as pollinator sources for sunflower (Helianthus annus). We estimated visitation rates by feral honey-bees, Apis mellifera, and native flower visitors (as a group) at 1, 5, 25, 50 and 100 m from a field margin in 17 sunflower fields 0-10 km distant from the nearest sierra. Honey-bees dominated the pollinator assemblage accounting for >90% of all visits to sunflower inflorescences. Honey-bee visitation was strongly affected by proximity to the sierras decreasing by about 70% in the most isolated fields. There was also a decline in honey-bee visitation with distance from the field margin, which was apparent with increasing field isolation, but undetected in fields nearby large expanses of natural habitat. The probability of observing a native visitor decreased with isolation from the sierras, but in other respects visitation by flower visitors other than honey-bees was mostly unaffected by the habitat factors assessed in this study. Overall, we found strong hierarchical and interactive effects between the study large and small-scale pollinator sources. These results emphasize the importance of preserving natural habitats and managing actively field verges in the absence of large remnants of natural habitat for improving pollinator services.

Experimental studies of narrow band effects in the actinides

Energy Technology Data Exchange (ETDEWEB)

Brodsky, M.B.

1976-01-01

In many actinide metallic systems the f-electrons exhibit band behavior. This is a consequence of direct f-f wave function overlap or hybridization of f-electrons with s-, p-, and d-electrons. The f-bands can be responsible for large electronic densities of states at the Fermi level which may lead to band magnetism of various types. Although the concept of valence instabilities must be approached cautiously especially in the light actinides, it would not be surprising to observe them in the future, especially in Am compounds.

Experimental studies of narrow band effects in the actinides

International Nuclear Information System (INIS)

Brodsky, M.B.

1976-01-01

In many actinide metallic systems the f-electrons exhibit band behavior. This is a consequence of direct f-f wave function overlap or hybridization of f-electrons with s-, p-, and d-electrons. The f-bands can be responsible for large electronic densities of states at the Fermi level which may lead to band magnetism of various types. Although the concept of valence instabilities must be approached cautiously especially in the light actinides, it would not be surprising to observe them in the future, especially in Am compounds

Modeling the effect of transient populations on epidemics in Washington DC.

Science.gov (United States)

Parikh, Nidhi; Youssef, Mina; Swarup, Samarth; Eubank, Stephen

2013-11-06

Large numbers of transients visit big cities, where they come into contact with many people at crowded areas. However, epidemiological studies have not paid much attention to the role of this subpopulation in disease spread. We evaluate the effect of transients on epidemics by extending a synthetic population model for the Washington DC metro area to include leisure and business travelers. A synthetic population is obtained by combining multiple data sources to build a detailed minute-by-minute simulation of population interaction resulting in a contact network. We simulate an influenza-like illness over the contact network to evaluate the effects of transients on the number of infected residents. We find that there are significantly more infections when transients are considered. Since much population mixing happens at major tourism locations, we evaluate two targeted interventions: closing museums and promoting healthy behavior (such as the use of hand sanitizers, covering coughs, etc.) at museums. Surprisingly, closing museums has no beneficial effect. However, promoting healthy behavior at the museums can both reduce and delay the epidemic peak. We analytically derive the reproductive number and perform stability analysis using an ODE-based model.

Modeling the effect of transient populations on epidemics in Washington DC

Science.gov (United States)

Parikh, Nidhi; Youssef, Mina; Swarup, Samarth; Eubank, Stephen

2013-11-01

Large numbers of transients visit big cities, where they come into contact with many people at crowded areas. However, epidemiological studies have not paid much attention to the role of this subpopulation in disease spread. We evaluate the effect of transients on epidemics by extending a synthetic population model for the Washington DC metro area to include leisure and business travelers. A synthetic population is obtained by combining multiple data sources to build a detailed minute-by-minute simulation of population interaction resulting in a contact network. We simulate an influenza-like illness over the contact network to evaluate the effects of transients on the number of infected residents. We find that there are significantly more infections when transients are considered. Since much population mixing happens at major tourism locations, we evaluate two targeted interventions: closing museums and promoting healthy behavior (such as the use of hand sanitizers, covering coughs, etc.) at museums. Surprisingly, closing museums has no beneficial effect. However, promoting healthy behavior at the museums can both reduce and delay the epidemic peak. We analytically derive the reproductive number and perform stability analysis using an ODE-based model.

Effect of large dose gamma-ray irradiation on polyimide

International Nuclear Information System (INIS)

Morita, Yohsuke; Watanabe, Kiyoshi; Yagyu, Hideki.

1988-01-01

In the radiation environment of atomic energy, space and so on, with the heightening of the performance of equipment, the organic materials having the radiation resistance up to several hundreds MGy have been demanded. Polyimide is one of a small number of the polymers which are considered to be applicable to such environment. However, actually the characteristics as the insulator for such large dose radiation environment have not been sufficiently verified. In this study, the gamma-ray of as large dose as 100 MGy was irradiated on the polyimides having different chemical structure in the air and in nitrogen, and the change of their mechanical and electrical characteristics was elucidated, at the same time, the structural change was examined. The four kinds of polyimides used for the experiment were three kinds of thermosetting type and thermoplastic polyether imide. Co-60 gamma-ray was irradiated at the dose rate of 17 kGy/h at room temperature. The tensile properties, volume resistivity, dielectric tangent, gel fraction, glass transition temperature and IR spectra were examined. In the air, the characteristics lowered by large dose irradiation due to the severance of main chains. In nitrogen, the deterioration was extremely slight, and cross-linking occurred. (K.I.)

THERAPEUTIC EFFECT OF SOLASODINE RHAMNOSYL GLYCOSIDES FOR LARGE SKIN CANCERS: TWO CLINICAL CASES

Directory of Open Access Journals (Sweden)

Bill E. Cham

2012-01-01

Full Text Available Solasodine rhamnosyl glycosides (BEC are a new class of antineoplastics, the efficiency of which administered via intravenous, intraperitoneal, and intratumoral routes is higher than that of many other antitumor agents. Early investigations have established the efficiency of topical BEC applications as a treatment option for non-melanoma skin cancers. There have recently been two clinical cases that count in favor of the fact that the cream formulation Curaderm containing BEC has a very high efficacy in the treatment of large non-melanoma skin cancers that are incurable by other existing methods. Also, Curaderm treatment shows a splendid cosmetic effect. 

Automated Atmospheric Composition Dataset Level Metadata Discovery. Difficulties and Surprises

Science.gov (United States)

Strub, R. F.; Falke, S. R.; Kempler, S.; Fialkowski, E.; Goussev, O.; Lynnes, C.

2015-12-01

The Atmospheric Composition Portal (ACP) is an aggregator and curator of information related to remotely sensed atmospheric composition data and analysis. It uses existing tools and technologies and, where needed, enhances those capabilities to provide interoperable access, tools, and contextual guidance for scientists and value-adding organizations using remotely sensed atmospheric composition data. The initial focus is on Essential Climate Variables identified by the Global Climate Observing System - CH4, CO, CO2, NO2, O3, SO2 and aerosols. This poster addresses our efforts in building the ACP Data Table, an interface to help discover and understand remotely sensed data that are related to atmospheric composition science and applications. We harvested GCMD, CWIC, GEOSS metadata catalogs using machine to machine technologies - OpenSearch, Web Services. We also manually investigated the plethora of CEOS data providers portals and other catalogs where that data might be aggregated. This poster is our experience of the excellence, variety, and challenges we encountered.Conclusions:1.The significant benefits that the major catalogs provide are their machine to machine tools like OpenSearch and Web Services rather than any GUI usability improvements due to the large amount of data in their catalog.2.There is a trend at the large catalogs towards simulating small data provider portals through advanced services. 3.Populating metadata catalogs using ISO19115 is too complex for users to do in a consistent way, difficult to parse visually or with XML libraries, and too complex for Java XML binders like CASTOR.4.The ability to search for Ids first and then for data (GCMD and ECHO) is better for machine to machine operations rather than the timeouts experienced when returning the entire metadata entry at once. 5.Metadata harvest and export activities between the major catalogs has led to a significant amount of duplication. (This is currently being addressed) 6.Most (if not

Individual and collective stock dynamics: intra-day seasonalities

International Nuclear Information System (INIS)

Allez, Romain; Bouchaud, Jean-Philippe

2011-01-01

We establish several new stylized facts concerning the intra-day seasonalities of stock dynamics. Beyond the well-known U-shaped pattern of the volatility, we find that the average correlation between stocks increases throughout the day, leading to a smaller relative dispersion between stocks. Somewhat paradoxically, the kurtosis (a measure of volatility surprises) reaches a minimum at the open of the market, when the volatility is at its peak. We confirm that the dispersion kurtosis is a markedly decreasing function of the index return. This means that during large market swings, the idiosyncratic component of the stock dynamics becomes sub-dominant. In a nutshell, the early hours of trading are dominated by idiosyncratic or sector-specific effects with little surprises, whereas the influence of the market factor increases throughout the day, and surprises become more frequent.

Multilevel landscape utilization of the Siberian flying squirrel: Scale effects on species habitat use.

Science.gov (United States)

Remm, Jaanus; Hanski, Ilpo K; Tuominen, Sakari; Selonen, Vesa

2017-10-01

Animals use and select habitat at multiple hierarchical levels and at different spatial scales within each level. Still, there is little knowledge on the scale effects at different spatial levels of species occupancy patterns. The objective of this study was to examine nonlinear effects and optimal-scale landscape characteristics that affect occupancy of the Siberian flying squirrel, Pteromys volans , in South- and Mid-Finland. We used presence-absence data ( n  = 10,032 plots of 9 ha) and novel approach to separate the effects on site-, landscape-, and regional-level occupancy patterns. Our main results were: landscape variables predicted the placement of population patches at least twice as well as they predicted the occupancy of particular sites; the clear optimal value of preferred habitat cover for species landscape-level abundance is a surprisingly low value (10% within a 4 km buffer); landscape metrics exert different effects on species occupancy and abundance in high versus low population density regions of our study area. We conclude that knowledge of regional variation in landscape utilization will be essential for successful conservation of the species. The results also support the view that large-scale landscape variables have high predictive power in explaining species abundance. Our study demonstrates the complex response of species occurrence at different levels of population configuration on landscape structure. The study also highlights the need for data in large spatial scale to increase the precision of biodiversity mapping and prediction of future trends.

The Effects of Deoxynivalenol and Zearalenone on the Pig Large Intestine. A Light and Electron Microscopy Study

Directory of Open Access Journals (Sweden)

Barbara Przybylska-Gornowicz

2018-04-01

Full Text Available The contamination of feed with mycotoxins results in reduced growth, feed refusal, immunosuppression, and health problems. Deoxynivalenol (DON and zearalenone (ZEN are among the most important mycotoxins. The aim of the study was to examine the effects of low doses of these mycotoxins on the histological structure and ultrastructure of the large intestine in the pig. The study was performed on 36 immature gilts of mixed breed (White Polish Big × Polish White Earhanging, which were divided into four groups administrated per os with ZEN at 40 µg/kg BW, DON at 12 µg/kg BW, a mixture of ZEN (40 µg/kg BW and DON (12 µg/kg BW or a placebo. The pigs were killed by intravenous overdose of pentobarbital after one, three, and six weeks of treatment. The cecum, ascending and descending colon samples were prepared for light and electron microscopy. Administration of toxins did not influence the architecture of the mucosa and submucosa in the large intestine. ZEN and ZEN + DON significantly decreased the number of goblet cells in the cecum and descending colon. The mycotoxins changed the number of lymphocytes and plasma cells in the large intestine, which usually increased in number. However, this effect differed between the intestine segments and toxins. Mycotoxins induced some changes in the ultrastructure of the mucosal epithelium. They did not affect the expression of proliferative cell nuclear antigen and the intestinal barrier permeability. The obtained results indicate that mycotoxins especially ZEN may influence the defense mechanisms of the large intestine.

Need for new effect based on large-scale development of renewable energy in Northern Europe

International Nuclear Information System (INIS)

Doorman, Gerard; Grinden, Bjoern; Fuchs, Ida

2007-02-01

Changes in the effect balance in Northern Europe between 2005 and 2020 are evaluated. Norway, Denmark, Sweden, Finland, Germany and the Netherlands are the countries included in the analysis. Scenarios from studies conducted in the different countries have been used as starting points. Some scenarios give explicit figures for effect installations, but most only provide estimations on the energy balance. In these cased it has been necessary to estimate how much effect there is behind the energy figures. Utilization time analyses have been employed for this, primarily. Moreover, emphasis has been put on the modelling of wind power's effect contribution, and a method based on the reliability of the production system has been employed, giving an effect varying between 18 and 24 percent in the different scenarios. Also, the need for regulation reserves has been considered. Four scenarios have been outlined along the axes growth in consumption (high/low) and share of renewable energy (high/low). All scenarios show considerable reductions in the effect balance from 2005 to 2020, varying from about 15.000 MW to 22.000 MW. The largest reduction is in Germany, but Sweden too has large reductions in each of the scenarios. The most important underlying causes are the reduction or dismantling of nuclear power and the development of large amounts of wind power, and in Germany also the development of solar power. In Norway too, the effect balance is weakened with the existing scenarios. Here, wind power and small-scale hydroelectric power contribute with relatively much energy, but little effect. The biggest insecurity in the analysis is how much thermal capacity there will be in operation in 2020, especially in Germany. In a system with much wind power, the utilization time for some of the thermal production may be short, and it may be phased out if no support schemes for effect reserves are set up. Thermal capacity as short term backup for wind power will have to compete with

Primordial Magnetic Field Effects on the CMB and Large-Scale Structure

Directory of Open Access Journals (Sweden)

Dai G. Yamazaki

2010-01-01

Full Text Available Magnetic fields are everywhere in nature, and they play an important role in every astronomical environment which involves the formation of plasma and currents. It is natural therefore to suppose that magnetic fields could be present in the turbulent high-temperature environment of the big bang. Such a primordial magnetic field (PMF would be expected to manifest itself in the cosmic microwave background (CMB temperature and polarization anisotropies, and also in the formation of large-scale structure. In this paper, we summarize the theoretical framework which we have developed to calculate the PMF power spectrum to high precision. Using this formulation, we summarize calculations of the effects of a PMF which take accurate quantitative account of the time evolution of the cutoff scale. We review the constructed numerical program, which is without approximation, and an improvement over the approach used in a number of previous works for studying the effect of the PMF on the cosmological perturbations. We demonstrate how the PMF is an important cosmological physical process on small scales. We also summarize the current constraints on the PMF amplitude Bλ and the power spectral index nB which have been deduced from the available CMB observational data by using our computational framework.

Entanglement transitions induced by large deviations

Science.gov (United States)

Bhosale, Udaysinh T.

2017-12-01

The probability of large deviations of the smallest Schmidt eigenvalue for random pure states of bipartite systems, denoted as A and B , is computed analytically using a Coulomb gas method. It is shown that this probability, for large N , goes as exp[-β N2Φ (ζ ) ] , where the parameter β is the Dyson index of the ensemble, ζ is the large deviation parameter, while the rate function Φ (ζ ) is calculated exactly. Corresponding equilibrium Coulomb charge density is derived for its large deviations. Effects of the large deviations of the extreme (largest and smallest) Schmidt eigenvalues on the bipartite entanglement are studied using the von Neumann entropy. Effect of these deviations is also studied on the entanglement between subsystems 1 and 2, obtained by further partitioning the subsystem A , using the properties of the density matrix's partial transpose ρ12Γ. The density of states of ρ12Γ is found to be close to the Wigner's semicircle law with these large deviations. The entanglement properties are captured very well by a simple random matrix model for the partial transpose. The model predicts the entanglement transition across a critical large deviation parameter ζ . Log negativity is used to quantify the entanglement between subsystems 1 and 2. Analytical formulas for it are derived using the simple model. Numerical simulations are in excellent agreement with the analytical results.

A Large Scale Test of the Effect of Social Class on Prosocial Behavior.

Science.gov (United States)

Korndörfer, Martin; Egloff, Boris; Schmukle, Stefan C

2015-01-01

Does being from a higher social class lead a person to engage in more or less prosocial behavior? Psychological research has recently provided support for a negative effect of social class on prosocial behavior. However, research outside the field of psychology has mainly found evidence for positive or u-shaped relations. In the present research, we therefore thoroughly examined the effect of social class on prosocial behavior. Moreover, we analyzed whether this effect was moderated by the kind of observed prosocial behavior, the observed country, and the measure of social class. Across eight studies with large and representative international samples, we predominantly found positive effects of social class on prosociality: Higher class individuals were more likely to make a charitable donation and contribute a higher percentage of their family income to charity (32,090 ≥ N ≥ 3,957; Studies 1-3), were more likely to volunteer (37,136 ≥N ≥ 3,964; Studies 4-6), were more helpful (N = 3,902; Study 7), and were more trusting and trustworthy in an economic game when interacting with a stranger (N = 1,421; Study 8) than lower social class individuals. Although the effects of social class varied somewhat across the kinds of prosocial behavior, countries, and measures of social class, under no condition did we find the negative effect that would have been expected on the basis of previous results reported in the psychological literature. Possible explanations for this divergence and implications are discussed.

The large-Nc renormalization group

International Nuclear Information System (INIS)

Dorey, N.

1995-01-01

In this talk, we review how effective theories of mesons and baryons become exactly soluble in the large-N c , limit. We start with a generic hadron Lagrangian constrained only by certain well-known large-N c , selection rules. The bare vertices of the theory are dressed by an infinite class of UV divergent Feynman diagrams at leading order in 1/N c . We show how all these leading-order dia, grams can be summed exactly using semiclassical techniques. The saddle-point field configuration is reminiscent of the chiral bag: hedgehog pions outside a sphere of radius Λ -1 (Λ being the UV cutoff of the effective theory) matched onto nucleon degrees of freedom for r ≤ Λ -1 . The effect of this pion cloud is to renormalize the bare nucleon mass, nucleon-Δ hyperfine mass splitting, and Yukawa couplings of the theory. The corresponding large-N c , renormalization group equations for these parameters are presented, and solved explicitly in a series of simple models. We explain under what conditions the Skyrmion emerges as a UV fixed-point of the RG flow as Λ → ∞

Effects of Vocal Emotion on Memory in Younger and Older Adults.

Science.gov (United States)

Pichora-Fuller, M Kathleen; Dupuis, Kate; Smith, Sherri L

2016-01-01

Emotional content can enhance memory for visual stimuli, and older adults often perform better if stimuli portray positive emotion. Vocal emotion can enhance the accuracy of word repetition in noise when vocal prosody portrays attention-capturing emotions such as fear and pleasant surprise. In the present study, the authors examined the effect of vocal emotion on the accuracy of repetition and recall in younger and older adults when words are presented in quiet or in a background of competing babble. Younger and older adults (Mage = 20 and 72 years, respectively) participated. Lists of 100 items (carrier phrase plus target word) were presented in recall sets of increasing size. Word repetition accuracy was tested after each item and recall after each trial in each set size. In Experiment 1, one list spoken in a neutral voice and another with emotion (fear, pleasant surprise, sad, neutral) were presented in quiet (n = 24 per group). In Experiment 2, participants (n = 12 per group) were presented the emotional list in noise. In quiet, word repetition accuracy was near perfect for both groups and did not vary systematically with set size for the list spoken in a neutral voice; however, for the emotional list, repetition was less accurate, especially for the older group. Recall in quiet was higher for younger than older adults; collapsed over groups, recall was higher for the neutral than for the emotional list and it decreased with increasing set size. In noise, emotion-specific effects emerged; word repetition for the older group and word recall for both groups (more for younger than older) was best for fear or pleasant surprise and worst for sad. In quiet, vocal emotion reduced the word repetition accuracy of the older group and recall accuracy for both groups. In noise, there were emotion-specific effects on the repetition accuracy of older adults and the recall accuracy of both groups. Both groups, but especially the younger group, performed better for items

A comparison of three approaches to compute the effective Reynolds number of the implicit large-eddy simulations

Energy Technology Data Exchange (ETDEWEB)

Zhou, Ye [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thornber, Ben [The Univ. of Sydney, Sydney, NSW (Australia)

2016-04-12

Here, the implicit large-eddy simulation (ILES) has been utilized as an effective approach for calculating many complex flows at high Reynolds number flows. Richtmyer–Meshkov instability (RMI) induced flow can be viewed as a homogeneous decaying turbulence (HDT) after the passage of the shock. In this article, a critical evaluation of three methods for estimating the effective Reynolds number and the effective kinematic viscosity is undertaken utilizing high-resolution ILES data. Effective Reynolds numbers based on the vorticity and dissipation rate, or the integral and inner-viscous length scales, are found to be the most self-consistent when compared to the expected phenomenology and wind tunnel experiments.

The effects of Strongylus vulgaris parasitism on eosinophil distribution and accumulation in equine large intestinal mucosa.

Science.gov (United States)

Rötting, A K; Freeman, D E; Constable, P D; Moore, R M; Eurell, J C; Wallig, M A; Hubert, J D

2008-06-01

Eosinophilic granulocytes have been associated with parasite or immune-mediated diseases, but their functions in other disease processes remain unclear. Cause and timing of eosinophil migration into the equine gastrointestinal mucosa are also unknown. To determine the effects of intestinal parasitism on eosinophils in equine large intestinal mucosa. Large intestinal mucosal samples were collected from horses and ponies (n = 16) from the general veterinary hospital population, ponies (n = 3) raised in a parasite-free environment, ponies experimentally infected with 500 infective Strongylus vulgaris larvae and treated with a proprietary anthelmintic drug (n = 14), and a similar group of ponies (n = 7) that received no anthelmintic treatment. Total eosinophil counts and eosinophil distribution in the mucosa were determined by histological examination. A mixed model analysis was performed and appropriate Bonferroni adjusted P values used for each family of comparisons. Pvulgaris and those raised in a parasite-free environment. Experimental infection with S. vulgaris, with or without subsequent anthelmintic treatment, did not change eosinophil counts, and counts were similar to those for horses from the general population. Migration of eosinophils to the equine large intestinal mucosa appears to be independent of exposure to parasites. Large intestinal mucosal eosinophils may have more functions in addition to their role in defence against parasites.

THE EFFECT OF LARGE-SCALE MAGNETIC TURBULENCE ON THE ACCELERATION OF ELECTRONS BY PERPENDICULAR COLLISIONLESS SHOCKS

International Nuclear Information System (INIS)

Guo Fan; Giacalone, Joe

2010-01-01

We study the physics of electron acceleration at collisionless shocks that move through a plasma containing large-scale magnetic fluctuations. We numerically integrate the trajectories of a large number of electrons, which are treated as test particles moving in the time-dependent electric and magnetic fields determined from two-dimensional hybrid simulations (kinetic ions and fluid electron). The large-scale magnetic fluctuations effect the electrons in a number of ways and lead to efficient and rapid energization at the shock front. Since the electrons mainly follow along magnetic lines of force, the large-scale braiding of field lines in space allows the fast-moving electrons to cross the shock front several times, leading to efficient acceleration. Ripples in the shock front occurring at various scales will also contribute to the acceleration by mirroring the electrons. Our calculation shows that this process favors electron acceleration at perpendicular shocks. The current study is also helpful in understanding the injection problem for electron acceleration by collisionless shocks. It is also shown that the spatial distribution of energetic electrons is similar to in situ observations. The process may be important to our understanding of energetic electrons in planetary bow shocks and interplanetary shocks, and explaining herringbone structures seen in some type II solar radio bursts.

Antibacterial activity of large-area monolayer graphene film manipulated by charge transfer.

Science.gov (United States)

Li, Jinhua; Wang, Gang; Zhu, Hongqin; Zhang, Miao; Zheng, Xiaohu; Di, Zengfeng; Liu, Xuanyong; Wang, Xi

2014-03-12

Graphene has attracted increasing attention for potential applications in biotechnology due to its excellent electronic property and biocompatibility. Here we use both Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) to investigate the antibacterial actions of large-area monolayer graphene film on conductor Cu, semiconductor Ge and insulator SiO2. The results show that the graphene films on Cu and Ge can surprisingly inhibit the growth of both bacteria, especially the former. However, the proliferation of both bacteria cannot be significantly restricted by the graphene film on SiO2. The morphology of S. aureus and E. coli on graphene films further confirms that the direct contact of both bacteria with graphene on Cu and Ge can cause membrane damage and destroy membrane integrity, while no evident membrane destruction is induced by graphene on SiO2. From the viewpoint of charge transfer, a plausible mechanism is proposed here to explain this phenomenon. This study may provide new insights for the better understanding of antibacterial actions of graphene film and for the better designing of graphene-based antibiotics or other biomedical applications.

The effects of spin in gases

International Nuclear Information System (INIS)

Laloee, F.; Freed, J.H.

1988-01-01

Low-density gases, in which atoms are separated by large distances, have long provided an enjoyable playground for physicists. One might suppose the pleasure of the playground would by now have been exhausted by the very simplicity of low-density gases. Recent work by a number of investigators including the author shows that this is not the case low-density gases continue to serve up a rich variety of phenomena as well as counterintuitive surprises. In particular, the macroscopic properties of a gas composed of individual hydrogen or helium atoms can under special circumstances by changed dramatically by quantum-mechanical effects. According to quantum theory, the nucleus of an atom behaves in a way similar to a rotating top, which has angular momentum about its axis of rotation; that is, the nucleus has spin, known more precisely as spin angular momentum. If the atoms of a gas are spin-polarized, so that their nuclei all have their spins pointing in the same direction, the viscosity of the gas can be changed enormously and so can its ability to conduct heat. Quantum-mechanical correlations among the nuclei called spin waves, which up to now had been observed only in certain liquids and solids such as magnets, can also arise. The changes are large enough for one to say the quantum-mechanical effects have caused the gas to take on entirely new properties. In a certain sense it is amazing to think that polarizing the nuclear spins can have any effect on the macroscopic properties of the gas, since the nuclear spins are son weakly coupled to the outside world. Yet the observations are in full agreement with with theory. Moreover, because spin-polarized gases are still fairly simple systems, they can be understood in terms fundamental principles, something that is still not possible to do in the case of liquids and solids

The effects of a stress-management training program in individuals at risk in the community at large

NARCIS (Netherlands)

Timmerman, IGH; Emmelkamp, PMG; Sanderman, R

In this study we examine the effects of a stress-management training program on individuals without serious (mental) health complaints but with an increased chance of developing them as a consequence of stress. Potential subjects were randomly selected from the community at large and, then screened

Large-scale pool fires

Directory of Open Access Journals (Sweden)

Steinhaus Thomas

2007-01-01

Full Text Available A review of research into the burning behavior of large pool fires and fuel spill fires is presented. The features which distinguish such fires from smaller pool fires are mainly associated with the fire dynamics at low source Froude numbers and the radiative interaction with the fire source. In hydrocarbon fires, higher soot levels at increased diameters result in radiation blockage effects around the perimeter of large fire plumes; this yields lower emissive powers and a drastic reduction in the radiative loss fraction; whilst there are simplifying factors with these phenomena, arising from the fact that soot yield can saturate, there are other complications deriving from the intermittency of the behavior, with luminous regions of efficient combustion appearing randomly in the outer surface of the fire according the turbulent fluctuations in the fire plume. Knowledge of the fluid flow instabilities, which lead to the formation of large eddies, is also key to understanding the behavior of large-scale fires. Here modeling tools can be effectively exploited in order to investigate the fluid flow phenomena, including RANS- and LES-based computational fluid dynamics codes. The latter are well-suited to representation of the turbulent motions, but a number of challenges remain with their practical application. Massively-parallel computational resources are likely to be necessary in order to be able to adequately address the complex coupled phenomena to the level of detail that is necessary.

A multiwavelength survey of H I-excess galaxies with surprisingly inefficient star formation

Science.gov (United States)

Geréb, K.; Janowiecki, S.; Catinella, B.; Cortese, L.; Kilborn, V.

2018-05-01

We present the results of a multiwavelength survey of H I-excess galaxies, an intriguing population with large H I reservoirs associated with little current star formation. These galaxies have stellar masses M⋆ > 1010 M⊙, and were identified as outliers in the gas fraction versus NUV-r colour and stellar mass surface density scaling relations based on the GALEX Arecibo SDSS Survey (GASS). We obtained H I interferometry with the Giant Metrewave Radio Telescope, Keck optical long-slit spectroscopy, and deep optical imaging (where available) for four galaxies. Our analysis reveals multiple possible reasons for the H I excess in these systems. One galaxy, AGC 10111, shows an H I disc that is counter-rotating with respect to the stellar bulge, a clear indication of external origin of the gas. Another galaxy appears to host a Malin 1-type disc, where a large specific angular momentum has to be invoked to explain the extreme M_{H I}/M⋆ ratio of 166 per cent. The other two galaxies have early-type morphology with very high gas fractions. The lack of merger signatures (unsettled gas, stellar shells, and streams) in these systems suggests that these gas-rich discs have been built several Gyr ago, but it remains unclear how the gas reservoirs were assembled. Numerical simulations of large cosmological volumes are needed to gain insight into the formation of these rare and interesting systems.

Orbital melanocytoma: When a tumor becomes a relieving surprise

Directory of Open Access Journals (Sweden)

Haytham E. Nasr

2018-06-01

Full Text Available Purpose: Melanocytomas are rare pigmented tumors that arise form melanocytes and have been reported in the central nervous system. Orbital melanocytomas “also known as blue nevus” are rarely reported. The occurrence of choroidal melanoma and orbital melanocytomas has never been described. Observations: This is a case of orbital melanocytoma in a 34 year old female who presented with left proptosis and ecchymosis. She has the right eye enucleated to treat a large choroidal melanoma, 6 years earlier. Orbital metastasis was suspected. After orbital imaging and systemic evaluation, incisional biopsy was planned yet the mass could be totally excised and it turned out to be melanocytoma. The condition was not associated with nevus of Ota and the patient is not known to have any predisposing condition for melanocytic lesions. Conclusion and importance: Melanocytoma and malignant melanoma share the same cell of origin. The benign course, the well differentiated cells, absence of anaplasia and the positive reaction to Human Melanoma Black-45 (HMB-45 and S-100 proteins established the diagnosis of the former. Such diagnosis was a relief for this one eyed patient.(HMB-45:human melanoma black-45. Keywords: Orbit, Melanocytoma, Choroidal melanoma, HMB-45, S-100

Effects of baryons on the statistical properties of large scale structure of the Universe

International Nuclear Information System (INIS)

Guillet, T.

2010-01-01

Observations of weak gravitational lensing will provide strong constraints on the cosmic expansion history and the growth rate of large scale structure, yielding clues to the properties and nature of dark energy. Their interpretation is impacted by baryonic physics, which are expected to modify the total matter distribution at small scales. My work has focused on determining and modeling the impact of baryons on the statistics of the large scale matter distribution in the Universe. Using numerical simulations, I have extracted the effect of baryons on the power spectrum, variance and skewness of the total density field as predicted by these simulations. I have shown that a model based on the halo model construction, featuring a concentrated central component to account for cool condensed baryons, is able to reproduce accurately, and down to very small scales, the measured amplifications of both the variance and skewness of the density field. Because of well-known issues with baryons in current cosmological simulations, I have extended the central component model to rely on as many observation-based ingredients as possible. As an application, I have studied the effect of baryons on the predictions of the upcoming Euclid weak lensing survey. During the course of this work, I have also worked at developing and extending the RAMSES code, in particular by developing a parallel self-gravity solver, which offers significant performance gains, in particular for the simulation of some astrophysical setups such as isolated galaxy or cluster simulations. (author) [fr

Control rod shadowing and anti-shadowing effects in a large gas-cooled fast reactor

International Nuclear Information System (INIS)

Girardin, G.; Chawla, R.; Rimpault, G.; Coddington, P.

2007-01-01

An investigation of control rod shadowing and anti-shadowing (interaction) effects has been carried out in the context of a design study of the control rod pattern for the large 2400 MWth Generation IV Gas-cooled Fast Reactor (GFR). For the calculations, the deterministic code system ERANOS-2.0 has been used, in association with a full core model including a European Fast Reactor (EFR)-type pattern for the control rods. More specifically, the core contains a total of 33 control (CSD) and safety (DSD) rods implemented in three banks: -1) a first bank of 6 CSD rods, placed at 64 cm from core centre in the inner fuel zone (Pu content 16.3 % vol.), -2) a safety bank consisting of 9 DSD rods, at an average distance of 118 cm, and -3) a third bank with 18 CSD rods, placed at 171 cm, i.e. at the interface between the inner and outer (Pu content 19.2 % vol.) core regions. Each control rod has been modelled as a homogeneous material containing 90%-enriched B 4 C, steel and helium. Considerable shadowing effects have been observed between the first bank and the safety bank, as also between individual rods within the first bank. Large anti-shadowing effects take place in an even greater number of the studied rod configurations. The largest interaction is between the two CSD banks, the anti-shadowing value being 46% in this case, implying that the total rod worth is increased by a factor of almost 2 when compared to the sum of the individual bank values. Additional investigations have been performed, in particular the computation of the first order eigenvalue and the eigenvalue separation. The main finding is that the interactions are lower when one of the control rod banks is located at a radial position corresponding to half the core radius. (authors)

Hydrologic effects of large southwestern USA wildfires significantly increase regional water supply: fact or fiction?

Science.gov (United States)

Wine, M. L.; Cadol, D.

2016-08-01

In recent years climate change and historic fire suppression have increased the frequency of large wildfires in the southwestern USA, motivating study of the hydrological consequences of these wildfires at point and watershed scales, typically over short periods of time. These studies have revealed that reduced soil infiltration capacity and reduced transpiration due to tree canopy combustion increase streamflow at the watershed scale. However, the degree to which these local increases in runoff propagate to larger scales—relevant to urban and agricultural water supply—remains largely unknown, particularly in semi-arid mountainous watersheds co-dominated by winter snowmelt and the North American monsoon. To address this question, we selected three New Mexico watersheds—the Jemez (1223 km2), Mogollon (191 km2), and Gila (4807 km2)—that together have been affected by over 100 wildfires since 1982. We then applied climate-driven linear models to test for effects of fire on streamflow metrics after controlling for climatic variability. Here we show that, after controlling for climatic and snowpack variability, significantly more streamflow discharged from the Gila watershed for three to five years following wildfires, consistent with increased regional water yield due to enhanced infiltration-excess overland flow and groundwater recharge at the large watershed scale. In contrast, we observed no such increase in discharge from the Jemez watershed following wildfires. Fire regimes represent a key difference between the contrasting responses of the Jemez and Gila watersheds with the latter experiencing more frequent wildfires, many caused by lightning strikes. While hydrologic dynamics at the scale of large watersheds were previously thought to be climatically dominated, these results suggest that if one fifth or more of a large watershed has been burned in the previous three to five years, significant increases in water yield can be expected.

Effects of finite-β and radial electric fields on neoclassical transport in the Large Helical Device

International Nuclear Information System (INIS)

Kanno, R.; Nakajima, N.; Sugama, H.; Okamoto, M.; Ogawa, Y.

1997-01-01

Effects of finite-β and radial electric fields on the neoclassical transport in the Large Helical Device are investigated with the DKES (Drift Kinetic Equation Solver) code. In the finite-β configuration, even orbits of deeply trapped particles deviate significantly from magnetic flux surfaces. Thus, neoclassical ripple transport coefficients in the finite-β configuration are several times larger than those in the vacuum configuration under the same condition of temperatures and radial electric fields. When the plasma temperature is several keV, a bifurcation of the electric fields appears under the ambipolarity condition, and sufficient large radial electric fields can be generated. As a result, the ExB drift rectifies orbits of particles and improves significantly the transport coefficients in the finite-β configuration. (author)

Developing Large Web Applications

CERN Document Server

Loudon, Kyle

2010-01-01

How do you create a mission-critical site that provides exceptional performance while remaining flexible, adaptable, and reliable 24/7? Written by the manager of a UI group at Yahoo!, Developing Large Web Applications offers practical steps for building rock-solid applications that remain effective even as you add features, functions, and users. You'll learn how to develop large web applications with the extreme precision required for other types of software. Avoid common coding and maintenance headaches as small websites add more pages, more code, and more programmersGet comprehensive soluti

Variability in mutational fitness effects prevents full lethal transitions in large quasispecies populations

Science.gov (United States)

Sardanyés, Josep; Simó, Carles; Martínez, Regina; Solé, Ricard V.; Elena, Santiago F.

2014-04-01

The distribution of mutational fitness effects (DMFE) is crucial to the evolutionary fate of quasispecies. In this article we analyze the effect of the DMFE on the dynamics of a large quasispecies by means of a phenotypic version of the classic Eigen's model that incorporates beneficial, neutral, deleterious, and lethal mutations. By parameterizing the model with available experimental data on the DMFE of Vesicular stomatitis virus (VSV) and Tobacco etch virus (TEV), we found that increasing mutation does not totally push the entire viral quasispecies towards deleterious or lethal regions of the phenotypic sequence space. The probability of finding regions in the parameter space of the general model that results in a quasispecies only composed by lethal phenotypes is extremely small at equilibrium and in transient times. The implications of our findings can be extended to other scenarios, such as lethal mutagenesis or genomically unstable cancer, where increased mutagenesis has been suggested as a potential therapy.

Effects of air pollution on infant and children respiratory mortality in four large Latin-American cities

International Nuclear Information System (INIS)

Gouveia, Nelson; Junger, Washington Leite; Romieu, Isabelle; Cifuentes, Luis A.; Ponce de Leon, Antonio; Vera, Jeanette; Strappa, Valentina; Hurtado-Díaz, Magali; Miranda-Soberanis, Victor; Rojas-Bracho, Leonora; Carbajal-Arroyo, Luz; Tzintzun-Cervantes, Guadalupe

2018-01-01

Objectives: Air pollution is an important public health concern especially for children who are particularly susceptible. Latin America has a large children population, is highly urbanized and levels of pollution are substantially high, making the potential health impact of air pollution quite large. We evaluated the effect of air pollution on children respiratory mortality in four large urban centers: Mexico City, Santiago, Chile, and Sao Paulo and Rio de Janeiro in Brazil. Methods: Generalized Additive Models in Poisson regression was used to fit daily time-series of mortality due to respiratory diseases in infants and children, and levels of PM 10 and O 3 . Single lag and constrained polynomial distributed lag models were explored. Analyses were carried out per cause for each age group and each city. Fixed- and random-effects meta-analysis was conducted in order to combine the city-specific results in a single summary estimate. Results: These cities host nearly 43 million people and pollution levels were above the WHO guidelines. For PM 10 the percentage increase in risk of death due to respiratory diseases in infants in a fixed effect model was 0.47% (0.09–0.85). For respiratory deaths in children 1–5 years old, the increase in risk was 0.58% (0.08–1.08) while a higher effect was observed for lower respiratory infections (LRI) in children 1–14 years old [1.38% (0.91–1.85)]. For O 3 , the only summarized estimate statistically significant was for LRI in infants. Analysis by season showed effects of O 3 in the warm season for respiratory diseases in infants, while negative effects were observed for respiratory and LRI deaths in children. Discussion: We provided comparable mortality impact estimates of air pollutants across these cities and age groups. This information is important because many public policies aimed at preventing the adverse effects of pollution on health consider children as the population group that deserves the highest protection

Reflections on Teaching a Large Class.

Science.gov (United States)

Miner, Rick

1992-01-01

Uses an analysis of small- and large-class differences as a framework for planning for and teaching a large class. Analyzes the process of developing and offering an organizational behavior class to 141 college students. Suggests ways to improve teaching effectiveness by minimizing psychological and physical distances, redistributing resources,…

A Large Scale Test of the Effect of Social Class on Prosocial Behavior

Science.gov (United States)

Korndörfer, Martin; Egloff, Boris; Schmukle, Stefan C.

2015-01-01

Does being from a higher social class lead a person to engage in more or less prosocial behavior? Psychological research has recently provided support for a negative effect of social class on prosocial behavior. However, research outside the field of psychology has mainly found evidence for positive or u-shaped relations. In the present research, we therefore thoroughly examined the effect of social class on prosocial behavior. Moreover, we analyzed whether this effect was moderated by the kind of observed prosocial behavior, the observed country, and the measure of social class. Across eight studies with large and representative international samples, we predominantly found positive effects of social class on prosociality: Higher class individuals were more likely to make a charitable donation and contribute a higher percentage of their family income to charity (32,090 ≥ N ≥ 3,957; Studies 1–3), were more likely to volunteer (37,136 ≥N ≥ 3,964; Studies 4–6), were more helpful (N = 3,902; Study 7), and were more trusting and trustworthy in an economic game when interacting with a stranger (N = 1,421; Study 8) than lower social class individuals. Although the effects of social class varied somewhat across the kinds of prosocial behavior, countries, and measures of social class, under no condition did we find the negative effect that would have been expected on the basis of previous results reported in the psychological literature. Possible explanations for this divergence and implications are discussed. PMID:26193099

Managing conflict between large carnivores and livestock.

Science.gov (United States)

van Eeden, Lily M; Crowther, Mathew S; Dickman, Chris R; Macdonald, David W; Ripple, William J; Ritchie, Euan G; Newsome, Thomas M

2018-02-01

Large carnivores are persecuted globally because they threaten human industries and livelihoods. How this conflict is managed has consequences for the conservation of large carnivores and biodiversity more broadly. Mitigating human-predator conflict should be evidence-based and accommodate people's values while protecting carnivores. Despite much research into human and large-carnivore coexistence strategies, there have been few attempts to document the success of conflict-mitigation strategies on a global scale. We conducted a meta-analysis of global research on conflict mitigation related to large carnivores and humans. We focused on conflicts that arise from the threat large carnivores pose to livestock. We first used structured and unstructured searching to identify replicated studies that used before-after or control-impact design to measure change in livestock loss as a result of implementing a management intervention. We then extracted relevant data from these studies to calculate an overall effect size for each intervention type. Research effort and focus varied among continents and aligned with the histories and cultures that shaped livestock production and attitudes toward carnivores. Livestock guardian animals most effectively reduced livestock losses. Lethal control was the second most effective control, although its success varied the most, and guardian animals and lethal control did not differ significantly. Financial incentives have promoted tolerance of large carnivores in some settings and reduced retaliatory killings. We suggest coexistence strategies be location-specific, incorporate cultural values and environmental conditions, and be designed such that return on financial investment can be evaluated. Improved monitoring of mitigation measures is urgently required to promote effective evidence-based policy. © 2017 Society for Conservation Biology.

Gauging policy-driven large-scale vegetation restoration programmes under a changing environment: Their effectiveness and socio-economic relationships.

Science.gov (United States)

Li, Ting; Lü, Yihe; Fu, Bojie; Comber, Alexis J; Harris, Paul; Wu, Lianhai

2017-12-31

Large-scale ecological restoration has been widely accepted globally as an effective strategy for combating environmental crises and to facilitate sustainability. Assessing the effectiveness of ecological restoration is vital for researchers, practitioners, and policy-makers. However, few practical tools are available to perform such tasks, particularly for large-scale restoration programmes in complex socio-ecological systems. By taking a "before and after" design, this paper formulates a composite index (E j ) based on comparing the trends of vegetation cover and vegetation productivity to assess ecological restoration effectiveness. The index reveals the dynamic and spatially heterogenic process of vegetation restoration across different time periods, which can be informative for ecological restoration management at regional scales. Effectiveness together with its relationship to socio-economic factors is explored via structural equation modeling for three time periods. The results indicate that the temporal scale is a crucial factor in representing restoration effectiveness, and that the effects of socio-economic factors can also vary with time providing insight for improving restoration effectiveness. A dual-track strategy, which promotes the development of tertiary industry in absorbing the rural labor force together with improvements in agricultural practices, is proposed as a promising strategy for enhancing restoration effectiveness. In this process, timely and long-term ecological restoration monitoring is advocated, so that the success and sustainability of such programmes is ensured, together with more informative decision making where socio-ecological interactions at differing temporal scales are key concerns. Copyright © 2017 Elsevier B.V. All rights reserved.

The mere exposure effect is sensitive to color information: evidence for color effects in a perceptual implicit memory test.

Science.gov (United States)

Hupbach, Almut; Melzer, André; Hardt, Oliver

2006-01-01

Priming effects in perceptual tests of implicit memory are assumed to be perceptually specific. Surprisingly, changing object colors from study to test did not diminish priming in most previous studies. However, these studies used implicit tests that are based on object identification, which mainly depends on the analysis of the object shape and therefore operates color-independently. The present study shows that color effects can be found in perceptual implicit tests when the test task requires the processing of color information. In Experiment 1, reliable color priming was found in a mere exposure design (preference test). In Experiment 2, the preference test was contrasted with a conceptually driven color-choice test. Altering the shape of object from study to test resulted in significant priming in the color-choice test but eliminated priming in the preference test. Preference judgments thus largely depend on perceptual processes. In Experiment 3, the preference and the color-choice test were studied under explicit test instructions. Differences in reaction times between the implicit and the explicit test suggest that the implicit test results were not an artifact of explicit retrieval attempts. In contrast with previous assumptions, it is therefore concluded that color is part of the representation that mediates perceptual priming.

Order of magnetic transition and large magnetocaloric effect in Er3Co

International Nuclear Information System (INIS)

Jun, Shen; Jian-Feng, Wu; Jin-Liang, Zhao; Feng-Xia, Hu; Ji-Rong, Sun; Bao-Gen, Shen

2010-01-01

We have studied the magnetic and magnetocaloric properties of the Er 3 Co compound, which undergoes ferromagnetic ordering below the Curie temperature T C = 13 K. It is found by fitting the isothermal magnetization curves that the Landau model is appropriate to describe the Er 3 Co compound. The giant magnetocaloric effect (MCE) without hysteresis loss around T C is found to result from the second-order ferromagnetic-to-paramagnetic transition. The maximal value of magnetic entropy change is 24.5 J/kg·K with a refrigerant capacity (RC) value of 476 J/kg for a field change of 0–5 T. Large reversible MEC and RC indicate the potentiality of Er 3 Co as a candidate magnetic refrigerant at low temperatures. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Computational materials science: Nanoscale plasticity

DEFF Research Database (Denmark)

Jacobsen, Karsten Wedel; Schiøtz, Jakob

2002-01-01

How does plastic deformation of polycrystalline materials with grain sizes less than 100 nm look at the atomic scale? A large-scale molecular dynamics simulation of nanocrystalline alluminium reveals some surprising behaviour.......How does plastic deformation of polycrystalline materials with grain sizes less than 100 nm look at the atomic scale? A large-scale molecular dynamics simulation of nanocrystalline alluminium reveals some surprising behaviour....

Possible future effects of large-scale algae cultivation for biofuels on coastal eutrophication in Europe.

Science.gov (United States)

Blaas, Harry; Kroeze, Carolien

2014-10-15

Biodiesel is increasingly considered as an alternative for fossil diesel. Biodiesel can be produced from rapeseed, palm, sunflower, soybean and algae. In this study, the consequences of large-scale production of biodiesel from micro-algae for eutrophication in four large European seas are analysed. To this end, scenarios for the year 2050 are analysed, assuming that in the 27 countries of the European Union fossil diesel will be replaced by biodiesel from algae. Estimates are made for the required fertiliser inputs to algae parks, and how this may increase concentrations of nitrogen and phosphorus in coastal waters, potentially leading to eutrophication. The Global NEWS (Nutrient Export from WaterSheds) model has been used to estimate the transport of nitrogen and phosphorus to the European coastal waters. The results indicate that the amount of nitrogen and phosphorus in the coastal waters may increase considerably in the future as a result of large-scale production of algae for the production of biodiesel, even in scenarios assuming effective waste water treatment and recycling of waste water in algae production. To ensure sustainable production of biodiesel from micro-algae, it is important to develop cultivation systems with low nutrient losses to the environment. Copyright © 2014 Elsevier B.V. All rights reserved.

Large magnetocaloric effect of GdNiAl{sub 2} compound

Energy Technology Data Exchange (ETDEWEB)

Dembele, S.N.; Ma, Z.; Shang, Y.F. [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China); Fu, H., E-mail: fuhao@uestc.edu.cn [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China); Balfour, E.A. [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China); Hadimani, R.L.; Jiles, D.C. [Department of Electrical and Computer Engineering, Iowa State University, Ames, IA 50011 (United States); Ames Laboratory, US Department of Energy, Ames, IA 50011 (United States); Teng, B.H.; Luo, Y. [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China)

2015-10-01

This paper presents the structure, magnetic properties, and magnetocaloric effect of the polycrystalline compound GdNiAl{sub 2}. Powder X-ray diffraction (XRD) measurement and Rietveld refinement revealed that GdNiAl{sub 2} alloy is CuMgAl{sub 2}-type phase structure with about 1 wt% GdNi{sub 2}Al{sub 3} secondary phase. Magnetic measurements suggest that the compound is ferromagnetic and undergoes a second-order phase transition near 28 K. The maximum value of magnetic entropy change reaches 16.0 J/kg K for an applied magnetic field change of 0–50 kOe and the relative cooling power was 6.4×10{sup 2} J/kg. It is a promising candidate as a magnetocaloric material working near liquid hydrogen temperature (~20 K) exhibiting large relative cooling power. - Highlights: • Preferred orientation with axis of [010] was found in the GdNiAl{sub 2} compound. • The ΔS{sub Mmax} and the RCP are 16.0 J/kg K and 640 J/kg, respectively, for ΔH=50 kOe. • Relative low rare earth content in GdNiAl{sub 2} comparing with other candidates.

Numerical study by large-eddy simulation on effects and mechanism of air-cooling enhancing technologies

International Nuclear Information System (INIS)

Tamura, Akinori; Kawamura, Toshinori; Ishida, Naoyuki; Kitou, Kazuaki

2014-01-01

Learning from the lessons of the Fukushima Daiichi nuclear incident in which a long-term station black-out occurred, we have been developing an air-cooling system for boiling water reactors that can operate without electricity for a virtually indefinite time. Improvement in the heat transfer performance of air-cooling is key to the development of the air-cooling system. We developed air-cooling enhancing technologies for the air-cooling system by using heat transfer fins, turbulence-enhancing ribs and a micro-fabrication surface. In our previous study, the performance of these air-cooling enhancing technologies was evaluated by heat transfer tests using a single pipe of the air-cooling heat exchanger. To achieve further improvement of the heat transfer performance, it is important to understand the mechanism of the air-cooling enhancing technologies. In this study, we used the numerical analysis which is based on the filtered incompressible Navier-Stokes equation and the filtered energy equation with the large-eddy simulation in order to investigate the effects and the mechanism of the developed air-cooling enhancing technologies. We found that the analysis results agreed well with the experimental results and the empirical formula results. The heat transfer enhancement mechanism of the heat transfer fin is due to an increase in the heat transfer area. Due to a decrease in the flow velocity at the base of the fins, the increase in the Nusselt number was approximately 15% smaller than the estimated value from the area increase. In the heat transfer enhancement by the turbulence-enhancing ribs, the unsteady behavior of the large-scale vortex generated by the flow separation plays an important role. The enhancement ratio of the Nusselt number by the micro-fabrication surface can be explained by the apparent thermal conductivity. The Nusselt number was increased 4-8% by the micro-fabrication surface. The effect of the micro-fabrication surface is increased by applying

The effects of large scale processing on caesium leaching from cemented simulant sodium nitrate waste

International Nuclear Information System (INIS)

Lee, D.J.; Brown, D.J.

1982-01-01

The effects of large scale processing on the properties of cemented simulant sodium nitrate waste have been investigated. Leach tests have been performed on full-size drums, cores and laboratory samples of cement formulations containing Ordinary Portland Cement (OPC), Sulphate Resisting Portland Cement (SRPC) and a blended cement (90% ground granulated blast furnace slag/10% OPC). In addition, development of the cement hydration exotherms with time and the temperature distribution in 220 dm 3 samples have been followed. (author)

Measuring happiness in large population

Science.gov (United States)

Wenas, Annabelle; Sjahputri, Smita; Takwin, Bagus; Primaldhi, Alfindra; Muhamad, Roby

2016-01-01

The ability to know emotional states for large number of people is important, for example, to ensure the effectiveness of public policies. In this study, we propose a measure of happiness that can be used in large scale population that is based on the analysis of Indonesian language lexicons. Here, we incorporate human assessment of Indonesian words, then quantify happiness on large-scale of texts gathered from twitter conversations. We used two psychological constructs to measure happiness: valence and arousal. We found that Indonesian words have tendency towards positive emotions. We also identified several happiness patterns during days of the week, hours of the day, and selected conversation topics.

Large scale vibration tests on pile-group effects using blast-induced ground motion

International Nuclear Information System (INIS)

Katsuichirou Hijikata; Hideo Tanaka; Takayuki Hashimoto; Kazushige Fujiwara; Yuji Miyamoto; Osamu Kontani

2005-01-01

Extensive vibration tests have been performed on pile-supported structures at a large-scale mining site. Ground motions induced by large-scale blasting operations were used as excitation forces for vibration tests. The main objective of this research is to investigate the dynamic behavior of pile-supported structures, in particular, pile-group effects. Two test structures were constructed in an excavated 4 m deep pit. Their test-structures were exactly the same. One structure had 25 steel piles and the other had 4 piles. The test pit was backfilled with sand of appropriate grain size distributions to obtain good compaction, especially between the 25 piles. Accelerations were measured at the structures, in the test pit and in the adjacent free field, and pile strains were measured. Dynamic modal tests of the pile-supported structures and PS measurements of the test pit were performed before and after the vibration tests to detect changes in the natural frequencies of the soil-pile-structure systems and the soil stiffness. The vibration tests were performed six times with different levels of input motions. The maximum horizontal acceleration recorded at the adjacent ground surface varied from 57 cm/s 2 to 1,683 cm/s 2 according to the distances between the test site and the blast areas. (authors)

Large scale reflood test

International Nuclear Information System (INIS)

Hirano, Kemmei; Murao, Yoshio

1980-01-01

The large-scale reflood test with a view to ensuring the safety of light water reactors was started in fiscal 1976 based on the special account act for power source development promotion measures by the entrustment from the Science and Technology Agency. Thereafter, to establish the safety of PWRs in loss-of-coolant accidents by joint international efforts, the Japan-West Germany-U.S. research cooperation program was started in April, 1980. Thereupon, the large-scale reflood test is now included in this program. It consists of two tests using a cylindrical core testing apparatus for examining the overall system effect and a plate core testing apparatus for testing individual effects. Each apparatus is composed of the mock-ups of pressure vessel, primary loop, containment vessel and ECCS. The testing method, the test results and the research cooperation program are described. (J.P.N.)

Charged black rings at large D

Energy Technology Data Exchange (ETDEWEB)

Chen, Bin [Department of Physics and State Key Laboratory of Nuclear Physics and Technology,Peking University,5 Yiheyuan Rd, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter,5 Yiheyuan Rd, Beijing 100871 (China); Center for High Energy Physics, Peking University,5 Yiheyuan Rd, Beijing 100871 (China); Li, Peng-Cheng; Wang, Zi-zhi [Department of Physics and State Key Laboratory of Nuclear Physics and Technology,Peking University,5 Yiheyuan Rd, Beijing 100871 (China)

2017-04-28

We study the charged slowly rotating black holes in the Einstein-Maxwell theory in the large dimensions (D). By using the 1/D expansion in the near regions of the black holes we obtain the effective equations for the charged slowly rotating black holes. The effective equations capture the dynamics of various stationary solutions, including the charged black ring, the charged slowly rotating Myers-Perry black hole and the charged slowly boosted black string. Via different embeddings we construct these stationary solutions explicitly. For the charged black ring at large D, we find that the charge lowers the angular momentum due to the regularity condition on the solution. By performing the perturbation analysis of the effective equations, we obtain the quasinormal modes of the charge perturbation and the gravitational perturbation analytically. Like the neutral case the charged thin black ring suffers from the Gregory-Laflamme-like instability under the non-axisymmetric perturbations, but the charge weakens the instability. Besides, we find that the large D analysis always respects the cosmic censorship.

Biomonitoring of Human Exposure to Prestige Oil: Effects on DNA and Endocrine Parameters

Directory of Open Access Journals (Sweden)

Beatriz Pérez-Cadahía

2008-01-01

Full Text Available Since 1960, about 400 tankers spilled more than 377765 tons of oil, with the Prestige accident (Galician coast, NW Spain, November 2002 the most recent. Taking into account the consistent large number of individuals exposed to oil that exists all over the world, it seems surprising the absence in the literature of studies focused on the chronic effects of this exposure on human health. In this work we evaluated the level of DNA damage by means of comet assay, and the potential endocrine alterations (prolactin and cortisol caused by Prestige oil exposure in a population of 180 individuals, classified in 3 groups according to the tasks performed, and 60 controls. Heavy metals in blood were determined as exposure biomarkers, obtaining significant increases of aluminum, nickel and lead in the exposed groups as compared to controls. Higher levels of genetic damage and endocrine alterations were also observed in the exposed population. DNA damage levels were influenced by age, sex, and the use of protective clothes, and prolactin concentrations by the last two factors. Surprisingly, the use of mask did not seem to protect individuals from genetic or endocrine alterations. Moreover, polymorphisms in genes encoding for the main enzymes involved in the metabolism of oil components were analyzed as susceptibility biomarkers. CYP1A1-3’UTR and EPHX1 codons 113 and 139 variant alleles were related to higher damage levels, while lower DNA damage was observed in GSTM1 and GSTT1 null individuals.

A structural study of [CpM(CO)3H] (M = Cr, Mo and W) by single-crystal X-ray diffraction and DFT calculations: sterically crowded yet surprisingly flexible molecules.

Science.gov (United States)

Burchell, Richard P L; Sirsch, Peter; Decken, Andreas; McGrady, G Sean

2009-08-14

The single-crystal X-ray structures of the complexes [CpCr(CO)3H] 1, [CpMo(CO)3H] 2 and [CpW(CO)3H] 3 are reported. The results indicate that 1 adopts a structure close to a distorted three-legged piano stool geometry, whereas a conventional four-legged piano stool arrangement is observed for 2 and 3. Further insight into the equilibrium geometries and potential energy surfaces of all three complexes was obtained by DFT calculations. These show that in the gas phase complex 1 also prefers a geometry close to a four-legged piano stool in line with its heavier congeners, and implying strong packing forces at work for 1 in the solid state. Comparison with their isolelectronic group 7 tricarbonyl counterparts [CpM(CO)3] (M = Mn 4 and Re 5) illustrates that 1, 2 and 3 are sterically crowded complexes. However, a surprisingly soft bending potential is evident for the M-H moiety, whose order (1 approximately = 2 < 3) correlates with the M-H bond strength rather than with the degree of congestion at the metal centre, indicating electronic rather than steric control of the potential. The calculations also reveal cooperative motions of the hydride and carbonyl ligands in the M(CO)3H unit, which allow the M-H moiety to move freely, in spite of the closeness of the four basal ligands, helping to explain the surprising flexibility of the crowded coordination sphere observed for this family of high CN complexes.

Finite size effects for giant magnons on physical strings

International Nuclear Information System (INIS)

Minahan, J.A.; Ohlsson Sax, O.

2008-01-01

Using finite gap methods, we find the leading order finite size corrections for an arbitrary number of giant magnons on physical strings, where the sum of the momenta is a multiple of 2π. Our results are valid for the Hofman-Maldacena fundamental giant magnons as well as their dyonic generalizations. The energy corrections turn out to be surprisingly simple, especially if all the magnons are fundamental, and at leading order are independent of the magnon flavors. We also show how to use the Bethe ansatz to find finite size corrections for dyonic giant magnons with large R-charges

Determinants of successful CD8+ T-cell adoptive immunotherapy for large established tumors in mice.

Science.gov (United States)

Klebanoff, Christopher A; Gattinoni, Luca; Palmer, Douglas C; Muranski, Pawel; Ji, Yun; Hinrichs, Christian S; Borman, Zachary A; Kerkar, Sid P; Scott, Christopher D; Finkelstein, Steven E; Rosenberg, Steven A; Restifo, Nicholas P

2011-08-15

Adoptive cell transfer (ACT) of tumor infiltrating or genetically engineered T cells can cause durable responses in patients with metastatic cancer. Multiple clinically modifiable parameters can comprise this therapy, including cell dose and phenotype, in vivo antigen restimulation, and common gamma-chain (γ(c)) cytokine support. However, the relative contributions of each these individual components to the magnitude of the antitumor response have yet to be quantified. To systematically and quantitatively appraise each of these variables, we employed the Pmel-1 mouse model treating large, established B16 melanoma tumors. In addition to cell dose and magnitude of in vivo antigen restimulation, we also evaluated the relative efficacy of central memory (T(CM)), effector memory (T(EM)), and stem cell memory (T(SCM)) subsets on the strength of tumor regression as well as the dose and type of clinically available γ(c) cytokines, including IL-2, IL-7, IL-15, and IL-21. We found that cell dose, T-cell differentiation status, and viral vaccine titer each were correlated strongly and significantly with the magnitude of tumor regression. Surprisingly, although the total number of IL-2 doses was correlated with tumor regression, no significant benefit to prolonged (≥6 doses) administration was observed. Moreover, the specific type and dose of γ(c) cytokine only moderately correlated with response. Collectively, these findings elucidate some of the key determinants of successful ACT immunotherapy for the treatment of cancer in mice and further show that γ(c) cytokines offer a similar ability to effectively drive antitumor T-cell function in vivo. ©2011 AACR.

Surface roughness effect on ultracold neutron interaction with a wall and implications for computer simulations

OpenAIRE

Steyerl, A.; Malik, S. S.; Desai, A. M.; Kaufman, C.

2009-01-01

We review the diffuse scattering and the loss coefficient in ultracold neutron reflection from slightly rough surfaces, report a surprising reduction in loss coefficient due to roughness, and discuss the possibility of transition from quantum treatment to ray optics. The results are used in a computer simulation of neutron storage in a recent neutron lifetime experiment that re-ported a large discrepancy of neutron lifetime with the current particle data value. Our partial re-analysis suggest...

Past lessons and future importance of polarization

International Nuclear Information System (INIS)

Lipkin, H.J.

1980-01-01

Polarization and spin effects have traditionally brought surprises to physicists particularly to those who thought that such effects were unimportant. In hadron physics, large unexplained effects keep turning up and are still unresolved puzzles. A good measurement of the uninteresting beta ray polarization could have discovered parity nonconservation many years before its prediction by Lee and Yang. Nobody knows whether there are further exciting discoveries of this kind waiting for polarization experiments

Choice of large projects

Energy Technology Data Exchange (ETDEWEB)

Harris, R

1978-08-01

Conventional cost/benefit or project analysis has generally not taken into account circumstances in which the project under consideration is large enough that its introduction to the economy would have significant general equilibrium effects. In this paper, rules are examined that would indicate whether such large projects should be accepted or rejected. The rules utilize information yielded by before-project and after-project equilibrium prices and production data. Rules are developed for the undistorted ''first-best'' case, the case in which the fixed costs of the project are covered by distortionary taxation, and for the case of projects producing public goods. 34 references.

Baseline CD4 lymphocyte count among HIV patients in Kano ...

African Journals Online (AJOL)

kemrilib

macrophages), the devastating effect of HIV on the immune system is not surprising. Given that HIV induced immunodeficiency is largely due to infection and gradual depletion of. CD4+ T-helper cells, CD4 count has become a useful indicator of immune function in infected patients. Hence CD4 count along with viral load ...

Quantifying cerebral asymmetries for language in dextrals and adextrals with random-effects meta analysis.

Directory of Open Access Journals (Sweden)

David Peter Carey

2014-11-01

Full Text Available Speech and language-related functions tend to depend on the left hemisphere more than the right in most right-handed (dextral participants. This relationship is less clear in non-right handed (adextral people, resulting in surprisingly polarised opinion on whether or not they are as lateralised as right handers. The present analysis investigates this issue by largely ignoring methodological differences between the different neuroscientific approaches to language lateralization, as well as discrepancies in how dextral and adextral participants were recruited or defined. Here we evaluate the tendency for dextrals to be more left hemisphere dominant than adextrals, using random effects meta analyses. In spite of several limitations, including sample size (in the adextrals in particular, missing details on proportions of groups who show directional effects in many experiments, and so on, the different paradigms all point to proportionally increased left hemispheric dominance in the dextrals. These results are analysed in light of the theoretical importance of these subtle differences for understanding the cognitive neuroscience of language, as well as the unusual asymmetry in most adextrals.

Quantifying cerebral asymmetries for language in dextrals and adextrals with random-effects meta analysis

Science.gov (United States)

Carey, David P.; Johnstone, Leah T.

2014-01-01

Speech and language-related functions tend to depend on the left hemisphere more than the right in most right-handed (dextral) participants. This relationship is less clear in non-right handed (adextral) people, resulting in surprisingly polarized opinion on whether or not they are as lateralized as right handers. The present analysis investigates this issue by largely ignoring methodological differences between the different neuroscientific approaches to language lateralization, as well as discrepancies in how dextral and adextral participants were recruited or defined. Here we evaluate the tendency for dextrals to be more left hemisphere dominant than adextrals, using random effects meta analyses. In spite of several limitations, including sample size (in the adextrals in particular), missing details on proportions of groups who show directional effects in many experiments, and so on, the different paradigms all point to proportionally increased left hemispheric dominance in the dextrals. These results are analyzed in light of the theoretical importance of these subtle differences for understanding the cognitive neuroscience of language, as well as the unusual asymmetry in most adextrals. PMID:25408673

Local decoherence-resistant quantum states of large systems

Energy Technology Data Exchange (ETDEWEB)

Mishra, Utkarsh; Sen, Aditi; Sen, Ujjwal, E-mail: ujjwal@hri.res.in

2015-02-06

We identify an effectively decoherence-free class of quantum states, each of which consists of a “minuscule” and a “large” sector, against local noise. In particular, the content of entanglement and other quantum correlations in the minuscule to large partition is independent of the number of particles in their large sectors, when all the particles suffer passage through local amplitude and phase damping channels. The states of the large sectors are distinct in terms of markedly different amounts of violation of Bell inequality. In case the large sector is macroscopic, such states are akin to the Schrödinger cat. - Highlights: • We identify an effectively decoherence-free class of quantum states of large systems. • We work with local noise models. • Decay of entanglement as well as information-theoretic quantum correlations considered. • The states are of the form of the Schrödinger cats, with minuscule and large sectors. • The states of the large sector are distinguishable by their violation of Bell inequality.

Surprisingly high specificity of the PPD skin test for M. tuberculosis infection from recent exposure in The Gambia.

Science.gov (United States)

Hill, Philip C; Brookes, Roger H; Fox, Annette; Jackson-Sillah, Dolly; Lugos, Moses D; Jeffries, David J; Donkor, Simon A; Adegbola, Richard A; McAdam, Keith P W J

2006-12-20

Options for intervention against Mycobacterium tuberculosis infection are limited by the diagnostic tools available. The Purified Protein Derivative (PPD) skin test is thought to be non-specific, especially in tropical settings. We compared the PPD skin test with an ELISPOT test in The Gambia. Household contacts over six months of age of sputum smear positive TB cases and community controls were recruited. They underwent a PPD skin test and an ELISPOT test for the T cell response to PPD and ESAT-6/CFP10 antigens. Responsiveness to M. tuberculosis exposure was analysed according to sleeping proximity to an index case using logistic regression. 615 household contacts and 105 community controls were recruited. All three tests assessed increased significantly in positivity with increasing M. tuberculosis exposure, the PPD skin test most dramatically (OR 15.7; 95% CI 6.6-35.3). While the PPD skin test positivity continued to trend downwards in the community with increasing distance from a known case (61.9% to 14.3%), the PPD and ESAT-6/CFP-10 ELISPOT positivity did not. The PPD skin test was more in agreement with ESAT-6/CFP-10 ELISPOT (75%, p = 0.01) than the PPD ELISPOT (53%, pPPD skin test positive increased (pPPD skin test negative decreased (pPPD skin test has surprisingly high specificity for M. tuberculosis infection from recent exposure in The Gambia. In this setting, anti-tuberculous prophylaxis in PPD skin test positive individuals should be revisited.

Ethics and Regulatory Challenges and Opportunities in Patient-Centered Comparative Effectiveness Research.

Science.gov (United States)

Sugarman, Jeremy

2016-04-01

The Affordable Care Act includes provisions for the conduct of large-scale, patient-centered comparative effectiveness research. Such efforts aim toward the laudable moral goal of having evidence to improve health care decision making. Nevertheless, these pragmatic clinical research efforts that typically pose minimal incremental risk and are enmeshed in routine care settings perhaps surprisingly encounter an array of ethics and regulatory challenges and opportunities for academic health centers. An emphasis on patient-centeredness forces an examination of the appropriateness of traditional methods used to protect the rights, interests, and welfare of participants. At the same time, meaningful collaboration with patients throughout the research process also necessitates ensuring that novel approaches to research (including recruitment and consent) entail necessary protections regarding such issues as privacy. As the scientific and logistical aspects of this research are being developed, substantial attention is being focused on the accompanying ethics and regulatory issues that have emerged, which should help to facilitate ethically appropriate research in a variety of contexts.

The Effect of Large Scale Salinity Gradient on Langmuir Turbulence

Science.gov (United States)

Fan, Y.; Jarosz, E.; Yu, Z.; Jensen, T.; Sullivan, P. P.; Liang, J.

2017-12-01

Langmuir circulation (LC) is believed to be one of the leading order causes of turbulent mixing in the upper ocean. It is important for momentum and heat exchange across the mixed layer (ML) and directly impact the dynamics and thermodynamics in the upper ocean and lower atmosphere including the vertical distributions of chemical, biological, optical, and acoustic properties. Based on Craik and Leibovich (1976) theory, large eddy simulation (LES) models have been developed to simulate LC in the upper ocean, yielding new insights that could not be obtained from field observations and turbulent closure models. Due its high computational cost, LES models are usually limited to small domain sizes and cannot resolve large-scale flows. Furthermore, most LES models used in the LC simulations use periodic boundary conditions in the horizontal direction, which assumes the physical properties (i.e. temperature and salinity) and expected flow patterns in the area of interest are of a periodically repeating nature so that the limited small LES domain is representative for the larger area. Using periodic boundary condition can significantly reduce computational effort in problems, and it is a good assumption for isotropic shear turbulence. However, LC is anisotropic (McWilliams et al 1997) and was observed to be modulated by crosswind tidal currents (Kukulka et al 2011). Using symmetrical domains, idealized LES studies also indicate LC could interact with oceanic fronts (Hamlington et al 2014) and standing internal waves (Chini and Leibovich, 2005). The present study expands our previous LES modeling investigations of Langmuir turbulence to the real ocean conditions with large scale environmental motion that features fresh water inflow into the study region. Large scale gradient forcing is introduced to the NCAR LES model through scale separation analysis. The model is applied to a field observation in the Gulf of Mexico in July, 2016 when the measurement site was impacted by

Large roomtemperature magnetocaloric effect with negligible magnetic hysteresis losses in Mn1-xVxCoGe alloys

International Nuclear Information System (INIS)

Ma, S.C.; Zheng, Y.X.; Xuan, H.C.; Shen, L.J.; Cao, Q.Q.; Wang, D.H.; Zhong, Z.C.; Du, Y.W.

2012-01-01

The magnetic and magnetocaloric properties have been investigated in a series of Mn 1-x V x CoGe (x=0.01, 0.02, 0.03, and 0.05) alloys. The substitution of V for Mn reduces the structural transformation temperature of MnCoGe alloy effectively and results in a second-order magnetic transition in Mn 0.95 V 0.05 CoGe alloys. Large room temperature magnetocaloric effect and almost zero magnetic hysteresis losses are simultaneously achieved in the alloys with x=0.01, 0.02, and 0.03. The reasons for the negligible magnetic hysteresis losses and the potential application for the roomtemperature magnetic refrigeration are discussed. - Highlights: → V-substitution for Mn reduces the structural transformation temperature of MnCoGe. → FM-PM transition presents the second-order nature in Mn0.95V0.05CoGe. → The first-order FM-PM transitions are observed for alloys with x=0.01, 0.02, and 0.03. → Large room temperature MCEs are achieved in these alloys. → Negligible magnetic HL is achieved for these alloys simultaneously.

The Large-scale Effect of Environment on Galactic Conformity

Science.gov (United States)

Sun, Shuangpeng; Guo, Qi; Wang, Lan; Wang, Jie; Gao, Liang; Lacey, Cedric G.; Pan, Jun

2018-04-01

We use a volume-limited galaxy sample from the SDSS Data Release 7 to explore the dependence of galactic conformity on the large-scale environment, measured on ˜ 4 Mpc scales. We find that the star formation activity of neighbour galaxies depends more strongly on the environment than on the activity of their primary galaxies. In under-dense regions most neighbour galaxies tend to be active, while in over-dense regions neighbour galaxies are mostly passive, regardless of the activity of their primary galaxies. At a given stellar mass, passive primary galaxies reside in higher density regions than active primary galaxies, leading to the apparently strong conformity signal. The dependence of the activity of neighbour galaxies on environment can be explained by the corresponding dependence of the fraction of satellite galaxies. Similar results are found for galaxies in a semi-analytical model, suggesting that no new physics is required to explain the observed large-scale conformity.

Six rules for accurate effective forecasting.

Science.gov (United States)

Saffo, Paul

2007-01-01

The primary goal of forecasting is to identify the full range of possibilities facing a company, society, or the world at large. In this article, Saffo demythologizes the forecasting process to help executives become sophisticated and participative consumers of forecasts, rather than passive absorbers. He illustrates how to use forecasts to at once broaden understanding of possibilities and narrow the decision space within which one must exercise intuition. The events of 9/11, for example, were a much bigger surprise than they should have been. After all, airliners flown into monuments were the stuff of Tom Clancy novels in the 1990s, and everyone knew that terrorists had a very personal antipathy toward the World Trade Center. So why was 9/11 such a surprise? What can executives do to avoid being blind-sided by other such wild cards, be they radical shifts in markets or the seemingly sudden emergence of disruptive technologies? In describing what forecasters are trying to achieve, Saffo outlines six simple, commonsense rules that smart managers should observe as they embark on a voyage of discovery with professional forecasters. Map a cone of uncertainty, he advises, look for the S curve, embrace the things that don't fit, hold strong opinions weakly, look back twice as far as you look forward, and know when not to make a forecast.

Crystal structure of di-μ-chlorido-bis[dichloridobis(methanol-κOiridium(III] dihydrate: a surprisingly simple chloridoiridium(III dinuclear complex with methanol ligands

Directory of Open Access Journals (Sweden)

Joseph S. Merola

2015-05-01

Full Text Available The reaction between IrCl3·xH2O in methanol led to the formation of small amounts of the title compound, [Ir2Cl6(CH3OH4]·2H2O, which consists of two IrCl4O2 octahedra sharing an edge via chloride bridges. The molecule lies across an inversion center. Each octahedron can be envisioned as being comprised of four chloride ligands in the equatorial plane with methanol ligands in the axial positions. A lattice water molecule is strongly hydrogen-bonded to the coordinating methanol ligands and weak interactions with coordinating chloride ligands lead to the formation of a three-dimensional network. This is a surprising structure given that, while many reactions of iridium chloride hydrate are carried out in alcoholic solvents, especially methanol and ethanol, this is the first structure of a chloridoiridium compound with only methanol ligands.

Corporate Characteristics, Political Embeddedness and Environmental Pollution by Large U.S. Corporations

Science.gov (United States)

Prechel, Harland; Zheng, Lu

2012-01-01

Organizational and environmental sociology contain surprisingly few studies of the corporation as one of the sources of environmental pollution. To fill this gap, we focus on the parent company as the unit of analysis and elaborate environmental theories that focus on the organizational and political-legal causes of pollution. Using a compiled…

Surprising finding on colonoscopy.

Science.gov (United States)

Griglione, Nicole; Naik, Jahnavi; Christie, Jennifer

2010-02-01

A 48-year-old man went to his primary care physician for his annual physical. He told his physician that for the past few years, he had intermittent, painless rectal bleeding consisting of small amounts of blood on the toilet paper after defecation. He also mentioned that he often spontaneously awoke, very early in the morning. His past medical history was unremarkable. The patient was born in Cuba but had lived in the United States for more than 30 years. He was divorced, lived alone, and had no children. He had traveled to Latin America-including Mexico, Brazil, and Cuba-off and on over the past 10 years. His last trip was approximately 2 years ago. His physical exam was unremarkable. Rectal examination revealed no masses or external hemorrhoids; stool was brown and Hemoccult negative. Labs were remarkable for eosinophilia ranging from 10% to 24% over the past several years (the white blood cell count ranged from 5200 to 5900/mcL). A subsequent colonoscopy revealed many white, thin, motile organisms dispersed throughout the colon. The organisms were most densely populated in the cecum. Of note, the patient also had nonbleeding internal hemorrhoids. An aspiration of the organisms was obtained and sent to the microbiology lab for further evaluation. What is your diagnosis? How would you manage this condition?

Feedback first: the surprisingly weak effects of magnetic fields, viscosity, conduction and metal diffusion on sub-L* galaxy formation

Science.gov (United States)

Su, Kung-Yi; Hopkins, Philip F.; Hayward, Christopher C.; Faucher-Giguère, Claude-André; Kereš, Dušan; Ma, Xiangcheng; Robles, Victor H.

2017-10-01

Using high-resolution simulations with explicit treatment of stellar feedback physics based on the FIRE (Feedback In Realistic Environments) project, we study how galaxy formation and the interstellar medium (ISM) are affected by magnetic fields, anisotropic Spitzer-Braginskii conduction and viscosity, and sub-grid metal diffusion from unresolved turbulence. We consider controlled simulations of isolated (non-cosmological) galaxies but also a limited set of cosmological 'zoom-in' simulations. Although simulations have shown significant effects from these physics with weak or absent stellar feedback, the effects are much weaker than those of stellar feedback when the latter is modelled explicitly. The additional physics have no systematic effect on galactic star formation rates (SFRs). In contrast, removing stellar feedback leads to SFRs being overpredicted by factors of ˜10-100. Without feedback, neither galactic winds nor volume-filling hot-phase gas exist, and discs tend to runaway collapse to ultra-thin scaleheights with unphysically dense clumps congregating at the galactic centre. With stellar feedback, a multi-phase, turbulent medium with galactic fountains and winds is established. At currently achievable resolutions and for the investigated halo mass range 1010-1013 M⊙, the additional physics investigated here (magnetohydrodynamic, conduction, viscosity, metal diffusion) have only weak (˜10 per cent-level) effects on regulating SFR and altering the balance of phases, outflows or the energy in ISM turbulence, consistent with simple equipartition arguments. We conclude that galactic star formation and the ISM are primarily governed by a combination of turbulence, gravitational instabilities and feedback. We add the caveat that active galactic nucleus feedback is not included in the present work.

Surprising structures hiding in Penrose’s future null infinity

Science.gov (United States)

Newman, Ezra T.

2017-07-01

Since the late1950s, almost all discussions of asymptotically flat (Einstein-Maxwell) space-times have taken place in the context of Penrose’s null infinity, I+. In addition, almost all calculations have used the Bondi coordinate and tetrad systems. Beginning with a known asymptotically flat solution to the Einstein-Maxwell equations, we show first, that there are other natural coordinate systems, near I+, (analogous to light-cones in flat-space) that are based on (asymptotically) shear-free null geodesic congruences (analogous to the flat-space case). Using these new coordinates and their associated tetrad, we define the complex dipole moment, (the mass dipole plus i times angular momentum), from the l  =  1 harmonic coefficient of a component of the asymptotic Weyl tensor. Second, from this definition, from the Bianchi identities and from the Bondi-Sachs mass and linear momentum, we show that there exists a large number of results—identifications and dynamics—identical to those of classical mechanics and electrodynamics. They include, among many others, {P}=M{v}+..., {L}= {r} × {P} , spin, Newton’s second law with the rocket force term (\\dotM v) and radiation reaction, angular momentum conservation and others. All these relations take place in the rather mysterious H-space rather than in space-time. This leads to the enigma: ‘why do these well known relations of classical mechanics take place in H-space?’ and ‘What is the physical meaning of H-space?’

Anthropic prediction for a large multi-jump landscape

International Nuclear Information System (INIS)

Schwartz-Perlov, Delia

2008-01-01

The assumption of a flat prior distribution plays a critical role in the anthropic prediction of the cosmological constant. In a previous paper we analytically calculated the distribution for the cosmological constant, including the prior and anthropic selection effects, in a large toy 'single-jump' landscape model. We showed that it is possible for the fractal prior distribution that we found to behave as an effectively flat distribution in a wide class of landscapes, but only if the single-jump size is large enough. We extend this work here by investigating a large (N∼10 500 ) toy 'multi-jump' landscape model. The jump sizes range over three orders of magnitude and an overall free parameter c determines the absolute size of the jumps. We will show that for 'large' c the distribution of probabilities of vacua in the anthropic range is effectively flat, and thus the successful anthropic prediction is validated. However, we argue that for small c, the distribution may not be smooth

Retained State Shareholding in Chinese PLCs: Does Government Ownership Reduce Corporate Value?

OpenAIRE

Estrin, Saul; Tian, Lihui

2005-01-01

The role of government shareholding in corporate performance is central to an understanding of China’s newly privatized large firms and the stock market. In this paper, we analyse shareholders as agents that can both harm and benefit companies. We examine the ownership structure of 826 listed corporations and find that government shareholding is surprisingly large. Its effect on corporate value is found to be negative, but non-monotonic. Up to a certain threshold, corporate value decreases as...

Self-organizing weights for Internet AS-graphs and surprisingly simple routing metrics

DEFF Research Database (Denmark)

Scholz, Jan Carsten; Greiner, Martin

The transport capacity of Internet-like communication networks and hence their efficiency may be improved by a factor of 5-10 through the use of highly optimized routing metrics, as demonstrated previously. Numerical determination of such routing metrics can be computationally demanding...... metrics. The new metrics have negligible computational cost and result in an approximately 5-fold performance increase, providing distinguished competitiveness with the computationally costly counterparts. They are applicable to very large networks and easy to implement in today's Internet routing...

Thermal cover needs of large ungulates: a review of hypothesis tests.

Science.gov (United States)

John G. Cook; Larry L. Irwin; Larry D. Bryant; Robert A. Riggs; Jack Ward. Thomas

2004-01-01

A great deal of big game research occurred in western North America during the 1960s through the 1980s, and many advances in our knowledge occurred as a result. Timber harvest increased during this period in many localities, and this trend was often perceived to threaten ungulate populations (Hieb 1976). Thus, it is not surprising that appreciable research in this era...

Active Luminous Blue Variables in the Large Magellanic Cloud

Energy Technology Data Exchange (ETDEWEB)

Walborn, Nolan R. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Gamen, Roberto C.; Lajús, Eduardo Fernández [Instituto de Astrofísica de La Plata, CONICET–UNLP and Facultad de Ciencias Astronómicas y Geofísicas, UNLP, Paseo del Bosque s/n, La Plata (Argentina); Morrell, Nidia I. [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Barbá, Rodolfo H. [Departamento de Física y Astronomía, Universidad de La Serena, Cisternas 1200 Norte, La Serena (Chile); Angeloni, Rodolfo, E-mail: walborn@stsci.edu, E-mail: rgamen@fcaglp.unlp.edu.ar, E-mail: eflajus@fcaglp.unlp.edu.ar, E-mail: nmorrell@lco.cl, E-mail: rbarba@dfuls.cl, E-mail: rangelon@gemini.edu [Gemini Observatory, Colina El Pino, Casilla 603, La Serena (Chile)

2017-07-01

We present extensive spectroscopic and photometric monitoring of two famous and currently highly active luminous blue variables (LBVs) in the Large Magellanic Cloud (LMC), together with more limited coverage of three further, lesser known members of the class. R127 was discovered as an Ofpe/WN9 star in the 1970s but entered a classical LBV outburst in or about 1980 that is still in progress, thus enlightening us about the minimum state of such objects. R71 is currently the most luminous star in the LMC and continues to provide surprises, such as the appearance of [Ca ii] emission lines, as its spectral type becomes unprecedentedly late. Most recently, R71 has developed inverse P Cyg profiles in many metal lines. The other objects are as follows: HDE 269582, now a “second R127” that has been followed from Ofpe/WN9 to A type in its current outburst; HDE 269216, which changed from late B in 2014 to AF in 2016, its first observed outburst; and R143 in the 30 Doradus outskirts. The light curves and spectroscopic transformations are correlated in remarkable detail and their extreme reproducibility is emphasized, both for a given object and among all of them. It is now believed that some LBVs proceed directly to core collapse. One of these unstable LMC objects may thus oblige in the near future, teaching us even more about the final stages of massive stellar evolution.

Active Luminous Blue Variables in the Large Magellanic Cloud

Science.gov (United States)

Walborn, Nolan R.; Gamen, Roberto C.; Morrell, Nidia I.; Barbá, Rodolfo H.; Fernández Lajús, Eduardo; Angeloni, Rodolfo

2017-07-01

We present extensive spectroscopic and photometric monitoring of two famous and currently highly active luminous blue variables (LBVs) in the Large Magellanic Cloud (LMC), together with more limited coverage of three further, lesser known members of the class. R127 was discovered as an Ofpe/WN9 star in the 1970s but entered a classical LBV outburst in or about 1980 that is still in progress, thus enlightening us about the minimum state of such objects. R71 is currently the most luminous star in the LMC and continues to provide surprises, such as the appearance of [Ca II] emission lines, as its spectral type becomes unprecedentedly late. Most recently, R71 has developed inverse P Cyg profiles in many metal lines. The other objects are as follows: HDE 269582, now a “second R127” that has been followed from Ofpe/WN9 to A type in its current outburst; HDE 269216, which changed from late B in 2014 to AF in 2016, its first observed outburst; and R143 in the 30 Doradus outskirts. The light curves and spectroscopic transformations are correlated in remarkable detail and their extreme reproducibility is emphasized, both for a given object and among all of them. It is now believed that some LBVs proceed directly to core collapse. One of these unstable LMC objects may thus oblige in the near future, teaching us even more about the final stages of massive stellar evolution.

Active Luminous Blue Variables in the Large Magellanic Cloud

International Nuclear Information System (INIS)

Walborn, Nolan R.; Gamen, Roberto C.; Lajús, Eduardo Fernández; Morrell, Nidia I.; Barbá, Rodolfo H.; Angeloni, Rodolfo

2017-01-01

We present extensive spectroscopic and photometric monitoring of two famous and currently highly active luminous blue variables (LBVs) in the Large Magellanic Cloud (LMC), together with more limited coverage of three further, lesser known members of the class. R127 was discovered as an Ofpe/WN9 star in the 1970s but entered a classical LBV outburst in or about 1980 that is still in progress, thus enlightening us about the minimum state of such objects. R71 is currently the most luminous star in the LMC and continues to provide surprises, such as the appearance of [Ca ii] emission lines, as its spectral type becomes unprecedentedly late. Most recently, R71 has developed inverse P Cyg profiles in many metal lines. The other objects are as follows: HDE 269582, now a “second R127” that has been followed from Ofpe/WN9 to A type in its current outburst; HDE 269216, which changed from late B in 2014 to AF in 2016, its first observed outburst; and R143 in the 30 Doradus outskirts. The light curves and spectroscopic transformations are correlated in remarkable detail and their extreme reproducibility is emphasized, both for a given object and among all of them. It is now believed that some LBVs proceed directly to core collapse. One of these unstable LMC objects may thus oblige in the near future, teaching us even more about the final stages of massive stellar evolution.

Effect of Large Negative Phase of Blast Loading on Structural Response of RC Elements

Directory of Open Access Journals (Sweden)

Syed Zubair Iman

2016-01-01

Full Text Available Structural response of reinforced concrete (RC elements for analysis and design are often obtained using the positive phase of the blast pressure curve disregarding the negative phase assuming insignificant contribution from the negative phase of the loading. Although, some insight on the effect of negative phase of blast pressure based on elastic single-degree-of-freedom (SDOF analysis was presented before, the influence of negative phase on different types of resistance functions of SDOF models and on realistic finite element analysis has not been explored. In this study, the effects of inclusion of pulse negative phase on structural response of RC elements from SDOF analysis and from more detailed finite element analysis have been investigated. Investigation of SDOF part has been conducted using MATLAB code that utilizes non-linear resistance functions of SDOF model. Detailed numerical investigation using finite element code DIANA was conducted on the significance of the negative phase on structural response. In the FE model, different support stiffness was used to explore the effect of support stiffness on the structural response due to blast negative phase. Results from SDOF and FE analyses present specific situations where the effect of large negative phase was found to be significant on the structural response of RC elements.

Large-scale multimedia modeling applications

International Nuclear Information System (INIS)

Droppo, J.G. Jr.; Buck, J.W.; Whelan, G.; Strenge, D.L.; Castleton, K.J.; Gelston, G.M.

1995-08-01

Over the past decade, the US Department of Energy (DOE) and other agencies have faced increasing scrutiny for a wide range of environmental issues related to past and current practices. A number of large-scale applications have been undertaken that required analysis of large numbers of potential environmental issues over a wide range of environmental conditions and contaminants. Several of these applications, referred to here as large-scale applications, have addressed long-term public health risks using a holistic approach for assessing impacts from potential waterborne and airborne transport pathways. Multimedia models such as the Multimedia Environmental Pollutant Assessment System (MEPAS) were designed for use in such applications. MEPAS integrates radioactive and hazardous contaminants impact computations for major exposure routes via air, surface water, ground water, and overland flow transport. A number of large-scale applications of MEPAS have been conducted to assess various endpoints for environmental and human health impacts. These applications are described in terms of lessons learned in the development of an effective approach for large-scale applications

Effects of long-term contracts on firms exercising market power in transmission constrained electricity markets

International Nuclear Information System (INIS)

Nam, Young Woo; Yoon, Yong Tae; Park, Jong-Keun; Hur, Don; Kim, Sung-Soo

2006-01-01

The electricity markets with only few large firms are often vulnerable to less competitive behaviors than the desired. The presence of transmission constraints further restrict the competition among firms and provide more opportunities for firms to exercise market power. While it is generally acknowledged that the long-term contracts provide good measures for mitigating market power in the spot market (thus reducing undesired price spikes), it is not even more clear how effective these contracts are if the market is severely limited due to transmission constraints. In this paper, an analytical approach through finding a Nash equilibrium is presented to investigate the effects of long-term contracts on firms exercising market power in a bid-based pool with transmission constraints. Surprisingly the analysis in this paper shows that the presence of long-term contracts may result in the reduced expected social welfare. A straightforward consequence of the analysis presented in this paper will be helpful for the regulators in Korea to reconsider offering vesting contracts to generating companies in the near future. (author)

Interactions among invasive plants: Lessons from Hawai‘i

Science.gov (United States)

D'Antonio, Carla M.; Ostertag, Rebecca; Cordell, Susan; Yelenik, Stephanie G.

2017-01-01

Most ecosystems have multiple-plant invaders rather than single-plant invaders, yet ecological studies and management actions focus largely on single invader species. There is a need for general principles regarding invader interactions across varying environmental conditions, so that secondary invasions can be anticipated and managers can allocate resources toward pretreatment or postremoval actions. By reviewing removal experiments conducted in three Hawaiian ecosystems (a dry tropical forest, a seasonally dry mesic forest, and a lowland wet forest), we evaluate the roles environmental harshness, priority effects, productivity potential, and species interactions have in influencing secondary invasions, defined here as invasions that are influenced either positively (facilitation) or negatively (inhibition/priority effects) by existing invaders. We generate a conceptual model with a surprise index to describe whether long-term plant invader composition and dominance is predictable or stochastic after a system perturbation such as a removal experiment. Under extremely low resource availability, the surprise index is low, whereas under intermediate-level resource environments, invader dominance is more stochastic and the surprise index is high. At high resource levels, the surprise index is intermediate: Invaders are likely abundant in the environment but their response to a perturbation is more predictable than at intermediate resource levels. We suggest further testing across environmental gradients to determine key variables that dictate the predictability of postremoval invader composition.

Large power microwave nonlinear effects on multifunction amplifier chip for Ka-band T/R module of phased array radar

Science.gov (United States)

Guo, Guo; Gu, Ling; Wu, Ruowu; Xu, Xiong; Zhou, Taifu; Niu, Xinjian; Liu, Yinghui; Wang, Hui; Wei, Yanyu; Guo, Changyong

2017-12-01

Nonlinear effects of large power millimeter wave on critical chips for the T/R module of phased array radar is experimental studied and analyzed in this paper. A multifunction amplifier chip is selected for our experiments. A solid continuous wave (CW) source and a large power pulsed magnetron are both employed to generate the Ka-band microwave. The input-output characteristics, the degradation and destroy threshold of the chips are obtained through a series of experimental tests. At last, the results are given by figures and analyzed theoretically.

Automatic management software for large-scale cluster system

International Nuclear Information System (INIS)

Weng Yunjian; Chinese Academy of Sciences, Beijing; Sun Gongxing

2007-01-01

At present, the large-scale cluster system faces to the difficult management. For example the manager has large work load. It needs to cost much time on the management and the maintenance of large-scale cluster system. The nodes in large-scale cluster system are very easy to be chaotic. Thousands of nodes are put in big rooms so that some managers are very easy to make the confusion with machines. How do effectively carry on accurate management under the large-scale cluster system? The article introduces ELFms in the large-scale cluster system. Furthermore, it is proposed to realize the large-scale cluster system automatic management. (authors)

The effect of random matter density perturbations on the large mixing angle solution to the solar neutrino problem

Science.gov (United States)

Guzzo, M. M.; Holanda, P. C.; Reggiani, N.

2003-08-01

The neutrino energy spectrum observed in KamLAND is compatible with the predictions based on the Large Mixing Angle realization of the MSW (Mikheyev-Smirnov-Wolfenstein) mechanism, which provides the best solution to the solar neutrino anomaly. From the agreement between solar neutrino data and KamLAND observations, we can obtain the best fit values of the mixing angle and square difference mass. When doing the fitting of the MSW predictions to the solar neutrino data, it is assumed the solar matter do not have any kind of perturbations, that is, it is assumed the the matter density monothonically decays from the center to the surface of the Sun. There are reasons to believe, nevertheless, that the solar matter density fluctuates around the equilibrium profile. In this work, we analysed the effect on the Large Mixing Angle parameters when the density matter randomically fluctuates around the equilibrium profile, solving the evolution equation in this case. We find that, in the presence of these density perturbations, the best fit values of the mixing angle and the square difference mass assume smaller values, compared with the values obtained for the standard Large Mixing Angle Solution without noise. Considering this effect of the random perturbations, the lowest island of allowed region for KamLAND spectral data in the parameter space must be considered and we call it very-low region.

Local field distribution near corrugated interfaces: Green function formalism versus effective medium theory

International Nuclear Information System (INIS)

Choy, C.W.; Xiao, J.J.; Yu, K.W.

2007-01-01

The recent Green function formalism (GFF) has been used to study the local field distribution near a periodic interface separating two homogeneous media of different dielectric constants. In the GFF, the integral equations can be solved conveniently because of the existence of an analytic expression for the kernel (Greenian). However, due to a severe singularity in the Greenian, the formalism was formerly applied to compute the electric fields away from the interface region. In this work, we have succeeded in extending the GFF to compute the electric field inside the interface region by taking advantage of a sum rule. To our surprise, the strengths of the electric fields are quite similar in both media across the interface, despite of the large difference in dielectric constants. Moreover, we propose a simple effective medium approximation (EMA) to compute the electric field inside the interface region. We show that the EMA can indeed give an excellent description of the electric field, except near a surface plasmon resonance

Can Effective Field Theory of inflation generate large tensor-to-scalar ratio within Randall–Sundrum single braneworld?

International Nuclear Information System (INIS)

Choudhury, Sayantan

2015-01-01

In this paper my prime objective is to explain the generation of large tensor-to-scalar ratio from the single field sub-Planckian inflationary paradigm within Randall–Sundrum (RS) single braneworld scenario in a model independent fashion. By explicit computation I have shown that the effective field theory prescription of brane inflation within RS single brane setup is consistent with sub-Planckian excursion of the inflaton field, which will further generate large value of tensor-to-scalar ratio, provided the energy density for inflaton degrees of freedom is high enough compared to the brane tension in high energy regime. Finally, I have mentioned the stringent theoretical constraint on positive brane tension, cut-off of the quantum gravity scale and bulk cosmological constant to get sub-Planckian field excursion along with large tensor-to-scalar ratio as recently observed by BICEP2 or at least generates the tensor-to-scalar ratio consistent with the upper bound of Planck (2013 and 2015) data and Planck+BICEP2+Keck Array joint constraint

Aging assessment of large electric motors in nuclear power plants

International Nuclear Information System (INIS)

Villaran, M.; Subudhi, M.

1996-03-01

Large electric motors serve as the prime movers to drive high capacity pumps, fans, compressors, and generators in a variety of nuclear plant systems. This study examined the stressors that cause degradation and aging in large electric motors operating in various plant locations and environments. The operating history of these machines in nuclear plant service was studied by review and analysis of failure reports in the NPRDS and LER databases. This was supplemented by a review of motor designs, and their nuclear and balance of plant applications, in order to characterize the failure mechanisms that cause degradation, aging, and failure in large electric motors. A generic failure modes and effects analysis for large squirrel cage induction motors was performed to identify the degradation and aging mechanisms affecting various components of these large motors, the failure modes that result, and their effects upon the function of the motor. The effects of large motor failures upon the systems in which they are operating, and on the plant as a whole, were analyzed from failure reports in the databases. The effectiveness of the industry's large motor maintenance programs was assessed based upon the failure reports in the databases and reviews of plant maintenance procedures and programs

Detection and Interpretation of Low-Level and High-Level Surprising and Important Events in Large-Scale Data Streams

Science.gov (United States)

2016-06-28

a current (start) state to one or several desired (goal) state or states. Note that like in standard search in Artificial Intelligence , the goal may...datasets. Publications: J. Zhao, C. Siagian, L. Itti, Fixation Bank : Learning to Reweight Fixation Candidates, In: Proc. IEEE Confer- ence on Computer...eyeglasses, In: Proc. IEEE/RSJ International Con- ference on Intelligent Robots and Systems (IROS), pp. 5674-5679, Nov 2013. [2013 acceptance rate: 43%] A

Simulated effects of host fish distribution on juvenile unionid mussel dispersal in a large river

Science.gov (United States)

Daraio, J.A.; Weber, L.J.; Zigler, S.J.; Newton, T.J.; Nestler, J.M.

2012-01-01

Larval mussels (Family Unionidae) are obligate parasites on fish, and after excystment from their host, as juveniles, they are transported with flow. We know relatively little about the mechanisms that affect dispersal and subsequent settlement of juvenile mussels in large rivers. We used a three-dimensional hydrodynamic model of a reach of the Upper Mississippi River with stochastic Lagrangian particle tracking to simulate juvenile dispersal. Sensitivity analyses were used to determine the importance of excystment location in two-dimensional space (lateral and longitudinal) and to assess the effects of vertical location (depth in the water column) on dispersal distances and juvenile settling distributions. In our simulations, greater than 50% of juveniles mussels settled on the river bottom within 500 m of their point of excystment, regardless of the vertical location of the fish in the water column. Dispersal distances were most variable in environments with higher velocity and high gradients in velocity, such as along channel margins, near the channel bed, or where effects of river bed morphology caused large changes in hydraulics. Dispersal distance was greater and variance was greater when juvenile excystment occurred in areas where vertical velocity (w) was positive (indicating an upward velocity) than when w was negative. Juvenile dispersal distance is likely to be more variable for mussels species whose hosts inhabit areas with steeper velocity gradients (e.g. channel margins) than a host that generally inhabits low-flow environments (e.g. impounded areas).