Optimizing Hybrid Spreading in Metapopulations

OpenAIRE

Zhang, Changwang; Zhou, Shi; Miller, Joel C.; Cox, Ingemar J.; Chain, Benjamin M.

2014-01-01

Epidemic spreading phenomena are ubiquitous in nature and society. Examples include the spreading of diseases, information, and computer viruses. Epidemics can spread by local spreading, where infected nodes can only infect a limited set of direct target nodes and global spreading, where an infected node can infect every other node. In reality, many epidemics spread using a hybrid mixture of both types of spreading. In this study we develop a theoretical framework for studying hybrid epidemic...

Global Landslides on Rapidly Spinning Spheroids

Science.gov (United States)

Scheeres, Daniel J.; Sanchez, P.

2013-10-01

The angle of repose and conditions for global landslides on the surfaces of small, rapidly spinning, spheroidal asteroids are studied. Applying techniques of soil mechanics, we develop a theory for, and examples of, how regolith will fail and flow in this microgravity environment. Our motivation is to develop an understanding of the "top-shaped" class of asteroids based on analytical soil mechanics. Our analysis transforms the entire asteroid surface into a local frame where we can model it as a conventional granular pile with a surface slope, acceleration and height variations as a function of the body's spin rate, shape and density. A general finding is that the lowest point on a rapidly spinning spheroid is at the equator with the effective height of surface material monotonically increasing towards the polar regions, where the height can be larger than the physical radius of the body. We study the failure conditions of both cohesionless and cohesive regolith, and develop specific predictions of the surface profile as a function of the regolith angle of friction and the maximum spin rate experienced by the body. The theory also provides simple guidelines on what the shape may look like, although we do not analyze gravitationally self-consistent evolution of the body shape. The theory is tested with soft-sphere discrete element method granular mechanics simulations to better understand the dynamical aspects of global asteroid landslides. We find significant differences between failure conditions for cohesive and cohesionless regolith. In the case of cohesive regolith, we show that extremely small values of strength (much less than that found in lunar regolith) can stabilize a surface even at very rapid spin rates. Cohesionless surfaces, as expected, fail whenever their surface slopes exceed the angle of friction. Based on our analysis we propose that global landslides and the flow of material towards the equator on spheroidal bodies are precipitated by exogenous

Cooperative spreading processes in multiplex networks.

Science.gov (United States)

Wei, Xiang; Chen, Shihua; Wu, Xiaoqun; Ning, Di; Lu, Jun-An

2016-06-01

This study is concerned with the dynamic behaviors of epidemic spreading in multiplex networks. A model composed of two interacting complex networks is proposed to describe cooperative spreading processes, wherein the virus spreading in one layer can penetrate into the other to promote the spreading process. The global epidemic threshold of the model is smaller than the epidemic thresholds of the corresponding isolated networks. Thus, global epidemic onset arises in the interacting networks even though an epidemic onset does not arise in each isolated network. Simulations verify the analysis results and indicate that cooperative spreading processes in multiplex networks enhance the final infection fraction.

An empirical model of global spread-f occurrence

International Nuclear Information System (INIS)

Singleton, D.G.

1974-09-01

A method of combining models of ionospheric F-layer peak electron density and irregularity incremental electron density into a model of the occurrence probability of the frequency spreading component of spread-F is presented. The predictions of the model are compared with spread-F occurrence data obtained under sunspot maximum conditions. Good agreement is obtained for latitudes less than 70 0 geomagnetic. At higher latitudes, the inclusion of a 'blackout factor' in the model allows it to accurately represent the data and, in so doing, resolves an apparent discrepancy in the occurrence statistics at high latitudes. The blackout factor is ascribed to the effect of polar blackout on the spread-F statistics and/or the lack of a definitve incremental electron density model for irregularities at polar latitudes. Ways of isolating these effects and assessing their relative importance in the blackout factor are discussed. The model, besides providing estimates of spread-F occurrence on a worldwide basis, which will be of value in the engineering of HF and VHF communications, also furnishes a means of further checking the irregularity incremental electron density model on which it is based. (author)

Can molecular diffusion explain Space Shuttle plume spreading?

Science.gov (United States)

Meier, R. R.; Plane, John M. C.; Stevens, Michael H.; Paxton, L. J.; Christensen, A. B.; Crowley, G.

2010-04-01

The satellite-borne Global Ultraviolet Imager (GUVI) has produced more than 20 images of NASA Space Shuttle main engine plumes in the lower thermosphere. These reveal atomic hydrogen and, by inference, water vapor transport over hemispherical-scale distances with speeds much faster than expected from models of thermospheric wind motions. Furthermore, the hydrogen plumes expand rapidly. We find rates that exceed the horizontal diffusion speed at nominal plume altitudes of 104-112 km. Kelley et al. (2009) have proposed a 2-D turbulence mechanism to explain the observed spreading rates (and rapid advection) of the plumes. But upon further investigation, we conclude that H atom diffusion can indeed account for the observed expansion rates by recognizing that vertical diffusion quickly conveys atoms to higher altitudes where horizontal diffusion is much more rapid. We also find evidence for H atom production directly during the Shuttle's main engine burn.

Phase Transitions of an Epidemic Spreading Model in Small-World Networks

Science.gov (United States)

Hua, Da-Yin; Gao, Ke

2011-06-01

We propose a modified susceptible-infected-refractory-susceptible (SIRS) model to investigate the global oscillations of the epidemic spreading in Watts—Strogatz (WS) small-world networks. It is found that when an individual immunity does not change or decays slowly in an immune period, the system can exhibit complex transition from an infecting stationary state to a large amplitude sustained oscillation or an absorbing state with no infection. When the immunity decays rapidly in the immune period, the transition to the global oscillation disappears and there is no oscillation. Furthermore, based on the spatio-temporal evolution patterns and the phase diagram, it is disclosed that a long immunity period takes an important role in the emergence of the global oscillation in small-world networks.

Optimizing hybrid spreading in metapopulations.

Science.gov (United States)

Zhang, Changwang; Zhou, Shi; Miller, Joel C; Cox, Ingemar J; Chain, Benjamin M

2015-04-29

Epidemic spreading phenomena are ubiquitous in nature and society. Examples include the spreading of diseases, information, and computer viruses. Epidemics can spread by local spreading, where infected nodes can only infect a limited set of direct target nodes and global spreading, where an infected node can infect every other node. In reality, many epidemics spread using a hybrid mixture of both types of spreading. In this study we develop a theoretical framework for studying hybrid epidemics, and examine the optimum balance between spreading mechanisms in terms of achieving the maximum outbreak size. We show the existence of critically hybrid epidemics where neither spreading mechanism alone can cause a noticeable spread but a combination of the two spreading mechanisms would produce an enormous outbreak. Our results provide new strategies for maximising beneficial epidemics and estimating the worst outcome of damaging hybrid epidemics.

Implications of the spatial dynamics of fire spread for the bistability of savanna and forest.

Science.gov (United States)

Schertzer, E; Staver, A C; Levin, S A

2015-01-01

The role of fire in expanding the global distribution of savanna is well recognized. Empirical observations and modeling suggest that fire spread has a threshold response to fuel-layer continuity, which sets up a positive feedback that maintains savanna-forest bistability. However, modeling has so far failed to examine fire spread as a spatial process that interacts with vegetation. Here, we use simple, well-supported assumptions about fire spread as an infection process and its effects on trees to ask whether spatial dynamics qualitatively change the potential for savanna-forest bistability. We show that the spatial effects of fire spread are the fundamental reason that bistability is possible: because fire spread is an infection process, it exhibits a threshold response to fuel continuity followed by a rapid increase in fire size. Other ecological processes affecting fire spread may also contribute including temporal variability in demography or fire spread. Finally, including the potential for spatial aggregation increases the potential both for savanna-forest bistability and for savanna and forest to coexist in a landscape mosaic.

Rapid localized spread and immunologic containment define Herpes simplex virus-2 reactivation in the human genital tract.

Science.gov (United States)

Schiffer, Joshua T; Swan, David; Al Sallaq, Ramzi; Magaret, Amalia; Johnston, Christine; Mark, Karen E; Selke, Stacy; Ocbamichael, Negusse; Kuntz, Steve; Zhu, Jia; Robinson, Barry; Huang, Meei-Li; Jerome, Keith R; Wald, Anna; Corey, Lawrence

2013-04-16

Herpes simplex virus-2 (HSV-2) is shed episodically, leading to occasional genital ulcers and efficient transmission. The biology explaining highly variable shedding patterns, in an infected person over time, is poorly understood. We sampled the genital tract for HSV DNA at several time intervals and concurrently at multiple sites, and derived a spatial mathematical model to characterize dynamics of HSV-2 reactivation. The model reproduced heterogeneity in shedding episode duration and viral production, and predicted rapid early viral expansion, rapid late decay, and wide spatial dispersion of HSV replication during episodes. In simulations, HSV-2 spread locally within single ulcers to thousands of epithelial cells in genital epithelium. DOI:http://dx.doi.org/10.7554/eLife.00288.001.

Rapid screening of operational freshwater availability using global models

NARCIS (Netherlands)

Straatsma, M.W.; Vermeulen, P.; Kuijper, Marijn; Bonte, Matthijs; Niele, Frank; Bierkens, M.F.P.

Freshwater shortage already affects large parts of the world, and is expected to increase rapidly over the coming decades as a result of increased water demands and the impacts of climate change. Global-scale water risk or stress maps are available online, but these lack quantitative information on

Ocean, Spreading Centre

Digital Repository Service at National Institute of Oceanography (India)

Krishna, K.S.

over the global midoceanic ridges have found some explicit relationships between spreading rate, seismic structure, and ridge-axis morphology. Bibliography Detrick, R. S., Buhl, P., Vera, E., Mutter, J., Orcutt, J., Madsen, J., and Brocher, T., 1987...

The link between rapid enigmatic amphibian decline and the globally emerging chytrid fungus.

Science.gov (United States)

Lötters, Stefan; Kielgast, Jos; Bielby, Jon; Schmidtlein, Sebastian; Bosch, Jaime; Veith, Michael; Walker, Susan F; Fisher, Matthew C; Rödder, Dennis

2009-09-01

Amphibians are globally declining and approximately one-third of all species are threatened with extinction. Some of the most severe declines have occurred suddenly and for unknown reasons in apparently pristine habitats. It has been hypothesized that these "rapid enigmatic declines" are the result of a panzootic of the disease chytridiomycosis caused by globally emerging amphibian chytrid fungus. In a Species Distribution Model, we identified the potential distribution of this pathogen. Areas and species from which rapid enigmatic decline are known significantly overlap with those of highest environmental suitability to the chytrid fungus. We confirm the plausibility of a link between rapid enigmatic decline in worldwide amphibian species and epizootic chytridiomycosis.

Population-level genomics identifies the emergence and global spread of a human transmissible multidrug-resistant nontuberculous mycobacterium

Science.gov (United States)

Rodriguez-Rincon, Daniela; Everall, Isobel; Brown, Karen P; Moreno, Pablo; Verma, Deepshikha; Hill, Emily; Drijkoningen, Judith; Gilligan, Peter; Esther, Charles R; Noone, Peadar G; Giddings, Olivia; Bell, Scott C.; Thomson, Rachel; Wainwright, Claire E.; Coulter, Chris; Pandey, Sushil; Wood, Michelle E; Stockwell, Rebecca E; Ramsay, Kay A; Sherrard, Laura J; Kidd, Timothy J; Jabbour, Nassib; Johnson, Graham R; Knibbs, Luke D; Morawska, Lidia; Sly, Peter D; Jones, Andrew; Bilton, Diana; Laurenson, Ian; Ruddy, Michael; Bourke, Stephen; Bowler, Ian CJW; Chapman, Stephen J; Clayton, Andrew; Cullen, Mairi; Daniels, Thomas; Dempsey, Owen; Denton, Miles; Desai, Maya; Drew, Richard J; Edenborough, Frank; Evans, Jason; Folb, Jonathan; Humphrey, Helen; Isalska, Barbara; Jensen-Fangel, Søren; Jönsson, Bodil; Jones, Andrew M.; Katzenstein, Terese L; Lillebaek, Troels; MacGregor, Gordon; Mayell, Sarah; Millar, Michael; Modha, Deborah; Nash, Edward F; O’Brien, Christopher; O’Brien, Deirdre; Ohri, Chandra; Pao, Caroline S; Peckham, Daniel; Perrin, Felicity; Perry, Audrey; Pressler, Tania; Prtak, Laura; Qvist, Tavs; Robb, Ali; Rodgers, Helen; Schaffer, Kirsten; Shafi, Nadia; van Ingen, Jakko; Walshaw, Martin; Watson, Danie; West, Noreen; Whitehouse, Joanna; Haworth, Charles S; Harris, Simon R; Ordway, Diane; Parkhill, Julian; Floto, R. Andres

2016-01-01

Lung infections with Mycobacterium abscessus, a species of multidrug resistant nontuberculous mycobacteria, are emerging as an important global threat to individuals with cystic fibrosis (CF) where they accelerate inflammatory lung damage leading to increased morbidity and mortality. Previously, M. abscessus was thought to be independently acquired by susceptible individuals from the environment. However, using whole genome analysis of a global collection of clinical isolates, we show that the majority of M. abscessus infections are acquired through transmission, potentially via fomites and aerosols, of recently emerged dominant circulating clones that have spread globally. We demonstrate that these clones are associated with worse clinical outcomes, show increased virulence in cell-based and mouse infection models, and thus represent an urgent international infection challenge. PMID:27846606

Hydrothermal plumes over spreading-center axes: Global distributions and geological inferences

Science.gov (United States)

Baker, Edward T.; German, Christopher R.; Elderfield, Henry

Seafloor hydrothermal circulation is the principal agent of energy and mass exchange between the ocean and the earth's crust. Discharging fluids cool hot rock, construct mineral deposits, nurture biological communities, alter deep-sea mixing and circulation patterns, and profoundly influence ocean chemistry and biology. Although the active discharge orifices themselves cover only a minuscule percentage of the ridge-axis seafloor, the investigation and quantification of their effects is enhanced as a consequence of the mixing process that forms hydrothermal plumes. Hydrothermal fluids discharged from vents are rapidly diluted with ambient seawater by factors of 104-105 [Lupton et al., 1985]. During dilution, the mixture rises tens to hundreds of meters to a level of neutral buoyancy, eventually spreading laterally as a distinct hydrographic and chemical layer with a spatial scale of tens to thousands of kilometers [e.g., Lupton and Craig, 1981; Baker and Massoth, 1987; Speer and Rona, 1989].

Genomic Analysis of the Emergence and Rapid Global Dissemination of the Clonal Group 258 Klebsiella pneumoniae Pandemic.

Directory of Open Access Journals (Sweden)

Jolene R Bowers

Full Text Available Multidrug-resistant Klebsiella pneumoniae producing the KPC carbapenemase have rapidly spread throughout the world, causing severe healthcare-associated infections with limited antimicrobial treatment options. Dissemination of KPC-producing K. pneumoniae is largely attributed to expansion of a single dominant strain, ST258. In this study, we explore phylogenetic relationships and evolution within ST258 and its clonal group, CG258, using whole genome sequence analysis of 167 isolates from 20 countries collected over 17 years. Our results show a common ST258 ancestor emerged from its diverse parental clonal group around 1995 and likely acquired blaKPC prior to dissemination. Over the past two decades, ST258 has remained highly clonal despite diversity in accessory elements and divergence in the capsule polysaccharide synthesis locus. Apart from the large recombination event that gave rise to ST258, few mutations set it apart from its clonal group. However, one mutation occurs in a global transcription regulator. Characterization of outer membrane protein sequences revealed a profile in ST258 that includes a truncated OmpK35 and modified OmpK37. Our work illuminates potential genomic contributors to the pathogenic success of ST258, helps us better understand the global dissemination of this strain, and identifies genetic markers unique to ST258.

Identifying influential spreaders in complex networks through local effective spreading paths

Science.gov (United States)

Wang, Xiaojie; Zhang, Xue; Yi, Dongyun; Zhao, Chengli

2017-05-01

How to effectively identify a set of influential spreaders in complex networks is of great theoretical and practical value, which can help to inhibit the rapid spread of epidemics, promote the sales of products by word-of-mouth advertising, and so on. A naive strategy is to select the top ranked nodes as identified by some centrality indices, and other strategies are mainly based on greedy methods and heuristic methods. However, most of those approaches did not concern the connections between nodes. Usually, the distances between the selected spreaders are very close, leading to a serious overlapping of their influence. As a consequence, the global influence of the spreaders in networks will be greatly reduced, which largely restricts the performance of those methods. In this paper, a simple and efficient method is proposed to identify a set of discrete yet influential spreaders. By analyzing the spreading paths in the network, we present the concept of effective spreading paths and measure the influence of nodes via expectation calculation. The numerical analysis in undirected and directed networks all show that our proposed method outperforms many other centrality-based and heuristic benchmarks, especially in large-scale networks. Besides, experimental results on different spreading models and parameters demonstrates the stability and wide applicability of our method.

Global Genomic Epidemiology of Salmonella enterica Serovar Typhimurium DT104

DEFF Research Database (Denmark)

Leekitcharoenphon, Pimlapas; Hendriksen, Rene S.; Le Hello, Simon

2016-01-01

It has been 30 years since the initial emergence and subsequent rapid global spread of multidrug-resistant Salmonella enterica serovar Typhimurium DT104 (MDR DT104). Nonetheless, its origin and transmission route have never been revealed. We used whole-genome sequencing (WGS) and temporally struc...

Bypassing the 'rapid-clearance-in-males-buffer': A fourth mechanism to explain how concurrency enhances STI spread.

Science.gov (United States)

Kenyon, Chris R

2017-12-01

A number of sexually transmitted infections (STIs) persist for a considerably shorter period in the male urethra than the vagina. If the gap between sequential partnerships is longer than the duration of STI colonization in males, then this would protect future female partners from this STI in a setting of serial monogamy. If, however, males have more than one partner at a time (concurrency), then this would enable the STI to bypass this gap/buffer. We therefore propose bypassing the rapid-clearance-in-males-buffer as a fourth mechanism, whereby concurrency could enhance the spread of STIs.

Global science: the eruption of Krakatau.

Science.gov (United States)

Dörries, Matthias

2003-01-01

The eruption of the volcano Krakatau in the Netherlands East Indies (Indonesia) in 1883 had worldwide impact. This was perceived in the three quite different types of global propagation that occurred after the eruption: a rapid pressure wave, noticeable only to measuring instruments, followed a few hours later by the spread of the news of the event, succeeded by a slowly expanding optical phenomenon that lasted for a couple of years. Krakatau was the first natural catastrophe of global magnitude that was almost immediately recognized as such throughout the world, largely thanks to the recently installed worldwide telegraphic network.

Global Navigation Satellite System (GNSS) Rapid Clock Product Summary from NASA CDDIS

Data.gov (United States)

National Aeronautics and Space Administration — This derived product set consists of Global Navigation Satellite System Rapid Clock Product Summary from the NASA Crustal Dynamics Data Information System (CDDIS)....

Mitochondrial Phylogenomics Resolves the Global Spread of Higher Termites, Ecosystem Engineers of the Tropics.

Science.gov (United States)

Bourguignon, Thomas; Lo, Nathan; Šobotník, Jan; Ho, Simon Y W; Iqbal, Naeem; Coissac, Eric; Lee, Maria; Jendryka, Martin M; Sillam-Dussès, David; Krížková, Barbora; Roisin, Yves; Evans, Theodore A

2017-03-01

The higher termites (Termitidae) are keystone species and ecosystem engineers. They have exceptional biomass and play important roles in decomposition of dead plant matter, in soil manipulation, and as the primary food for many animals, especially in the tropics. Higher termites are most diverse in rainforests, with estimated origins in the late Eocene (∼54 Ma), postdating the breakup of Pangaea and Gondwana when most continents became separated. Since termites are poor fliers, their origin and spread across the globe requires alternative explanation. Here, we show that higher termites originated 42-54 Ma in Africa and subsequently underwent at least 24 dispersal events between the continents in two main periods. Using phylogenetic analyses of mitochondrial genomes from 415 species, including all higher termite taxonomic and feeding groups, we inferred 10 dispersal events to South America and Asia 35-23 Ma, coinciding with the sharp decrease in global temperature, sea level, and rainforest cover in the Oligocene. After global temperatures increased, 23-5 Ma, there was only one more dispersal to South America but 11 to Asia and Australia, and one dispersal back to Africa. Most of these dispersal events were transoceanic and might have occurred via floating logs. The spread of higher termites across oceans was helped by the novel ecological opportunities brought about by environmental and ecosystem change, and led termites to become one of the few insect groups with specialized mammal predators. This has parallels with modern invasive species that have been able to thrive in human-impacted ecosystems. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Information spreading dynamics in hypernetworks

Science.gov (United States)

Suo, Qi; Guo, Jin-Li; Shen, Ai-Zhong

2018-04-01

Contact pattern and spreading strategy fundamentally influence the spread of information. Current mathematical methods largely assume that contacts between individuals are fixed by networks. In fact, individuals are affected by all his/her neighbors in different social relationships. Here, we develop a mathematical approach to depict the information spreading process in hypernetworks. Each individual is viewed as a node, and each social relationship containing the individual is viewed as a hyperedge. Based on SIS epidemic model, we construct two spreading models. One model is based on global transmission, corresponding to RP strategy. The other is based on local transmission, corresponding to CP strategy. These models can degenerate into complex network models with a special parameter. Thus hypernetwork models extend the traditional models and are more realistic. Further, we discuss the impact of parameters including structure parameters of hypernetwork, spreading rate, recovering rate as well as information seed on the models. Propagation time and density of informed nodes can reveal the overall trend of information dissemination. Comparing these two models, we find out that there is no spreading threshold in RP, while there exists a spreading threshold in CP. The RP strategy induces a broader and faster information spreading process under the same parameters.

Rapid estimation of the economic consequences of global earthquakes

Science.gov (United States)

Jaiswal, Kishor; Wald, David J.

2011-01-01

The U.S. Geological Survey's (USGS) Prompt Assessment of Global Earthquakes for Response (PAGER) system, operational since mid 2007, rapidly estimates the most affected locations and the population exposure at different levels of shaking intensities. The PAGER system has significantly improved the way aid agencies determine the scale of response needed in the aftermath of an earthquake. For example, the PAGER exposure estimates provided reasonably accurate assessments of the scale and spatial extent of the damage and losses following the 2008 Wenchuan earthquake (Mw 7.9) in China, the 2009 L'Aquila earthquake (Mw 6.3) in Italy, the 2010 Haiti earthquake (Mw 7.0), and the 2010 Chile earthquake (Mw 8.8). Nevertheless, some engineering and seismological expertise is often required to digest PAGER's exposure estimate and turn it into estimated fatalities and economic losses. This has been the focus of PAGER's most recent development. With the new loss-estimation component of the PAGER system it is now possible to produce rapid estimation of expected fatalities for global earthquakes (Jaiswal and others, 2009). While an estimate of earthquake fatalities is a fundamental indicator of potential human consequences in developing countries (for example, Iran, Pakistan, Haiti, Peru, and many others), economic consequences often drive the responses in much of the developed world (for example, New Zealand, the United States, and Chile), where the improved structural behavior of seismically resistant buildings significantly reduces earthquake casualties. Rapid availability of estimates of both fatalities and economic losses can be a valuable resource. The total time needed to determine the actual scope of an earthquake disaster and to respond effectively varies from country to country. It can take days or sometimes weeks before the damage and consequences of a disaster can be understood both socially and economically. The objective of the U.S. Geological Survey's PAGER system is

Global environment and cogeneration

International Nuclear Information System (INIS)

Miyahara, Atsushi

1992-01-01

The environment problems on global scale have been highlighted in addition to the local problems due to the rapid increase of population, the increase of energy demand and so on. The global environment summit was held in Brazil. Now, global environment problems are the problems for mankind, and their importance seems to increase toward 21st century. In such circumstances, cogeneration can reduce carbon dioxide emission in addition to energy conservation, therefore, attention has been paid as the countermeasure for global environment. The background of global environment problems is explained. As to the effectiveness of cogeneration for global environment, the suitability of city gas to environment, energy conservation, the reduction of carbon dioxide and nitrogen oxides emission are discussed. As for the state of spread of cogeneration, as of March, 1992, those of 2250 MW in terms of power generation capacity have been installed in Japan. It is forecast that cogeneration will increase hereafter. As the future systems of cogeneration, city and industry energy center conception, industrial repowering, multiple house cogeneration and fuel cells are described. (K.I.)

Free energy analysis of cell spreading.

Science.gov (United States)

McEvoy, Eóin; Deshpande, Vikram S; McGarry, Patrick

2017-10-01

In this study we present a steady-state adaptation of the thermodynamically motivated stress fiber (SF) model of Vigliotti et al. (2015). We implement this steady-state formulation in a non-local finite element setting where we also consider global conservation of the total number of cytoskeletal proteins within the cell, global conservation of the number of binding integrins on the cell membrane, and adhesion limiting ligand density on the substrate surface. We present a number of simulations of cell spreading in which we consider a limited subset of the possible deformed spread-states assumed by the cell in order to examine the hypothesis that free energy minimization drives the process of cell spreading. Simulations suggest that cell spreading can be viewed as a competition between (i) decreasing cytoskeletal free energy due to strain induced assembly of cytoskeletal proteins into contractile SFs, and (ii) increasing elastic free energy due to stretching of the mechanically passive components of the cell. The computed minimum free energy spread area is shown to be lower for a cell on a compliant substrate than on a rigid substrate. Furthermore, a low substrate ligand density is found to limit cell spreading. The predicted dependence of cell spread area on substrate stiffness and ligand density is in agreement with the experiments of Engler et al. (2003). We also simulate the experiments of Théry et al. (2006), whereby initially circular cells deform and adhere to "V-shaped" and "Y-shaped" ligand patches. Analysis of a number of different spread states reveals that deformed configurations with the lowest free energy exhibit a SF distribution that corresponds to experimental observations, i.e. a high concentration of highly aligned SFs occurs along free edges, with lower SF concentrations in the interior of the cell. In summary, the results of this study suggest that cell spreading is driven by free energy minimization based on a competition between decreasing

Rapid spread and association of Schmallenberg virus with ruminant abortions and foetal death in Austria in 2012/2013.

Science.gov (United States)

Steinrigl, Adolf; Schiefer, Peter; Schleicher, Corina; Peinhopf, Walter; Wodak, Eveline; Bagó, Zoltán; Schmoll, Friedrich

2014-10-15

Schmallenberg virus (SBV) has emerged in summer-autumn 2011 in north-western Europe. Since then, SBV has been continuously spreading over Europe, including Austria, where antibodies to SBV, as well as SBV genome, were first detected in autumn 2012. This study was performed to demonstrate the dynamics of SBV spread within Austria, after its probable first introduction in summer 2012. True seroprevalence estimates for cattle and small ruminates were calculated to demonstrate temporal and regional differences of infection. Furthermore, the probability of SBV genome detection in foetal tissues of aborted or stillborn cattle and small ruminants as well as in allantoic fluid samples from cows with early foetal losses was retrospectively assessed. SBV first reached Austria most likely in July-August 2012, as indicated by retrospective detection of SBV antibodies and SBV genome in archived samples. From August to October 2012, a rapid increase in seroprevalence to over 98% in cattle and a contemporaneous peak in the detection of SBV genome in foetal tissues and allantoic fluid samples was noted, indicating widespread acute infections. Notably, foetal malformations were absent in RT-qPCR positive foetuses at this time of the epidemic. SBV spread within Austrian cattle reached a plateau phase as early as October 2012, without significant regional differences in SBV seroprevalence (98.4-100%). Estimated true seroprevalences among small ruminates were comparatively lower than in cattle and regionally different (58.3-95.6% in October 2012), potentially indicating an eastward spread of the infection, as well as different infection dynamics between cattle and small ruminants. Additionally, the probability of SBV genome detection over time differed significantly between small ruminant and cattle samples subjected to RT-qPCR testing. Copyright © 2014 Elsevier B.V. All rights reserved.

Introduction: simultaneously global and local: reassessing smallpox vaccination and its spread, 1789-1900.

Science.gov (United States)

Bhattacharya, Sanjoy; Brimnes, Niels

2009-01-01

The last two decades have seen a reawakening of scholarly interest in the history of smallpox prevention. Accounts of vaccination and others efforts at controlling smallpox have moved away from heroic narratives toward more nuanced and contextualized understandings. It is now accepted that several viruses traveled under the vaccine label from the outset, and it has been demonstrated that a variety of techniques were used to perform vaccination operations. The character of nineteenth century sea voyages that took the vaccine to distant territories has also been re-examined; sometimes the spread of the vaccine was caused by private networks and ad hoc decisions, while at other times it was the result of enterprises with close resemblances to contemporary centralized vaccination campaigns. Looking beyond Europe and North America we encounter a variety of state attitudes toward vaccination, ranging from concentrated efforts to spread the technique to efforts more uncertain and diluted. Although the reluctance to accept vaccination has been amply documented, recent studies emphasize this should not be attributed to simplistic dichotomies of modernity versus tradition or science versus culture; instead, instances of resistance are best studied as specific contextualized interactions. Indeed, factors like favorable geography, strong bureaucratic structures, and the absence of variolation seem to have helped the relatively smooth transfer of vaccination technologies. Perhaps most important, recent research encourages us to continue to study smallpox vaccination as a phenomenon that was simultaneously global and local.

Turbulence Spreading into Linearly Stable Zone and Transport Scaling

International Nuclear Information System (INIS)

Hahm, T.S.; Diamond, P.H.; Lin, Z.; Itoh, K.; Itoh, S.-I.

2003-01-01

We study the simplest problem of turbulence spreading corresponding to the spatio-temporal propagation of a patch of turbulence from a region where it is locally excited to a region of weaker excitation, or even local damping. A single model equation for the local turbulence intensity I(x, t) includes the effects of local linear growth and damping, spatially local nonlinear coupling to dissipation and spatial scattering of turbulence energy induced by nonlinear coupling. In the absence of dissipation, the front propagation into the linearly stable zone occurs with the property of rapid progression at small t, followed by slower subdiffusive progression at late times. The turbulence radial spreading into the linearly stable zone reduces the turbulent intensity in the linearly unstable zone, and introduces an additional dependence on the rho* is always equal to rho i/a to the turbulent intensity and the transport scaling. These are in broad, semi-quantitative agreements with a number of global gyrokinetic simulation results with zonal flows and without zonal flows. The front propagation stops when the radial flux of fluctuation energy from the linearly unstable region is balanced by local dissipation in the linearly stable region

Dogwood Anthracnose and its Spread in the South

Science.gov (United States)

Robert L. Anderson; John L. Knighten; Keith Langdon; Floyd Hedrix; Ron Roncadori

In the 15 years since it was first reported in the United States, dogwood anthracnose (caused by Discula destructive sp. nov.) has spread rapidly and caused serious losses among flowering dogwoods (Cornus florida L.), particularly in the South. Infection begins in leaves and spreads to twigs and branches, which dieback. Main-stem infections cause cankers, which kill...

Rapid deployable global sensing hazard alert system

Science.gov (United States)

Cordaro, Joseph V; Tibrea, Steven L; Shull, Davis J; Coleman, Jerry T; Shuler, James M

2015-04-28

A rapid deployable global sensing hazard alert system and associated methods of operation are provided. An exemplary system includes a central command, a wireless backhaul network, and a remote monitoring unit. The remote monitoring unit can include a positioning system configured to determine a position of the remote monitoring unit based on one or more signals received from one or more satellites located in Low Earth Orbit. The wireless backhaul network can provide bidirectional communication capability independent of cellular telecommunication networks and the Internet. An exemplary method includes instructing at least one of a plurality of remote monitoring units to provide an alert based at least in part on a location of a hazard and a plurality of positions respectively associated with the plurality of remote monitoring units.

Hybrid epidemic spreading - from Internet worms to HIV infection

OpenAIRE

Zhang, C.

2015-01-01

Epidemic phenomena are ubiquitous, ranging from infectious diseases, computer viruses, to information dissemination. Epidemics have traditionally been studied as a single spreading process, either in a fully mixed population or on a network. Many epidemics, however, are hybrid, employing more than one spreading mechanism. For example, the Internet worm Conficker spreads locally targeting neighbouring computers in local networks as well as globally by randomly probing any computer on the Inter...

Molecular phylogeography of canine distemper virus: Geographic origin and global spreading.

Science.gov (United States)

Panzera, Yanina; Sarute, Nicolás; Iraola, Gregorio; Hernández, Martín; Pérez, Ruben

2015-11-01

Canine distemper virus (CDV) (Paramyxoviridae-Morbillivirus) is a worldwide spread virus causing a fatal systemic disease in a broad range of carnivore hosts. In this study we performed Bayesian inferences using 208 full-length hemagglutinin gene nucleotide sequences isolated in 16 countries during 37 years (1975-2011). The estimated time to the most recent common ancestor suggested that current CDV strains emerged in the United States in the 1880s. This ancestor diversified through time into two ancestral clades, the current America 1 lineage that recently spread to Asia, and other ancestral clade that diversified and spread worldwide to originate the remaining eight lineages characterized to date. The spreading of CDV was characterized by several migratory events with posterior local differentiation, and expansion of the virus host range. A significant genetic flow between domestic and wildlife hosts is displayed; being domestic hosts the main viral reservoirs worldwide. This study is an extensive and integrative description of spatio/temporal population dynamics of CDV lineages that provides a novel evolutionary paradigm about the origin and dissemination of the current strains of the virus. Copyright © 2015 Elsevier Inc. All rights reserved.

FACTORS INFLUENCING YIELD SPREADS OF THE MALAYSIAN BONDS

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Norliza Ahmad

2009-01-01

Full Text Available Malaysian bond market is developing rapidly but not much is understood in terms of macroeconomic factors that could influence the yield spread of the Ringgit Malaysian denominated bonds. Based on a multifactor model, this paper examines the impact of four macroeconomic factors namely: Kuala Lumpur Composite Index (KLCI, Industry Production Index (IPI, Consumer Price Index (CPI and interest rates (IR on bond yield spread of the Malaysian Government Securities (MGS and Corporate Bonds (CBs for a period from January 2001 to December 2008. The findings support the expected hypotheses that CPI and IR are the major drivers that influence the changes in MGS yield spreads. However IPI and KLCI have weak and no influence on MGS yield spreads respectively Whilst IR, CPI and IPI have significant influence on the yield spreads of CB1, CB2 and CB3, KLCI has significant influence only on the CB1 yield spread but not on CB2 and CB3 yield spreads.

Regime-dependent determinants of Euro area sovereign CDS spreads

NARCIS (Netherlands)

Blommestein, H.J.; Eijffinger, Sylvester; Qian, Zongxin

We study the determinants of sovereign CDS spreads of five Euro area countries (Greece, Ireland, Italy, Portugal, and Spain) after the collapse of Lehman Brothers. We find that global and/or European Monetary Union (EMU)-wide factors are the main drivers of changes in the sovereign CDS spreads in

Modulators of mercury risk to wildlife and humans in the context of rapid global change

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Eagles-Smith, Collin A.; Silbergeld, Ellen K.; Basu, Niladri; Bustamante, Paco; Diaz-Barriga, Fernando; Hopkins, William A.; Kidd, Karen A.; Nyland, Jennifer F.

2018-01-01

Environmental mercury (Hg) contamination is an urgent global health threat. The complexity of Hg in the environment can hinder accurate determination of ecological and human health risks, particularly within the context of the rapid global changes that are altering many ecological processes, socioeconomic patterns, and other factors like infectious disease incidence, which can affect Hg exposures and health outcomes. However, the success of global Hg-reduction efforts depends on accurate assessments of their effectiveness in reducing health risks. In this paper, we examine the role that key extrinsic and intrinsic drivers play on several aspects of Hg risk to humans and organisms in the environment. We do so within three key domains of ecological and human health risk. First, we examine how extrinsic global change drivers influence pathways of Hg bioaccumulation and biomagnification through food webs. Next, we describe how extrinsic socioeconomic drivers at a global scale, and intrinsic individual-level drivers, influence human Hg exposure. Finally, we address how the adverse health effects of Hg in humans and wildlife are modulated by a range of extrinsic and intrinsic drivers within the context of rapid global change. Incorporating components of these three domains into research and monitoring will facilitate a more holistic understanding of how ecological and societal drivers interact to influence Hg health risks.

Social networks and spreading of epidemics

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Trimper, Steffen; Zheng, Dafang; Brandau, Marian

2004-05-01

Epidemiological processes are studied within a recently proposed social network model using the susceptible-infected-refractory dynamics (SIR) of an epidemic. Within the network model, a population of individuals may be characterized by H independent hierarchies or dimensions, each of which consists of groupings of individuals into layers of subgroups. Detailed numerical simulations reveals that for H > 1, the global spreading results regardless of the degree of homophily α of the individuals forming a social circle. For H = 1, a transition from a global to a local spread occurs as the population becomes decomposed into increasingly homophilous groups. Multiple dimensions in classifying individuals (nodes) thus make a society (computer network) highly susceptible to large scale outbreaks of infectious diseases (viruses). The SIR-model can be extended by the inclusion of waiting times resulting in modified distribution function of the recovered.

The spread and effect of HIV-1 infection in sub-Saharan Africa.

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Buvé, Anne; Bishikwabo-Nsarhaza, Kizito; Mutangadura, Gladys

2002-06-08

Africa is the continent most severely affected by the global HIV-1 epidemic, with east and southern Africa in general more severely affected than west and central Africa. Differences in the spread of the epidemic can be accounted for by a complex interplay of sexual behaviour and biological factors that affect the probability of HIV-1 transmission per sex act. Sexual behaviour patterns are determined by cultural and socioeconomic contexts. In sub-Saharan Africa, some traditions and socioeconomic developments have contributed to the extensive spread of HIV-1 infection, including the subordinate position of women, impoverishment and decline of social services, rapid urbanisation and modernisation, and wars and conflicts. Populations in many parts of Africa are becoming trapped in a vicious circle as the HIV-1 epidemic leads to high mortality rates in young and economically productive age groups, and thus leads to further impoverishment. Interventions to control HIV-1 should not only target individuals, but also aim to change those aspects of cultural and socioeconomic context that increase the vulnerability to HIV-1 of people and communities.

Rapid spread of suicide by charcoal burning from 2007 to 2011 in Korea.

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Lee, Ah-Rong; Ahn, Myung Hee; Lee, Tae Yeop; Park, Subin; Hong, Jin Pyo

2014-11-30

Despite rapid increase of suicide by charcoal burning within 5 years, little is known about the characteristics of charcoal burning suicide in Korea. This study aimed to examine the trends and risk factors in the spread of suicide using this method. We identified an association between media reporting of suicide by charcoal burning and its incidence. Data on suicide from 2007 to 2011 were obtained from the Korean National Statistical Office. Cross-correlation analysis was used. Increasing incidence of suicide by charcoal burning was correlated with higher education levels, male sex, and the latter half of the year. Victims of charcoal burning suicide were more likely to be young, male, single, highly educated, professional, urban-based, and to die between October and December. Internet reports of suicide via charcoal burning tended to precede the increased incidence of suicide using this method, but only during the early period of the suicide epidemic. Our findings suggest that one episode of heavy media coverage of a novel method, such as charcoal burning, is sufficient to increase the prevalence of suicide by that method even after media coverage decreases. These findings are expected to contribute to the prevention of increasing rates of suicide by charcoal burning. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Spread of endemic disease and global change in an educational project: proposition of relationships developed in a twin partnership

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Michela Viale

2012-07-01

Full Text Available The sudden event of the spread of dengue fever (or break-bone fever that appeared for the first time in Cape Verde in 2009 revealed that inappropriate management of waste can be considered a major cause of the spread of this disease. Dengue fever is a tropical infectious disease that is caused by the dengue virus. Its vector, the mosquito Aedes aegypti, found an optimal environment for its life cycle in the context of Cape Verde, with the persistence of water in abandoned waste objects. The connection between the topics of Earth sciences and the spread of this disease is not obvious, but it was explored and illustrated in a school partnership. Activities with pupils and students provided an opportunity to investigate how some global phenomena, like climate change (with an increase in local rainfall and higher temperatures, are related to local events, such as the spread of dengue fever. Preventive strategies are conditioned by the geomorphology of the territory and by the complex relationships that connect the geosphere and the biosphere. For this reason, it is important to be aware of the risk of breaking these delicate balances, and hence activating unexpected consequences. The roles played by both partners linked knowledge about the natural dynamics of our planet with the development of appropriate behavior, thus contributing to the formation of responsible citizenship, to preserve and protect the environment. The partnership encouraged students to develop sustainable management strategies against dengue fever, and consequently against waste, actively involving them at school, at home, and in their community. In this study, we present a case study of the role of a school partnership in a complex problem, such as the spread of dengue fever and environmental pollution.

The impact of awareness on epidemic spreading in networks.

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Wu, Qingchu; Fu, Xinchu; Small, Michael; Xu, Xin-Jian

2012-03-01

We explore the impact of awareness on epidemic spreading through a population represented by a scale-free network. Using a network mean-field approach, a mathematical model for epidemic spreading with awareness reactions is proposed and analyzed. We focus on the role of three forms of awareness including local, global, and contact awareness. By theoretical analysis and simulation, we show that the global awareness cannot decrease the likelihood of an epidemic outbreak while both the local awareness and the contact awareness can. Also, the influence degree of the local awareness on disease dynamics is closely related with the contact awareness.

Rapid fore-arc extension and detachment-mode spreading following subduction initiation

NARCIS (Netherlands)

Morris, Antony; Anderson, Mark W.; Omer, Ahmed; Maffione, Marco; van Hinsbergen, Douwe J.J.

2017-01-01

Most ophiolites have geochemical signatures that indicate formation by suprasubduction seafloor spreading above newly initiated subduction zones, and hence they record fore-arc processes operating following subduction initiation. They are frequently underlain by a metamorphic sole formed at the top

REGIME SWITCHING DETERMINANTS OF SOVEREIGN CDS SPREADS: EVIDENCE FROM TURKEY

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Umurcan Polat

2017-12-01

Full Text Available In this study, it is assessed the main determinants of sovereign CDS spreads in Turkey from January 2006 to December 2015. Before delving into the nonlinear Markov regime-switching model estimation, a conventional one-state linear model is estimated answering to what extent the sovereign credit risk is affected in between global and country-specific market variables and by credit ratings announcement changes. In broad strokes, the regime-switching analysis reveals that among domestic variables, it is the foreign exchange rate that affects the sovereign credit risk more in more volatile periods and among global variables, the indicators standing for global volatility risk premiums and international liquidity primarily influence the changes in the sovereign CDS spread in turbulent regimes whereas proxies for global risk free rate are significant more in tranquil regimes.

The landscape genetics of infectious disease emergence and spread.

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Biek, Roman; Real, Leslie A

2010-09-01

The spread of parasites is inherently a spatial process often embedded in physically complex landscapes. It is therefore not surprising that infectious disease researchers are increasingly taking a landscape genetics perspective to elucidate mechanisms underlying basic ecological processes driving infectious disease dynamics and to understand the linkage between spatially dependent population processes and the geographic distribution of genetic variation within both hosts and parasites. The increasing availability of genetic information on hosts and parasites when coupled to their ecological interactions can lead to insights for predicting patterns of disease emergence, spread and control. Here, we review research progress in this area based on four different motivations for the application of landscape genetics approaches: (i) assessing the spatial organization of genetic variation in parasites as a function of environmental variability, (ii) using host population genetic structure as a means to parameterize ecological dynamics that indirectly influence parasite populations, for example, gene flow and movement pathways across heterogeneous landscapes and the concurrent transport of infectious agents, (iii) elucidating the temporal and spatial scales of disease processes and (iv) reconstructing and understanding infectious disease invasion. Throughout this review, we emphasize that landscape genetic principles are relevant to infection dynamics across a range of scales from within host dynamics to global geographic patterns and that they can also be applied to unconventional 'landscapes' such as heterogeneous contact networks underlying the spread of human and livestock diseases. We conclude by discussing some general considerations and problems for inferring epidemiological processes from genetic data and try to identify possible future directions and applications for this rapidly expanding field.

FACTORS INFLUENCING YIELD SPREADS OF THE MALAYSIAN BONDS

OpenAIRE

Norliza Ahmad; Joriah Muhammad; Tajul Ariffin Masron

2009-01-01

Malaysian bond market is developing rapidly but not much is understood in terms of macroeconomic factors that could influence the yield spread of the Ringgit Malaysian denominated bonds. Based on a multifactor model, this paper examines the impact of four macroeconomic factors namely: Kuala Lumpur Composite Index (KLCI), Industry Production Index (IPI), Consumer Price Index (CPI) and interest rates (IR) on bond yield spread of the Malaysian Government Securities (MGS) and Corporate Bonds (CBs...

Lattice model for influenza spreading with spontaneous behavioral changes.

Science.gov (United States)

Fierro, Annalisa; Liccardo, Antonella

2013-01-01

Individual behavioral response to the spreading of an epidemic plays a crucial role in the progression of the epidemic itself. The risk perception induces individuals to adopt a protective behavior, as for instance reducing their social contacts, adopting more restrictive hygienic measures or undergoing prophylaxis procedures. In this paper, starting with a previously developed lattice-gas SIR model, we construct a coupled behavior-disease model for influenza spreading with spontaneous behavioral changes. The focus is on self-initiated behavioral changes that alter the susceptibility to the disease, without altering the contact patterns among individuals. Three different mechanisms of awareness spreading are analyzed: the local spreading due to the presence in the neighborhood of infective individuals; the global spreading due to the news published by the mass media and to educational campaigns implemented at institutional level; the local spreading occurring through the "thought contagion" among aware and unaware individuals. The peculiarity of the present approach is that the awareness spreading model is calibrated on available data on awareness and concern of the population about the risk of contagion. In particular, the model is validated against the A(H1N1) epidemic outbreak in Italy during the 2009/2010 season, by making use of the awareness data gathered by the behavioral risk factor surveillance system (PASSI). We find that, increasing the accordance between the simulated awareness spreading and the PASSI data on risk perception, the agreement between simulated and experimental epidemiological data improves as well. Furthermore, we show that, within our model, the primary mechanism to reproduce a realistic evolution of the awareness during an epidemic, is the one due to globally available information. This result highlights how crucial is the role of mass media and educational campaigns in influencing the epidemic spreading of infectious diseases.

Lattice model for influenza spreading with spontaneous behavioral changes.

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Annalisa Fierro

Full Text Available Individual behavioral response to the spreading of an epidemic plays a crucial role in the progression of the epidemic itself. The risk perception induces individuals to adopt a protective behavior, as for instance reducing their social contacts, adopting more restrictive hygienic measures or undergoing prophylaxis procedures. In this paper, starting with a previously developed lattice-gas SIR model, we construct a coupled behavior-disease model for influenza spreading with spontaneous behavioral changes. The focus is on self-initiated behavioral changes that alter the susceptibility to the disease, without altering the contact patterns among individuals. Three different mechanisms of awareness spreading are analyzed: the local spreading due to the presence in the neighborhood of infective individuals; the global spreading due to the news published by the mass media and to educational campaigns implemented at institutional level; the local spreading occurring through the "thought contagion" among aware and unaware individuals. The peculiarity of the present approach is that the awareness spreading model is calibrated on available data on awareness and concern of the population about the risk of contagion. In particular, the model is validated against the A(H1N1 epidemic outbreak in Italy during the 2009/2010 season, by making use of the awareness data gathered by the behavioral risk factor surveillance system (PASSI. We find that, increasing the accordance between the simulated awareness spreading and the PASSI data on risk perception, the agreement between simulated and experimental epidemiological data improves as well. Furthermore, we show that, within our model, the primary mechanism to reproduce a realistic evolution of the awareness during an epidemic, is the one due to globally available information. This result highlights how crucial is the role of mass media and educational campaigns in influencing the epidemic spreading of infectious

Rapid Internationalization of SMEs: Evidence from Born Global Firms in Chile

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Christian A. Cancino

2014-10-01

Full Text Available The literature on born global firms in developed countries has revealed some factors that influence the rapid internationalization of Small and Medium Enterprises (SMEs, such as the technological level of the sector in which the firm participates, psychological and geographical distances from the target markets, and the existence of contact networks. To date, little research has been carried out on this topic for Latin American countries. This paper explores how certain determinants influence Chilean born global firms. A logistic regression model is used to analyze 112 SMEs with regular export activities. The results show that Chilean born global firms are influenced by national and international contact networks that their founders are able to generate. The psychological distance between Chilean SMEs and developed countries in Asia, North America and Europe also influences the internationalization of Chilean SMEs. The principal characteristic of Chilean born global firms is their lack of participation in highly technological sectors, with these SMEs instead being involved in sectors that actively exploit natural resources. The results of this study permit certain public policy recommendations to be made that might boost the development of export SMEs.

Dynamics of cell area and force during spreading.

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Brill-Karniely, Yifat; Nisenholz, Noam; Rajendran, Kavitha; Dang, Quynh; Krishnan, Ramaswamy; Zemel, Assaf

2014-12-16

Experiments on human pulmonary artery endothelial cells are presented to show that cell area and the force exerted on a substrate increase simultaneously, but with different rates during spreading; rapid-force increase systematically occurred several minutes past initial spreading. We examine this theoretically and present three complementary mechanisms that may accompany the development of lamellar stress during spreading and underlie the observed behavior. These include: 1), the dynamics of cytoskeleton assembly at the cell basis; 2), the strengthening of acto-myosin forces in response to the generated lamellar stresses; and 3), the passive strain-stiffening of the cytoskeleton. Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.

[Globalization and infectious diseases].

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Mirski, Tomasz; Bartoszcze, Michał; Bielawska-Drózd, Agata

2011-01-01

Globalization is a phenomenon characteristic of present times. It can be considered in various aspects: economic, environmental changes, demographic changes, as well as the development of new technologies. All these aspects of globalization have a definite influence on the emergence and spread of infectious diseases. Economic aspects ofglobalization are mainly the trade development, including food trade, which has an impact on the spread of food-borne diseases. The environmental changes caused by intensive development of industry, as a result of globalization, which in turn affects human health. The demographic changes are mainly people migration between countries and rural and urban areas, which essentially favors the global spread of many infectious diseases. While technological advances prevents the spread of infections, for example through better access to information, it may also increase the risk, for example through to create opportunities to travel into more world regions, including the endemic regions for various diseases. The phenomenon ofglobalization is also closely associated with the threat of terrorism, including bioterrorism. It forces the governments of many countries to develop effective programs to protect and fight against this threat.

Sovereign bonds in developing countries: Drivers of issuance and spreads

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Andrea F. Presbitero

2016-06-01

Full Text Available In the last decade there has been a new wave of sovereign bond issuances in Africa. What determines the ability of developing countries to issue bonds in international capital and what explains the spreads on these bonds? This paper examines these questions using a dataset that includes 105 developing countries during the period 1995–2014. We find that a country is more likely to issue a bond when, in comparison with non-issuing peers, it is larger in economic size, has higher per capita GDP, a lower public debt, and a more effective government. Spreads on sovereign bonds are lower for countries with strong external and fiscal positions, as well as robust economic growth and government effectiveness. We also find that primary spreads for the average Sub-Saharan African issuer are higher than in other regions. With regard to global factors, our results confirm the existing evidence that issuances are more likely during periods of global liquidity and high commodity prices, especially for Sub-Saharan African countries, and spreads are higher in periods of higher market volatility.

Process contributions to the intermodel spread in amplified Arctic warming

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Boeke, R.; Taylor, P. C.

2016-12-01

The Arctic is warming at a rate more than twice the global average. This robust climate system response to an external forcing is referred to as Arctic Amplification (AA). While Coupled Model Intercomparison Project 5 (CMIP5) climate models simulate AA, the largest intermodel spread in projected warming is also found in the Arctic. Quantifying the amount of polar warming relative to global warming influences how society adapts to climate change; a 2°C increase in global mean temperature would result in a polar warming between 4-8°C according to the intermodel spread in CMIP5 simulations. A trove of previous work has considered AA diagnostically using variations in the surface energy budget to attribute the intermodel spread in AA to an assortment of feedbacks—surface albedo, cloud, surface turbulent flux, and atmospheric and oceanic energy transport. We consider a systems-thinking approach treating AA as a process that evolves over time. We hypothesize that two specific components of the AA process are most important and influence the intermodel spread. (1) The inability of the Arctic system to effectively remove excess heat sourced from natural variability. The change in the efficiency of the `Arctic air conditioner' is thought to be due to thinner and less extensive sea ice and the resulting ice albedo feedback. (2) The process through which energy is stored in the ocean and exchanged with the atmosphere within the context of the sea ice annual cycle is also important. This study uses CMIP5 simulations from the historical and RCP8.5 (Representative Concentration Pathway; an emission scenario with forcing increasing to 8.5 W m-2 by 2100) to analyze how the AA process operates in present and future climate. The intermodel spread in these processes and the influence on the spread in AA are discussed. This approach identifies models that more realistically simulate the AA process and will aid in narrowing intermodel spread in Arctic surface temperature

Red brome (Bromus rubens subsp. madritensis) in North America: Possible modes for early introductions, subsequent spread

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Salo, L.F.

2005-01-01

Although invasions by exotic plants have increased dramatically as human travel and commerce have increased, few have been comprehensively described. Understanding the patterns of invasive species spread over space and time will help guide management activities and policy. Tracing the earliest appearances of an exotic plant reveals likely sites of introduction, paving the way for genetic studies to quantify founder events and identify potential source populations. Red brome (Bromus madritensis subsp. rubens) is a Mediterranean winter annual grass that has invaded even relatively undisturbed areas of western North America, where it threatens native plant communities. This study used herbarium records and contemporary published accounts to trace the early introductions and subsequent spread of red brome in western North America. The results challenge the most frequently cited sources describing the early history of this grass and suggest three possible modes for early introductions: the California Gold Rush and Central Valley wheat, southern California shipping, and northern California sheep. Subsequent periods of most rapid spread into new areas, from 1930 to 1942, and of greatest spread into new regions, during the past 50 years, coincide with warm Pacific Decadal Oscillation regimes, which are linked to increased winter precipitation in the southwestern USA and northern Mexico. Global environmental change, including increased atmospheric CO2 levels and N deposition, may be contributing to the success of red brome, relative to native species.

Understanding the spreading patterns of mobile phone viruses

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Wang, Pu; Gonzalez, Marta; Hidalgo, Cesar; Barabasi, Albert-Laszlo

2009-03-01

Mobile viruses are little more than a nuisance today, but given our increased reliance on wireless communication, in the near future they could pose more risk than their PC based counterparts. Despite of the more than three hundred mobile viruses known so far, little is known about their spreading pattern, partly due to a lack of data on the communication and travel patterns of mobile phone users. Starting from the traffic and the communication pattern of six million mobile phone users, we model the vulnerability of mobile communications against potential virus outbreaks. We show that viruses exploiting Bluetooth and multimedia messaging services (MMS) follow markedly different spreading patterns. The Bluetooth virus can reach all susceptible handsets, but spreads relatively slowly, as its spread is driven by human mobility. In contrast, an MMS virus can spread rapidly, but because the underlying social network is fragmented, it can reach only a small fraction of all susceptible users. This difference affects both their spreading rate, the number of infected users, as well as the defense measures one needs to take to protect the system against potential viral outbreak.

Rapidly changing treatment options adding burden to the management of typhoid fever

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Jaspal Kaur

2015-01-01

Full Text Available Typhoid fever continues to be a global public health problem. It is caused by the facultative intracellular organisms Salmonella enteric serotype Typhi and Salmonella paratyphi. Antimicrobial therapy is the mainstay for treatment of typhoid fever. Chloramphenicol, ampicillin, and cotrimoxazole had been in use for decades for treating enteric fever. But the emergence and rapid spread of drug resistance has resulted in rapid shift of treatment options from chloramphenicol to fluoroquinolones to third generation cephalosporins to azithromycin with tigecycline and carbapenems in line, thus adding burden to the health-care sector in developing countries. Rational and judicious antibiotic prescribing practices by health professionals are necessary to prevent further development of drug resistance and help in re-emergence of sensitive strains.

Global Stability of an Epidemic Model of Computer Virus

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Xiaofan Yang

2014-01-01

Full Text Available With the rapid popularization of the Internet, computers can enter or leave the Internet increasingly frequently. In fact, no antivirus software can detect and remove all sorts of computer viruses. This implies that viruses would persist on the Internet. To better understand the spread of computer viruses in these situations, a new propagation model is established and analyzed. The unique equilibrium of the model is globally asymptotically stable, in accordance with the reality. A parameter analysis of the equilibrium is also conducted.

Reprising the globalization dimensions of international health.

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Labonté, Ronald

2018-05-18

Globalization is a fairly recent addition to the panoply of concepts describing the internationalization of health concerns. What distinguishes it from 'international health' or its newer morphing into 'global health' is a specific analytical concern with how globalization processes, past or present, but particularly since the start of our neoliberal era post-1980, is affecting health outcomes. Globalization processes influence health through multiple social pathways: from health systems and financing reforms to migration flows and internal displacement; via trade and investment treaties, labour market 'flexibilization', and the spread of unhealthy commodities; or through deploying human rights and environment protection treaties, and strengthening health diplomacy efforts, to create more equitable and sustainable global health outcomes. Globalization and Health was a pioneer in its focus on these critical facets of our health, well-being, and, indeed, planetary survival. In this editorial, the journal announces a re-focusing on this primary aim, announcing a number of new topic Sections and an expanded editorial capacity to ensure that submissions are 'on target' and processed rapidly, and that the journal continues to be on the leading edge of some of the most contentious and difficult health challenges confronting us.

The GLEaMviz computational tool, a publicly available software to explore realistic epidemic spreading scenarios at the global scale

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Quaggiotto Marco

2011-02-01

Full Text Available Abstract Background Computational models play an increasingly important role in the assessment and control of public health crises, as demonstrated during the 2009 H1N1 influenza pandemic. Much research has been done in recent years in the development of sophisticated data-driven models for realistic computer-based simulations of infectious disease spreading. However, only a few computational tools are presently available for assessing scenarios, predicting epidemic evolutions, and managing health emergencies that can benefit a broad audience of users including policy makers and health institutions. Results We present "GLEaMviz", a publicly available software system that simulates the spread of emerging human-to-human infectious diseases across the world. The GLEaMviz tool comprises three components: the client application, the proxy middleware, and the simulation engine. The latter two components constitute the GLEaMviz server. The simulation engine leverages on the Global Epidemic and Mobility (GLEaM framework, a stochastic computational scheme that integrates worldwide high-resolution demographic and mobility data to simulate disease spread on the global scale. The GLEaMviz design aims at maximizing flexibility in defining the disease compartmental model and configuring the simulation scenario; it allows the user to set a variety of parameters including: compartment-specific features, transition values, and environmental effects. The output is a dynamic map and a corresponding set of charts that quantitatively describe the geo-temporal evolution of the disease. The software is designed as a client-server system. The multi-platform client, which can be installed on the user's local machine, is used to set up simulations that will be executed on the server, thus avoiding specific requirements for large computational capabilities on the user side. Conclusions The user-friendly graphical interface of the GLEaMviz tool, along with its high level

Wavelength-Hopping Time-Spreading Optical CDMA With Bipolar Codes

Science.gov (United States)

Kwong, Wing C.; Yang, Guu-Chang; Chang, Cheng-Yuan

2005-01-01

Two-dimensional wavelength-hopping time-spreading coding schemes have been studied recently for supporting greater numbers of subscribers and simultaneous users than conventional one-dimensional approaches in optical code-division multiple-access (OCDMA) systems. To further improve both numbers without sacrificing performance, a new code design utilizing bipolar codes for both wavelength hopping and time spreading is studied and analyzed in this paper. A rapidly programmable, integratable hardware design for this new coding scheme, based on arrayed-waveguide gratings, is also discussed.

The Impact of Indonesia Sovereign Credit Rating Upgrades and Investment Grade Status on the Sovereign Spread Changes

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Dwi Anggi Novianti

2013-01-01

Full Text Available Getting sovereign credit rating upgrades and achieving investment grade status are main goals for countries in order to gain lower yield spread and cost of borrowing. By using ordinary least square method, this research is aimed to analyze the impact of Indonesia sovereign credit rating up-grade and investment grade status on sovereign spread changes. The result shows that the sovereign credit rating upgrades within speculative grade category and investment grade status for Indonesia do not significantly impact sovereign spread reduction. On the other hand, the global condition, especially global risk appetite, has significant impact to Indonesia sovereign yield spread. The research also indicates that Indonesia macroeconomic fundamentals do not significantly explain the movement of sovereign yield spread. Keywords: Yield spread, sovereign credit rating, investment grade, Indonesia

Spread of carbapenem-resistant Acinetobacter baumannii global clone 2 in Asia and AbaR-type resistance islands.

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Kim, Dae Hun; Choi, Ji-Young; Kim, Hae Won; Kim, So Hyun; Chung, Doo Ryeon; Peck, Kyong Ran; Thamlikitkul, Visanu; So, Thomas Man-Kit; Yasin, Rohani M D; Hsueh, Po-Ren; Carlos, Celia C; Hsu, Li Yang; Buntaran, Latre; Lalitha, M K; Song, Jae-Hoon; Ko, Kwan Soo

2013-11-01

In this surveillance study, we identified the genotypes, carbapenem resistance determinants, and structural variations of AbaR-type resistance islands among carbapenem-resistant Acinetobacter baumannii (CRAB) isolates from nine Asian locales. Clonal complex 92 (CC92), corresponding to global clone 2 (GC2), was the most prevalent in most Asian locales (83/108 isolates; 76.9%). CC108, or GC1, was a predominant clone in India. OXA-23 oxacillinase was detected in CRAB isolates from most Asian locales except Taiwan. blaOXA-24 was found in CRAB isolates from Taiwan. AbaR4-type resistance islands, which were divided into six subtypes, were identified in most CRAB isolates investigated. Five isolates from India, Malaysia, Singapore, and Hong Kong contained AbaR3-type resistance islands. Of these, three isolates harbored both AbaR3- and AbaR4-type resistance islands simultaneously. In this study, GC2 was revealed as a prevalent clone in most Asian locales, with the AbaR4-type resistance island predominant, with diverse variants. The significance of this study lies in identifying the spread of global clones of carbapenem-resistant A. baumannii in Asia.

Market Mobilities/Immobilities: Mutation, Path-Dependency, and the Spread of Charter School Policies in the United States

Science.gov (United States)

Cohen, Dan

2017-01-01

Over the past 25 years charter school policies have spread through the United States at a rapid pace. However, despite this rapid growth these policies have spread unevenly across the country with important variations in how charter school systems function in each state. Drawing on case studies in Michigan and Oregon, this article argues that…

Effects of Evaporation/Condensation on Spreading and Contact Angle of a Volatile Liquid Drop

Science.gov (United States)

Zhang, Nengli; Chao, David F.; Singh, Bhim S. (Technical Monitor)

2000-01-01

Effects of evaporation/condensation on spreading and contact angle were experimentally studied. A sessile drop of R-113 was tested at different vapor environments to determine the effects of evaporation/condensation on the evolution of contact diameter and contact angle of the drop. Condensation on the drop surface occurs at both the saturated and a nonsaturated vapor environments and promotes the spreading. When the drop is placed in the saturated vapor environment it tends to completely wetting and spreads rapidly. In a nonsaturated vapor environment, the evolution of the sessile drop is divided three stages: condensation-spreading stage, evaporation-retracting stage and rapid contracting stage. In the first stage the drop behaves as in the saturated environment. In the evaporation -retracting stage, the competition between spreading and evaporation of the drop determines the evolution characteristics of the contact diameter and the contact angle. A lower evaporation rate struggles against the spreading power to turn the drop from spreading to retracting with a continuous increase of the contact angle. The drop placed in open air has a much higher evaporation rate. The strong evaporation suppresses the spreading and accelerates the retraction of the drop with a linear decrease of the contact diameter. The contraction of the evaporating drops is gradually accelerated when the contact diameter decreases to 3 min and less till drying up, though the evaporation rate is gradually slowing down.

Spreading dynamics of 2D dipolar Langmuir monolayer phases.

Science.gov (United States)

Heinig, P; Wurlitzer, S; Fischer, Th M

2004-07-01

We study the spreading of a liquid 2D dipolar droplet in a Langmuir monolayer. Interfacial tensions (line tensions) and microscopic contact angles depend on the scale on which they are probed and obey a scaling law. Assuming rapid equilibration of the microscopic contact angle and ideal slippage of the 2D solid/liquid and solid/gas boundary, the driving force of spreading is merely expressed by the shape-dependent long-range interaction integrals. We obtain good agreement between experiment and numerical simulations using this theory.

Impact of international and local conditions on sovereign bond spreads: International evidence

Directory of Open Access Journals (Sweden)

Selma Izadi

2018-03-01

Full Text Available This paper examines the effect of international and domestic factors on the sovereign bond spreads for 22 developed countries in North America, Europe and Pacific Rim regions. First, for all the regions the impact of global factors on the sovereign bond spreads is more intense than regional factors. Second, the findings confirm that for the bond spreads of each region over its domestic government bonds, the countries’ local fundamentals are better determinants of the spreads compared to the spread over US government bonds as a safe haven. Third, the influence of worldwide factors in the Eurozone compared to other regions bond spreads is less. Fourth, the relationship of the market sentiment and the investor risk aversion with the sovereign bond spreads of all regions is positive. Equity market volatility plays significant role in yield speads in international bond markets.

Turbulent forces within river plumes affect spread

Science.gov (United States)

Bhattacharya, Atreyee

2012-08-01

When rivers drain into oceans through narrow mouths, hydraulic forces squeeze the river water into buoyant plumes that are clearly visible in satellite images. Worldwide, river plumes not only disperse freshwater, sediments, and nutrients but also spread pollutants and organisms from estuaries into the open ocean. In the United States, the Columbia River—the largest river by volume draining into the Pacific Ocean from North America—generates a plume at its mouth that transports juvenile salmon and other fish into the ocean. Clearly, the behavior and spread of river plumes, such as the Columbia River plume, affect the nation's fishing industry as well as the global economy.

The role of international travel in the worldwide spread of multiresistant Enterobacteriaceae.

Science.gov (United States)

van der Bij, Akke K; Pitout, Johann D D

2012-09-01

From international tourists to war-displaced refugees, more people are on the move than ever before. This provides the opportunity for a variety of antimicrobial-resistant bacteria to be carried from one geographic location to another. The Enterobacteriaceae are among the most important causes of serious hospital-acquired and community-onset bacterial infections in humans, and resistance to antimicrobial agents in these bacteria has become an increasingly relevant problem. International travel and tourism are important modes for the acquisition and spread of antimicrobial-resistant Enterobacteriaceae, especially CTX-M-producing Escherichia coli. Infections with KPC-, VIM-, OXA-48- and NDM-producing Enterobacteriaceae in developed countries have been associated with visiting and being hospitalized in endemic areas such as the USA, Greece and Israel for KPCs, Greece for VIMs, Turkey for OXA-48, and the Indian subcontinent for NDMs. To combat the spread of antimicrobial-resistant Enterobacteriaceae, the French Healthcare Safety Advisory Committee recently issued national recommendations for screening and contact isolation precautions for patients transferred from, or hospitalized outside, France. For effective public and patient health interventions, it is important to understand the role of international travel in the spread of antimicrobial-resistant Enterobacteriaceae. We urgently need well-designed studies to evaluate the transmission potential and risks for colonization and infections due to multiresistant Enterobacteriaceae in travellers who have recently visited or have been hospitalized in endemic areas. The emergence of CTX-M-, KPC- and NDM-producing bacteria is a good example of the role that globalization plays in the rapid dissemination of new antibiotic resistance mechanisms.

Global Delivery Models

DEFF Research Database (Denmark)

Manning, Stephan; Larsen, Marcus M.; Bharati, Pratyush

2013-01-01

This article examines antecedents and performance implications of global delivery models (GDMs) in global business services. GDMs require geographically distributed operations to exploit both proximity to clients and time-zone spread for efficient service delivery. We propose and empirically show...

Modelling fast spreading patterns of airborne infectious diseases using complex networks

Science.gov (United States)

Brenner, Frank; Marwan, Norbert; Hoffmann, Peter

2017-04-01

The pandemics of SARS (2002/2003) and H1N1 (2009) have impressively shown the potential of epidemic outbreaks of infectious diseases in a world that is strongly connected. Global air travelling established an easy and fast opportunity for pathogens to migrate globally in only a few days. This made epidemiological prediction harder. By understanding this complex development and its link to climate change we can suggest actions to control a part of global human health affairs. In this study we combine the following data components to simulate the outbreak of an airborne infectious disease that is directly transmitted from human to human: em{Global Air Traffic Network (from openflights.org) with information on airports, airport location, direct flight connection, airplane type} em{Global population dataset (from SEDAC, NASA)} em{Susceptible-Infected-Recovered (SIR) compartmental model to simulate disease spreading in the vicinity of airports. A modified Susceptible-Exposed-Infected-Recovered (SEIR) model to analyze the impact of the incubation period.} em{WATCH-Forcing-Data-ERA-Interim (WFDEI) climate data: temperature, specific humidity, surface air pressure, and water vapor pressure} These elements are implemented into a complex network. Nodes inside the network represent airports. Each single node is equipped with its own SIR/SEIR compartmental model with node specific attributes. Edges between those nodes represent direct flight connections that allow infected individuals to move between linked nodes. Therefore the interaction of the set of unique SIR models creates the model dynamics we will analyze. To better figure out the influence on climate change on disease spreading patterns, we focus on Influenza-like-Illnesses (ILI). The transmission rate of ILI has a dependency on climate parameters like humidity and temperature. Even small changes of environmental variables can trigger significant differences in the global outbreak behavior. Apart from the direct

Epidemic cholera in Latin America: spread and routes of transmission.

Science.gov (United States)

Guthmann, J P

1995-12-01

In the most recent epidemic of cholera in Latin America, nearly a million cases were reported and almost 9000 people died between January 1991 and December 1993. The epidemic spread rapidly from country to country, affecting in three years all the countries of Latin America except Uruguay and the Caribbean. Case-control studies carried out in Peru showed a significant association between drinking water and risk of disease. Cholera was associated with the consumption of unwashed fruit and vegetables, with eating food from street vendors and with contaminated crabmeat transported in travellers' luggage. This article documents the spread of the epidemic and its routes of transmission and discusses whether the introduction of the epidemic to Peru and its subsequent spread throughout the continent could have been prevented.

Avian Influenza spread and transmission dynamics

Science.gov (United States)

Bourouiba, Lydia; Gourley, Stephen A.; Liu, Rongsong; Takekawa, John Y.; Wu, Jianhong; Chen, Dongmei; Moulin, Bernard; Wu, Jianhong

2015-01-01

The spread of highly pathogenic avian influenza (HPAI) viruses of type A of subtype H5N1 has been a serious threat to global public health. Understanding the roles of various (migratory, wild, poultry) bird species in the transmission of these viruses is critical for designing and implementing effective control and intervention measures. Developing appropriate models and mathematical techniques to understand these roles and to evaluate the effectiveness of mitigation strategies have been a challenge. Recent development of the global health surveillance (especially satellite tracking and GIS techniques) and the mathematical theory of dynamical systems combined have gradually shown the promise of some cutting-edge methodologies and techniques in mathematical biology to meet this challenge.

The emergence of pan-resistant Gram-negative pathogens merits a rapid global political response.

Science.gov (United States)

Walsh, Timothy R; Toleman, Mark A

2012-01-01

Recent media coverage of New Delhi metallo-β-lactamase (NDM-1) put antibiotic resistance back on the political map if only for the wrong reasons, mainly the reaction to the naming of NDM-1 and the incorrect assumption that medical tourism was being deliberately targeted. However, work on NDM-1 has most certainly highlighted the rapid dissemination of new antibiotic resistance mechanisms via economic globalization. The example of NDM-1 has also magnified the desperate need for a publicly funded global antibiotic surveillance system rather than just national or regional systems. Furthermore, there is a pressing need to establish a global task force to enforce international transparency and accountability on antibiotic stewardship and the implementation of measures to curb antibiotic resistance. An international antibiotic stewardship index should be established that is related to each country's gross domestic product (GDP) and assesses how much of their GDP is committed to publically funded health initiatives aimed at controlling antibiotic resistance.

A spread willingness computing-based information dissemination model.

Science.gov (United States)

Huang, Haojing; Cui, Zhiming; Zhang, Shukui

2014-01-01

This paper constructs a kind of spread willingness computing based on information dissemination model for social network. The model takes into account the impact of node degree and dissemination mechanism, combined with the complex network theory and dynamics of infectious diseases, and further establishes the dynamical evolution equations. Equations characterize the evolutionary relationship between different types of nodes with time. The spread willingness computing contains three factors which have impact on user's spread behavior: strength of the relationship between the nodes, views identity, and frequency of contact. Simulation results show that different degrees of nodes show the same trend in the network, and even if the degree of node is very small, there is likelihood of a large area of information dissemination. The weaker the relationship between nodes, the higher probability of views selection and the higher the frequency of contact with information so that information spreads rapidly and leads to a wide range of dissemination. As the dissemination probability and immune probability change, the speed of information dissemination is also changing accordingly. The studies meet social networking features and can help to master the behavior of users and understand and analyze characteristics of information dissemination in social network.

The rapid spread of carbapenem-resistant Enterobacteriaceae

Science.gov (United States)

Potter, Robert F.; D’Souza, Alaric W.; Dantas, Gautam

2016-01-01

Carbapenems, our one-time silver bullet for multidrug resistant bacterial infections, are now threatened by widespread dissemination of carbapenem-resistant Enterobacteriaceae (CRE). Successful expansion of Enterobacteriaceae clonal groups and frequent horizontal gene transfer of carbapenemase expressing plasmids are causing increasing carbapenem resistance. Recent advances in genetic and phenotypic detection facilitate global surveillance of CRE diversity and prevalence. In particular, whole genome sequencing enabled efficient tracking, annotation, and study of genetic elements colocalized with carbapenemase genes on chromosomes and on plasmids. Improved characterization helps detail the co-occurrence of other antibiotic resistance genes in CRE isolates and helps identify pan-drug resistance mechanisms. The novel β-lactamase inhibitor, avibactam, combined with ceftazidime or aztreonam, is a promising CRE treatment compared to current colistin or tigecycline regimens. To halt increasing CRE-associated morbidity and mortality, we must continue quality, cooperative monitoring and urgently investigate novel treatments. PMID:27912842

Complementary factors contributing to the rapid spread of HIV-I in sub-Saharan Africa: a review.

Science.gov (United States)

Nyindo, M

2005-01-01

To examine and establish complementary factors that contribute to the alarmingly high prevalence of HIV-1 in sub-Saharan Africa (SSA) in order to create awareness and suggest possible measures to avert the spread of the pandemic. Review of literature via Medline, the Internet, articles in refereed journals, and un-refereed features from the East Africa media houses and personal communications. Most published data from 1981 to September 2004 found to have revealed an impact on the spread of HIV-1 in SSA were included in the review. Therefore, all selected articles were read and critically evaluated. Where possible the number of citations articles which had been received were sought to established the degree of impact. Abstracts of all articles identified were accessed, read and analysed to determined possible relevance to the spread of HIV-1. When relevance was established from the abstract the entire paper was read and important points were included in the review. A matrix was drawn to include all subtitles (e.g. polygamy, circumcision, poverty, etc). Below each subtitle all published works were included and prioritised. Published works that were found to have impact were included in the review. Finally a percent composite picture of all factors was drawn in an attempt to prioritise the factors, not withstanding the fact that most factors are interrelated and complementary. There are many reasons why the spread of HIV-1 in SSA has not been declining over the years. Main risk factors for HIV-1 infection and AIDS disease in SSA were found to include poverty, famine, low status of women in society, corruption, naive risk taking perception, resistance to sexual behaviour change, high prevalence of sexually transmitted infections (STI), internal conflicts and refugee status, antiquated beliefs, lack of recreational facilities, ignorance of individual's HIV status, child and adult prostitution, uncertainty of safety of blood intended for transfusion, widow inheritance

Multidrug-resistant Gram-negative bacteria: a product of globalization.

Science.gov (United States)

Hawkey, P M

2015-04-01

Global trade and mobility of people has increased rapidly over the last 20 years. This has had profound consequences for the evolution and the movement of antibiotic resistance genes. There is increasing exposure of populations all around the world to resistant bacteria arising in the emerging economies. Arguably the most important development of the last two decades in the field of antibiotic resistance is the emergence and spread of extended-spectrum β-lactamases (ESBLs) of the CTX-M group. A consequence of the very high rates of ESBL production among Enterobacteriaceae in Asian countries is that there is a substantial use of carbapenem antibiotics, resulting in the emergence of plasmid-mediated resistance to carbapenems. This article reviews the emergence and spread of multidrug-resistant Gram-negative bacteria, focuses on three particular carbapenemases--imipenem carbapenemases, Klebsiella pneumoniae carbapenemase, and New Delhi metallo-β-lactamase--and highlights the importance of control of antibiotic use. Copyright © 2015. Published by Elsevier Ltd.

The rapid spread of carbapenem-resistant Enterobacteriaceae.

Science.gov (United States)

Potter, Robert F; D'Souza, Alaric W; Dantas, Gautam

2016-11-01

Carbapenems, our one-time silver bullet for multidrug resistant bacterial infections, are now threatened by widespread dissemination of carbapenem-resistant Enterobacteriaceae (CRE). Successful expansion of Enterobacteriaceae clonal groups and frequent horizontal gene transfer of carbapenemase expressing plasmids are causing increasing carbapenem resistance. Recent advances in genetic and phenotypic detection facilitate global surveillance of CRE diversity and prevalence. In particular, whole genome sequencing enabled efficient tracking, annotation, and study of genetic elements colocalized with carbapenemase genes on chromosomes and on plasmids. Improved characterization helps detail the co-occurrence of other antibiotic resistance genes in CRE isolates and helps identify pan-drug resistance mechanisms. The novel β-lactamase inhibitor, avibactam, combined with ceftazidime or aztreonam, is a promising CRE treatment compared to current colistin or tigecycline regimens. To halt increasing CRE-associated morbidity and mortality, we must continue quality, cooperative monitoring and urgently investigate novel treatments. Copyright © 2016 Elsevier Ltd. All rights reserved.

Performance Analysis of Cell-Phone Worm Spreading in Cellular Networks through Opportunistic Communications

Directory of Open Access Journals (Sweden)

YAHUI, W.

2012-05-01

Full Text Available Worms spreading directly between cell-phones over short-range radio (Bluetooth, WiFi, etc. are increasing rapidly. Communication by these technologies is opportunistic and has very close relation with the social characteristics of the phone carriers. In this paper, we try to evaluate the impact of different characteristics on the spreading performance of worms. On the other hand, the behaviors of worms may have certain impact, too. For example, worms may make phones be completely dysfunctional and these phones can be seen as killed. We study the impact of the killing speed. Using the Markov model, we propose some theoretical models to evaluate the spreading performance in different cases. Simulation results show the accuracy of our models. Numerical results show that if users do not believe the data coming from others easily, the worms may bring less damage. Surprisingly, if the users are more willing to install the anti-virus software, the worms may bring bigger damage when the software becomes to be outdated with high probability. Though the worms can bring big damage on the network temporarily by killing phones rapidly, numerical results show that this behavior may decrease the total damage in the long time. Therefore, killing nodes more rapidly may be not optimal for worms.

Spread of white-nose syndrome on a network regulated by geography and climate.

Science.gov (United States)

Maher, Sean P; Kramer, Andrew M; Pulliam, J Tomlin; Zokan, Marcus A; Bowden, Sarah E; Barton, Heather D; Magori, Krisztian; Drake, John M

2012-01-01

Wildlife and plant diseases can reduce biodiversity, disrupt ecosystem services and threaten human health. Emerging pathogens have displayed a variety of spatial spread patterns due to differences in host ecology, including diffusive spread from an epicentre (West Nile virus), jump dispersal on a network (foot-and-mouth disease), or a combination of these (Sudden oak death). White-nose syndrome is a highly pathogenic infectious disease of bats currently spreading across North America. Understanding how bat ecology influences this spread is crucial to management of infected and vulnerable populations. Here we show that white-nose syndrome spread is not diffusive but rather mediated by patchily distributed habitat and large-scale gradients in winter climate. Simulations predict rapid expansion and infection of most counties with caves in the contiguous United States by winter 2105-2106. Our findings show the unique pattern of white-nose syndrome spread corresponds to ecological traits of the host and suggest hypotheses for transmission mechanisms acting at the local scale.

Retrospective analysis of EAB spread: understanding the effect of landscape pattern on invasion and propagation

Science.gov (United States)

Susan J. Crocker; Greg C. Liknes; Dacia M. Meneguzzo

2011-01-01

Spread of emerald ash borer (Agrilus planipennis Fairmaire, EAB) in the United States has been rapid and extensive. Nearly 10 years after its initial detection near Detroit, Michigan, EAB is now found in 15 states spanning a radius greater than 500 miles. While human activity has been central to facilitating the spread of EAB over long distances, the...

Addressing Barriers to the Development and Adoption of Rapid Diagnostic Tests in Global Health

Directory of Open Access Journals (Sweden)

Eric Miller

2015-06-01

Full Text Available Immunochromatographic rapid diagnostic tests (RDTs have demonstrated significant potential for use as point-of- care diagnostic tests in resource-limited settings. Most notably, RDTs for malaria have reached an unparalleled level of technological maturity and market penetration, and are now considered an important complement to standard microscopic methods of malaria diagnosis. However, the technical development of RDTs for other infectious diseases, and their uptake within the global health community as a core diagnostic modality, has been hindered by a number of extant challenges. These range from technical and biological issues, such as the need for better affinity agents and biomarkers of disease, to social, infrastructural, regulatory and economic barriers, which have all served to slow their adoption and diminish their impact. In order for the immunochromatographic RDT format to be successfully adapted to other disease targets, to see widespread distribution, and to improve clinical outcomes for patients on a global scale, these challenges must be identified and addressed, and the global health community must be engaged in championing the broader use of RDTs.

Addressing Barriers to the Development and Adoption of Rapid Diagnostic Tests in Global Health

Directory of Open Access Journals (Sweden)

Eric Miller

2015-06-01

Full Text Available Immunochromatographic rapid diagnostic tests (RDTs have demonstrated significant potential for use as point-of-care diagnostic tests in resource-limited settings. Most notably, RDTs for malaria have reached an unparalleled level of technological maturity and market penetration, and are now considered an important complement to standard microscopic methods of malaria diagnosis. However, the technical development of RDTs for other infectious diseases, and their uptake within the global health community as a core diagnostic modality, has been hindered by a number of extant challenges. These range from technical and biological issues, such as the need for better affinity agents and biomarkers of disease, to social, infrastructural, regulatory and economic barriers, which have all served to slow their adoption and diminish their impact. In order for the immunochromatographic RDT format to be successfully adapted to other disease targets, to see widespread distribution, and to improve clinical outcomes for patients on a global scale, these challenges must be identified and addressed, and the global health community must be engaged in championing the broader use of RDTs.

Addressing Barriers to the Development and Adoption of Rapid Diagnostic Tests in Global Health.

Science.gov (United States)

Miller, Eric; Sikes, Hadley D

Immunochromatographic rapid diagnostic tests (RDTs) have demonstrated significant potential for use as point-of-care diagnostic tests in resource-limited settings. Most notably, RDTs for malaria have reached an unparalleled level of technological maturity and market penetration, and are now considered an important complement to standard microscopic methods of malaria diagnosis. However, the technical development of RDTs for other infectious diseases, and their uptake within the global health community as a core diagnostic modality, has been hindered by a number of extant challenges. These range from technical and biological issues, such as the need for better affinity agents and biomarkers of disease, to social, infrastructural, regulatory and economic barriers, which have all served to slow their adoption and diminish their impact. In order for the immunochromatographic RDT format to be successfully adapted to other disease targets, to see widespread distribution, and to improve clinical outcomes for patients on a global scale, these challenges must be identified and addressed, and the global health community must be engaged in championing the broader use of RDTs.

A Spread Willingness Computing-Based Information Dissemination Model

Science.gov (United States)

Cui, Zhiming; Zhang, Shukui

2014-01-01

This paper constructs a kind of spread willingness computing based on information dissemination model for social network. The model takes into account the impact of node degree and dissemination mechanism, combined with the complex network theory and dynamics of infectious diseases, and further establishes the dynamical evolution equations. Equations characterize the evolutionary relationship between different types of nodes with time. The spread willingness computing contains three factors which have impact on user's spread behavior: strength of the relationship between the nodes, views identity, and frequency of contact. Simulation results show that different degrees of nodes show the same trend in the network, and even if the degree of node is very small, there is likelihood of a large area of information dissemination. The weaker the relationship between nodes, the higher probability of views selection and the higher the frequency of contact with information so that information spreads rapidly and leads to a wide range of dissemination. As the dissemination probability and immune probability change, the speed of information dissemination is also changing accordingly. The studies meet social networking features and can help to master the behavior of users and understand and analyze characteristics of information dissemination in social network. PMID:25110738

A Spread Willingness Computing-Based Information Dissemination Model

Directory of Open Access Journals (Sweden)

Haojing Huang

2014-01-01

Full Text Available This paper constructs a kind of spread willingness computing based on information dissemination model for social network. The model takes into account the impact of node degree and dissemination mechanism, combined with the complex network theory and dynamics of infectious diseases, and further establishes the dynamical evolution equations. Equations characterize the evolutionary relationship between different types of nodes with time. The spread willingness computing contains three factors which have impact on user’s spread behavior: strength of the relationship between the nodes, views identity, and frequency of contact. Simulation results show that different degrees of nodes show the same trend in the network, and even if the degree of node is very small, there is likelihood of a large area of information dissemination. The weaker the relationship between nodes, the higher probability of views selection and the higher the frequency of contact with information so that information spreads rapidly and leads to a wide range of dissemination. As the dissemination probability and immune probability change, the speed of information dissemination is also changing accordingly. The studies meet social networking features and can help to master the behavior of users and understand and analyze characteristics of information dissemination in social network.

Globalization and democracy

Directory of Open Access Journals (Sweden)

DEEPAK NAYYAR

2015-09-01

Full Text Available ABSTRACTThe gathering momentum of globalization in the world economy has coincided with the spread of political democracy across countries. Economies have become global. But politics remains national. This essay explores the relationship between globalization and democracy, which is neither linear nor characterized by structural rigidities. It seeks to analyze how globalization might constrain degrees of freedom for nation states and space for democratic politics, and how political democracy within countries might exercise some checks and balances on markets and globalization. The essential argument is that the relationship between globalization and democracy is dialectical and does not conform to ideological caricatures.

A metric of influential spreading during contagion dynamics through the air transportation network.

Directory of Open Access Journals (Sweden)

Christos Nicolaides

Full Text Available The spread of infectious diseases at the global scale is mediated by long-range human travel. Our ability to predict the impact of an outbreak on human health requires understanding the spatiotemporal signature of early-time spreading from a specific location. Here, we show that network topology, geography, traffic structure and individual mobility patterns are all essential for accurate predictions of disease spreading. Specifically, we study contagion dynamics through the air transportation network by means of a stochastic agent-tracking model that accounts for the spatial distribution of airports, detailed air traffic and the correlated nature of mobility patterns and waiting-time distributions of individual agents. From the simulation results and the empirical air-travel data, we formulate a metric of influential spreading--the geographic spreading centrality--which accounts for spatial organization and the hierarchical structure of the network traffic, and provides an accurate measure of the early-time spreading power of individual nodes.

Global malaria connectivity through air travel

OpenAIRE

Huang, Zhuojie; Tatem, Andrew J

2013-01-01

Background Air travel has expanded at an unprecedented rate and continues to do so. Its effects have been seen on malaria in rates of imported cases, local outbreaks in non-endemic areas and the global spread of drug resistance. With elimination and global eradication back on the agenda, changing levels and compositions of imported malaria in malaria-free countries, and the threat of artemisinin resistance spreading from Southeast Asia, there is a need to better understand how the modern flow...

The Key Role of Eyewitnesses in Rapid Impact Assessment of Global Earthquake

Science.gov (United States)

Bossu, R.; Steed, R.; Mazet-Roux, G.; Roussel, F.; Etivant, C.; Frobert, L.; Godey, S.

2014-12-01

Uncertainties in rapid impact assessments of global earthquakes are intrinsically large because they rely on 3 main elements (ground motion prediction models, building stock inventory and related vulnerability) which values and/or spatial variations are poorly constrained. Furthermore, variations of hypocentral location and magnitude within their respective uncertainty domain can lead to significantly different shaking level for centers of population and change the scope of the disaster. We present the strategy and methods implemented at the Euro-Med Seismological Centre (EMSC) to rapidly collect in-situ observations on earthquake effects from eyewitnesses for reducing uncertainties of rapid earthquake impact assessment. It comprises crowdsourced information (online questionnaires, pics) as well as information derived from real time analysis of web traffic (flashourcing technique), and more recently deployment of QCN (Quake Catcher Network) low cost sensors. We underline the importance of merging results of different methods to improve performances and reliability of collected data.We try to better understand and respond to public demands and expectations after earthquakes through improved information services and diversification of information tools (social networks, smartphone app., browsers adds-on…), which, in turn, drive more eyewitnesses to our services and improve data collection. We will notably present our LastQuake Twitter feed (Quakebot) and smartphone applications (IOs and android) which only report earthquakes that matter for the public and authorities, i.e. felt and damaging earthquakes identified thanks to citizen generated information.

Epidemic spreading on dual-structure networks with mobile agents

Science.gov (United States)

Yao, Yiyang; Zhou, Yinzuo

2017-02-01

The rapid development of modern society continually transforms the social structure which leads to an increasingly distinct dual structure of higher population density in urban areas and lower density in rural areas. Such structure may induce distinctive spreading behavior of epidemics which does not happen in a single type structure. In this paper, we study the epidemic spreading of mobile agents on dual structure networks based on SIRS model. First, beyond the well known epidemic threshold for generic epidemic model that when the infection rate is below the threshold a pertinent infectious disease will die out, we find the other epidemic threshold which appears when the infection rate of a disease is relatively high. This feature of two thresholds for the SIRS model may lead to the elimination of infectious disease when social network has either high population density or low population density. Interestingly, however, we find that when a high density area is connected to a low density may cause persistent spreading of the infectious disease, even though the same disease will die out when it spreads in each single area. This phenomenon indicates the critical role of the connection between the two areas which could radically change the behavior of spreading dynamics. Our findings, therefore, provide new understanding of epidemiology pertinent to the characteristic modern social structure and have potential to develop controlling strategies accordingly.

Epidemic spreading on interconnected networks.

Science.gov (United States)

Saumell-Mendiola, Anna; Serrano, M Ángeles; Boguñá, Marián

2012-08-01

Many real networks are not isolated from each other but form networks of networks, often interrelated in nontrivial ways. Here, we analyze an epidemic spreading process taking place on top of two interconnected complex networks. We develop a heterogeneous mean-field approach that allows us to calculate the conditions for the emergence of an endemic state. Interestingly, a global endemic state may arise in the coupled system even though the epidemics is not able to propagate on each network separately and even when the number of coupling connections is small. Our analytic results are successfully confronted against large-scale numerical simulations.

Economic impact from unrestricted spread of potato cyst nematodes in australia.

Science.gov (United States)

Hodda, M; Cook, D C

2009-12-01

ABSTRACT Potato cyst nematodes (PCN) (Globodera spp.) are quarantine pests with serious potential economic consequences. Recent new detections in Australia, Canada, and the United States have focussed attention on the consequences of spread and economic justifications for alternative responses. Here, a full assessment of the economic impact of PCN spread from a small initial incursion is presented. Models linking spread, population growth, and economic impact are combined to estimate costs of spread without restriction in Australia. Because the characteristics of the Australian PCN populations are currently unknown, the known ranges of parameters were used to obtain cost scenarios, an approach which makes the model predictions applicable generally. Our analysis indicates that mean annual costs associated with spread of PCN would increase rapidly initially, associated with increased testing. Costs would then increase more slowly to peak at over AUD$20 million per year approximately 10 years into the future. Afterward, this annual cost would decrease slightly due to discounting factors. Mean annual costs over 20 years were $18.7 million, with a 90% confidence interval between AUD$11.9 million and AUD$27.0 million. Thus, cumulative losses to Australian agriculture over 20 years may exceed $370 million without action to prevent spread of PCN and entry to new areas.

Information spread of emergency events: path searching on social networks.

Science.gov (United States)

Dai, Weihui; Hu, Hongzhi; Wu, Tunan; Dai, Yonghui

2014-01-01

Emergency has attracted global attentions of government and the public, and it will easily trigger a series of serious social problems if it is not supervised effectively in the dissemination process. In the Internet world, people communicate with each other and form various virtual communities based on social networks, which lead to a complex and fast information spread pattern of emergency events. This paper collects Internet data based on data acquisition and topic detection technology, analyzes the process of information spread on social networks, describes the diffusions and impacts of that information from the perspective of random graph, and finally seeks the key paths through an improved IBF algorithm. Application cases have shown that this algorithm can search the shortest spread paths efficiently, which may help us to guide and control the information dissemination of emergency events on early warning.

Information Spread of Emergency Events: Path Searching on Social Networks

Directory of Open Access Journals (Sweden)

Weihui Dai

2014-01-01

Full Text Available Emergency has attracted global attentions of government and the public, and it will easily trigger a series of serious social problems if it is not supervised effectively in the dissemination process. In the Internet world, people communicate with each other and form various virtual communities based on social networks, which lead to a complex and fast information spread pattern of emergency events. This paper collects Internet data based on data acquisition and topic detection technology, analyzes the process of information spread on social networks, describes the diffusions and impacts of that information from the perspective of random graph, and finally seeks the key paths through an improved IBF algorithm. Application cases have shown that this algorithm can search the shortest spread paths efficiently, which may help us to guide and control the information dissemination of emergency events on early warning.

Real-time numerical forecast of global epidemic spreading: case study of 2009 A/H1N1pdm

Directory of Open Access Journals (Sweden)

Tizzoni Michele

2012-12-01

Full Text Available Abstract Background Mathematical and computational models for infectious diseases are increasingly used to support public-health decisions; however, their reliability is currently under debate. Real-time forecasts of epidemic spread using data-driven models have been hindered by the technical challenges posed by parameter estimation and validation. Data gathered for the 2009 H1N1 influenza crisis represent an unprecedented opportunity to validate real-time model predictions and define the main success criteria for different approaches. Methods We used the Global Epidemic and Mobility Model to generate stochastic simulations of epidemic spread worldwide, yielding (among other measures the incidence and seeding events at a daily resolution for 3,362 subpopulations in 220 countries. Using a Monte Carlo Maximum Likelihood analysis, the model provided an estimate of the seasonal transmission potential during the early phase of the H1N1 pandemic and generated ensemble forecasts for the activity peaks in the northern hemisphere in the fall/winter wave. These results were validated against the real-life surveillance data collected in 48 countries, and their robustness assessed by focusing on 1 the peak timing of the pandemic; 2 the level of spatial resolution allowed by the model; and 3 the clinical attack rate and the effectiveness of the vaccine. In addition, we studied the effect of data incompleteness on the prediction reliability. Results Real-time predictions of the peak timing are found to be in good agreement with the empirical data, showing strong robustness to data that may not be accessible in real time (such as pre-exposure immunity and adherence to vaccination campaigns, but that affect the predictions for the attack rates. The timing and spatial unfolding of the pandemic are critically sensitive to the level of mobility data integrated into the model. Conclusions Our results show that large-scale models can be used to provide valuable real

Spreading dynamics of an e-commerce preferential information model on scale-free networks

Science.gov (United States)

Wan, Chen; Li, Tao; Guan, Zhi-Hong; Wang, Yuanmei; Liu, Xiongding

2017-02-01

In order to study the influence of the preferential degree and the heterogeneity of underlying networks on the spread of preferential e-commerce information, we propose a novel susceptible-infected-beneficial model based on scale-free networks. The spreading dynamics of the preferential information are analyzed in detail using the mean-field theory. We determine the basic reproductive number and equilibria. The theoretical analysis indicates that the basic reproductive number depends mainly on the preferential degree and the topology of the underlying networks. We prove the global stability of the information-elimination equilibrium. The permanence of preferential information and the global attractivity of the information-prevailing equilibrium are also studied in detail. Some numerical simulations are presented to verify the theoretical results.

Contributions of Different Cloud Types to Feedbacks and Rapid Adjustments in CMIP5*

Energy Technology Data Exchange (ETDEWEB)

Zelinka, Mark D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Program for Climate Model Diagnosis and Intercomparison; Klein, Stephen A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Program for Climate Model Diagnosis and Intercomparison; Taylor, Karl E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Program for Climate Model Diagnosis and Intercomparison; Andrews, Timothy [Met Office Hadley Center, Exeter (United Kingdom); Webb, Mark J. [Met Office Hadley Center, Exeter (United Kingdom); Gregory, Jonathan M. [Univ. of Reading, Exeter (United Kingdom). National Center for Atmospheric Science; Forster, Piers M. [Univ. of Leeds (United Kingdom)

2013-07-01

When using five climate model simulations of the response to an abrupt quadrupling of CO₂, the authors perform the first simultaneous model intercomparison of cloud feedbacks and rapid radiative adjustments with cloud masking effects removed, partitioned among changes in cloud types and gross cloud properties. After CO₂ quadrupling, clouds exhibit a rapid reduction in fractional coverage, cloud-top pressure, and optical depth, with each contributing equally to a 1.1 W m^-2 net cloud radiative adjustment, primarily from shortwave radiation. Rapid reductions in midlevel clouds and optically thick clouds are important in reducing planetary albedo in every model. As the planet warms, clouds become fewer, higher, and thicker, and global mean net cloud feedback is positive in all but one model and results primarily from increased trapping of longwave radiation. As was true for earlier models, high cloud changes are the largest contributor to intermodel spread in longwave and shortwave cloud feedbacks, but low cloud changes are the largest contributor to the mean and spread in net cloud feedback. The importance of the negative optical depth feedback relative to the amount feedback at high latitudes is even more marked than in earlier models. Furthermore, the authors show that the negative longwave cloud adjustment inferred in previous studies is primarily caused by a 1.3 W m^-2 cloud masking of CO₂ forcing. Properly accounting for cloud masking increases net cloud feedback by 0.3 W m^-2 K^-1, whereas accounting for rapid adjustments reduces by 0.14 W m^-2 K^-1 the ensemble mean net cloud feedback through a combination of smaller positive cloud amount and altitude feedbacks and larger negative optical depth feedbacks.

Spreading convulsions, spreading depolarization and epileptogenesis in human cerebral cortex

DEFF Research Database (Denmark)

Dreier, Jens P; Major, Sebastian; Pannek, Heinz-Wolfgang

2012-01-01

Spreading depolarization of cells in cerebral grey matter is characterized by massive ion translocation, neuronal swelling and large changes in direct current-coupled voltage recording. The near-complete sustained depolarization above the inactivation threshold for action potential generating...... stimulations. Eventually, epileptic field potentials were recorded during the period that had originally seen spreading depression of activity. Such spreading convulsions are characterized by epileptic field potentials on the final shoulder of the large slow potential change of spreading depolarization. We...

Population migration and the spread of types 1 and 2 human immunodeficiency viruses.

Science.gov (United States)

Quinn, T C

1994-03-29

Over 14 million people are estimated to be infected with the human immunodeficiency viruses (HIV), with nearly three-fourths of the infected persons residing in developing countries. One factor responsible for dissemination of both HIV-1 and HIV-2 worldwide was the intense migration of individuals, from rural to urban centers with subsequent return migration and internationally due to civil wars, tourism, business purposes, and the drug trade. In sub-Saharan Africa, between 1960 and 1980, urban centers with more than 500,000 inhabitants increased from 3 to 28, and more than 75 military coups occurred in 30 countries. The result was a massive migration of rural inhabitants to urban centers concomitant with the spread of HIV-1 to large population centers. With the associated demographic, economic, and social changes, an epidemic of sexually transmitted diseases and HIV-1 was ignited. Migratory patterns were also responsible for the spread of endemic HIV-2 to neighboring West African countries and eventually to Europe, the Americans, and India. Although Southeast Asia was the last region in which HIV-1 was introduced, it has the greatest potential for rapid spread due to population density and inherent risk behaviors. Thus, the migration of poor, rural, and young sexually active individuals to urban centers coupled with large international movements of HIV-infected individuals played a prominent role in the dissemination of HIV globally. The economic recession has aggravated the transmission of HIV by directly increasing the population at risk through increased urban migration, disruption of rural families and cultural values, poverty, and prostitution and indirectly through a decrease in health care provision. Consequently, social and economic reform as well as sexual behavior education need to be intensified if HIV transmission is to be controlled.

Global Rapid Flood Mapping System with Spaceborne SAR Data

Science.gov (United States)

Yun, S. H.; Owen, S. E.; Hua, H.; Agram, P. S.; Fattahi, H.; Liang, C.; Manipon, G.; Fielding, E. J.; Rosen, P. A.; Webb, F.; Simons, M.

2017-12-01

As part of the Advanced Rapid Imaging and Analysis (ARIA) project for Natural Hazards, at NASA's Jet Propulsion Laboratory and California Institute of Technology, we have developed an automated system that produces derived products for flood extent map generation using spaceborne SAR data. The system takes user's input of area of interest polygons and time window for SAR data search (pre- and post-event). Then the system automatically searches and downloads SAR data, processes them to produce coregistered SAR image pairs, and generates log amplitude ratio images from each pair. Currently the system is automated to support SAR data from the European Space Agency's Sentinel-1A/B satellites. We have used the system to produce flood extent maps from Sentinel-1 SAR data for the May 2017 Sri Lanka floods, which killed more than 200 people and displaced about 600,000 people. Our flood extent maps were delivered to the Red Cross to support response efforts. Earlier we also responded to the historic August 2016 Louisiana floods in the United States, which claimed 13 people's lives and caused over $10 billion property damage. For this event, we made synchronized observations from space, air, and ground in close collaboration with USGS and NOAA. The USGS field crews acquired ground observation data, and NOAA acquired high-resolution airborne optical imagery within the time window of +/-2 hours of the SAR data acquisition by JAXA's ALOS-2 satellite. The USGS coordinates of flood water boundaries were used to calibrate our flood extent map derived from the ALOS-2 SAR data, and the map was delivered to FEMA for estimating the number of households affected. Based on the lessons learned from this response effort, we customized the ARIA system automation for rapid flood mapping and developed a mobile friendly web app that can easily be used in the field for data collection. Rapid automatic generation of SAR-based global flood maps calibrated with independent observations from

Improved but unsustainable: accounting for sachet water in post-2015 goals for global safe water.

Science.gov (United States)

Stoler, Justin

2012-12-01

The advent and rapid spread of sachet drinking water in West Africa presents a new challenge for providing sustainable access to global safe water. Sachet water has expanded drinking water access and is often of sufficient quality to serve as an improved water source for Millennium Development Goals (MDG) monitoring purposes, yet sachets are an unsustainable water delivery vehicle due to their overwhelming plastic waste burden. Monitoring of primary drinking water sources in West Africa generally ignores sachet water, despite its growing ubiquity. Sub-Saharan Africa as a region is unlikely to meet the MDG Target for drinking water provision, and post-2015 monitoring activities may depend upon rapid adaptability to local drinking water trends. © 2012 Blackwell Publishing Ltd.

Masculine sex ratios, population age structure and the potential spread of HIV in China

OpenAIRE

M. Giovanna Merli; Sara Hertog

2010-01-01

There is much speculation regarding the contribution of China's changing demography to the spread of HIV/AIDS. We employ a bio-behavioral macrosimulation model of the heterosexual spread of HIV/AIDS to evaluate the roles that China's unique demographic conditions -- (1) masculine sex ratios at birth and (2) a population age structure that reflects rapid fertility decline since the 1970's -- play in altering the market for sexual partners, thereby potentially fueling an increase...

Dynamics of epidemic spreading model with drug-resistant variation on scale-free networks

Science.gov (United States)

Wan, Chen; Li, Tao; Zhang, Wu; Dong, Jing

2018-03-01

Considering the influence of the virus' drug-resistant variation, a novel SIVRS (susceptible-infected-variant-recovered-susceptible) epidemic spreading model with variation characteristic on scale-free networks is proposed in this paper. By using the mean-field theory, the spreading dynamics of the model is analyzed in detail. Then, the basic reproductive number R0 and equilibriums are derived. Studies show that the existence of disease-free equilibrium is determined by the basic reproductive number R0. The relationships between the basic reproductive number R0, the variation characteristic and the topology of the underlying networks are studied in detail. Furthermore, our studies prove the global stability of the disease-free equilibrium, the permanence of epidemic and the global attractivity of endemic equilibrium. Numerical simulations are performed to confirm the analytical results.

Ensemble Forecasts with Useful Skill-Spread Relationships for African meningitis and Asia Streamflow Forecasting

Science.gov (United States)

Hopson, T. M.

2014-12-01

One potential benefit of an ensemble prediction system (EPS) is its capacity to forecast its own forecast error through the ensemble spread-error relationship. In practice, an EPS is often quite limited in its ability to represent the variable expectation of forecast error through the variable dispersion of the ensemble, and perhaps more fundamentally, in its ability to provide enough variability in the ensembles dispersion to make the skill-spread relationship even potentially useful (irrespective of whether the EPS is well-calibrated or not). In this paper we examine the ensemble skill-spread relationship of an ensemble constructed from the TIGGE (THORPEX Interactive Grand Global Ensemble) dataset of global forecasts and a combination of multi-model and post-processing approaches. Both of the multi-model and post-processing techniques are based on quantile regression (QR) under a step-wise forward selection framework leading to ensemble forecasts with both good reliability and sharpness. The methodology utilizes the ensemble's ability to self-diagnose forecast instability to produce calibrated forecasts with informative skill-spread relationships. A context for these concepts is provided by assessing the constructed ensemble in forecasting district-level humidity impacting the incidence of meningitis in the meningitis belt of Africa, and in forecasting flooding events in the Brahmaputra and Ganges basins of South Asia.

Spreading Depression, Spreading Depolarizations, and the Cerebral Vasculature

DEFF Research Database (Denmark)

Ayata, Cenk; Lauritzen, Martin

2015-01-01

Spreading depression (SD) is a transient wave of near-complete neuronal and glial depolarization associated with massive transmembrane ionic and water shifts. It is evolutionarily conserved in the central nervous systems of a wide variety of species from locust to human. The depolarization spreads...

Simulative Global Warming Negatively Affects Cotton Fiber Length through Shortening Fiber Rapid Elongation Duration.

Science.gov (United States)

Dai, Yanjiao; Yang, Jiashuo; Hu, Wei; Zahoor, Rizwan; Chen, Binglin; Zhao, Wenqing; Meng, Yali; Zhou, Zhiguo

2017-08-23

Global warming could possibly increase the air temperature by 1.8-4.0 °C in the coming decade. Cotton fiber is an essential raw material for the textile industry. Fiber length, which was found negatively related to the excessively high temperature, determines yarn quality to a great extent. To investigate the effects of global warming on cotton fiber length and its mechaism, cottons grown in artificially elevated temperature (34.6/30.5 °C, T day /T night ) and ambient temperature (31.6/27.3 °C) regions have been investigated. Becaused of the high sensitivities of enzymes V-ATPase, PEPC, and genes GhXTH1 and GhXTH2 during fiber elongation when responding to high temperature stress, the fiber rapid elongation duration (FRED) has been shortened, which led to a significant suppression on final fiber length. Through comprehensive analysis, T night had a great influence on fiber elongation, which means T n could be deemed as an ideal index for forecasting the degree of high temperature stress would happen to cotton fiber property in future. Therefore, we speculate the global warming would bring unfavorable effects on cotton fiber length, which needs to take actions in advance for minimizing the loss in cotton production.

Resolving vorticity-driven lateral fire spread using the WRF-Fire coupled atmosphere–fire numerical model

OpenAIRE

Simpson, C. C.; Sharples, J. J.; Evans, J. P.

2014-01-01

Fire channelling is a form of dynamic fire behaviour, during which a wildland fire spreads rapidly across a steep lee-facing slope in a direction transverse to the background winds, and is often accompanied by a downwind extension of the active flaming region and extreme pyro-convection. Recent work using the WRF-Fire coupled atmosphere-fire model has demonstrated that fire channelling can be characterised as vorticity-driven lateral fire spread (VDLS). In t...

A Finsler geodesic spray paradigm for wildfire spread modelling

DEFF Research Database (Denmark)

Markvorsen, Steen

2015-01-01

represents the local fire templates. The ‘paradigm’ part of the present proposal is thus concerned with the corresponding shift of attention from the actual fire-lines to consider instead the geodesic spray - the ‘fire-particles’ - which together, side by side, mold the fire-lines at each instant of time...... and thence eventually constitute the local and global structure of the wildfire spread....

The Epidemiology of Carbapenem-Resistant Enterobacteriaceae: The Impact and Evolution of a Global Menace

Science.gov (United States)

Weinstein, Robert A.

2017-01-01

Abstract Carbapenem-resistant Enterobacteriaceae (CRE) are a serious public health threat. Infections due to these organisms are associated with significant morbidity and mortality. Mechanisms of drug resistance in gram-negative bacteria (GNB) are numerous; β-lactamase genes carried on mobile genetic elements are a key mechanism for the rapid spread of antibiotic-resistant GNB worldwide. Transmissible carbapenem-resistance in Enterobacteriaceae has been recognized for the last 2 decades, but global dissemination of carbapenemase-producing Enterobacteriaceae (CPE) is a more recent problem that, once initiated, has been occurring at an alarming pace. In this article, we discuss the evolution of CRE, with a focus on the epidemiology of the CPE pandemic; review risk factors for colonization and infection with the most common transmissible CPE worldwide, Klebsiella pneumoniae carbapenemase–producing K. pneumoniae; and present strategies used to halt the striking spread of these deadly pathogens. PMID:28375512

Analytical solution of a stochastic model of risk spreading with global coupling

Science.gov (United States)

Morita, Satoru; Yoshimura, Jin

2013-11-01

We study a stochastic matrix model to understand the mechanics of risk spreading (or bet hedging) by dispersion. Up to now, this model has been mostly dealt with numerically, except for the well-mixed case. Here, we present an analytical result that shows that optimal dispersion leads to Zipf's law. Moreover, we found that the arithmetic ensemble average of the total growth rate converges to the geometric one, because the sample size is finite.

Global spread of mouse-adapted Staphylococcus aureus lineages CC1, CC15, and CC88 among mouse breeding facilities.

Science.gov (United States)

Mrochen, Daniel M; Grumann, Dorothee; Schulz, Daniel; Gumz, Janine; Trübe, Patricia; Pritchett-Corning, Kathleen; Johnson, Sarah; Nicklas, Werner; Kirsch, Petra; Martelet, Karine; Brandt, Jens van den; Berg, Sabine; Bröker, Barbara M; Wiles, Siouxsie; Holtfreter, Silva

2017-11-20

We previously reported that laboratory mice from all global vendors are frequently colonized with Staphylococcus aureus (S. aureus). Genotyping of a snap sample of murine S. aureus isolates from Charles River, US, showed that mice were predominantly colonized with methicillin-sensitive CC88 strains. Here, we expanded our view and investigated whether laboratory mice from other global animal facilities are colonized with similar strains or novel S. aureus lineages, and whether the murine S. aureus isolates show features of host adaptation. In total, we genotyped 230 S. aureus isolates from various vendor facilities of laboratory mice around the globe (Charles River facilities in the USA, Canada, France, and Germany; another US facility) and university- or company-associated breeding facilities in Germany, China and New Zealand. Spa typing was performed to analyse the clonal relationship of the isolates. Moreover, multiplex PCRs were performed for human-specific virulence factors, the immune-evasion cluster (IEC) and superantigen genes (SAg). We found a total of 58 different spa types that clustered into 15 clonal complexes (CCs). Three of these S. aureus lineages had spread globally among laboratory mice and accounted for three quarters of the isolates: CC1 (13.5%), CC15 (14.3%), and CC88 (47.0%). Compared to human colonizing isolates of the same lineages, the murine isolates frequently lacked IEC genes and SAg genes on mobile genetic elements, implying long-term adaptation to the murine host. In conclusion, laboratory mice from various vendors are colonized with host-adapted S. aureus-strains of a few lineages, predominantly the CC88 lineage. S. aureus researchers must be cautioned that S. aureus colonization might be a relevant confounder in infection and vaccination studies and are therefore advised to screen their mice before experimentation. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

Adoption of rapid diagnostic tests for the diagnosis of malaria, a preliminary analysis of the Global Fund program data, 2005 to 2010.

Directory of Open Access Journals (Sweden)

Jinkou Zhao

Full Text Available The World Health Organization Guidelines for the Treatment of Malaria, in 2006 and 2010, recommend parasitological confirmation of malaria before commencing treatment. Although microscopy has been the mainstay of malaria diagnostics, the magnitude of diagnostic scale up required to follow the Guidelines suggests that rapid diagnostic tests (RDTs will be a large component. This study analyzes the adoption of rapid diagnostic testing in malaria programs supported by the Global Fund to fight AIDS, Tuberculosis and Malaria (Global Fund, the leading international funder of malaria control globally.We analyzed, for the period 2005 to 2010, Global Fund programmatic data for 81 countries on the quantity of RDTs planned; actual quantities of RDTs and artemisinin-based combination treatments (ACTs procured in 2009 and 2010; RDT-related activities including RDTs distributed, RDTs used, total diagnostic tests including RDTs and microscopy performed, health facilities equipped with RDTs; personnel trained to perform rapid diagnostic malaria test; and grant budgets allocated to malaria diagnosis. In 2010, diagnosis accounted for 5.2% of malaria grant budget. From 2005 to 2010, the procurement plans include148 million RDTs through 96 malaria grants in 81 countries. Around 115 million parasitological tests, including RDTs, had reportedly been performed from 2005 to 2010. Over this period, 123,132 health facilities were equipped with RDTs and 137,140 health personnel had been trained to perform RDT examinations. In 2009 and 2010, 41 million RDTs and 136 million ACTs were purchased. The ratio of procured RDTs to ACTs was 0.26 in 2009 and 0.34 in 2010.Global Fund financing has enabled 81 malaria-endemic countries to adopt WHO guidelines by investing in RDTs for malaria diagnosis, thereby helping improve case management of acute febrile illness in children. However, roll-out of parasitological diagnosis lags behind the roll-out of ACT-based treatment, and will

Has the First Global Financial Crisis Changed the Entrepreneurial Values in Digitalized Marketing-based Societies? The Case of GEM Latin American Countries

OpenAIRE

José Manuel Saiz Álvarez; Alicia Coduras Martínez; Carlos Cuervo Arango

2017-01-01

As the world economy is globalized, crises are rapidly spread due to the massive use of ICTs (Information and Communication Technologies), also affecting the entrepreneurial values involved in business creation processes. In this sense, digital marketing has a key role to play, as it can serve as a tool based on technology applied to foster nascent entrepreneurship. Using data for GEM Latin American countries, and applying clustering analysis based on the K-means method, the objective of this...

Controlling the spread of carbapenemase-producing Gram-negatives: therapeutic approach and infection control.

Science.gov (United States)

Carmeli, Y; Akova, M; Cornaglia, G; Daikos, G L; Garau, J; Harbarth, S; Rossolini, G M; Souli, M; Giamarellou, H

2010-02-01

Although the rapid spread of carbapenemase-producing Gram-negatives (CPGNs) is providing the scientific community with a great deal of information about the molecular epidemiology of these enzymes and their genetic background, data on how to treat multidrug-resistant or extended drug-resistant carbapenemase-producing Enterobacteriaceae and how to contain their spread are still surprisingly limited, in spite of the rapidly increasing prevalence of these organisms and of their isolation from patients suffering from life-threatening infections. Limited clinical experience and several in vitro synergy studies seem to support the view that antibiotic combinations should be preferred to monotherapies. But, in light of the data available to date, it is currently impossible to quantify the real advantage of drug combinations in the treatment of these infections. Comprehensive clinical studies of the main therapeutic options, broken down by pathogen, enzyme and clinical syndrome, are definitely lacking and, as carbapenemases keep spreading, are urgently needed. This spread is unveiling the substantial unpreparedness of European public health structures to face this worrisome emergency, although experiences from different countries-chiefly Greece and Israel-have shown that CPGN transmission and cross-infection can cause a substantial threat to the healthcare system. This unpreparedness also affects the treatment of individual patients and infection control policies, with dramatic scarcities of both therapeutic options and infection control measures. Although correct implementation of such measures is presumably cumbersome and expensive, the huge clinical and public health problems related to CPGN transmission, alongside the current scarcity of therapeutic options, seem to fully justify this choice.

Roles of the spreading scope and effectiveness in spreading dynamics on multiplex networks

Science.gov (United States)

Li, Ming; Liu, Run-Ran; Peng, Dan; Jia, Chun-Xiao; Wang, Bing-Hong

2018-02-01

Comparing with single networks, the multiplex networks bring two main effects on the spreading process among individuals. First, the pathogen or information can be transmitted to more individuals through different layers at one time, which enlarges the spreading scope. Second, through different layers, an individual can also transmit the pathogen or information to the same individuals more than once at one time, which makes the spreading more effective. To understand the different roles of the spreading scope and effectiveness, we propose an epidemic model on multiplex networks with link overlapping, where the spreading effectiveness of each interaction as well as the variety of channels (spreading scope) can be controlled by the number of overlapping links. We find that for Poisson degree distribution, increasing the epidemic scope (the first effect) is more efficient than enhancing epidemic probability (the second effect) to facilitate the spreading process. However, for power-law degree distribution, the effects of the two factors on the spreading dynamics become complicated. Enhancing epidemic probability makes pathogen or rumor easier to outbreak in a finite system. But after that increasing epidemic scopes is still more effective for a wide spreading. Theoretical results along with reasonable explanation for these phenomena are all given in this paper, which indicates that the epidemic scope could play an important role in the spreading dynamics.

Health, globalization and developing countries.

Science.gov (United States)

Cilingiroglu, Nesrin

2005-02-01

In health care today, scientific and technological frontiers are expanding at unprecedented rates, even as economic and financial pressures shrink profit margins, intensify competition, and constrain the funds available for investment. Therefore, the world today has more economic, and social opportunities for people than 10 or 100 years since globalization has created a new ground somewhat characterized by rapid economic transformation, deregulation of national markets by new trade regimes, amazing transport, electronic communication possibilities and high turnover of foreign investment and capital flow as well as skilled labor. These trends can easily mask great inequalities in developing countries such as importation and spreading of infectious and non-communicable diseases; miniaturization of movement of medical technology; health sector trades management driven by economics without consideration to the social and health aspects and its effects, increasing health inequalities and their economic and social burden creation; multinational companies' cheap labor employment promotion in widening income differentials; and others. As a matter of fact, all these factors are major determinants of ill health. Health authorities of developing countries have to strengthen their regulatory framework in order to ensure that national health systems derive maximum benefit in terms of equity, quality and efficiency, while reducing potential social cost to a minimum generated risky side of globalization.

Effects of q-profile structure on turbulence spreading: A fluctuation intensity transport analysis

Energy Technology Data Exchange (ETDEWEB)

Yi, S.; Kwon, J. M. [National Fusion Research Institute, Eoeun-dong, Yuseong-gu, Daejeon 305-333 (Korea, Republic of); Diamond, P. H. [National Fusion Research Institute, Eoeun-dong, Yuseong-gu, Daejeon 305-333 (Korea, Republic of); Center for Astrophysics and Space Sciences and Department of Physics, University of California San Diego, La Jolla, California 92093-0429 (United States); Hahm, T. S. [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)

2014-09-15

This paper studies effects of q-profile structure on turbulence spreading. It reports results of numerical experiments using global gyrokinetic simulations. We examine propagation of turbulence, triggered by an identical linear instability in a source region, into an adjacent, linearly stable region with variable q-profile. The numerical experiments are designed so as to separate the physics of turbulence spreading from that of linear stability. The strength of turbulence spreading is measured by the penetration depth of turbulence. Dynamics of spreading are elucidated by fluctuation intensity balance analysis, using a model intensity evolution equation which retains nonlinear diffusion and damping, and linear growth. It is found that turbulence spreading is strongly affected by magnetic shear s, but is hardly altered by the safety factor q itself. There is an optimal range of modest magnetic shear which maximizes turbulence spreading. For high to modest shear values, the spreading is enhanced by the increase of the mode correlation length with decreasing magnetic shear. However, the efficiency of spreading drops for sufficiently low magnetic shear even though the mode correlation length is comparable to that for the case of optimal magnetic shear. The reduction of spreading is attributed to the increase in time required for the requisite nonlinear mode-mode interactions. The effect of increased interaction time dominates that of increased mode correlation length. Our findings of the reduction of spreading and the increase in interaction time at weak magnetic shear are consistent with the well-known benefit of weak or reversed magnetic shear for core confinement enhancement. Weak shear is shown to promote locality, as well as stability.

Spread effects - methodology

International Nuclear Information System (INIS)

2004-01-01

Diffusion of technology, environmental effects and rebound effects are the principal effects from the funding of renewable energy and energy economising. It is difficult to estimate the impact of the spread effects both prior to the measures are implemented and after the measures are carried out. Statistical methods can be used to estimate the spread effects, but they are insecure and always need to be complemented with qualitative and subjective evaluations. It is more adequate to evaluate potential spread effects from market and market data surveillance for a selection of technologies and parties. Based on this information qualitative indicators for spread effects can be constructed and used both ex ante and ex post (ml)

Agricultural pathogen decontamination technology-reducing the threat of infectious agent spread.

Energy Technology Data Exchange (ETDEWEB)

Betty, Rita G.; Bieker, Jill Marie; Tucker, Mark David

2005-10-01

Outbreaks of infectious agricultural diseases, whether natural occurring or introduced intentionally, could have catastrophic impacts on the U.S. economy. Examples of such agricultural pathogens include foot and mouth disease (FMD), avian influenza (AI), citrus canker, wheat and soy rust, etc. Current approaches to mitigate the spread of agricultural pathogens include quarantine, development of vaccines for animal diseases, and development of pathogen resistant crop strains in the case of plant diseases. None of these approaches is rapid, and none address the potential persistence of the pathogen in the environment, which could lead to further spread of the agent and damage after quarantine is lifted. Pathogen spread in agricultural environments commonly occurs via transfer on agricultural equipment (transportation trailers, tractors, trucks, combines, etc.), having components made from a broad range of materials (galvanized and painted steel, rubber tires, glass and Plexiglas shields, etc), and under conditions of heavy organic load (mud, soil, feces, litter, etc). A key element of stemming the spread of an outbreak is to ensure complete inactivation of the pathogens in the agricultural environment and on the equipment used in those environments. Through the combination of enhanced agricultural pathogen decontamination chemistry and a validated inactivation verification methodology, important technologies for incorporation as components of a robust response capability will be enabled. Because of the potentially devastating economic impact that could result from the spread of infectious agricultural diseases, the proposed capability components will promote critical infrastructure protection and greater border and food supply security. We investigated and developed agricultural pathogen decontamination technologies to reduce the threat of infectious-agent spread, and thus enhance agricultural biosecurity. Specifically, enhanced detergency versions of the patented

Global Delivery Models

DEFF Research Database (Denmark)

Manning, Stephan; Møller Larsen, Marcus; Bharati, Pratyush

-zone spread allowing for 24/7 service delivery and access to resources. Based on comprehensive data we show that providers are likely to establish GDM configurations when clients value access to globally distributed talent pools and speed of service delivery, and in particular when services are highly...

Collective behavior in the spatial spreading of obesity

Science.gov (United States)

Gallos, Lazaros K.; Barttfeld, Pablo; Havlin, Shlomo; Sigman, Mariano; Makse, Hernán A.

2012-06-01

Obesity prevalence is increasing in many countries at alarming levels. A difficulty in the conception of policies to reverse these trends is the identification of the drivers behind the obesity epidemics. Here, we implement a spatial spreading analysis to investigate whether obesity shows spatial correlations, revealing the effect of collective and global factors acting above individual choices. We find a regularity in the spatial fluctuations of their prevalence revealed by a pattern of scale-free long-range correlations. The fluctuations are anomalous, deviating in a fundamental way from the weaker correlations found in the underlying population distribution indicating the presence of collective behavior, i.e., individual habits may have negligible influence in shaping the patterns of spreading. Interestingly, we find the same scale-free correlations in economic activities associated with food production. These results motivate future interventions to investigate the causality of this relation providing guidance for the implementation of preventive health policies.

Complicated acute appendicitis presenting as a rapidly progressive soft tissue infection of the abdominal wall: a case report.

Science.gov (United States)

Beerle, Corinne; Gelpke, Hans; Breitenstein, Stefan; Staerkle, Ralph F

2016-12-01

We report a case of a rare complication of acute appendicitis with perforation through the abdominal wall. The case points out that an intraabdominal origin should be considered in patients presenting with rapidly spreading soft tissue infections of the trunk. A 58-year-old European woman presented to our hospital with a 1-week history of severe abdominal pain accompanied by rapidly spreading erythema and emphysema of the lower abdomen. On admission, the patient was in septic shock with leukocytosis and elevation of C-reactive protein. Among other diagnoses, necrotizing fasciitis was suspected. Computed tomography showed a large soft tissue infection with air-fluid levels spreading through the lower abdominal wall. During the operation, we found a perforated appendicitis breaking through the fascia and causing a rapidly progressive soft tissue infection of the abdominal wall. Appendicitis was the origin of the soft tissue infection. The abdominal wall was only secondarily involved. Even though perforated appendicitis as an etiology of a rapidly progressive soft tissue infection of the abdominal wall is very rare, it should be considered in the differential diagnosis of abdominal wall cellulitis. The distinction between rapidly spreading subcutaneous infection with abscess formation and early onset of necrotizing fasciitis is often difficult and can be confirmed only by surgical intervention.

Potential economic impact of introduction and spread of the red imported fire ant, Solenopsis invicta, in Hawaii

Science.gov (United States)

Gutrich, J.J.; VanGelder, E.; Loope, L.

2007-01-01

Globally, many invasive alien species have caused extensive ecological and economic damage from either accidental or intentional introduction. The red imported fire ant, Solenopsis invicta, has created billions of dollars in costs annually, spreading as an invasive species across the southern United States. In 1998, the red imported fire ant spread into California creating a highly probable future introduction via shipped products to Hawaii. This paper presents the estimation of potential economic impacts of the red imported fire ant (RIFA) to the state of Hawaii. Evaluation of impacts focuses on the economic sectors of (1) households, (2) agriculture (cattle and crop production), (3) infrastructure (cemeteries, churches, cities, electrical, telephone, and cable services, highways, hospitals and schools), (4) recreation, tourism and business (hotels/resort areas, golf courses, commercial businesses and tourists), and (5) government expenditures (with minimal intervention). The full annual economic costs of the red imported fire ant to Hawaii are estimated (in US$ 2006) to be $211 million/year, comprised of $77 million in damages and expenditures and $134 million in foregone outdoor opportunities to households and tourists. The present value of the projected costs of RIFA over a 20-year period after introduction total $2.5 billion. RIFA invasions across the globe indicate that economic cost-effective action in Hawaii entails implementation of prevention, early detection and rapid response treatment programs for RIFA. ?? 2007 Elsevier Ltd. All rights reserved.

Asymptotic behaviour for a system describing epidemics with migration and spatial spread of infection

International Nuclear Information System (INIS)

Kirane, M.; Kouachi, S.

1991-08-01

A parabolic system with linear interactions is considered with specific applications to the spread of infectious diseases. Using a Payne-type functional we prove the global existence of a unique solution and analyze its large time behaviour. (author). 14 refs

[Periodization of international spread of acupuncture-moxibustion and their characteristics at each period].

Science.gov (United States)

Bai, Xing-hua

2014-11-01

The history of international spread of Chinese acupuncture and moxibustion is divided into three sta ges in this paper, and the spreading characteristics are analyzed. The first stage is approximately from the 6th century to the end of the 15th century, during which acupuncture and moxibustion were spread to neighboring countries by personnel exchanges; the spread towards Korean peninsula, Japan and Vietnam was considered the most successful communication. The second stage lasts from the beginning of 16th century to 1970. At the early time of this stage, the employees of the Dutch East Indian Company introduced acupuncture and moxibustion to European countries through Indonesia and Japan, leading to a short and small fashion; also the United States and Australia were involved. At the late time of this stage, by medical aid teams dispatched by China government, acupuncture and moxibustion were introduced to African countries. The third stage starts from 1971. With the establishment of Sino-US diplomatic relations as an opportunity, acupuncture and moxibustion were being spread rapidly to the world through radio, TV and internet. So far it has been introduced to more than 140 countries and areas. Performing serious studies on the spreading characteristics of three stages will promote the international communication of acupuncture and moxibustion, by which the world will have a better understanding onthe broad and profound traditional cultures of China.

Combinatorics of spreads and parallelisms

CERN Document Server

Johnson, Norman

2010-01-01

Partitions of Vector Spaces Quasi-Subgeometry Partitions Finite Focal-SpreadsGeneralizing André SpreadsThe Going Up Construction for Focal-SpreadsSubgeometry Partitions Subgeometry and Quasi-Subgeometry Partitions Subgeometries from Focal-SpreadsExtended André SubgeometriesKantor's Flag-Transitive DesignsMaximal Additive Partial SpreadsSubplane Covered Nets and Baer Groups Partial Desarguesian t-Parallelisms Direct Products of Affine PlanesJha-Johnson SL(2,

Factors Important for Rapid Internationalization : A Multiple Case-Study of Born Global Internet-Based Service Firms in Sweden

OpenAIRE

Burman, Anna; Stjernström, Ida

2017-01-01

The evolution of globalization and technology have changed the playground for international business and made it possible for smaller businesses to compete internationally among large and capital intensive companies. Markets become increasingly alike with converging product preferences and changing the world into one large integrated marketplace easily accessible for firms of all sizes. Recent research in the field of International Business has shed light on small firms that rapidly become in...

A stochastic model of depolarization enhancement due to large energy spread in electron storage rings

International Nuclear Information System (INIS)

Buon, J.

1988-10-01

A new semiclassical and stochastic model of spin diffusion is used to obtain numerical predictions for depolarization enhancement due to beam energy spread. It confirms the results of previous models for the synchrotron sidebands of isolated spin resonances. A satisfactory agreement is obtained with the width of a synchrotron satellite observed at SPEAR. For HERA and LEP, at Z 0 energy, the depolarization enhancement is of the order of a few units and increases very rapidly with the energy spread. Large reduction of polarization degree is expected in these rings

Analytic calculation of depolarization due to large energy spread in high-energy electron storage rings

International Nuclear Information System (INIS)

Buon, J.

1989-08-01

A new semiclassical and stochastic model of spin diffusion is used to obtain numerical predictions for depolarization enhancement due to beam energy spread. It confirms the results of previous models for the synchrotron sidebands of spin resonances. A satisfactory agreement is obtained with the width of a synchrotron satellite observed at SPEAR. For HERA, TRISTAN, and LEP at Z 0 energy, the depolarization enhancement is of the order of a few units and increases very rapidly with the energy spread. Large reduction of polarization degree is expected in these rings

Conditions for Viral Influence Spreading through Multiplex Correlated Social Networks

Science.gov (United States)

Hu, Yanqing; Havlin, Shlomo; Makse, Hernán A.

2014-04-01

A fundamental problem in network science is to predict how certain individuals are able to initiate new networks to spring up "new ideas." Frequently, these changes in trends are triggered by a few innovators who rapidly impose their ideas through "viral" influence spreading, producing cascades of followers and fragmenting an old network to create a new one. Typical examples include the rise of scientific ideas or abrupt changes in social media, like the rise of Facebook to the detriment of Myspace. How this process arises in practice has not been conclusively demonstrated. Here, we show that a condition for sustaining a viral spreading process is the existence of a multiplex-correlated graph with hidden "influence links." Analytical solutions predict percolation-phase transitions, either abrupt or continuous, where networks are disintegrated through viral cascades of followers, as in empirical data. Our modeling predicts the strict conditions to sustain a large viral spreading via a scaling form of the local correlation function between multilayers, which we also confirm empirically. Ultimately, the theory predicts the conditions for viral cascading in a large class of multiplex networks ranging from social to financial systems and markets.

Age, spreading rates, and spreading asymmetry of the world's ocean crust

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The authors present four companion digital models of the age, age uncertainty, spreading rates and spreading asymmetries of the world's ocean basins as geographic...

Impact of Rapid Susceptibility Testing and Antibiotic Selection Strategy on the Emergence and Spread of Antibiotic Resistance in Gonorrhea.

Science.gov (United States)

Tuite, Ashleigh R; Gift, Thomas L; Chesson, Harrell W; Hsu, Katherine; Salomon, Joshua A; Grad, Yonatan H

2017-11-27

Increasing antibiotic resistance limits treatment options for gonorrhea. We examined the impact of a hypothetical point-of-care (POC) test reporting antibiotic susceptibility profiles on slowing resistance spread. A mathematical model describing gonorrhea transmission incorporated resistance emergence probabilities and fitness costs associated with resistance based on characteristics of ciprofloxacin (A), azithromycin (B), and ceftriaxone (C). We evaluated time to 1% and 5% prevalence of resistant strains among all isolates with the following: (1) empiric treatment (B and C), and treatment guided by POC tests determining susceptibility to (2) A only and (3) all 3 antibiotics. Continued empiric treatment without POC testing was projected to result in >5% of isolates being resistant to both B and C within 15 years. Use of either POC test in 10% of identified cases delayed this by 5 years. The 3 antibiotic POC test delayed the time to reach 1% prevalence of triply-resistant strains by 6 years, whereas the A-only test resulted in no delay. Results were less sensitive to assumptions about fitness costs and test characteristics with increasing test uptake. Rapid diagnostics reporting antibiotic susceptibility may extend the usefulness of existing antibiotics for gonorrhea treatment, but ongoing monitoring of resistance patterns will be critical. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Global Reproduction and Transformation of Science Education

Science.gov (United States)

Tobin, Kenneth

2011-01-01

Neoliberalism has spread globally and operates hegemonically in many fields, including science education. I use historical auto/ethnography to examine global referents that have mediated the production of contemporary science education to explore how the roles of teachers and learners are related to macrostructures such as neoliberalism and…

Export Processing Zones and Global Class Formation

NARCIS (Netherlands)

Neveling, Patrick

2015-01-01

This chapter is concerned with one of the most striking developments in the global political economy of capitalism after the Second World War; the rise of export processing zones and special economic zones. Building on long-term ethnohistorical research on the zones’ global spread from one zone in

Ecosystem Interactions Underlie the Spread of Avian Influenza A Viruses with Pandemic Potential.

Directory of Open Access Journals (Sweden)

Justin Bahl

2016-05-01

Full Text Available Despite evidence for avian influenza A virus (AIV transmission between wild and domestic ecosystems, the roles of bird migration and poultry trade in the spread of viruses remain enigmatic. In this study, we integrate ecosystem interactions into a phylogeographic model to assess the contribution of wild and domestic hosts to AIV distribution and persistence. Analysis of globally sampled AIV datasets shows frequent two-way transmission between wild and domestic ecosystems. In general, viral flow from domestic to wild bird populations was restricted to within a geographic region. In contrast, spillover from wild to domestic populations occurred both within and between regions. Wild birds mediated long-distance dispersal at intercontinental scales whereas viral spread among poultry populations was a major driver of regional spread. Viral spread between poultry flocks frequently originated from persistent lineages circulating in regions of intensive poultry production. Our analysis of long-term surveillance data demonstrates that meaningful insights can be inferred from integrating ecosystem into phylogeographic reconstructions that may be consequential for pandemic preparedness and livestock protection.

Ecosystem Interactions Underlie the Spread of Avian Influenza A Viruses with Pandemic Potential

Science.gov (United States)

Bahl, Justin; Pham, Truc T.; Hill, Nichola J.; Hussein, Islam T. M.; Ma, Eric J.; Easterday, Bernard C.; Halpin, Rebecca A.; Stockwell, Timothy B.; Wentworth, David E.; Kayali, Ghazi; Krauss, Scott; Schultz-Cherry, Stacey; Webster, Robert G.; Webby, Richard J.; Swartz, Michael D.; Smith, Gavin J. D.; Runstadler, Jonathan A.

2016-01-01

Despite evidence for avian influenza A virus (AIV) transmission between wild and domestic ecosystems, the roles of bird migration and poultry trade in the spread of viruses remain enigmatic. In this study, we integrate ecosystem interactions into a phylogeographic model to assess the contribution of wild and domestic hosts to AIV distribution and persistence. Analysis of globally sampled AIV datasets shows frequent two-way transmission between wild and domestic ecosystems. In general, viral flow from domestic to wild bird populations was restricted to within a geographic region. In contrast, spillover from wild to domestic populations occurred both within and between regions. Wild birds mediated long-distance dispersal at intercontinental scales whereas viral spread among poultry populations was a major driver of regional spread. Viral spread between poultry flocks frequently originated from persistent lineages circulating in regions of intensive poultry production. Our analysis of long-term surveillance data demonstrates that meaningful insights can be inferred from integrating ecosystem into phylogeographic reconstructions that may be consequential for pandemic preparedness and livestock protection. PMID:27166585

Education, Meritocracy and the Global War for Talent

Science.gov (United States)

Brown, Phillip; Tannock, Stuart

2009-01-01

Talk of the rise of a global war for talent and emergence of a new global meritocracy has spread from the literature on human resource management to shape nation-state discourse on managed migration and immigration reform. This article examines the implications that the global war for talent have for education policy. Given that this talent war is…

Globalization, culture and psychology.

Science.gov (United States)

Melluish, Steve

2014-10-01

This article outlines the cultural and psychological effects of globalization. It looks at the impact of globalization on identity; ideas of privacy and intimacy; the way we understand and perceive psychological distress; and the development of the profession of psychology around the world. The article takes a critical perspective on globalization, seeing it as aligned with the spread of neoliberal capitalism, a tendency towards cultural homogenization, the imposition of dominant 'global north' ideas and the resultant growing inequalities in health and well-being. However, it also argues that the increased interconnectedness created by globalization allows for greater acknowledgement of our common humanity and for collective efforts to be developed to tackle what are increasingly global problems. This requires the development of more nuanced understandings of cultural differences and of indigenous psychologies.

Plan Quality and Treatment Efficiency for Radiosurgery to Multiple Brain Metastases: Non-Coplanar RapidArc vs Gamma Knife

Directory of Open Access Journals (Sweden)

Haisong eLiu

2016-02-01

Full Text Available Objectives: This study compares the dosimetry and efficiency of two modern radiosurgery (SRS modalities for multiple brain metastases (Gamma Knife and LINAC-based RapidArc/volumetric modulated arc therapy, with a special focus on the comparison of low dose spread.Methods: Six patients with three or four small brain metastases were used in this study. The size of targets varied from 0.1 ~ 10.5 cc. SRS doses were prescribed according to size of lesions. SRS plans were made using both Gamma Knife® Perfexion and a single-isocenter, multiple non-coplanar RapidArc®. Dosimetric parameters analyzed included RTOG conformity index (CI, gradient index (GI, 12 Gy isodose volume (V12Gy for each target, and the dose spread (Dspread for each plan. Dspread reflects SRS plan’s capability of confining radiation to within the local vicinity of the lesion and to not spread out to the surrounding normal brain tissues. Each plan has a dose (Dspread, such that once dose decreases below Dspread (on total tissue DVH, isodose volume starts increasing dramatically. Dspread is defined as that dose when volume increase first exceeds 20 cc per 0.1 Gy dose decrease. Results: RapidArc SRS has smaller CI (1.19 ±0.14 vs. 1.50 ± 0.16, p<0.001 and larger GI (4.77 ± 1.49 vs. 3.65 ± 0.98, p <0.01. V12Gy results were comparable (2.73 ± 1.38 cc vs. 3.06 ± 2.20 cc, p = 0.58. Moderate to lower dose spread, V6, V4.5, and V3, were also equivalent. Gamma Knife plans achieved better very low dose spread (≤3 Gy and also had slightly smaller Dspread, 1.9 Gy vs 2.5 Gy. Total treatment time for Gamma Knife is estimated between 60~100 min. Gamma Knife treatments are between 3~5 times longer compared to RapidArc treatment techniques.Conclusion: Dosimetric parameters reflecting prescription dose conformality (CI, dose fall off (GI, radiation necrosis indicator (V12Gy, and dose spread (Dspread were compared between Gamma Knife SRS and RapidArc SRS for multi-mets. RapidArc plans have

Supply chains in global production

Directory of Open Access Journals (Sweden)

Anatolii Mazaraki

2017-10-01

Full Text Available Introduction. Analyzing the current processes of global sales and sales interaction over the past two decades shows that the world’s system of exchanges has undergone significant changes that have been caused by a multitude of factors. The formation of a complex model of global production, determined by the peculiarities of the transformation of individual economies’ growth models, the specifics of their industrialization and the forms of development of their national production business, its institutional and market-wise restructuring and the degree of inclusion in the system of international division of labor. The change in the level and depth of the specialization of individual countries in the field of production and sale of products, in turn, has accelerated the overcoming of economic distance (which is measured by the cost of transport and information services. Based on the above, namely, within the framework of forming a new model of global production, the issue of studying the role and value of supply chains in this model is made relevant. Aim and tasks. The purpose of the article is to study the modern transformation of supply chains within the global production system. The findings will allow to determine what exactly needs to be done in the direction of further redeveloping the regulatory tools of global supply chain management. Research results. The article presents the results of studying the transformation of supply chains’ role in global production. It is determined that taking into account the existing specificity of industrialization and fragmentation of national production, as well as the rapid spread of the results of scientific and technological progress in the world economy, there is a need for a more thorough study of this change. As a result of analyzing open source statistical data, a conclusion was reached regarding the transition from the competition of individual business entities to the competition of global

Medical Tourism, Medical Migration, and Global Justice: Implications for Biosecurity in a Globalized World.

Science.gov (United States)

Cohen, I Glenn

2017-05-01

We live in the age of globalization. In medicine, that globalization has brought many benefits such as the diffusion of technology and the spread of health care training, but it has also brought threats to biosecurity. This article examines how medical tourism and medical migration pose risks to biosecurity. It also argues that designing legal responses to these risks requires not only technical competence but also a theory of global justice to guide that design. © The Author 2017. Published by Oxford University Press; all rights reserved. For Permissions, please email: journals.permissions@oup.com.

The current state of PET spread in China

International Nuclear Information System (INIS)

Zhang Hong

2009-01-01

Chinese nuclear medicine has 53 years history since 1956, and now is spreading in the country with the development of economy. Positron emission tomography (PET) has a rapid development in China, especially in the application of oncology, neurological and cardiologic diseases. The research of molecular imaging including PET also has been initiated. Zhejiang University as the largest university in China, has established the center of excellence in molecular imaging to improve the development of molecular imaging, which has active partnership and collaborative relationship with Japan, USA and European countries. The future of molecular imaging including PET in China is bright. (author)

The VULCANO spreading programme

Energy Technology Data Exchange (ETDEWEB)

Cognet, G.; Laffont, G.; Jegou, C.; Journeau, C.; Sudreau, F.; Pierre, J.; Ramacciotti, M. [CEA (Atomic Energy Commission), DRN/DER - Bat. 212, CEA Cadarache, 13108 St. Paul Lez Durance (France)

1999-07-01

Among the currently studied core-catcher projects, some of them suppose corium spreading before cooling, in particular the EPR (European Pressurized Reactor) core-catcher concept is based on mixing the corium with a special concrete, spreading the molten mixture on a large multi-layer surface cooled from the bottom and subsequently cooling by flooding with water. Therefore, melt spreading deserves intensive investigation in order to determine and quantify key phenomena which govern the stopping of spreading. In France, for some years, the Nuclear Reactor Division of the Atomic Energy Commission (CEA/DRN) has undertaken a large program to improve knowledge on corium behaviour and coolability. This program is based on experimental and theoretical investigations which are finally gathered in scenario and mechanistic computer codes. In this framework, the real material experimental programme, VULCANO, conducted within an European frame, is currently devoted to the study of corium spreading. In 1997 and 1998, several tests have been performed on dry corium spreading with various composition of melts. Although all the observed phenomena, in particular the differences between simulant and real material melts have not been yet totally explained, these tests have already provided a lot of information about: The behaviour of complex mixtures including refractory oxides, silica, iron oxides and in one case iron metal; Spreading progression, which was never stopped in any of these tests by a crust formation at the front; The structure of spread melts (porosity, crusts,...); Physico-chemical interaction between melt and the refractory substratum which was composed of zirconia bricks. (authors)

The VULCANO spreading programme

International Nuclear Information System (INIS)

Cognet, G.; Laffont, G.; Jegou, C.; Journeau, C.; Sudreau, F.; Pierre, J.; Ramacciotti, M.

1999-01-01

Among the currently studied core-catcher projects, some of them suppose corium spreading before cooling, in particular the EPR (European Pressurized Reactor) core-catcher concept is based on mixing the corium with a special concrete, spreading the molten mixture on a large multi-layer surface cooled from the bottom and subsequently cooling by flooding with water. Therefore, melt spreading deserves intensive investigation in order to determine and quantify key phenomena which govern the stopping of spreading. In France, for some years, the Nuclear Reactor Division of the Atomic Energy Commission (CEA/DRN) has undertaken a large program to improve knowledge on corium behaviour and coolability. This program is based on experimental and theoretical investigations which are finally gathered in scenario and mechanistic computer codes. In this framework, the real material experimental programme, VULCANO, conducted within an European frame, is currently devoted to the study of corium spreading. In 1997 and 1998, several tests have been performed on dry corium spreading with various composition of melts. Although all the observed phenomena, in particular the differences between simulant and real material melts have not been yet totally explained, these tests have already provided a lot of information about: The behaviour of complex mixtures including refractory oxides, silica, iron oxides and in one case iron metal; Spreading progression, which was never stopped in any of these tests by a crust formation at the front; The structure of spread melts (porosity, crusts,...); Physico-chemical interaction between melt and the refractory substratum which was composed of zirconia bricks. (authors)

Emergence and nosocomial spread of carbapenem-resistant OXA-232-producing Klebsiella pneumoniae in Brunei Darussalam

NARCIS (Netherlands)

Abdul Momin, Muhd Haziq Fikry; Liakopoulos, Apostolos; Phee, Lynette M.; Wareham, David W.

2017-01-01

Objectives Carbapenem-resistant Enterobacteriaceae (CRE) are identified as a major global health concern. The success of CRE is facilitated by the emergence, acquisition and spread of successful clones carrying plasmid-encoded resistance genes. In this study, an outbreak of carbapenem-resistant

Development and Validation of a Lateral Flow Immunoassay for Rapid Detection of NDM-Producing Enterobacteriaceae

Science.gov (United States)

Boutal, Hervé; Naas, Thierry; Devilliers, Karine; Oueslati, Saoussen; Bernabeu, Sandrine; Simon, Stéphanie

2017-01-01

ABSTRACT The global spread of carbapenemase-producing Enterobacteriaceae (CPE) that are often resistant to most, if not all, classes of antibiotics is a major public health concern. The NDM-1 carbapenemase is among the most worrisome carbapenemases given its rapid worldwide spread. We have developed and evaluated a lateral flow immunoassay (LFIA) (called the NDM LFIA) for the rapid and reliable detection of NDM-like carbapenemase-producing Enterobacteriaceae from culture colonies. We evaluated the NDM LFIA using 175 reference enterobacterial isolates with characterized β-lactamase gene content and 74 nonduplicate consecutive carbapenem-resistant clinical isolates referred for expertise to the French National Reference Center (NRC) for Antibiotic Resistance during a 1-week period (in June 2016). The reference collection included 55 non-carbapenemase producers and 120 carbapenemase producers, including 27 NDM producers. All 27 NDM-like carbapenemase producers of the reference collection were correctly detected in less than 15 min by the NDM LFIA, including 22 strains producing NDM-1, 2 producing NDM-4, 1 producing NDM-5, 1 producing NDM-7, and 1 producing NDM-9. All non-NDM-1 producers gave a negative result with the NDM LFIA. No cross-reaction was observed with carbapenemases (VIM, IMP, NDM, KPC, and OXA-48-like), extended-spectrum β-lactamases (ESBLs) (TEM, SHV, and CTX-M), AmpCs (CMY-2, DHA-2, and ACC-1), and oxacillinases (OXA-1, -2, -9, and -10). Similarly, among the 74 referred nonduplicate consecutive clinical isolates, all 7 NDM-like producers were identified. Overall, the sensitivity and specificity of the assay were 100% for NDM-like carbapenemase detection with strains cultured on agar. The NDM LFIA was efficient, rapid, and easy to implement in the routine workflow of a clinical microbiology laboratory for the confirmation of NDM-like carbapenemase-producing Enterobacteriaceae. PMID:28404680

Crop domestication facilitated rapid geographic expansion of a specialist pollinator, the squash bee Peponapis pruinosa

Science.gov (United States)

Over the past 10,000 years, humans have facilitated rapid range expansions of animal, plants and microorganisms, often accompanying agriculture’s spread. Three squash species were early domesticates in the New World. Their spreading cultivation out of the Southwest across much of today’s USA has bee...

EFFECTS OF THE GLOBAL FINANCIAL CRISIS IN THE BANKING SYSTEM OF KOSOVO

Directory of Open Access Journals (Sweden)

Myrvete Badivuku-Pantina

2012-09-01

Full Text Available Financial crises are phenomena that happened before and continue to happen even nowadays. There were many financial crises in the last century, starting with the Great Depression of 1929 and continuing with other financial crisis, and it was believed that people would learn from their previous experiences and would not allow the crisis to happen again. But the financial crisis of 2007, created the impression that no one wanted to learn for the real causes of their occurrence and consequences, often disastrous for countries and the globe, and as such allowed the crisis to be repeated. Effects of the 2007 financial crisis, which originally started in the USA’s mortgage market and which was quickly spread all over the world, even to this date it still continues to have effect on real economies of many states, e.g. Greece. The spread of the crisis was primarily due to globalization and commercial trades among countries. Because of the dependence of economies on one another it was created the domino effect and all the countries were affected from the crisis. As a result, the crisis seems to have revealed the disadvantages of globalization. Finances of the world were shocked and rapid fluctuations were reflected in the stock prices. Kosovo, as a new and small country in the Western Balkans is not much globalized and open which was beneficial in preventing it from being affected from the global financial crisis. Its economy has slightly felt the effect of the crisis because the banking system in Kosovo is not much open to the international financial markets as they operate mostly with their clients’ deposits. The purpose of this research is to assess the implications of the global financial crisis in the banking system of Kosovo, and also to identify the measures that the Central Bank and the Government should undertake in order to protect the economy from external implications.

Warning signals for eruptive events in spreading fires.

Science.gov (United States)

Fox, Jerome M; Whitesides, George M

2015-02-24

Spreading fires are noisy (and potentially chaotic) systems in which transitions in dynamics are notoriously difficult to predict. As flames move through spatially heterogeneous environments, sudden shifts in temperature, wind, or topography can generate combustion instabilities, or trigger self-stabilizing feedback loops, that dramatically amplify the intensities and rates with which fires propagate. Such transitions are rarely captured by predictive models of fire behavior and, thus, complicate efforts in fire suppression. This paper describes a simple, remarkably instructive physical model for examining the eruption of small flames into intense, rapidly moving flames stabilized by feedback between wind and fire (i.e., "wind-fire coupling"-a mechanism of feedback particularly relevant to forest fires), and it presents evidence that characteristic patterns in the dynamics of spreading flames indicate when such transitions are likely to occur. In this model system, flames propagate along strips of nitrocellulose with one of two possible modes of propagation: a slow, structured mode, and a fast, unstructured mode sustained by wind-fire coupling. Experimental examination of patterns in dynamics that emerge near bifurcation points suggests that symptoms of critical slowing down (i.e., the slowed recovery of the system from perturbations as it approaches tipping points) warn of impending transitions to the unstructured mode. Findings suggest that slowing responses of spreading flames to sudden changes in environment (e.g., wind, terrain, temperature) may anticipate the onset of intense, feedback-stabilized modes of propagation (e.g., "blowup fires" in forests).

The Benefits and Limitations of Crowdsourced Information for Rapid Damage Assessment of Global Earthquakes

Science.gov (United States)

Bossu, R.; Landès, M.; Roussel, F.

2017-12-01

The Internet has fastened the collection of felt reports and macroseismic data after global earthquakes. At the European-Mediterranean Seismological Centre (EMSC), where the traditional online questionnaires have been replace by thumbnail-based questionnaires, an average of half of the reports are collected within 10 minutes of an earthquake's occurrence. In regions where EMSC is well identified this goes down to 5 min. The user simply specifies the thumbnail corresponding to observed effects erasing languages barriers and improving collection via small smartphone screens. A previous study has shown that EMSC data is well correlated with "Did You Feel It" (DYFI) data and 3 independent, manually collected datasets. The efficiency and rapidity of felt report collection through thumbnail-based questionnaires does not necessarily mean that they offer a complete picture of the situation for all intensities values, especially the higher ones. There are several potential limitations. Demographics probably play a role but so might eyewitnesses' behaviors: it is probably not their priority to report when their own safety and that of their loved ones is at stake. We propose to test this hypothesis on EMSC felt reports and to extend the study to LastQuake smartphone application uses. LastQuake is a free smartphone app providing very rapid information on felt earthquakes. There are currently 210 000 active users around the world covering almost every country except for a few ones in Sub-Saharan Africa. Along with felt reports we also analyze the characteristics of LastQuake app launches. For both composite datasets created from 108 earthquakes, we analyze the rapidity of eyewitnesses' reaction and how it changes with intensity values and surmise how they reflect different types of behaviors. We will show the intrinsic limitations of crowdsourced information for rapid situation awareness. More importantly, we will show in which cases the lack of crowdsourced information could

Entrepreneurship in the World: The Analysis of the Global Entrepreneurship Index in the Period 2015-2017

Directory of Open Access Journals (Sweden)

Grădinaru Cătălin

2017-01-01

Full Text Available The last decades have witnessed the rapid spread of entrepreneurship all over the world. Consequently, the state of entrepreneurship has significantly improved. The aim of the paper is to present the evolution of the top ten countries in the world according to the Global Entrepreneurship Index in the period 2015-2017. The research methodology is based on a quantitative method. The paper shows that the top ten countries in the world according to this index in the last three years were the same in a high proportion and demonstrates the absolute domination of the United States of America and the growing presence of the European countries.

Virulence evolution at the front line of spreading epidemics.

Science.gov (United States)

Griette, Quentin; Raoul, Gaël; Gandon, Sylvain

2015-11-01

Understanding and predicting the spatial spread of emerging pathogens is a major challenge for the public health management of infectious diseases. Theoretical epidemiology shows that the speed of an epidemic is governed by the life-history characteristics of the pathogen and its ability to disperse. Rapid evolution of these traits during the invasion may thus affect the speed of epidemics. Here we study the influence of virulence evolution on the spatial spread of an epidemic. At the edge of the invasion front, we show that more virulent and transmissible genotypes are expected to win the competition with other pathogens. Behind the front line, however, more prudent exploitation strategies outcompete virulent pathogens. Crucially, even when the presence of the virulent mutant is limited to the edge of the front, the invasion speed can be dramatically altered by pathogen evolution. We support our analysis with individual-based simulations and we discuss the additional effects of demographic stochasticity taking place at the front line on virulence evolution. We confirm that an increase of virulence can occur at the front, but only if the carrying capacity of the invading pathogen is large enough. These results are discussed in the light of recent empirical studies examining virulence evolution at the edge of spreading epidemics. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

Evolution of spreading rate and H2 production by serpentinization at mid-ocean ridges from 200 Ma to Present

Science.gov (United States)

Andreani, M.; García del Real, P.; Daniel, I.; Wright, N.; Coltice, N.

2017-12-01

Mid-oceanic ridge (MOR) spreading rate spatially varies today from 20 to 200 mm/yr and geological records attest of important temporal variations, at least during the past 200 My. The spreading rate has a direct impact on the mechanisms accomodating extension (magmatic vs tectonic), hence on the nature of the rocks forming the oceanic lithosphere. The latter is composed of variable amount of magmatic and mantle rocks, that dominate at fast and (ultra-) slow spreading ridges, respectively. Serpentinization of mantle rocks contributes to global fluxes and notably to those of hydrogen and carbon by providing a pathways for dihydrogen (H2) production, carbone storage by mineralization, and carbon reduction to CH4 and possibly complex organic compounds. Quantification of the global chemical impact of serpentinization through geological time requires a coupling of geochemical parameters with plate-tectonic reconstructions. Here we quantify serpentinization extent and concurrent H2 production at MOR from the Jurassic (200 Ma) to present day (0 Ma). We coupled mean values of relevant petro-chemical parameters such as the proportion of mantle rocks, initial iron in olivine, iron redox state in serpentinites, % of serpentinization to high-resolution models of plate motion within the GPlates infrastructure to estimate the lengths in 1 Myr intervals for the global MOR plate boundary (spreading and transform components), and spreading ridges as a function of their rate. The model sensitivity to selected parameters has been tested. The results show that fragmentation of Pangea resulted in elevated H2 rates (>1012 to 1013 mol/yr) starting at 160 Ma compared to Late Mesozoic (<160 Ma) rates (<1011-1012 mol/yr). From 160 Ma to present, the coupled opening of the Atlantic and Indian oceans as well as the variation in spreading rates maintained H2 generation in the 1012 mol/yr level, but with significant excursions mainly related to the length of ultra-slow spreading segments. For

Global earthquake casualties due to secondary effects: A quantitative analysis for improving rapid loss analyses

Science.gov (United States)

Marano, K.D.; Wald, D.J.; Allen, T.I.

2010-01-01

This study presents a quantitative and geospatial description of global losses due to earthquake-induced secondary effects, including landslide, liquefaction, tsunami, and fire for events during the past 40 years. These processes are of great importance to the US Geological Survey's (USGS) Prompt Assessment of Global Earthquakes for Response (PAGER) system, which is currently being developed to deliver rapid earthquake impact and loss assessments following large/significant global earthquakes. An important question is how dominant are losses due to secondary effects (and under what conditions, and in which regions)? Thus, which of these effects should receive higher priority research efforts in order to enhance PAGER's overall assessment of earthquakes losses and alerting for the likelihood of secondary impacts? We find that while 21.5% of fatal earthquakes have deaths due to secondary (non-shaking) causes, only rarely are secondary effects the main cause of fatalities. The recent 2004 Great Sumatra-Andaman Islands earthquake is a notable exception, with extraordinary losses due to tsunami. The potential for secondary hazards varies greatly, and systematically, due to regional geologic and geomorphic conditions. Based on our findings, we have built country-specific disclaimers for PAGER that address potential for each hazard (Earle et al., Proceedings of the 14th World Conference of the Earthquake Engineering, Beijing, China, 2008). We will now focus on ways to model casualties from secondary effects based on their relative importance as well as their general predictability. ?? Springer Science+Business Media B.V. 2009.

Epidemic Spread of Symbiotic and Non-Symbiotic Bradyrhizobium Genotypes Across California.

Science.gov (United States)

Hollowell, A C; Regus, J U; Gano, K A; Bantay, R; Centeno, D; Pham, J; Lyu, J Y; Moore, D; Bernardo, A; Lopez, G; Patil, A; Patel, S; Lii, Y; Sachs, J L

2016-04-01

The patterns and drivers of bacterial strain dominance remain poorly understood in natural populations. Here, we cultured 1292 Bradyrhizobium isolates from symbiotic root nodules and the soil root interface of the host plant Acmispon strigosus across a >840-km transect in California. To investigate epidemiology and the potential role of accessory loci as epidemic drivers, isolates were genotyped at two chromosomal loci and were assayed for presence or absence of accessory "symbiosis island" loci that encode capacity to form nodules on hosts. We found that Bradyrhizobium populations were very diverse but dominated by few haplotypes-with a single "epidemic" haplotype constituting nearly 30 % of collected isolates and spreading nearly statewide. In many Bradyrhizobium lineages, we inferred presence and absence of the symbiosis island suggesting recurrent evolutionary gain and or loss of symbiotic capacity. We did not find statistical phylogenetic evidence that the symbiosis island acquisition promotes strain dominance and both symbiotic and non-symbiotic strains exhibited population dominance and spatial spread. Our dataset reveals that a strikingly few Bradyrhizobium genotypes can rapidly spread to dominate a landscape and suggests that these epidemics are not driven by the acquisition of accessory loci as occurs in key human pathogens.

The Epidemiology of Carbapenem-Resistant Enterobacteriaceae: The Impact and Evolution of a Global Menace.

Science.gov (United States)

Logan, Latania K; Weinstein, Robert A

2017-02-15

Carbapenem-resistant Enterobacteriaceae (CRE) are a serious public health threat. Infections due to these organisms are associated with significant morbidity and mortality. Mechanisms of drug resistance in gram-negative bacteria (GNB) are numerous; β-lactamase genes carried on mobile genetic elements are a key mechanism for the rapid spread of antibiotic-resistant GNB worldwide. Transmissible carbapenem-resistance in Enterobacteriaceae has been recognized for the last 2 decades, but global dissemination of carbapenemase-producing Enterobacteriaceae (CPE) is a more recent problem that, once initiated, has been occurring at an alarming pace. In this article, we discuss the evolution of CRE, with a focus on the epidemiology of the CPE pandemic; review risk factors for colonization and infection with the most common transmissible CPE worldwide, Klebsiella pneumoniae carbapenemase-producing K. pneumoniae; and present strategies used to halt the striking spread of these deadly pathogens. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Do pathogens become more virulent as they spread? Evidence from the amphibian declines in Central America.

Science.gov (United States)

Phillips, Ben L; Puschendorf, Robert

2013-09-07

The virulence of a pathogen can vary strongly through time. While cyclical variation in virulence is regularly observed, directional shifts in virulence are less commonly observed and are typically associated with decreasing virulence of biological control agents through coevolution. It is increasingly appreciated, however, that spatial effects can lead to evolutionary trajectories that differ from standard expectations. One such possibility is that, as a pathogen spreads through a naive host population, its virulence increases on the invasion front. In Central America, there is compelling evidence for the recent spread of pathogenic Batrachochytrium dendrobatidis (Bd) and for its strong impact on amphibian populations. Here, we re-examine data on Bd prevalence and amphibian population decline across 13 sites from southern Mexico through Central America, and show that, in the initial phases of the Bd invasion, amphibian population decline lagged approximately 9 years behind the arrival of the pathogen, but that this lag diminished markedly over time. In total, our analysis suggests an increase in Bd virulence as it spread southwards, a pattern consistent with rapid evolution of increased virulence on Bd's invading front. The impact of Bd on amphibians might therefore be driven by rapid evolution in addition to more proximate environmental drivers.

The global interdependence among oil-equity nexuses

International Nuclear Information System (INIS)

Huang, Shupei; An, Haizhong; Gao, Xiangyun; Wen, Shaobo; Jia, Xiaoliang

2016-01-01

We propose a global network model to investigate the interdependence among the oil-equity nexuses from different countries in various time horizons based on wavelet coherence and gray correlation. The stock indexes from 28 countries and crude oil prices of WTI (​West Texas Intermediate price) and Brent are the sample. We obtain the following primary results: Oil-equity nexuses throughout the world are well-integrated across time scales; Ireland, the Netherlands, Norway, Singapore, Demark, Germany and the Czech Republic for Brent-stock nexuses and Ireland, the Netherlands, Netherlands, Singapore, Japan, Germany and Malaysia for WTI-stock nexuses, successively corresponding to the frequency bands of 4 days–256 days, can be treated as a benchmark and can spread their fluctuations to other nexuses easily and rapidly. By contrast, China is more isolated in most time horizons and could be the ideal risk-hedging choice. Next, the global interdependence among oil-stock nexuses is characterized by the clustering effect, by which geographical factors and the oil production-consumption profile can exert their influence in most time horizons. In contrast, the speculation deals as well as energy policy and stagey are primarily influential in certain frequency bands. Thus, the decision-making for different time horizons could consider corresponding references. - Highlights: • Global interactions among oil-stock nexuses are invested. • Interdependence among oil-stock nexuses for Brent and WTI are both integrated. • Oil-stock nexuses networks are characterized by Multiscale and cluster effecting.

Exploring bounty and spread

DEFF Research Database (Denmark)

Pedersen, Rasmus Rex

2018-01-01

indications of the consequences of this shift. The article builds on existing research in the cultural industries and 'the industrial information economy' (Benkler 2006) and seeks to provide knowledge on the im- pact of music streaming on the Danish market for recorded music. Central to this topic are new......This article analyses the structural effects of the transition from the sale of music in physical and digital form to the access-based business model of music streaming. The global music streaming market is currently maturing rapidly, and as early adap- tors, the Nordic countries provide early...

The Challenges for the Multilateral Trading System Raised by the Ongoing Structural Transformations in the Global Economy

Directory of Open Access Journals (Sweden)

Agnes Ghibuțiu

2012-04-01

Full Text Available Over the last decade, international trade has been growing faster than global production, steadily increasing interdependence among nations. Sustained trade growth has been accompanied by profound changes in the patterns of trade flows, reflecting new production structures emerging under the impact of rapid progress in the development of transport, communications and information technologies, major shifts in the patterns of demand, rapid expansion of global production networks, and increasing integration of developing countries into the world economy. While global trade relations experienced a dramatic transformation during the last decade, the multilateral trading system and the WTO – the venue for international trade cooperation – failed to keep pace with the rapidly changing trade environment. Consequently, the world trade rule-book that is currently guiding international trade relations as a result of the Uruguay Round (1986-1994 and the creation of the WTO (in 1995 is stuck in the requirements of 20st century trade. Improving and adjusting multilateral trade rules and disciplines ranked among the main objectives of the Doha Round launched in 2001. However, trade negotiations have been stalled since 2008. And with this impasse, the legislative function of the WTO responsible for the elaboration of new rules has been also blocked, hindering thus the process of adjustment. This paper addresses the main challenges confrunting the multilateral trading system both in the long and short-term in its endeavour to adjust to the new realities of 21st century trade. More specifically, it takes a look at the key problems arising for international cooperation in trade from: (1 the continually shifting weight of economic power and influence within the world economy; (2 the dynamic spread of global production networks operated by TNCs; and (3 the explosion of regionalism and preferential trade agreements. Finally, the paper highlights the vital

Teaching for Global Competence in a Rapidly Changing World

Science.gov (United States)

Colvin, Richard Lee; Edwards, Virginia

2018-01-01

This new publication sets forward the PISA framework for global competence developed by the Organisation for Economic Cooperation and Development (OECD), which aligns closely with the definition developed by the Center for Global Education at Asia Society. Based on the Center's extensive experience supporting educators in integrating global…

The Global Internet Pandemic

Science.gov (United States)

Carter, Deborah Joy

2009-01-01

The global rise of Internet-based education is discussed in relation to models drawn from social studies and epidemiology. Experiential and data density models are highlighted, also the capacity for technological change, and phenomena observed in the spread of disease. The lesson of these illustrations is that even apparently permanent phenomena…

Journalism in the jaw of globalism

Directory of Open Access Journals (Sweden)

Đorđević Živorad

2009-01-01

Full Text Available Globalism has always been an important factor of both survival and development of human civilization. However, contemporary processes of globalization are founded upon accomplishment of interests of powerful states, powerful individuals and their domination. Journalism has made a great contribution to the accomplishment of goals of contemporary globalism. Instead of creative engagement in spreading of truth and objective informing, journalists are becoming transmission in publicity control and redirecting of its consciousness toward virtual. Hence the weaking of position and reputation of journalism.

Interrogating globalization and culture in anthropological perspective the Indian experience

OpenAIRE

Mondal, Sekh

2012-01-01

The present article is an attempt to examine and highlight the issues of cultural globalization and globalization of cultures with particular reference to India. To deal with these, I will discuss and analyze the concepts of globalization, cultural globalization and the nature of interrelation between global and local cultures in general and of India in particular. How the non-Indian global cultural elements are spreading among the Indians and how the Indian cultural elements are diffusing ov...

Reverse preferential spread in complex networks

Science.gov (United States)

Toyoizumi, Hiroshi; Tani, Seiichi; Miyoshi, Naoto; Okamoto, Yoshio

2012-08-01

Large-degree nodes may have a larger influence on the network, but they can be bottlenecks for spreading information since spreading attempts tend to concentrate on these nodes and become redundant. We discuss that the reverse preferential spread (distributing information inversely proportional to the degree of the receiving node) has an advantage over other spread mechanisms. In large uncorrelated networks, we show that the mean number of nodes that receive information under the reverse preferential spread is an upper bound among any other weight-based spread mechanisms, and this upper bound is indeed a logistic growth independent of the degree distribution.

Natural transformation of Vibrio parahaemolyticus: A rapid method to create genetic deletions.

Science.gov (United States)

Chimalapati, Suneeta; de Souza Santos, Marcela; Servage, Kelly; De Nisco, Nicole J; Dalia, Ankur B; Orth, Kim

2018-03-19

The Gram-negative bacterium Vibrio parahaemolyticus is an opportunistic human pathogen and the leading cause of seafood borne acute gastroenteritis worldwide. Recently, this bacterium was implicated as the etiologic agent of a severe shrimp disease with consequent devastating outcomes to shrimp farming. In both cases, acquisition of genetic material via horizontal transfer provided V. parahaemolyticus with new virulence tools to cause disease. Dissecting the molecular mechanisms of V. parahaemolyticus pathogenesis often requires manipulating its genome. Classically, genetic deletions in V. parahaemolyticus are performed using a laborious, lengthy, multi-step process. Herein, we describe a fast and efficient method to edit this bacterium's genome based on V. parahaemolyticus natural competence. Although this method is similar to one previously described, V. parahaemolyticus requires counter selection for curing of acquired plasmids due to its recalcitrant nature of retaining extrachromosomal DNA. We believe this approach will be of use to the Vibrio community. Importance Spreading of Vibrios throughout the world correlates with increased global temperatures. As they spread, they find new niches to survive, proliferate and invade. Therefore, genetic manipulation of Vibrios is of utmost importance for studying these species. Herein, we have delineated and validated a rapid method to create genetic deletions in Vibrio parahaemolyticus This study provides insightful methodology for studies with other Vibrio species. Copyright © 2018 American Society for Microbiology.

[Globalization and infectious diseases: the past and future].

Science.gov (United States)

Scotto, Gaetano

2011-03-01

Globalization is a widely-used term that can be defined in a number of different ways. When used in an economic context, it refers to the reduction and removal of barriers between national borders in order to facilitate the flow of goods, capital, services and labour. Globalization is not a new phenomenon. Today the concept of globalization can be extended to include global exposure to infectious diseases, which is becoming more apparent. The aim of this article is to examine the influence of globalization on the outbreak and spread of infections in the world.

How Is Mono Spread?

Science.gov (United States)

... How Is Mono Spread? Print My sister has mononucleosis. I drank out of her drink before we ... that I have mono now? – Kyle* Mono, or mononucleosis, is spread through direct contact with saliva. This ...

Wet climate and transportation routes accelerate spread of human plague

Science.gov (United States)

Xu, Lei; Stige, Leif Chr.; Kausrud, Kyrre Linné; Ben Ari, Tamara; Wang, Shuchun; Fang, Xiye; Schmid, Boris V.; Liu, Qiyong; Stenseth, Nils Chr.; Zhang, Zhibin

2014-01-01

Currently, large-scale transmissions of infectious diseases are becoming more closely associated with accelerated globalization and climate change, but quantitative analyses are still rare. By using an extensive dataset consisting of date and location of cases for the third plague pandemic from 1772 to 1964 in China and a novel method (nearest neighbour approach) which deals with both short- and long-distance transmissions, we found the presence of major roads, rivers and coastline accelerated the spread of plague and shaped the transmission patterns. We found that plague spread velocity was positively associated with wet conditions (measured by an index of drought and flood events) in China, probably due to flood-driven transmission by people or rodents. Our study provides new insights on transmission patterns and possible mechanisms behind variability in transmission speed, with implications for prevention and control measures. The methodology may also be applicable to studies of disease dynamics or species movement in other systems. PMID:24523275

The Mirage of Global Democracy

NARCIS (Netherlands)

de Wilde, J.H.

The literature about global democracy deals with two different types of democratization: Type 1 is about spreading democracy across sovereign states as the basis for good governance. It focuses on the quality of the state/society-nexus: the balance between coercion, reward and identity. Type 2 is

Rapid characterization of thermoelectric properties of composition spread (La1-xCax)VO3 films

International Nuclear Information System (INIS)

Itaka, K.; Wang, Q.J.; Minami, H.; Kawaji, H.; Koinuma, H.

2004-01-01

Vanadium oxides possess various interesting properties due to multivalence of a vanadium atom and attract our interest as a target material for the exploration of new applications. We investigated vanadates (La 1-x Ca x )VO 3 with a perovskite structure as thermoelectric (TE) materials because heavy electrons in vanadates are expected to generate large thermopower. To proceed the investigation of thermoelectric properties of the composition spread library more efficiently, we devised a new instrument of multi-channel measurement of their thermoelectric properties. The polarity of Seebeck coefficients changed from positive (0≤x≤0.2) to negative (0.2 3 (x∼0)

The global partnership: its achievements, missed opportunities and potential to address future threats from the spread of CBRN materials and expertise - 59335

International Nuclear Information System (INIS)

Heyes, Alan; Bowen, Wyn; Chalmers, Hugh

2012-01-01

Document available in abstract form only. Full text of publication follows: In 2002, the G8 launched the Global Partnership (GP) against the Spread of Weapons and Materials of Mass Destruction. The partnerships budget was placed at $20 billion over 10 years, and it was supported by some 23 countries and the European Union (EU).Though it has had little public recognition, the partnership has been one of the G8's most successful initiatives and has led to many benefits, including improved international security and addressing a sizeable proportion of the Cold War nuclear and chemical weapons arsenal in the Former Soviet Union. Its future, however, remains undecided, as its funding is set to expire in less than two years. In 2009 and 2010 Kings College London with generous funding support from the US John D. and Catherine T. MacArthur Foundation, carried out a detailed evaluation of the achievements and benefits of the GP to date, its failings and lost opportunities, and potential future direction. Our findings indicate that the partnership has aided security in the Former Soviet Union and had a significant number of wider benefits with the potential to continue to do the same on a broader geographic level in future. As such, it is a valuable tool to assist the international community to work together to address global threats relating to chemical, biological, radiological and nuclear materials and related expertise and the G8 should take steps to renew its funding. (authors)

HIV Cell-to-Cell Spread Results in Earlier Onset of Viral Gene Expression by Multiple Infections per Cell.

Directory of Open Access Journals (Sweden)

Mikaël Boullé

2016-11-01

Full Text Available Cell-to-cell spread of HIV, a directed mode of viral transmission, has been observed to be more rapid than cell-free infection. However, a mechanism for earlier onset of viral gene expression in cell-to-cell spread was previously uncharacterized. Here we used time-lapse microscopy combined with automated image analysis to quantify the timing of the onset of HIV gene expression in a fluorescent reporter cell line, as well as single cell staining for infection over time in primary cells. We compared cell-to-cell spread of HIV to cell-free infection, and limited both types of transmission to a two-hour window to minimize differences due to virus transit time to the cell. The mean time to detectable onset of viral gene expression in cell-to-cell spread was accelerated by 19% in the reporter cell line and by 35% in peripheral blood mononuclear cells relative to cell-free HIV infection. Neither factors secreted by infected cells, nor contact with infected cells in the absence of transmission, detectably changed onset. We recapitulated the earlier onset by infecting with multiple cell-free viruses per cell. Surprisingly, the acceleration in onset of viral gene expression was not explained by cooperativity between infecting virions. Instead, more rapid onset was consistent with a model where the fastest expressing virus out of the infecting virus pool sets the time for infection independently of the other co-infecting viruses.

Hybrid spread spectrum radio system

Science.gov (United States)

Smith, Stephen F [London, TN; Dress, William B [Camas, WA

2010-02-09

Systems and methods are described for hybrid spread spectrum radio systems. A method, includes receiving a hybrid spread spectrum signal including: fast frequency hopping demodulating and direct sequence demodulating a direct sequence spread spectrum signal, wherein multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies.

Global positioning system and associated technologies in animal behaviour and ecological research

Science.gov (United States)

Tomkiewicz, Stanley M.; Fuller, Mark R.; Kie, John G.; Bates, Kirk K.

2010-01-01

Biologists can equip animals with global positioning system (GPS) technology to obtain accurate (less than or equal to 30 m) locations that can be combined with sensor data to study animal behaviour and ecology. We provide the background of GPS techniques that have been used to gather data for wildlife studies. We review how GPS has been integrated into functional systems with data storage, data transfer, power supplies, packaging and sensor technologies to collect temperature, activity, proximity and mortality data from terrestrial species and birds. GPS 'rapid fixing' technologies combined with sensors provide location, dive frequency and duration profiles, and underwater acoustic information for the study of marine species. We examine how these rapid fixing technologies may be applied to terrestrial and avian applications. We discuss positional data quality and the capability for high-frequency sampling associated with GPS locations. We present alternatives for storing and retrieving data by using dataloggers (biologging), radio-frequency download systems (e.g. very high frequency, spread spectrum), integration of GPS with other satellite systems (e.g. Argos, Globalstar) and potential new data recovery technologies (e.g. network nodes). GPS is one component among many rapidly evolving technologies. Therefore, we recommend that users and suppliers interact to ensure the availability of appropriate equipment to meet animal research objectives.

Aristides Leão: a birth centennial homage with comments on his spreading depression

Directory of Open Access Journals (Sweden)

Eliasz Engelhardt

2015-06-01

Full Text Available The year of 2014 is the birth centenary of Aristides Azevedo Pacheco Leão (1914-1993, and also marks seventy years of the publication of his discovery of the novel electrophysiological phenomenon, named by him “spreading depression” (SD, soon designated “Leão’s wave” or “Leão’s spreading depression”. This was a remarkable scientific milestone, and the author must be celebrated for this achievement, as the studies he triggered proceeded worldwide, with new concepts, as spreading depolarization, until the present days. Robust experimental and clinical evidence emerged to suggest that these and related electrophysiological phenomena are involved in the mechanisms of migraine aura, acute cerebrovascular diseases, traumatic brain injury, transient global amnesia, epileptic seizures, and their pathophysiological characteristics come to offer new therapeutic perspectives. He was a remarkable and complex personality, and the authors remit the readers to a paper where his personal life is contemplated.

Has the First Global Financial Crisis Changed the Entrepreneurial Values in Digitalized Marketing-based Societies? The Case of GEM Latin American Countries

Directory of Open Access Journals (Sweden)

José Manuel Saiz Álvarez

2017-07-01

Full Text Available As the world economy is globalized, crises are rapidly spread due to the massive use of ICTs (Information and Communication Technologies, also affecting the entrepreneurial values involved in business creation processes. In this sense, digital marketing has a key role to play, as it can serve as a tool based on technology applied to foster nascent entrepreneurship. Using data for GEM Latin American countries, and applying clustering analysis based on the K-means method, the objective of this work is to test if the actual First Global Financial Crisis (FGFC has altered the entrepreneurial values in Latin American firms. The main result of this work is that the traits of entrepreneurial activity in GEM Latin American countries have progressively shifted from quantity to quality, so digital marketing is having an increasing importance.

TOWARD A GLOBAL EVOLUTIONARY MODEL OF PROTOPLANETARY DISKS

Energy Technology Data Exchange (ETDEWEB)

Bai, Xue-Ning, E-mail: xbai@cfa.harvard.edu [Institute for Theory and Computation, Harvard-Smithsonian Center for Astrophysics, 60 Garden St., MS-51, Cambridge, MA 02138 (United States)

2016-04-20

A global picture of the evolution  of protoplanetary disks (PPDs) is key to understanding almost every aspect of planet formation, where standard α-disk models have been continually employed for their simplicity. In the meantime, disk mass loss has been conventionally attributed to photoevaporation, which controls disk dispersal. However, a paradigm shift toward accretion driven by magnetized disk winds has taken place in recent years, thanks to studies of non-ideal magnetohydrodynamic effects in PPDs. I present a framework of global PPD evolution aiming to incorporate these advances, highlighting the role of wind-driven accretion and wind mass loss. Disk evolution is found to be largely dominated by wind-driven processes, and viscous spreading is suppressed. The timescale of disk evolution is controlled primarily by the amount of external magnetic flux threading the disks, and how rapidly the disk loses the flux. Rapid disk dispersal can be achieved if the disk is able to hold most of its magnetic flux during the evolution. In addition, because wind launching requires a sufficient level of ionization at the disk surface (mainly via external far-UV (FUV) radiation), wind kinematics is also affected by the FUV penetration depth and disk geometry. For a typical disk lifetime of a few million years, the disk loses approximately the same amount of mass through the wind as through accretion onto the protostar, and most of the wind mass loss proceeds from the outer disk via a slow wind. Fractional wind mass loss increases with increasing disk lifetime. Significant wind mass loss likely substantially enhances the dust-to-gas mass ratio and promotes planet formation.

TOWARD A GLOBAL EVOLUTIONARY MODEL OF PROTOPLANETARY DISKS

International Nuclear Information System (INIS)

Bai, Xue-Ning

2016-01-01

A global picture of the evolution  of protoplanetary disks (PPDs) is key to understanding almost every aspect of planet formation, where standard α-disk models have been continually employed for their simplicity. In the meantime, disk mass loss has been conventionally attributed to photoevaporation, which controls disk dispersal. However, a paradigm shift toward accretion driven by magnetized disk winds has taken place in recent years, thanks to studies of non-ideal magnetohydrodynamic effects in PPDs. I present a framework of global PPD evolution aiming to incorporate these advances, highlighting the role of wind-driven accretion and wind mass loss. Disk evolution is found to be largely dominated by wind-driven processes, and viscous spreading is suppressed. The timescale of disk evolution is controlled primarily by the amount of external magnetic flux threading the disks, and how rapidly the disk loses the flux. Rapid disk dispersal can be achieved if the disk is able to hold most of its magnetic flux during the evolution. In addition, because wind launching requires a sufficient level of ionization at the disk surface (mainly via external far-UV (FUV) radiation), wind kinematics is also affected by the FUV penetration depth and disk geometry. For a typical disk lifetime of a few million years, the disk loses approximately the same amount of mass through the wind as through accretion onto the protostar, and most of the wind mass loss proceeds from the outer disk via a slow wind. Fractional wind mass loss increases with increasing disk lifetime. Significant wind mass loss likely substantially enhances the dust-to-gas mass ratio and promotes planet formation

Geographical spread of global emissions: Within-country inequalities are large and increasing

International Nuclear Information System (INIS)

Sauter, Caspar; Grether, Jean-Marie; Mathys, Nicole A.

2016-01-01

In spite of the extensive literature on greenhouse gas emission inequalities at the world-wide level, most of the evidence so far has been based on country-level data. However, the within-country dimension matters for both the implementation and the policy formation of climate policies. As a preliminary step towards a better understanding of within-country inequalities, this paper measures their extent for the two major greenhouse gases, CO_2 and CH_4, over the 1970–2008 period. Using Theil-index decompositions, we show that within-country inequalities account for the bulk of global inequality, and tend to increase over the sample period, in contrast with diminishing between-country inequalities. Including differences across sectors reveals that between-sector inequalities matter more than between-country inequalities, and between-sector inequalities become the dominant source of global inequality at the end of the sample period in the CO_2 case. Finally, estimated social tensions arising from the disconnection between emissions and future damages turn out to be increasing as soon as within-country disparities are taken into account. These orders of magnitude should be kept in mind while discussing the efficiency and fairness of alternative paths in combating global warming. - Highlights: • We estimate global spatial CO_2 and CH_4 inequality using grid data for 1970–2008. • Overall spatial emission inequality is constant for CO_2 and increasing for CH_4. • Within-country inequality is rising and constitutes the main bulk of overall inequality. • An important part of within country inequality is due to differences among sectors. • The gap between emitters and victims is rising within countries.

Investors’ Risk Appetite and Global Financial Market Conditions

OpenAIRE

Brenda Gonzalez-Hermosillo

2008-01-01

A structural vector autoregression model is developed to analyze the dynamics of bond spreads among a sample of mature and developing countries during periods of financial stress in the last decade. The model identifies and quantifies the contribution on bond spreads from global market conditions (including funding liquidity, market liquidity, as well as credit and volatility risks), contagion effects, and idiosyncratic factors. While idiosyncratic factors explain a large amount of the change...

Synchronous x-ray and radio mode switches: a rapid global transformation of the pulsar magnetosphere.

Science.gov (United States)

Hermsen, W; Hessels, J W T; Kuiper, L; van Leeuwen, J; Mitra, D; de Plaa, J; Rankin, J M; Stappers, B W; Wright, G A E; Basu, R; Alexov, A; Coenen, T; Grießmeier, J-M; Hassall, T E; Karastergiou, A; Keane, E; Kondratiev, V I; Kramer, M; Kuniyoshi, M; Noutsos, A; Serylak, M; Pilia, M; Sobey, C; Weltevrede, P; Zagkouris, K; Asgekar, A; Avruch, I M; Batejat, F; Bell, M E; Bell, M R; Bentum, M J; Bernardi, G; Best, P; Bîrzan, L; Bonafede, A; Breitling, F; Broderick, J; Brüggen, M; Butcher, H R; Ciardi, B; Duscha, S; Eislöffel, J; Falcke, H; Fender, R; Ferrari, C; Frieswijk, W; Garrett, M A; de Gasperin, F; de Geus, E; Gunst, A W; Heald, G; Hoeft, M; Horneffer, A; Iacobelli, M; Kuper, G; Maat, P; Macario, G; Markoff, S; McKean, J P; Mevius, M; Miller-Jones, J C A; Morganti, R; Munk, H; Orrú, E; Paas, H; Pandey-Pommier, M; Pandey, V N; Pizzo, R; Polatidis, A G; Rawlings, S; Reich, W; Röttgering, H; Scaife, A M M; Schoenmakers, A; Shulevski, A; Sluman, J; Steinmetz, M; Tagger, M; Tang, Y; Tasse, C; ter Veen, S; Vermeulen, R; van de Brink, R H; van Weeren, R J; Wijers, R A M J; Wise, M W; Wucknitz, O; Yatawatta, S; Zarka, P

2013-01-25

Pulsars emit from low-frequency radio waves up to high-energy gamma-rays, generated anywhere from the stellar surface out to the edge of the magnetosphere. Detecting correlated mode changes across the electromagnetic spectrum is therefore key to understanding the physical relationship among the emission sites. Through simultaneous observations, we detected synchronous switching in the radio and x-ray emission properties of PSR B0943+10. When the pulsar is in a sustained radio-"bright" mode, the x-rays show only an unpulsed, nonthermal component. Conversely, when the pulsar is in a radio-"quiet" mode, the x-ray luminosity more than doubles and a 100% pulsed thermal component is observed along with the nonthermal component. This indicates rapid, global changes to the conditions in the magnetosphere, which challenge all proposed pulsar emission theories.

Would There Be One Standard English as the Global Language?

Directory of Open Access Journals (Sweden)

Ienneke Indra Dewi

2010-04-01

Full Text Available Article intends to investigate whether there is the possibility of having English as a global language used all over the world with one variety only. One variety of English will reduce the miscommunication among people speaking English. The research was conducted by library research by looking at the requirements of a global language, its spread in the world, and the related problems. The results show that English has fulfilled the requirements of a global language looking from its history and the spread of its speakers. However, it has a lot of varieties in either English speaking countries or in the developing countries where English functions as a second and foreign language. The varieties are found not only in the pronunciation, but in the vocabulary and grammar as well. Usually the native languages play an important role in these varieties. All these facts indicate that English might become a global language. However, having one variety of English still needs a long time to go.

Global and local targeted immunization in networks with community structure

International Nuclear Information System (INIS)

Yan, Shu; Tang, Shaoting; Pei, Sen; Zheng, Zhiming; Fang, Wenyi

2015-01-01

Immunization plays an important role in the field of epidemic spreading in complex networks. In previous studies, targeted immunization has been proved to be an effective strategy. However, when extended to networks with community structure, it is unknown whether the superior strategy is to vaccinate the nodes who have the most connections in the entire network (global strategy), or those in the original community where epidemic starts to spread (local strategy). In this work, by using both analytic approaches and simulations, we observe that the answer depends on the closeness between communities. If communities are tied closely, the global strategy is superior to the local strategy. Otherwise, the local targeted immunization is advantageous. The existence of a transitional value of closeness implies that we should adopt different strategies. Furthermore, we extend our investigation from two-community networks to multi-community networks. We consider the mode of community connection and the location of community where epidemic starts to spread. Both simulation results and theoretical predictions show that local strategy is a better option for immunization in most cases. But if the epidemic begins from a core community, global strategy is superior in some cases. (paper)

Default Spread dan Term Spread sebagai Variabel Proxy Siklus Bisnis pada Model Fama-French

Directory of Open Access Journals (Sweden)

Edwin Hendra

2015-08-01

Full Text Available This research aims to apply the Fama-French models and test the effect of alternative variable of bond yield spread, default spread (RBBB – RAAA and RAAA – RF, and the term spread (RSUN10-RSUN1, as proxy variables of the business cycle, in IDX stock data during 2005-2010. Four types of asset pricing models tested are Sharpe-Lintner CAPM, Fama-French models, Hwang et al.model, and hybrid model. The results showed that the size effect and value effect has an impact on excess stock returns. Slopes of market beta, SMB, and HML are more sensitive to stock big size and high B / M. Default spreads and term spreads in Hwang et al. model can explain the value effect, and weakly explain the size effect, meanwhile the power of explanation disappeared on Hybrid models. Based on the assessment adjusted R2 and the frequency of rejection of non-zero alpha, is found that the hybrid model is the most suitable model.  

Masculine sex ratios, population age structure and the potential spread of HIV in China

Directory of Open Access Journals (Sweden)

M. Giovanna Merli

2010-01-01

Full Text Available There is much speculation regarding the contribution of China's changing demography to the spread of HIV/AIDS. We employ a bio-behavioral macrosimulation model of the heterosexual spread of HIV/AIDS to evaluate the roles that China's unique demographic conditions -- (1 masculine sex ratios at birth and (2 a population age structure that reflects rapid fertility decline since the 1970's -- play in altering the market for sexual partners, thereby potentially fueling an increase in behaviors associated with greater risk of HIV infection. We first simulate the relative contributions of the sex ratio at birth and the population age structure to the oversupply of males in the market for sexual partners and show that the sex ratio at birth only aggravates the severe oversupply of males which is primarily a consequence of the population age structure. We then examine the potential consequences of this demographic distortion for the spread of HIV infection and show that, to the extent that males adapt to the dearth of suitable female partners by seeking unprotected sexual contacts with female sex workers, the impact of the oversupply of males in the sexual partnership market on the spread of HIV will be severe.

Reliability and Efficiency of Generalized Rumor Spreading Model on Complex Social Networks

International Nuclear Information System (INIS)

Naimi, Yaghoob; Naimi, Mohammad

2013-01-01

We introduce the generalized rumor spreading model and investigate some properties of this model on different complex social networks. Despite pervious rumor models that both the spreader-spreader (SS) and the spreader-stifler (SR) interactions have the same rate α, we define α (1) and α (2) for SS and SR interactions, respectively. The effect of variation of α (1) and α (2) on the final density of stiflers is investigated. Furthermore, the influence of the topological structure of the network in rumor spreading is studied by analyzing the behavior of several global parameters such as reliability and efficiency. Our results show that while networks with homogeneous connectivity patterns reach a higher reliability, scale-free topologies need a less time to reach a steady state with respect the rumor. (interdisciplinary physics and related areas of science and technology)

Fast Evaporation of Spreading Droplets of Colloidal Suspensions

Science.gov (United States)

Maki, Kara; Kumar, Satish

2011-11-01

When a coffee droplet dries on a countertop, a dark ring of coffee solute is left behind, a phenomenon often referred to as ``the coffee-ring effect.'' A closely related yet less-well-explored phenomenon is the formation of a layer of particles, or skin, at the surface of the droplet. In this work, we explore the behavior of a mathematical model that can qualitatively describe both phenomena. We consider a thin axisymmetric droplet of a colloidal suspension on a horizontal substrate undergoing spreading and rapid evaporation. The lubrication approximation is applied to simplify the mass and momentum conservation equations, and the colloidal particles are allowed to influence droplet rheology through their effect on the viscosity. By describing the transport of the colloidal particles with the full convection-diffusion equation, we are able to capture depthwise gradients in particle concentration and thus describe skin formation, a feature neglected in prior models of droplet evaporation. Whereas capillarity creates a flow that drives particles to the contact line to produce a coffee-ring, Marangoni flows can compete with this and promote skin formation. Increases in viscosity due to particle concentration slow down droplet dynamics, and can lead to a significant reduction in the spreading rate.

Destructive disinfection of infected brood prevents systemic disease spread in ant colonies.

Science.gov (United States)

Pull, Christopher D; Ugelvig, Line V; Wiesenhofer, Florian; Grasse, Anna V; Tragust, Simon; Schmitt, Thomas; Brown, Mark Jf; Cremer, Sylvia

2018-01-09

In social groups, infections have the potential to spread rapidly and cause disease outbreaks. Here, we show that in a social insect, the ant Lasius neglectus , the negative consequences of fungal infections ( Metarhizium brunneum ) can be mitigated by employing an efficient multicomponent behaviour, termed destructive disinfection, which prevents further spread of the disease through the colony. Ants specifically target infected pupae during the pathogen's non-contagious incubation period, utilising chemical 'sickness cues' emitted by pupae. They then remove the pupal cocoon, perforate its cuticle and administer antimicrobial poison, which enters the body and prevents pathogen replication from the inside out. Like the immune system of a metazoan body that specifically targets and eliminates infected cells, ants destroy infected brood to stop the pathogen completing its lifecycle, thus protecting the rest of the colony. Hence, in an analogous fashion, the same principles of disease defence apply at different levels of biological organisation.

Spread effects - methodology; Spredningseffekter - metodegrunnlag

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-07-01

Diffusion of technology, environmental effects and rebound effects are the principal effects from the funding of renewable energy and energy economising. It is difficult to estimate the impact of the spread effects both prior to the measures are implemented and after the measures are carried out. Statistical methods can be used to estimate the spread effects, but they are insecure and always need to be complemented with qualitative and subjective evaluations. It is more adequate to evaluate potential spread effects from market and market data surveillance for a selection of technologies and parties. Based on this information qualitative indicators for spread effects can be constructed and used both ex ante and ex post (ml)

Synergy in spreading processes: from exploitative to explorative foraging strategies.

Science.gov (United States)

Pérez-Reche, Francisco J; Ludlam, Jonathan J; Taraskin, Sergei N; Gilligan, Christopher A

2011-05-27

An epidemiological model which incorporates synergistic effects that allow the infectivity and/or susceptibility of hosts to be dependent on the number of infected neighbors is proposed. Constructive synergy induces an exploitative behavior which results in a rapid invasion that infects a large number of hosts. Interfering synergy leads to a slower and sparser explorative foraging strategy that traverses larger distances by infecting fewer hosts. The model can be mapped to a dynamical bond percolation with spatial correlations that affect the mechanism of spread but do not influence the critical behavior of epidemics. © 2011 American Physical Society

Global equivalent magnetization of the oceanic lithosphere

Science.gov (United States)

Dyment, J.; Choi, Y.; Hamoudi, M.; Lesur, V.; Thebault, E.

2015-11-01

As a by-product of the construction of a new World Digital Magnetic Anomaly Map over oceanic areas, we use an original approach based on the global forward modeling of seafloor spreading magnetic anomalies and their comparison to the available marine magnetic data to derive the first map of the equivalent magnetization over the World's ocean. This map reveals consistent patterns related to the age of the oceanic lithosphere, the spreading rate at which it was formed, and the presence of mantle thermal anomalies which affects seafloor spreading and the resulting lithosphere. As for the age, the equivalent magnetization decreases significantly during the first 10-15 Myr after its formation, probably due to the alteration of crustal magnetic minerals under pervasive hydrothermal alteration, then increases regularly between 20 and 70 Ma, reflecting variations in the field strength or source effects such as the acquisition of a secondary magnetization. As for the spreading rate, the equivalent magnetization is twice as strong in areas formed at fast rate than in those formed at slow rate, with a threshold at ∼40 km/Myr, in agreement with an independent global analysis of the amplitude of Anomaly 25. This result, combined with those from the study of the anomalous skewness of marine magnetic anomalies, allows building a unified model for the magnetic structure of normal oceanic lithosphere as a function of spreading rate. Finally, specific areas affected by thermal mantle anomalies at the time of their formation exhibit peculiar equivalent magnetization signatures, such as the cold Australian-Antarctic Discordance, marked by a lower magnetization, and several hotspots, marked by a high magnetization.

Epidemic spreading on adaptively weighted scale-free networks.

Science.gov (United States)

Sun, Mengfeng; Zhang, Haifeng; Kang, Huiyan; Zhu, Guanghu; Fu, Xinchu

2017-04-01

We introduce three modified SIS models on scale-free networks that take into account variable population size, nonlinear infectivity, adaptive weights, behavior inertia and time delay, so as to better characterize the actual spread of epidemics. We develop new mathematical methods and techniques to study the dynamics of the models, including the basic reproduction number, and the global asymptotic stability of the disease-free and endemic equilibria. We show the disease-free equilibrium cannot undergo a Hopf bifurcation. We further analyze the effects of local information of diseases and various immunization schemes on epidemic dynamics. We also perform some stochastic network simulations which yield quantitative agreement with the deterministic mean-field approach.

Globalization, Sustainable Development and Universities

Science.gov (United States)

Toakley, Arthur Raymond

2004-01-01

Globalization is a natural outcome of the sustained technological and economic growth, which originated with the Industrial Revolution in Britain during the 18th century. This path to continuing economic growth spread initially to continental Europe and North America, and brought with it the creation of large towns and substantial social change.…

Degree of host susceptibility in the initial disease outbreak influences subsequent epidemic spread

Science.gov (United States)

Severns, Paul M.; Estep, Laura K.; Sackett, Kathryn E.; Mundt, Christopher C.

2014-01-01

Summary Disease epidemics typically begin as an outbreak of a relatively small, spatially explicit population of infected individuals (focus), in which disease prevalence increases and rapidly spreads into the uninfected, at-risk population. Studies of epidemic spread typically address factors influencing disease spread through the at-risk population, but the initial outbreak may strongly influence spread of the subsequent epidemic.We initiated wheat stripe rust Puccinia striiformis f. sp. tritici epidemics to assess the influence of the focus on final disease prevalence when the degree of disease susceptibility differed between the at-risk and focus populations.When the focus/at-risk plantings consisted of partially genetic resistant and susceptible cultivars, final disease prevalence was statistically indistinguishable from epidemics produced by the focus cultivar in monoculture. In these experimental epidemics, disease prevalence was not influenced by the transition into an at-risk population that differed in disease susceptibility. Instead, the focus appeared to exert a dominant influence on the subsequent epidemic.Final disease prevalence was not consistently attributable to either the focus or the at-risk population when focus/at-risk populations were planted in a factorial set-up with a mixture (~28% susceptible and 72% resistant) and susceptible individuals. In these experimental epidemics, spatial heterogeneity in disease susceptibility within the at-risk population appeared to counter the dominant influence of the focus.Cessation of spore production from the focus (through fungicide/glyphosate application) after 1.3 generations of stripe rust spread did not reduce final disease prevalence, indicating that the focus influence on disease spread is established early in the epidemic.Synthesis and applications. Our experiments indicated that outbreak conditions can be highly influential on epidemic spread, even when disease resistance in the at-risk population

[Scientometric and publication malpractices. The appearance of globalization in biomedical publishing].

Science.gov (United States)

Fazekas, T; Varró, V

2001-09-16

Attention is drawn to publication and scientometric malpractices utilized by biomedical authors who do not adhere to the accepted ethical norms. The difference between duplicate/redundant and bilingual publications is defined. In the course of discussion of the manipulations that may be observed in the field of scientometry, it is pointed out that abstract of congress lectures/posters can not be taken into consideration for scientometric purposes even if such abstracts are published in journals with impact factors. A further behavioral form is likewise regarded as unacceptable from the aspect of publication ethics: when a physician who has participated in a multicentre, randomized clinical trial receives recognition (in an appendix or in an acknowledgement of an article) as having contributed data, but assesses this appreciation as co-authorship and thereby attempts to augment the value of his or her publication activity. The effects of globalization on biomedical publication activity are considered, and evidence is provided that the rapidly spreading electronic publication for a give rise to new types of ethical dilemmas. It is recommended that, in the current age of Anglo-American globalization, greater emphasis should be placed on the development of medical publication in the mother tongue (Hungarian).

Globalization, Tax Competition and Tax Burden İn Turkey

Directory of Open Access Journals (Sweden)

Veli KARGI

2016-07-01

Full Text Available 1990’s world was quite different from the world of 1950’s. Especially in the last twenty years, the increasing involvement of Japan in the world economy since the 1990s, in addition to the dominance of globalization and market economy throughout the world, the rapid spread of information resulting from the developments in IT-technology and the international competition emerging in the field of technology have all led to some significant developments in the world economy. Reduction of high mobility income and corporate tax rates due to tax competition may cause an unjust distribution of the tax burden. The fact that indirect taxation constitutes about 70% of the tax revenues obtained in Turkey can be taken as an indication of the unfairness in the distribution of tax burden in Turkey. In this study, following a definition of globalization and tax competition, classification of tax competition, reasons for increasing tax competition, benefits and losses of tax competition are explained, and changes introduced by various countries in their tax systems due to tax competition, the distribution of tax burden resulting from tax competition in Turkey and the effectiveness of the new income tax law in Turkey in terms of tax competition are analyzed.

Trends in spread of the particle therapy of cancers to areal bases

International Nuclear Information System (INIS)

Abe, Mitsuyuki; Aoki, Takashi; Tsujii, Hirohiko

2009-01-01

In Japan, the rate of cancer death accounts for 30%, now there are 8 facilities having the cancer particle therapy (PT) which is promising due to its highly effective, short term, non-surgical, not always expensive treatment, and local areas have tended to construct such facility for their people. This special article describes trends in the title concerning the areal intention for setting up the therapeutic bases, global trend of PT, research and development in manufacturers of PT equipments, and response of health insurer to the trend. The article contains following 15 topics presented by 15 authors or groups of the academia, official and company institutes, prefectural officers, manufacturers and an insurer, and by Editorial. Topics are: Significance and future view of PT in cancer treatment; Present state of construction of PT facilities in various areas; Fifteen year-results of PT in near-infrared spectroscopy (NIRS) and its effort to spread the therapy; Gumma University's 21st century program COE (Center of Excellence), Medical and Biological Studies with Accelerator Technology; Project for constructing Fukui Prefectural Proton PT Center; The role of Proton PT Center in southern Tohoku area as the first private facility; PT center by Foundation of Medipolis Medical Research Institute in southern Kyushu area; Global trend of PT; Spread of PT and the role of health insurance in it/Mitsui-Sumitomo's health insurance, Kirameki, the contribution to general public; Mitsubishi Electric Corp.'s effort to spread PT equipments; Toshiba's effort; Hitachi's effort; Sumitomo Heavy Industries' effort; Effort by Chiyoda Technol Corp. and Still River Systems to develop the next generation superconducting PT equipment; and Overview by Editorial/Complicated trend in invitation and construction of PT facilities. (K.T.)

Rapid evolution and spread of carbapenemases among Enterobacteriaceae in Europe.

Science.gov (United States)

Cantón, R; Akóva, M; Carmeli, Y; Giske, C G; Glupczynski, Y; Gniadkowski, M; Livermore, D M; Miriagou, V; Naas, T; Rossolini, G M; Samuelsen, Ø; Seifert, H; Woodford, N; Nordmann, P

2012-05-01

Plasmid-acquired carbapenemases in Enterobacteriaceae, which were first discovered in Europe in the 1990s, are now increasingly being identified at an alarming rate. Although their hydrolysis spectrum may vary, they hydrolyse most β-lactams, including carbapenems. They are mostly of the KPC, VIM, NDM and OXA-48 types. Their prevalence in Europe as reported in 2011 varies significantly from high (Greece and Italy) to low (Nordic countries). The types of carbapenemase vary among countries, partially depending on the cultural/population exchange relationship between the European countries and the possible reservoirs of each carbapenemase. Carbapenemase producers are mainly identified among Klebsiella pneumoniae and Escherichia coli, and still mostly in hospital settings and rarely in the community. Although important nosocomial outbreaks with carbapenemase-producing Enterobacteriaceae have been extensively reported, many new cases are still related to importation from a foreign country. Rapid identification of colonized or infected patients and screening of carriers is possible, and will probably be effective for prevention of a scenario of endemicity, as now reported for extended-spectrum β-lactamase (mainly CTX-M) producers in all European countries. © 2012 The Authors. Clinical Microbiology and Infection © 2012 European Society of Clinical Microbiology and Infectious Diseases.

Globalization, English Language Policy, and Teacher Agency: Focus on Asia

Science.gov (United States)

Hamid, M. Obaidul; Nguyen, Hoa Thi Mai

2016-01-01

This paper focuses on English teachers in Asia in the context of globalization, the global spread of English and the emergence of English as an "Asian language." It highlights the dilemmas facing these teachers in meeting the growing social demands of English proficiency in a technology-influenced, managerial and neoliberal education…

The reconciliation of an F-region irregularity model with sunspot-cycle variations in spread-F occurrence

International Nuclear Information System (INIS)

Singleton, D.G.

1974-11-01

A recently proposed means of combining models of ionospheric F-layer peak electron density and irregularity incremental electron density (ΔN) so as to simulate the global occurrence probability of the frequency spreading component of spread-F is discussed. This procedure is then used to model experimental spread-F occurrence results. It is found possible to readily simulate the sunspot-maximum results, independently of season, with only small adjustments to the amplitudes of the empirical expressions used to ΔN in the several latitude regimes. However, at sunspot minimum and for each season, the ΔN model requires modification in the equatorial and mid-latitude regions of high irregularity incidence, before successful simulations of the spread-F data can be obtained. These modifications, which include a broadening of the equatorial region and a polewards shift to the mid-latitude region with decreasing sunspot number, are discussed in detail. It is concluded that the scintillation data base, from which the original ΔN model derives, is not sufficiently representative with regard to sunspot number and magnetic index. The use of the spread-F adaptation of the ΔN model, as well as its original scintillation version, to rectify these failings of the ΔN model are also discussed. (author)

Fluorescent visualization of a spreading surfactant

Energy Technology Data Exchange (ETDEWEB)

Fallest, David W; Lichtenberger, Adele M; Fox, Christopher J; Daniels, Karen E, E-mail: kdaniel@ncsu.ed [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States)

2010-07-15

The spreading of surfactants on thin films is an industrially and medically important phenomenon, but the dynamics are highly nonlinear and visualization of the surfactant dynamics has been a long-standing experimental challenge. We perform the first quantitative, spatiotemporally resolved measurements of the spreading of an insoluble surfactant on a thin fluid layer. During the spreading process, we directly observe both the radial height profile of the spreading droplet and the spatial distribution of the fluorescently tagged surfactant. We find that the leading edge of a spreading circular layer of surfactant forms a Marangoni ridge in the underlying fluid, with a trough trailing the ridge as expected. However, several novel features are observed using the fluorescence technique, including a peak in the surfactant concentration that trails the leading edge, and a flat, monolayer-scale spreading film that differs from concentration profiles predicted by current models. Both the Marangoni ridge and the surfactant leading edge can be described to spread as R{approx}t{sup {delta}}. We find spreading exponents {delta}{sub H}{approx}0.30 and {delta}{sub {Gamma}}{approx}0.22 for the ridge peak and surfactant leading edge, respectively, which are in good agreement with theoretical predictions of {delta}=1/4. In addition, we observe that the surfactant leading edge initially leads the peak of the Marangoni ridge, with the peak later catching up to the leading edge.

Information spread in networks: Games, optimal control, and stabilization

Science.gov (United States)

Khanafer, Ali

This thesis focuses on designing efficient mechanisms for controlling information spread in networks. We consider two models for information spread. The first one is the well-known distributed averaging dynamics. The second model is a nonlinear one that describes virus spread in computer and biological networks. We seek to design optimal, robust, and stabilizing controllers under practical constraints. For distributed averaging networks, we study the interaction between a network designer and an adversary. We consider two types of attacks on the network. In Attack-I, the adversary strategically disconnects a set of links to prevent the nodes from reaching consensus. Meanwhile, the network designer assists the nodes in reaching consensus by changing the weights of a limited number of links in the network. We formulate two problems to describe this competition where the order in which the players act is reversed in the two problems. Although the canonical equations provided by the Pontryagin's Maximum Principle (MP) seem to be intractable, we provide an alternative characterization for the optimal strategies that makes connection to potential theory. Further, we provide a sufficient condition for the existence of a saddle-point equilibrium (SPE) for the underlying zero-sum game. In Attack-II, the designer and the adversary are both capable of altering the measurements of all nodes in the network by injecting global signals. We impose two constraints on both players: a power constraint and an energy constraint. We assume that the available energy to each player is not sufficient to operate at maximum power throughout the horizon of the game. We show the existence of an SPE and derive the optimal strategies in closed form for this attack scenario. As an alternative to the "network designer vs. adversary" framework, we investigate the possibility of stabilizing unknown network diffusion processes using a distributed mechanism, where the uncertainty is due to an attack

A multiplex lateral flow immunoassay for the rapid identification of NDM-, KPC-, IMP- and VIM-type and OXA-48-like carbapenemase-producing Enterobacteriaceae

Science.gov (United States)

Boutal, Hervé; Vogel, Anaïs; Bernabeu, Sandrine; Devilliers, Karine; Creton, Elodie; Cotellon, Garence; Plaisance, Marc; Oueslati, Saoussen; Dortet, Laurent; Jousset, Agnès; Simon, Stéphanie; Naas, Thierry; Volland, Hervé

2018-01-01

Abstract Objectives The global spread of carbapenemase-producing Enterobacteriaceae represents a substantial challenge in clinical practice and rapid and reliable detection of these organisms is essential. The aim of this study was to develop and validate a lateral flow immunoassay (Carba5) for the detection of the five main carbapenemases (KPC-, NDM-, VIM- and IMP-type and OXA-48-like). Methods Carba5 was retrospectively and prospectively evaluated using 296 enterobacterial isolates from agar culture. An isolated colony was suspended in extraction buffer and then loaded on the manufactured Carba5. Results All 185 isolates expressing a carbapenemase related to one of the Carba5 targets were correctly and unambiguously detected in Enterobacteriaceae. PMID:29365094

Terrestrial spreading centers under Venus conditions - Evaluation of a crustal spreading model for Western Aphrodite Terra

Science.gov (United States)

Sotin, C.; Senske, D. A.; Head, J. W.; Parmentier, E. M.

1989-01-01

The model of Reid and Jackson (1981) for terrestrial spreading centers is applied to Venus conditions. On the basis of spreading rate, mantle temperature, and surface temperature, the model predicts both isostatic topography and crustal thickness. The model and Pioneer Venus altimetry and gravity data are used to test the hypothesis of Head and Crumpler (1987) that Western Aphrodite Terra is the location of crustal spreading on Venus. It is concluded that a spreading center model for Ovda Regio in Western Aphrodite Terra could account for the observed topography and line-of-sight gravity anomalies found in the Pioneer data.

Sharing Data for Global Infectious Disease Surveillance and Outbreak Detection

DEFF Research Database (Denmark)

Aarestrup, Frank Møller; Koopmans, Marion G.

2016-01-01

Rapid global sharing and comparison of epidemiological and genomic data on infectious diseases would enable more rapid and efficient global outbreak control and tracking of diseases. Several barriers for global sharing exist but, in our opinion, the presumed magnitude of the problems appears larger...

Language Learning Motivation, Global English and Study Modes: A Comparative Study

Science.gov (United States)

Lanvers, Ursula

2017-01-01

Exploring the popular explanation that the global spread of English may demotivate students with English as their first language to learn other languages, this study investigates relations between student motivation and perception of Global English and tests for differences between traditional "campus" and distance university students…

Does media coverage influence the spread of drug addiction?

Science.gov (United States)

Ma, Mingju; Liu, Sanyang; Li, Jun

2017-09-01

In this paper, a three dimensional drug model is constructed to investigate the impact of media coverage on the spread and control of drug addiction. The dynamical behavior of the model is studied by using the basic reproduction number R0. The drug-free equilibrium is globally asymptotically stable if R0 drug addiction equilibrium is locally stable if R0 > 1. The results demonstrate that the media effect in human population cannot change the stabilities of equilibria but can affect the number of drug addicts. Sensitivity analyses are performed to seek for effective control measures for drug treatment. Numerical simulations are given to support the theoretical results.

The impact of rapid economic growth and globalization on zinc nutrition in South Korea.

Science.gov (United States)

Kwun, In-Sook; Do, Mi-Sook; Chung, Hae-Rang; Kim, Yang Ha; Beattie, John H

2009-08-01

Zn deficiency may be widespread in Asian countries such as South Korea. However, dietary habits have changed in response to rapid economic growth and globalization. Zn nutrition in South Koreans has therefore been assessed during a period (1969-1998) of unprecedented economic growth. Cross-sectional food consumption data from the Korean National Nutrition Survey Reports (KNNSR) of South Korea at four separate time points (1969, 1978, 1988 and 1998) were used to calculate Zn, Ca and phytate intakes using various food composition tables, databases and literature values. Nutrient values in local foods were cited from their analysed values. Average Zn intake was 5.8, 4.8 and 5.3 mg/d for 1969, 1978 and 1988 respectively, increasing to 7.3 mg/d in 1998 (73 % of the Korean Dietary Reference Intake). The phytate:Zn molar ratio decreased from 21 to 8 during the study period. Dietary Zn depletion due to marked decreases in cereal consumption, particularly barley which has a low Zn bioavailability, was counterbalanced by marked increases in the consumption of meat and fish, which are also Zn-rich foods. Reduced phytate consumption coincident with increased Zn intake suggests that Zn bioavailability also improved, particularly by 1998. Although total Zn intake was not greatly affected over the initial period of economic growth in South Korea (1969-1988), Zn contributions from different food sources changed markedly and both Zn intake and potential bioavailability were improved by 1998. The study may have implications for Zn nutrition in other Asian countries currently experiencing rapid economic growth.

Application of a bias-corrected meta-frontier approach and an endogenous switching regression to analyze the technical efficiency of conservation tillage for wheat in South Asia

NARCIS (Netherlands)

Aravindakshan, Sreejith; Rossi, Frederick; Amjath-Babu, T.S.; Veettil, Prakashan Chellattan; Krupnik, Timothy J.

2018-01-01

Conservation tillage (CT) options are among the most rapidly spreading land preparation and crop establishment techniques globally. In South Asia, CT has spread dramatically over the last decade, a result of strong policy support and increasing availability of appropriate machinery. Although many

Distribution, spread, and ecological associations of the introduced ant Pheidole obscurithorax in the southeastern United States

Directory of Open Access Journals (Sweden)

Shonna R. Storz

2004-04-01

Full Text Available A field survey of the southeastern United States showed that Pheidole obscurithorax Naves, an ant introduced from South America, inhabits a 80-km-wide band along the coast between Mobile, Alabama, and Tallahassee, Florida, and is continuing to increase its range. In Tallahassee P. obscurithorax is rapidly spreading, and its nest density increased by a factor of 6.4 over a two-year period. Evidence suggests that P. obscurithorax has spread gradually by natural means. It coexists with the fire ant Solenopsis invicta Buren, appears to be part of a largely exotic community of ants that are tolerant of highly disturbed habitats, and seems to have little negative effect on the ant communities that it invades.

[Environmental drivers of emergence and spreading of Vibrio epidemics in South America].

Science.gov (United States)

Gavilán, Ronnie G; Martínez-Urtaza, Jaime

2011-03-01

Vibrio cholerae and V. parahaemolyticus are the two Vibrio species with a major impact on human health. Diseases caused by both pathogens are acquiring increasing relevance due to their expansion at global scale. In this paper, we resume the ecological aspects associated with the arrival and spreading of infections caused by V. parahaemolyticus and V. cholerae in Peru from a South American perspective. Moreover, we discuss the similarities in the emergence in Peru of cholera cases in 1991 and V. parahaemolyticus infections in 1997. These constituted exceptional experiments to evaluate the relationships between the Vibrio epidemics and changes in the environment. The epidemic radiations of V. cholerae and V. parahaemolyticus constitute to clear examples supporting the oceanic dispersion of pathogenic vibrios and have enabled the identification of El Niño events as a potential mechanism for the spreading of diseases through the ocean.

Global health in an open world requires an open mind

DEFF Research Database (Denmark)

Sodemann, Morten

Why global health? Health has never been more clearly global than now. Social media have reorganized our way of talking, discussing and interacting globally by spreading happiness, hate speech, obesity and knowledge at the same time. Diseases have never had respect for border control. Polio has s...... is not a fashionable subject anymore but the story of HIV/AIDS is a lesson to global health decision makers. Rephrasing Elisabeth Pisani: whores have wisdom, and we had better open our minds and face it...

Spreading to localized targets in complex networks

Science.gov (United States)

Sun, Ye; Ma, Long; Zeng, An; Wang, Wen-Xu

2016-12-01

As an important type of dynamics on complex networks, spreading is widely used to model many real processes such as the epidemic contagion and information propagation. One of the most significant research questions in spreading is to rank the spreading ability of nodes in the network. To this end, substantial effort has been made and a variety of effective methods have been proposed. These methods usually define the spreading ability of a node as the number of finally infected nodes given that the spreading is initialized from the node. However, in many real cases such as advertising and news propagation, the spreading only aims to cover a specific group of nodes. Therefore, it is necessary to study the spreading ability of nodes towards localized targets in complex networks. In this paper, we propose a reversed local path algorithm for this problem. Simulation results show that our method outperforms the existing methods in identifying the influential nodes with respect to these localized targets. Moreover, the influential spreaders identified by our method can effectively avoid infecting the non-target nodes in the spreading process.

Estimation of wave directional spreading

Digital Repository Service at National Institute of Oceanography (India)

Deo, M.C.; Gondane, D.S.; SanilKumar, V.

One of the useful measures of waves directional spreading at a given location is the directional spreading parameter. This paper presents a new approach to arrive at its characteristic value using the computational technique of Artificial Neural...

Metabolic and hemodynamic activation of postischemic rat brain by cortical spreading depression.

Science.gov (United States)

Kocher, M

1990-07-01

Following transient ischemia of the brain, the coupling between somatosensory activation and the hemodynamic-metabolic response is abolished for a certain period despite the partial recovery of somatosensory evoked responses. To determine whether this disturbance is due to alterations of the stimulus-induced neuronal excitation or to a breakdown of the coupling mechanisms, cortical spreading depression was used as a metabolic stimulus in rats before and after ischemia. Adult rats were subjected to 30 min of global forebrain ischemia and 3-6 h of recirculation. EEG, cortical direct current (DC) potential, and laser-Doppler flow were continuously recorded. Local CBF (LCBF), local CMRglc (LCMRglc), regional tissue contents of ATP, glucose, and lactate, and regional pH were determined by quantitative autoradiography, substrate-induced bioluminescence, and fluorometry. Amplitude and frequency of the DC shifts did not differ between groups. In control animals, spreading depression induced a 77% rise in cortical glucose consumption, a 66% rise in lactate content, and a drop in tissue pH of 0.3 unit. ATP and glucose contents were not depleted. During the passage of DC shifts, transient increases (less than 2 min) in laser-Doppler flow were observed, followed by a post-spreading depression hypoperfusion. A comparable although less expressed pattern of hemodynamic and metabolic changes was observed in the postischemic rats. Although baseline LCMRglc was depressed after ischemia, it was activated 47% during spreading depression. Lactate increased by 26%, pH decreased by 0.3 unit, and ATP and glucose remained unchanged. The extent of the transient increase in laser-Doppler flow did not differ from that of the control group, and a post-spreading depression hypoperfusion was also found.(ABSTRACT TRUNCATED AT 250 WORDS)

Searching for the most cost-effective strategy for controlling epidemics spreading on regular and small-world networks.

Science.gov (United States)

Kleczkowski, Adam; Oleś, Katarzyna; Gudowska-Nowak, Ewa; Gilligan, Christopher A

2012-01-07

We present a combined epidemiological and economic model for control of diseases spreading on local and small-world networks. The disease is characterized by a pre-symptomatic infectious stage that makes detection and control of cases more difficult. The effectiveness of local (ring-vaccination or culling) and global control strategies is analysed by comparing the net present values of the combined cost of preventive treatment and illness. The optimal strategy is then selected by minimizing the total cost of the epidemic. We show that three main strategies emerge, with treating a large number of individuals (global strategy, GS), treating a small number of individuals in a well-defined neighbourhood of a detected case (local strategy) and allowing the disease to spread unchecked (null strategy, NS). The choice of the optimal strategy is governed mainly by a relative cost of palliative and preventive treatments. If the disease spreads within the well-defined neighbourhood, the local strategy is optimal unless the cost of a single vaccine is much higher than the cost associated with hospitalization. In the latter case, it is most cost-effective to refrain from prevention. Destruction of local correlations, either by long-range (small-world) links or by inclusion of many initial foci, expands the range of costs for which the NS is most cost-effective. The GS emerges for the case when the cost of prevention is much lower than the cost of treatment and there is a substantial non-local component in the disease spread. We also show that local treatment is only desirable if the disease spreads on a small-world network with sufficiently few long-range links; otherwise it is optimal to treat globally. In the mean-field case, there are only two optimal solutions, to treat all if the cost of the vaccine is low and to treat nobody if it is high. The basic reproduction ratio, R(0), does not depend on the rate of responsive treatment in this case and the disease always invades

Review Essay: Moving beyond Global Encounters toward Global Reciprocity: Christian Education in East Asian Perspectives

Science.gov (United States)

Kim, Hyun-Sook

2015-01-01

Christianity as a world religion was propagated from Europe and North America to Africa and Asia. Global Christianity spread to East Asia when Robert Morrison (1782-1843) arrived in Canton, China in 1807, and later in the late 19th-century Protestant missionaries from North America arrived in Japan and Korea. This Christianity experienced a modern…

Spreading gossip in social networks

Science.gov (United States)

Lind, Pedro G.; da Silva, Luciano R.; Andrade, José S., Jr.; Herrmann, Hans J.

2007-09-01

We study a simple model of information propagation in social networks, where two quantities are introduced: the spread factor, which measures the average maximal reachability of the neighbors of a given node that interchange information among each other, and the spreading time needed for the information to reach such a fraction of nodes. When the information refers to a particular node at which both quantities are measured, the model can be taken as a model for gossip propagation. In this context, we apply the model to real empirical networks of social acquaintances and compare the underlying spreading dynamics with different types of scale-free and small-world networks. We find that the number of friendship connections strongly influences the probability of being gossiped. Finally, we discuss how the spread factor is able to be applied to other situations.

Spreading gossip in social networks.

Science.gov (United States)

Lind, Pedro G; da Silva, Luciano R; Andrade, José S; Herrmann, Hans J

2007-09-01

We study a simple model of information propagation in social networks, where two quantities are introduced: the spread factor, which measures the average maximal reachability of the neighbors of a given node that interchange information among each other, and the spreading time needed for the information to reach such a fraction of nodes. When the information refers to a particular node at which both quantities are measured, the model can be taken as a model for gossip propagation. In this context, we apply the model to real empirical networks of social acquaintances and compare the underlying spreading dynamics with different types of scale-free and small-world networks. We find that the number of friendship connections strongly influences the probability of being gossiped. Finally, we discuss how the spread factor is able to be applied to other situations.

Population History and Pathways of Spread of the Plant Pathogen Phytophthora plurivora

Science.gov (United States)

Schoebel, Corine N.; Stewart, Jane; Gruenwald, Niklaus J.; Rigling, Daniel; Prospero, Simone

2014-01-01

Human activity has been shown to considerably affect the spread of dangerous pests and pathogens worldwide. Therefore, strict regulations of international trade exist for particularly harmful pathogenic organisms. Phytophthora plurivora, which is not subject to regulations, is a plant pathogen frequently found on a broad range of host species, both in natural and artificial environments. It is supposed to be native to Europe while resident populations are also present in the US. We characterized a hierarchical sample of isolates from Europe and the US and conducted coalescent-, migration, and population genetic analysis of sequence and microsatellite data, to determine the pathways of spread and the demographic history of this pathogen. We found P. plurivora populations to be moderately diverse but not geographically structured. High levels of gene flow were observed within Europe and unidirectional from Europe to the US. Coalescent analyses revealed a signal of a recent expansion of the global P. plurivora population. Our study shows that P. plurivora has most likely been spread around the world by nursery trade of diseased plant material. In particular, P. plurivora was introduced into the US from Europe. International trade has allowed the pathogen to colonize new environments and/or hosts, resulting in population growth. PMID:24427303

COMBINED SURGERY OF SPREAD THYROID CANCER

Directory of Open Access Journals (Sweden)

V. Zh. Brzhezovsky

2014-01-01

Full Text Available Results of treating of 99 patients with differentiated thyroid cancer spreading beyond the capsule of the organ were analysed. In most cases with spreading the tumor to the tracheal rings performing of organ-preserving operations (from “window-like” tracheal resections to circular tracheal resection with intertracheal anastomosis is possible. Choosing of type of operation to be performed depends on localisation and spread of tumor invasion of trachea, pharynx and esophagus. Using of combined operations in patients with locally-spread thyroid cancer allows to achieve long and stable remission in most of the cases.

Spread of the invasive ladybird Harmonia axyridis in the Czech Republic and Denmark

DEFF Research Database (Denmark)

Nedved, Oldrich; Steenberg, Tove; Harding, Susanne

2008-01-01

Faculty of Agricultural Sciences, University OF Aarhus, Skovbrynet 14, DK-2800 Kgs. Lyngby, Denmark 4 Faculty of Life Sciences, University of Copenhagen, Bülowsvej 13, DK - 1870 Frederiksberg C, Denmark nedved@prf.jcu.cz Introduction: Harmonia axyridis (Coleoptera: Coccinellidae) is an invasive alien......Spread of the invasive ladybird Harmonia axyridis in the Czech Republic and Denmark Oldřich Nedvěd1,2 and Tove Steenberg3 and SUSANNE HARDING4 1Faculty of Science, University of South Bohemia, and 2Institute of Entomology, Biology Centre; Branišovská 31, CZ370 05 České Budějovice, Czech Republic. 3...... that H. axyridis will continue to spread rapidly in Europe, particularly northwards and eastwards. Although there may consequently be a reduction in pest insects, our records support that this species may have significant detrimental impact. The records of the axyridis colour morph in the Czech Republic...

A New Rapid Simplified Model for Urban Rainstorm Inundation with Low Data Requirements

Directory of Open Access Journals (Sweden)

Ji Shen

2016-11-01

Full Text Available This paper proposes a new rapid simplified inundation model (NRSIM for flood inundation caused by rainstorms in an urban setting that can simulate the urban rainstorm inundation extent and depth in a data-scarce area. Drainage basins delineated from a floodplain map according to the distribution of the inundation sources serve as the calculation cells of NRSIM. To reduce data requirements and computational costs of the model, the internal topography of each calculation cell is simplified to a circular cone, and a mass conservation equation based on a volume spreading algorithm is established to simulate the interior water filling process. Moreover, an improved D8 algorithm is outlined for the simulation of water spilling between different cells. The performance of NRSIM is evaluated by comparing the simulated results with those from a traditional rapid flood spreading model (TRFSM for various resolutions of digital elevation model (DEM data. The results are as follows: (1 given high-resolution DEM data input, the TRFSM model has better performance in terms of precision than NRSIM; (2 the results from TRFSM are seriously affected by the decrease in DEM data resolution, whereas those from NRSIM are not; and (3 NRSIM always requires less computational time than TRFSM. Apparently, compared with the complex hydrodynamic or traditional rapid flood spreading model, NRSIM has much better applicability and cost-efficiency in real-time urban inundation forecasting for data-sparse areas.

Deciphering emerging Zika and dengue viral epidemics: Implications for global maternal–child health burden

Directory of Open Access Journals (Sweden)

Ernest Tambo

2016-05-01

Full Text Available Summary: Since its discovery in 1947 in Uganda and control and eradication efforts have aimed at its vectors (Aedes mosquitoes in Latin America in the 1950s, an absolute neglect of Zika programs and interventions has been documented in Aedes endemic and epidemic-prone countries. The current unprecedented Zika viral epidemics and rapid spread in the Western hemisphere pose a substantial global threat, with associated anxiety and consequences. The lack of safe and effective drugs and vaccines against Zika or dengue epidemics further buttresses the realization from the West Africa Ebola outbreak that most emerging disease-prone countries are still poorly prepared for an emergency response. This paper examines knowledge gaps in both emerging and neglected arthropod-borne flavivirus infectious diseases associated with poverty and their implications for fostering local, national and regional emerging disease preparedness, effective and robust surveillance–response systems, sustained control and eventual elimination. Strengthening the regional and Global Health Flavivirus Surveillance-Response Network (GHFV-SRN with other models of socio-economic, climatic, environmental and ecological mitigation and adaptation strategies will be necessary to improve evidence-based national and global maternal–child health agenda and action plans. Keywords: Zika virus, Epidemics, Health, Preparedness, Surveillance, Maternal–child

Initial spread of {sup 137}Cs from the Fukushima Dai-ichi Nuclear Power Plant over the Japan continental shelf. A study using a high-resolution, global-coastal nested ocean model

Energy Technology Data Exchange (ETDEWEB)

Lai, Z. [Sun Yat-Sen Univ., Guangzhou (China). School of Marine Sciences; Univ. of Massachusetts-Dartmouth, New Bedford, MA (United States). School for Marine Science and Technology; Key Laboratory of Marine Resources and Coastal Engineering in Guangdong Province, Guangzhou (China); Chen, C.; Lin, H. [Univ. of Massachusetts-Dartmouth, New Bedford, MA (United States). School for Marine Science and Technology; Shanghai Ocean Univ. (China). International Center for Marine Studies; Beardsley, R. [Woods Hole Oceanographic Institution, Woods Hole, MA (United States). Dept. of Physical Oceanography; Ji, R. [Woods Hole Oceanographic Institution, Woods Hole, MA (United States). Dept. of Biology; Shanghai Ocean Univ. (China). International Center for Marine Studies; Sasaki, J. [The Univ. of Tokyo, Kashiwa (Japan). Dept. of Socio-Cultural Environmental Studies; Lin, J. [Woods Hole Oceanographic Institution, Woods Hole, MA (United States). Dept. of Geology and Geophysics

2013-07-01

The 11 March 2011 tsunami triggered by the M9 and M7.9 earthquakes off the Tohoku coast destroyed facilities at the Fukushima Dai-ichi Nuclear Power Plant (FNPP) leading to a significant long-term flow of the radionuclide {sup 137}Cs into coastal waters. A high-resolution, global-coastal nested ocean model was first constructed to simulate the 11 March tsunami and coastal inundation. Based on the model's success in reproducing the observed tsunami and coastal inundation, model experiments were then conducted with differing grid resolution to assess the initial spread of {sup 137}Cs over the eastern shelf of Japan. The {sup 137}Cs was tracked as a conservative tracer (without radioactive decay) in the three-dimensional model flow field over the period of 26 March-31 August 2011. The results clearly show that for the same {sup 137}Cs discharge, the model-predicted spreading of {sup 137}Cs was sensitive not only to model resolution but also the FNPP seawall structure. A coarse-resolution (∝2 km) model simulation led to an overestimation of lateral diffusion and thus faster dispersion of {sup 137}Cs from the coast to the deep ocean, while advective processes played a more significant role when the model resolution at and around the FNPP was refined to ∝5 m. By resolving the pathways from the leaking source to the southern and northern discharge canals, the high-resolution model better predicted the {sup 137}Cs spreading in the inner shelf where in situ measurements were made at 30 km off the coast. The overestimation of {sup 137}Cs concentration near the coast is thought to be due to the omission of sedimentation and biogeochemical processes as well as uncertainties in the amount of {sup 137}Cs leaking from the source in the model. As a result, a biogeochemical module should be included in the model for more realistic simulations of the fate and spreading of {sup 137}Cs in the ocean.

Epidemic spreading through direct and indirect interactions.

Science.gov (United States)

Ganguly, Niloy; Krueger, Tyll; Mukherjee, Animesh; Saha, Sudipta

2014-09-01

In this paper we study the susceptible-infected-susceptible epidemic dynamics, considering a specialized setting where popular places (termed passive entities) are visited by agents (termed active entities). We consider two types of spreading dynamics: direct spreading, where the active entities infect each other while visiting the passive entities, and indirect spreading, where the passive entities act as carriers and the infection is spread via them. We investigate in particular the effect of selection strategy, i.e., the way passive entities are chosen, in the spread of epidemics. We introduce a mathematical framework to study the effect of an arbitrary selection strategy and derive formulas for prevalence, extinction probabilities, and epidemic thresholds for both indirect and direct spreading. We also obtain a very simple relationship between the extinction probability and the prevalence. We pay special attention to preferential selection and derive exact formulas. The analysis reveals that an increase in the diversity in the selection process lowers the epidemic thresholds. Comparing the direct and indirect spreading, we identify regions in the parameter space where the prevalence of the indirect spreading is higher than the direct one.

A Global Rapid Integrated Monitoring System for Water Cycle and Water Resource Assessment (Global-RIMS)

Science.gov (United States)

Roads, John; Voeroesmarty, Charles

2005-01-01

The main focus of our work was to solidify underlying data sets, the data processing tools and the modeling environment needed to perform a series of long-term global and regional hydrological simulations leading eventually to routine hydrometeorological predictions. A water and energy budget synthesis was developed for the Mississippi River Basin (Roads et al. 2003), in order to understand better what kinds of errors exist in current hydrometeorological data sets. This study is now being extended globally with a larger number of observations and model based data sets under the new NASA NEWS program. A global comparison of a number of precipitation data sets was subsequently carried out (Fekete et al. 2004) in which it was further shown that reanalysis precipitation has substantial problems, which subsequently led us to the development of a precipitation assimilation effort (Nunes and Roads 2005). We believe that with current levels of model skill in predicting precipitation that precipitation assimilation is necessary to get the appropriate land surface forcing.

Rapid parallel evolution overcomes global honey bee parasite.

Science.gov (United States)

Oddie, Melissa; Büchler, Ralph; Dahle, Bjørn; Kovacic, Marin; Le Conte, Yves; Locke, Barbara; de Miranda, Joachim R; Mondet, Fanny; Neumann, Peter

2018-05-16

In eusocial insect colonies nestmates cooperate to combat parasites, a trait called social immunity. However, social immunity failed for Western honey bees (Apis mellifera) when the ectoparasitic mite Varroa destructor switched hosts from Eastern honey bees (Apis cerana). This mite has since become the most severe threat to A. mellifera world-wide. Despite this, some isolated A. mellifera populations are known to survive infestations by means of natural selection, largely by supressing mite reproduction, but the underlying mechanisms of this are poorly understood. Here, we show that a cost-effective social immunity mechanism has evolved rapidly and independently in four naturally V. destructor-surviving A. mellifera populations. Worker bees of all four 'surviving' populations uncapped/recapped worker brood cells more frequently and targeted mite-infested cells more effectively than workers in local susceptible colonies. Direct experiments confirmed the ability of uncapping/recapping to reduce mite reproductive success without sacrificing nestmates. Our results provide striking evidence that honey bees can overcome exotic parasites with simple qualitative and quantitative adaptive shifts in behaviour. Due to rapid, parallel evolution in four host populations this appears to be a key mechanism explaining survival of mite infested colonies.

Early and rapid globalization as part of innovation and growth strategies

DEFF Research Database (Denmark)

Zijdemans, Erik; Azimi, Zohreh; Tanev, Stoyan

propositions (Bailetti & Zijdemans, 2014). The GVG was tested empirically through its application to 12 cybersecurity start-ups in Ottawa, ON, Canada. Additionally, the applicability of the GVG was validated by an in depth case study of a business development agency focusing on supporting the global start......) – a framework linking the ex-ante value drivers and ex-post characteristics of BG firms. Our aim is to use the GVG to help innovative start-ups in making strategic ex-ante decisions contributing to the development of competitive global business models, complementary global resources and differentiated value...... of newly created technology firms. The preliminary results indicate that business development agencies currently do not actively or efficiently support the global start of new firms. They need however appropriate tools and mechanisms that would help them developing such capacity....

Global health politics: neither solidarity nor policy: Comment on "Globalization and the diffusion of ideas: why we should acknowledge the roots of mainstream ideas in global health".

Science.gov (United States)

Méndez, Claudio A

2014-07-01

The global health agenda has been dominating the current global health policy debate. Furthermore, it has compelled countries to embrace strategies for tackling health inequalities in a wide range of public health areas. The article by Robert and colleagues highlights that although globalization has increased opportunities to share and spread ideas, there is still great asymmetry of power according to the countries' economic and political development. It also emphasizes how policy diffusion from High Income Countries (HICs) to Low- and Middle-Income Countries (LMICs) have had flaws at understanding their political, economic, and cultural backgrounds while they are pursuing knowledge translation. Achieving a fair global health policy diffusion of ideas would imply a call for a renewal on political elites worldwide at coping global health politics. Accordingly, moving towards fairness in disseminating global health ideas should be driven by politics not only as one of the social determinants of health, but the main determinant of health and well-being among-and within-societies.

Rapid Response in Psychological Treatments for Binge-Eating Disorder

Science.gov (United States)

Hilbert, Anja; Hildebrandt, Thomas; Agras, W. Stewart; Wilfley, Denise E.; Wilson, G. Terence

2015-01-01

Objective Analysis of short- and long-term effects of rapid response across three different treatments for binge-eating disorder (BED). Method In a randomized clinical study comparing interpersonal psychotherapy (IPT), cognitive-behavioral guided self-help (CBTgsh), and behavioral weight loss (BWL) treatment in 205 adults meeting DSM-IV criteria for BED, the predictive value of rapid response, defined as ≥ 70% reduction in binge-eating by week four, was determined for remission from binge-eating and global eating disorder psychopathology at posttreatment, 6-, 12-, 18-, and 24-month follow-up. Results Rapid responders in CBTgsh, but not in IPT or BWL, showed significantly greater rates of remission from binge-eating than non-rapid responders, which was sustained over the long term. Rapid and non-rapid responders in IPT and rapid responders in CBTgsh showed a greater remission from binge-eating than non-rapid responders in CBTgsh and BWL. Rapid responders in CBTgsh showed greater remission from binge-eating than rapid responders in BWL. Although rapid responders in all treatments had lower global eating disorder psychopathology than non-rapid responders in the short term, rapid responders in CBTgsh and IPT were more improved than those in BWL and non-rapid responders in each treatment. Rapid responders in BWL did not differ from non-rapid responders in CBTgsh and IPT. Conclusions Rapid response is a treatment-specific positive prognostic indicator of sustained remission from binge-eating in CBTgsh. Regarding an evidence-based stepped care model, IPT, equally efficacious for rapid and non-rapid responders, could be investigated as a second-line treatment in case of non-rapid response to first-line CBTgsh. PMID:25867446

Forecasting oil price movements with crack spread futures

International Nuclear Information System (INIS)

Murat, Atilim; Tokat, Ekin

2009-01-01

In oil markets, the crack spread refers to the crude-product price relationship. Refiners are major participants in oil markets and they are primarily exposed to the crack spread. In other words, refiner activity is substantially driven by the objective of protecting the crack spread. Moreover, oil consumers are active participants in the oil hedging market and they are frequently exposed to the crack spread. From another perspective, hedge funds are heavily using crack spread to speculate in oil markets. Based on the high volume of crack spread futures trading in oil markets, the question we want to raise is whether the crack spread futures can be a good predictor of oil price movements. We investigated first whether there is a causal relationship between the crack spread futures and the spot oil markets in a vector error correction framework. We found the causal impact of crack spread futures on spot oil market both in the long- and the short-run after April 2003 where we detected a structural break in the model. To examine the forecasting performance, we use the random walk model (RWM) as a benchmark, and we also evaluate the forecasting power of crack spread futures against the crude oil futures. The results showed that (a) both the crack spread futures and the crude oil futures outperformed the RWM; and (b) the crack spread futures are almost as good as the crude oil futures in predicting the movements in spot oil markets. (author)

Ancestral genetic diversity associated with the rapid spread of stress-tolerant coral symbionts in response to Holocene climate change

KAUST Repository

Hume, Benjamin C. C.

2016-04-05

Coral communities in the Persian/Arabian Gulf (PAG) withstand unusually high salinity levels and regular summer temperature maxima of up to ∼35 °C that kill conspecifics elsewhere. Due to the recent formation of the PAG and its subsequent shift to a hot climate, these corals have had only <6, 000 y to adapt to these extreme conditions and can therefore inform on how coral reefs may respond to global warming. One key to coral survival in the world\\'s warmest reefs are symbioses with a newly discovered alga, Symbiodinium thermophilum. Currently, it is unknown whether this symbiont originated elsewhere or emerged from unexpectedly fast evolution catalyzed by the extreme environment. Analyzing genetic diversity of symbiotic algae across >5, 000 km of the PAG, the Gulf of Oman, and the Red Sea coastline, we show that S. thermophilum is a member of a highly diverse, ancient group of symbionts cryptically distributed outside the PAG. We argue that the adjustment to temperature extremes by PAG corals was facilitated by the positive selection of preadapted symbionts. Our findings suggest that maintaining the largest possible pool of potentially stress-tolerant genotypes by protecting existing biodiversity is crucial to promote rapid adaptation to present-day climate change, not only for coral reefs, but for ecosystems in general.

The Convergence of a Virus, Mosquitoes, and Human Travel in Globalizing the Zika Epidemic.

Science.gov (United States)

Imperato, Pascal James

2016-06-01

The Zika virus was first identified in 1947 in the Zika Forest of Uganda. It was discovered in a rhesus monkey that had been placed in a cage on a sentinel platform in the forest by the Virus Research Institute. When this writer visited the institute and the Zika Forest in 1961, work was underway to identify mosquito species at various levels of the tree canopy. This was done through the placement of traps at various levels of a 120-foot-high steel tower which this writer climbed. At that time, researchers isolated 12 strains of Zika virus from traps on the tower. Over the next six decades, the virus spread slowly to other parts of Africa, and eventually appeared in Southeast Asia, transmitted by Aedes aegypti and other Aedes mosquito species. By 1981, only 14 cases of illness had been reported as due to the Zika virus. Since most infections with this virus are either mild or asymptomatic, its true geographic spread was not fully appreciated. The current globalization of the Zika epidemic began on the Pacific island of Yap in the Federated States of Polynesia in 2007. This was the first known presence of the Zika virus outside of Africa and Southeast Asia. It was estimated that 73 % of the island's population had been infected. In 2013, the virus spread to French Polynesia where an estimated 28,000 cases occurred in a population of 270,000. During that year and afterwards, microcephaly and other congenital abnormalities were observed in the infants of women who were pregnant when they contracted the virus. It is currently not known if cases of microcephaly have resulted from infection of pregnant women or from infection plus some other co-factor. The epidemic rapidly spread to the Cook Islands and Easter Island. In 2015, Zika virus infection was diagnosed in Brazil where it was associated with microcephaly in the infants of some women who were pregnant when they contracted the disease. Cases of the Guillain-Barré syndrome were also found to be associated with

Existence of global attractor for the Trojan Y Chromosome model

Directory of Open Access Journals (Sweden)

Xiaopeng Zhao

2012-04-01

Full Text Available This paper is concerned with the long time behavior of solution for the equation derived by the Trojan Y Chromosome (TYC model with spatial spread. Based on the regularity estimates for the semigroups and the classical existence theorem of global attractors, we prove that this equations possesses a global attractor in $H^k(\\Omega^4$ $(k\\geq 0$ space.

Navigate the Digital Rapids

Science.gov (United States)

Lindsay, Julie; Davis, Vicki

2010-01-01

How can teachers teach digital citizenship when the digital landscape is changing so rapidly? How can teachers teach proper online social interactions when the students are outside their classroom and thus outside their control? Will encouraging students to engage in global collaborative environments land teachers in hot water? These are the…

Gossip spread in social network Models

Science.gov (United States)

Johansson, Tobias

2017-04-01

Gossip almost inevitably arises in real social networks. In this article we investigate the relationship between the number of friends of a person and limits on how far gossip about that person can spread in the network. How far gossip travels in a network depends on two sets of factors: (a) factors determining gossip transmission from one person to the next and (b) factors determining network topology. For a simple model where gossip is spread among people who know the victim it is known that a standard scale-free network model produces a non-monotonic relationship between number of friends and expected relative spread of gossip, a pattern that is also observed in real networks (Lind et al., 2007). Here, we study gossip spread in two social network models (Toivonen et al., 2006; Vázquez, 2003) by exploring the parameter space of both models and fitting them to a real Facebook data set. Both models can produce the non-monotonic relationship of real networks more accurately than a standard scale-free model while also exhibiting more realistic variability in gossip spread. Of the two models, the one given in Vázquez (2003) best captures both the expected values and variability of gossip spread.

Perineural spread in head and neck tumors.

Science.gov (United States)

Brea Álvarez, B; Tuñón Gómez, M

2014-01-01

Perineural spread is the dissemination of some types of head and neck tumors along nervous structures. Perineural spread has negative repercussions on treatment because it requires more extensive resection and larger fields of irradiation. Moreover, perineural spread is associated with increased local recurrence, and it is considered an independent indicator of poor prognosis in the TNM classification for tumor staging. However, perineural spread often goes undetected on imaging studies. In this update, we review the concept of perineural spread, its pathogenesis, and the main pathways and connections among the facial nerves, which are essential to understand this process. Furthermore, we discuss the appropriate techniques for imaging studies, and we describe and illustrate the typical imaging signs that help identify perineural spread on CT and MRI. Finally, we discuss the differential diagnosis with other entities. Copyright © 2013 SERAM. Published by Elsevier Espana. All rights reserved.

Catalunya a l'aldea global

OpenAIRE

Pes, Àngel

1999-01-01

Small societies must also adapt to an increasingly integrated world, econmmically, culturally and politically. Globalization is a polifaceted phenomenon transforming the world into a global village. Three examples of globalisation are the rapidly extended financial crisis, with the threat of global recession; the arrest of Pinochet in London on a Spanish warrant, marking the birth of a global public opinion; and the acceptance of differences as a way to solve conflicts both in Nor...

Initial spread of "1"3"7Cs from the Fukushima Dai-ichi Nuclear Power Plant over the Japan continental shelf. A study using a high-resolution, global-coastal nested ocean model

International Nuclear Information System (INIS)

Lai, Z.; Chen, C.; Lin, H.; Shanghai Ocean Univ.; Beardsley, R.; Ji, R.; Shanghai Ocean Univ.; Sasaki, J.; Lin, J.

2013-01-01

The 11 March 2011 tsunami triggered by the M9 and M7.9 earthquakes off the Tohoku coast destroyed facilities at the Fukushima Dai-ichi Nuclear Power Plant (FNPP) leading to a significant long-term flow of the radionuclide "1"3"7Cs into coastal waters. A high-resolution, global-coastal nested ocean model was first constructed to simulate the 11 March tsunami and coastal inundation. Based on the model's success in reproducing the observed tsunami and coastal inundation, model experiments were then conducted with differing grid resolution to assess the initial spread of "1"3"7Cs over the eastern shelf of Japan. The "1"3"7Cs was tracked as a conservative tracer (without radioactive decay) in the three-dimensional model flow field over the period of 26 March-31 August 2011. The results clearly show that for the same "1"3"7Cs discharge, the model-predicted spreading of "1"3"7Cs was sensitive not only to model resolution but also the FNPP seawall structure. A coarse-resolution (∝2 km) model simulation led to an overestimation of lateral diffusion and thus faster dispersion of "1"3"7Cs from the coast to the deep ocean, while advective processes played a more significant role when the model resolution at and around the FNPP was refined to ∝5 m. By resolving the pathways from the leaking source to the southern and northern discharge canals, the high-resolution model better predicted the "1"3"7Cs spreading in the inner shelf where in situ measurements were made at 30 km off the coast. The overestimation of "1"3"7Cs concentration near the coast is thought to be due to the omission of sedimentation and biogeochemical processes as well as uncertainties in the amount of "1"3"7Cs leaking from the source in the model. As a result, a biogeochemical module should be included in the model for more realistic simulations of the fate and spreading of "1"3"7Cs in the ocean.

Development of Pistachio (Pistacia vera L.) spread.

Science.gov (United States)

Shakerardekani, Ahmad; Karim, Roselina; Ghazali, Hasanah Mohd; Chin, Nyuk Ling

2013-03-01

Pistachio nut (Pistacia vera L.) is one of the most delicious and nutritious nuts in the world. Pistachio spreads were developed using pistachio paste as the main component, icing sugar, soy protein isolate (SPI), and red palm oil (RPO), at different ratios. The highest mean scores of all the sensory attributes were depicted by spreads that were made without addition of SPI. It was found that the work of shear was 0 to 11.0 kg s for an acceptable spread. Sensory spreadability, overall texture, spreadability, and overall acceptability were negatively correlated (R > 0.83) with the work of shear of spreads. The findings indicated that the presence of RPO had a direct effect on the viscoelastic behavior of the pistachio spreads. The a values, which are related to the green color of the pistachio product ranged from 1.7 to 3.9 for spread without addition of RPO, and 4.0 to 5.3 in the presence of RPO. The development of pistachio spread would potentially increase the food uses of pistachio and introduce consumers with a healthier snack food. © 2013 Institute of Food Technologists®

Spatio-temporal dynamics of global H5N1 outbreaks match bird migration patterns

Directory of Open Access Journals (Sweden)

Yali Si

2009-11-01

Full Text Available The global spread of highly pathogenic avian influenza H5N1 in poultry, wild birds and humans, poses a significant pandemic threat and a serious public health risk. An efficient surveillance and disease control system relies on the understanding of the dispersion patterns and spreading mechanisms of the virus. A space-time cluster analysis of H5N1 outbreaks was used to identify spatio-temporal patterns at a global scale and over an extended period of time. Potential mechanisms explaining the spread of the H5N1 virus, and the role of wild birds, were analyzed. Between December 2003 and December 2006, three global epidemic phases of H5N1 influenza were identified. These H5N1 outbreaks showed a clear seasonal pattern, with a high density of outbreaks in winter and early spring (i.e., October to March. In phase I and II only the East Asia Australian flyway was affected. During phase III, the H5N1 viruses started to appear in four other flyways: the Central Asian flyway, the Black Sea Mediterranean flyway, the East Atlantic flyway and the East Africa West Asian flyway. Six disease cluster patterns along these flyways were found to be associated with the seasonal migration of wild birds. The spread of the H5N1 virus, as demonstrated by the space-time clusters, was associated with the patterns of migration of wild birds. Wild birds may therefore play an important role in the spread of H5N1 over long distances. Disease clusters were also detected at sites where wild birds are known to overwinter and at times when migratory birds were present. This leads to the suggestion that wild birds may also be involved in spreading the H5N1 virus over short distances.

Impact of the Internet on Globalization : Industrial Internet

OpenAIRE

Jukics, Márk

2016-01-01

The thesis consists of two main parts. The first part is the theoretical framework, the second part is about assisting in a project of Centria University of Applied Sciences. The theoretical part of the thesis expounds the evolution and the benefits of the industrial internet. It explains the roots of globalization, internet, and industries. Lean manufacturing and management is also involved in the theory, as this way of management is successfully spreading by the help of globalization. I...

Essays on globalization, monetary policy and financial crisis'

NARCIS (Netherlands)

Qian, Z.

2012-01-01

This thesis focuses on three interlinked topics. Chapter 2 studies the determinants of sovereign CDS spreads in Greece, Ireland, Italy, Portugal and Spain during the recent global financial crisis and European debt crisis. Chapter 3 introduces a model on the interactions between monetary policy

Emergence and spreading potential of Zika virus

Directory of Open Access Journals (Sweden)

Alvaro Fajardo

2016-10-01

Full Text Available Zika virus (ZIKV is an arthropod-borne Flavivirus (family Flaviviridae closely related to dengue, yellow fever and West Nile viruses. ZIKV remained neglected, confined to enzootic transmission cycles in Africa and Asia, until the first significant outbreak was reported in Micronesia in 2007. Subsequent epidemics of growing incidence occurred in French Polynesia and other South Pacific Islands, and recently, in the Americas. The latter and currently ongoing outbreak of unprecedented incidence revealed the association of ZIKV infection with the occurrence of severe congenital malformations and neurological diseases, leading to a widespread concern about its potential to pose a global public health threat. Serological and molecular data suggest that the genetic and geographic diversification of ZIKV may be greatly underestimated. Here we discuss several ecological and epidemiological aspects, together with the evolutionary processes that may have driven the emergence and abrupt spread of ZIKV in the Americas.

renewables 2011 - Global status report

International Nuclear Information System (INIS)

Sawin, Janet L.; Martinot, Eric; Barnes, Douglas; Martinot, Eric; McCrone, Angus; Roussell, Jodie; Sawin, Janet L.; Sims, Ralph; Sonntag-O'Brien, Virginia; Adib, Rana; Skeen, Jonathan; Musolino, Evan; Riahi, Lily; Mastny, Lisa

2011-01-01

Changes in renewable energy markets, investments, industries, and policies have been so rapid in recent years that perceptions of the status of renewable energy can lag years behind the reality. This report captures that reality and provides a unique overview of renewable energy worldwide as of early 2011. The report covers both current status and key trends; by design, it does not provide analysis or forecast the future. Global energy consumption rebounded in 2010 after an overall downturn in 2009. Renewable energy, which experienced no downturn in 2009, continued to grow strongly in all end-use sectors - power, heat and transport - and supplied an estimated 16% of global final energy consumption. Renewable energy accounted for approximately half of the estimated 194 gigawatts (GW) of new electric capacity added globally during the year. Renewables delivered close to 20% of global electricity supply in 2010, and by early 2011 they comprised one quarter of global power capacity from all sources. In several countries, renewables represent a rapidly growing share of total energy supply, including heat and transport

Toward 3D Printing of Medical Implants: Reduced Lateral Droplet Spreading of Silicone Rubber under Intense IR Curing.

Science.gov (United States)

Stieghorst, Jan; Majaura, Daniel; Wevering, Hendrik; Doll, Theodor

2016-03-01

The direct fabrication of silicone-rubber-based individually shaped active neural implants requires high-speed-curing systems in order to prevent extensive spreading of the viscous silicone rubber materials during vulcanization. Therefore, an infrared-laser-based test setup was developed to cure the silicone rubber materials rapidly and to evaluate the resulting spreading in relation to its initial viscosity, the absorbed infrared radiation, and the surface tensions of the fabrication bed's material. Different low-adhesion materials (polyimide, Parylene-C, polytetrafluoroethylene, and fluorinated ethylenepropylene) were used as bed materials to reduce the spreading of the silicone rubber materials by means of their well-known weak surface tensions. Further, O2-plasma treatment was performed on the bed materials to reduce the surface tensions. To calculate the absorbed radiation, the emittance of the laser was measured, and the absorptances of the materials were investigated with Fourier transform infrared spectroscopy in attenuated total reflection mode. A minimum silicone rubber spreading of 3.24% was achieved after 2 s curing time, indicating the potential usability of the presented high-speed-curing process for the direct fabrication of thermal-curing silicone rubbers.

Experiments on non-isothermal spreading

International Nuclear Information System (INIS)

Ehrhard, P.

1992-09-01

Experiments are performed on axisymmetric spreading of viscous drops on glass plates. Two liquids are investigated: silicone oil (M-100) spreads to 'infinity' and paraffin oil spreads to a finite-radius steady state. The experiments with silicone oil partly recover the behaviour of previous workers data; those experiments with paraffin oil provide new data. It is found that gravitational forces dominate at long enough times while at shorter times capillary forces dominate. When the plate is heated or cooled with respect to the ambient gas, thermocapillary forces generate flows that alter the spreading dynamics. Heating (cooling) the plate is found to retard (augment) the streading. Moreover, in case of partial wetting, the finally-approached drop radius is smaller (larger) for a heated (cooled) plate. These data are all new. All these observations are in excellent quantitative agreement with the related model predictions of Ehrhard and Davis (1991). A breakdown of the axisymmetric character of the flow is observed only for very long times and/or very thin liquid layers. (orig.) [de

Global phylogeography of the widely introduced North West Pacific ascidian Styela clava.

Science.gov (United States)

Goldstien, Sharyn J; Dupont, Lise; Viard, Frédérique; Hallas, Paul J; Nishikawa, Teruaki; Schiel, David R; Gemmell, Neil J; Bishop, John D D

2011-02-22

The solitary ascidian Styela clava Herdman, 1882 is considered to be native to Japan, Korea, northern China and the Russian Federation in the NW Pacific, but it has spread globally over the last 80 years and is now established as an introduced species on the east and west coasts of North America, Europe, Australia and New Zealand. In eastern Canada it reaches sufficient density to be a serious pest to aquaculture concerns. We sequenced a fragment of the cytochrome oxidase subunit I mitochondrial gene (COI) from a total of 554 individuals to examine the genetic relationships of 20 S. clava populations sampled throughout the introduced and native ranges, in order to investigate invasive population characteristics. The data presented here show a moderate level of genetic diversity throughout the northern hemisphere. The southern hemisphere (particularly New Zealand) displays a greater amount of haplotype and nucleotide diversity in comparison. This species, like many other invasive species, shows a range of genetic diversities among introduced populations independent of the age of incursion. The successful establishment of this species appears to be associated with multiple incursions in many locations, while other locations appear to have experienced rapid expansion from a potentially small population with reduced genetic diversity. These contrasting patterns create difficulties when attempting to manage and mitigate a species that continues to spread among ports and marinas around the world.

Heat transfer and fire spread

Science.gov (United States)

Hal E. Anderson

1969-01-01

Experimental testing of a mathematical model showed that radiant heat transfer accounted for no more than 40% of total heat flux required to maintain rate of spread. A reasonable prediction of spread was possible by assuming a horizontal convective heat transfer coefficient when certain fuel and flame characteristics were known. Fuel particle size had a linear relation...

Energy Spread Sources in TESLA and TTF

International Nuclear Information System (INIS)

Mosnier, A.; Tessier, J.M.

1995-03-01

The beam energy spread in the TESLA linac must be small enough to limit the emittance dilution due to the dispersive effects. This report summarizes the major sources of energy spread both for the TESLA linac and the TTF linac, where these estimations will be carefully checked with beam experiments. The first part recalls the intra-bunch energy spread while the second part looks into the bunch-to-bunch energy spread induced by rf field fluctuations within the bunch train and from pulse-to-pulse. (author). 3 refs., 4 figs

Population studies of Cercospora zeae-maydis and related Cercospora fungi

OpenAIRE

Okori, Patrick

2004-01-01

Grey leaf spot caused by Cercospora zeae-maydis is considered a global threat to maize production. In Africa, the disease was first reported just over 10 years ago, but has rapidly spread to most maize growing countries of sub-Saharan Africa. Being a rapidly spreading new disease in the region, demands for a quick but effective control strategy. Since pathogen populations cause epiphytotics, it is logical that control strategies should target populations rather than individuals. Effectiveness...

Economic growth, urbanization, globalization, and the risks of emerging infectious diseases in China: A review.

Science.gov (United States)

Wu, Tong; Perrings, Charles; Kinzig, Ann; Collins, James P; Minteer, Ben A; Daszak, Peter

2017-02-01

Three interrelated world trends may be exacerbating emerging zoonotic risks: income growth, urbanization, and globalization. Income growth is associated with rising animal protein consumption in developing countries, which increases the conversion of wild lands to livestock production, and hence the probability of zoonotic emergence. Urbanization implies the greater concentration and connectedness of people, which increases the speed at which new infections are spread. Globalization-the closer integration of the world economy-has facilitated pathogen spread among countries through the growth of trade and travel. High-risk areas for the emergence and spread of infectious disease are where these three trends intersect with predisposing socioecological conditions including the presence of wild disease reservoirs, agricultural practices that increase contact between wildlife and livestock, and cultural practices that increase contact between humans, wildlife, and livestock. Such an intersection occurs in China, which has been a "cradle" of zoonoses from the Black Death to avian influenza and SARS. Disease management in China is thus critical to the mitigation of global zoonotic risks.

Coding-Spreading Tradeoff in CDMA Systems

National Research Council Canada - National Science Library

Bolas, Eduardo

2002-01-01

.... Comparing different combinations of coding and spreading with a traditional DS-CDMA, as defined in the IS-95 standard, allows the criteria to be defined for the best coding-spreading tradeoff in CDMA systems...

Deterministic ripple-spreading model for complex networks.

Science.gov (United States)

Hu, Xiao-Bing; Wang, Ming; Leeson, Mark S; Hines, Evor L; Di Paolo, Ezequiel

2011-04-01

This paper proposes a deterministic complex network model, which is inspired by the natural ripple-spreading phenomenon. The motivations and main advantages of the model are the following: (i) The establishment of many real-world networks is a dynamic process, where it is often observed that the influence of a few local events spreads out through nodes, and then largely determines the final network topology. Obviously, this dynamic process involves many spatial and temporal factors. By simulating the natural ripple-spreading process, this paper reports a very natural way to set up a spatial and temporal model for such complex networks. (ii) Existing relevant network models are all stochastic models, i.e., with a given input, they cannot output a unique topology. Differently, the proposed ripple-spreading model can uniquely determine the final network topology, and at the same time, the stochastic feature of complex networks is captured by randomly initializing ripple-spreading related parameters. (iii) The proposed model can use an easily manageable number of ripple-spreading related parameters to precisely describe a network topology, which is more memory efficient when compared with traditional adjacency matrix or similar memory-expensive data structures. (iv) The ripple-spreading model has a very good potential for both extensions and applications.

Dynamics of Ionic Shifts in Cortical Spreading Depression.

Science.gov (United States)

Enger, Rune; Tang, Wannan; Vindedal, Gry Fluge; Jensen, Vidar; Johannes Helm, P; Sprengel, Rolf; Looger, Loren L; Nagelhus, Erlend A

2015-11-01

Cortical spreading depression is a slowly propagating wave of near-complete depolarization of brain cells followed by temporary suppression of neuronal activity. Accumulating evidence indicates that cortical spreading depression underlies the migraine aura and that similar waves promote tissue damage in stroke, trauma, and hemorrhage. Cortical spreading depression is characterized by neuronal swelling, profound elevation of extracellular potassium and glutamate, multiphasic blood flow changes, and drop in tissue oxygen tension. The slow speed of the cortical spreading depression wave implies that it is mediated by diffusion of a chemical substance, yet the identity of this substance and the pathway it follows are unknown. Intercellular spread between gap junction-coupled neurons or glial cells and interstitial diffusion of K(+) or glutamate have been proposed. Here we use extracellular direct current potential recordings, K(+)-sensitive microelectrodes, and 2-photon imaging with ultrasensitive Ca(2+) and glutamate fluorescent probes to elucidate the spatiotemporal dynamics of ionic shifts associated with the propagation of cortical spreading depression in the visual cortex of adult living mice. Our data argue against intercellular spread of Ca(2+) carrying the cortical spreading depression wavefront and are in favor of interstitial K(+) diffusion, rather than glutamate diffusion, as the leading event in cortical spreading depression. © The Author 2015. Published by Oxford University Press.

Resource Allocation with Adaptive Spread Spectrum OFDM Using 2D Spreading for Power Line Communications

Science.gov (United States)

Baudais, Jean-Yves; Crussière, Matthieu

2007-12-01

Bit-loading techniques based on orthogonal frequency division mutiplexing (OFDM) are frequently used over wireline channels. In the power line context, channel state information can reasonably be obtained at both transmitter and receiver sides, and adaptive loading can advantageously be carried out. In this paper, we propose to apply loading principles to an spread spectrum OFDM (SS-OFDM) waveform which is a multicarrier system using 2D spreading in the time and frequency domains. The presented algorithm handles the subcarriers, spreading codes, bits and energies assignment in order to maximize the data rate and the range of the communication system. The optimization is realized at a target symbol error rate and under spectral mask constraint as usually imposed. The analytical study shows that the merging principle realized by the spreading code improves the rate and the range of the discrete multitone (DMT) system in single and multiuser contexts. Simulations have been run over measured power line communication (PLC) channel responses and highlight that the proposed system is all the more interesting than the received signal-to-noise ratio (SNR) is low.

Spread and Liquidity Issues: A markets comparison

Directory of Open Access Journals (Sweden)

Strašek Sebastjan

2016-03-01

Full Text Available The financial crises are closely connected with spread changes and liquidity issues. After defining and addressing spread considerations, we research in this paper the topic of liquidity issues in times of economic crisis. We analyse the liquidity effects as recorded on spreads of securities from different markets. We stipulate that higher international risk aversion in times of financial crises coincides with widening security spreads. The paper then introduces liquidity as a risk factor into the standard value-at-risk framework, using GARCH methodology. The comparison of results of these models suggests that the size of the tested markets does not have a strong effect on the models. Thus, we find that spread analysis is an appropriate tool for analysing liquidity issues during a financial crisis.

Focus: global currents in national histories of science: the "global turn" and the history of science in Latin America.

Science.gov (United States)

McCook, Stuart

2013-12-01

The "global turn" in the history of science offers new ways to think about how to do national and regional histories of science, in this case the history of science in Latin America. For example, it questions structuralist and diffusionist models of the spread of science and shows the often active role that people in Latin America (and the rest of the Global South) played in the construction of "universal" scientific knowledge. It suggests that even national or regional histories of science must be situated in a global context; all too often, such histories have treated global processes as a distant backdrop. At the same time, historians need to pay constant attention to the role of power in the construction of scientific knowledge. Finally, this essay highlights a methodological tool for writing globally inflected histories of science: the method of "following".

Global trends in satellite-based emergency mapping

Science.gov (United States)

Voigt, Stefan; Giulio-Tonolo, Fabio; Lyons, Josh; Kučera, Jan; Jones, Brenda; Schneiderhan, Tobias; Platzeck, Gabriel; Kaku, Kazuya; Hazarika, Manzul Kumar; Czaran, Lorant; Li, Suju; Pedersen, Wendi; James, Godstime Kadiri; Proy, Catherine; Muthike, Denis Macharia; Bequignon, Jerome; Guha-Sapir, Debarati

2016-01-01

Over the past 15 years, scientists and disaster responders have increasingly used satellite-based Earth observations for global rapid assessment of disaster situations. We review global trends in satellite rapid response and emergency mapping from 2000 to 2014, analyzing more than 1000 incidents in which satellite monitoring was used for assessing major disaster situations. We provide a synthesis of spatial patterns and temporal trends in global satellite emergency mapping efforts and show that satellite-based emergency mapping is most intensively deployed in Asia and Europe and follows well the geographic, physical, and temporal distributions of global natural disasters. We present an outlook on the future use of Earth observation technology for disaster response and mitigation by putting past and current developments into context and perspective.

Evaluating the links between climate, disease spread, and amphibian declines.

Science.gov (United States)

Rohr, Jason R; Raffel, Thomas R; Romansic, John M; McCallum, Hamish; Hudson, Peter J

2008-11-11

Human alteration of the environment has arguably propelled the Earth into its sixth mass extinction event and amphibians, the most threatened of all vertebrate taxa, are at the forefront. Many of the worldwide amphibian declines have been caused by the chytrid fungus, Batrachochytrium dendrobatidis (Bd), and two contrasting hypotheses have been proposed to explain these declines. Positive correlations between global warming and Bd-related declines sparked the chytrid-thermal-optimum hypothesis, which proposes that global warming increased cloud cover in warm years that drove the convergence of daytime and nighttime temperatures toward the thermal optimum for Bd growth. In contrast, the spatiotemporal-spread hypothesis states that Bd-related declines are caused by the introduction and spread of Bd, independent of climate change. We provide a rigorous test of these hypotheses by evaluating (i) whether cloud cover, temperature convergence, and predicted temperature-dependent Bd growth are significant positive predictors of amphibian extinctions in the genus Atelopus and (ii) whether spatial structure in the timing of these extinctions can be detected without making assumptions about the location, timing, or number of Bd emergences. We show that there is spatial structure to the timing of Atelopus spp. extinctions but that the cause of this structure remains equivocal, emphasizing the need for further molecular characterization of Bd. We also show that the reported positive multi-decade correlation between Atelopus spp. extinctions and mean tropical air temperature in the previous year is indeed robust, but the evidence that it is causal is weak because numerous other variables, including regional banana and beer production, were better predictors of these extinctions. Finally, almost all of our findings were opposite to the predictions of the chytrid-thermal-optimum hypothesis. Although climate change is likely to play an important role in worldwide amphibian declines

Topology dependent epidemic spreading velocity in weighted networks

International Nuclear Information System (INIS)

Duan, Wei; Qiu, Xiaogang; Quax, Rick; Lees, Michael; Sloot, Peter M A

2014-01-01

Many diffusive processes occur on structured networks with weighted links, such as disease spread by airplane transport or information diffusion in social networks or blogs. Understanding the impact of weight-connectivity correlations on epidemic spreading in weighted networks is crucial to support decision-making on disease control and other diffusive processes. However, a real understanding of epidemic spreading velocity in weighted networks is still lacking. Here we conduct a numerical study of the velocity of a Reed–Frost epidemic spreading process in various weighted network topologies as a function of the correlations between edge weights and node degrees. We find that a positive weight-connectivity correlation leads to a faster epidemic spreading compared to an unweighted network. In contrast, we find that both uncorrelated and negatively correlated weight distributions lead to slower spreading processes. In the case of positive weight-connectivity correlations, the acceleration of spreading velocity is weak when the heterogeneity of weight distribution increases. (paper)

Explaining the luminosity spread in young clusters: proto and pre-main sequence stellar evolution in a molecular cloud environment

Science.gov (United States)

Jensen, Sigurd S.; Haugbølle, Troels

2018-02-01

Hertzsprung-Russell diagrams of star-forming regions show a large luminosity spread. This is incompatible with well-defined isochrones based on classic non-accreting protostellar evolution models. Protostars do not evolve in isolation of their environment, but grow through accretion of gas. In addition, while an age can be defined for a star-forming region, the ages of individual stars in the region will vary. We show how the combined effect of a protostellar age spread, a consequence of sustained star formation in the molecular cloud, and time-varying protostellar accretion for individual protostars can explain the observed luminosity spread. We use a global magnetohydrodynamic simulation including a sub-scale sink particle model of a star-forming region to follow the accretion process of each star. The accretion profiles are used to compute stellar evolution models for each star, incorporating a model of how the accretion energy is distributed to the disc, radiated away at the accretion shock, or incorporated into the outer layers of the protostar. Using a modelled cluster age of 5 Myr, we naturally reproduce the luminosity spread and find good agreement with observations of the Collinder 69 cluster, and the Orion Nebular Cluster. It is shown how stars in binary and multiple systems can be externally forced creating recurrent episodic accretion events. We find that in a realistic global molecular cloud model massive stars build up mass over relatively long time-scales. This leads to an important conceptual change compared to the classic picture of non-accreting stellar evolution segmented into low-mass Hayashi tracks and high-mass Henyey tracks.

A network model for Ebola spreading.

Science.gov (United States)

Rizzo, Alessandro; Pedalino, Biagio; Porfiri, Maurizio

2016-04-07

The availability of accurate models for the spreading of infectious diseases has opened a new era in management and containment of epidemics. Models are extensively used to plan for and execute vaccination campaigns, to evaluate the risk of international spreadings and the feasibility of travel bans, and to inform prophylaxis campaigns. Even when no specific therapeutical protocol is available, as for the Ebola Virus Disease (EVD), models of epidemic spreading can provide useful insight to steer interventions in the field and to forecast the trend of the epidemic. Here, we propose a novel mathematical model to describe EVD spreading based on activity driven networks (ADNs). Our approach overcomes the simplifying assumption of homogeneous mixing, which is central to most of the mathematically tractable models of EVD spreading. In our ADN-based model, each individual is not bound to contact every other, and its network of contacts varies in time as a function of an activity potential. Our model contemplates the possibility of non-ideal and time-varying intervention policies, which are critical to accurately describe EVD spreading in afflicted countries. The model is calibrated from field data of the 2014 April-to-December spreading in Liberia. We use the model as a predictive tool, to emulate the dynamics of EVD in Liberia and offer a one-year projection, until December 2015. Our predictions agree with the current vision expressed by professionals in the field, who consider EVD in Liberia at its final stage. The model is also used to perform a what-if analysis to assess the efficacy of timely intervention policies. In particular, we show that an earlier application of the same intervention policy would have greatly reduced the number of EVD cases, the duration of the outbreak, and the infrastructures needed for the implementation of the intervention. Copyright © 2016 Elsevier Ltd. All rights reserved.

Epidemic spreading in time-varying community networks.

Science.gov (United States)

Ren, Guangming; Wang, Xingyuan

2014-06-01

The spreading processes of many infectious diseases have comparable time scale as the network evolution. Here, we present a simple networks model with time-varying community structure, and investigate susceptible-infected-susceptible epidemic spreading processes in this model. By both theoretic analysis and numerical simulations, we show that the efficiency of epidemic spreading in this model depends intensively on the mobility rate q of the individuals among communities. We also find that there exists a mobility rate threshold qc. The epidemic will survive when q > qc and die when q epidemic spreading in complex networks with community structure.

Post-Tanner spreading of nematic droplets

International Nuclear Information System (INIS)

Mechkov, S; Oshanin, G; Cazabat, A M

2009-01-01

The quasistationary spreading of a circular liquid drop on a solid substrate typically obeys the so-called Tanner law, with the instantaneous base radius R(t) growing with time as R∼t 1/10 -an effect of the dominant role of capillary forces for a small-sized droplet. However, for droplets of nematic liquid crystals, a faster spreading law sets in at long times, so that R∼t α with α significantly larger than the Tanner exponent 1/10. In the framework of the thin film model (or lubrication approximation), we describe this 'acceleration' as a transition to a qualitatively different spreading regime driven by a strong substrate-liquid interaction specific to nematics (antagonistic anchoring at the interfaces). The numerical solution of the thin film equation agrees well with the available experimental data for nematics, even though the non-Newtonian rheology has yet to be taken into account. Thus we complement the theory of spreading with a post-Tanner stage, noting that the spreading process can be expected to cross over from the usual capillarity-dominated stage to a regime where the whole reservoir becomes a diffusive film in the sense of Derjaguin.

Ideas and institutions in global governance - the case of microcredit

DEFF Research Database (Denmark)

Aagaard, Peter

There is a growing demand for effective strategic problem solving in relation to a wide array of global policy problems such as AIDS, poverty, global warming, etc. This makes the introduction of new policy ideas for institutional change increasingly important in global governance. But researchers...... need a new approach in order to better grasp the complexity in global problem solving. We need to know more about how ideas emerge, spread and transform in a complex, networked global environment. New literature on institutional dynamics can inform the literature on global governance networks......, especially when it comes to the meta-governance of global networks. Based on a case study of microcredit and its emergence as a policy idea in development policy, the paper will illustrate the use of institutional dynamic conceptualisation in global governance....

A Role for Human Skin Mast Cells in Dengue Virus Infection and Systemic Spread.

Science.gov (United States)

Troupin, Andrea; Shirley, Devon; Londono-Renteria, Berlin; Watson, Alan M; McHale, Cody; Hall, Alex; Hartstone-Rose, Adam; Klimstra, William B; Gomez, Gregorio; Colpitts, Tonya M

2016-12-01

Dengue virus (DENV) is a mosquito-borne flavivirus that causes serious global human disease and mortality. Skin immune cells are an important component of initial DENV infection and systemic spread. Here, we show that mast cells are a target of DENV in human skin and that DENV infection of skin mast cells induces degranulation and alters cytokine and growth factor expression profiles. Importantly, to our knowledge, we also demonstrate for the first time that DENV localizes within secretory granules in infected skin mast cells. In addition, DENV within extracellular granules was infectious in vitro and in vivo, trafficking through lymph to draining lymph nodes in mice. We demonstrate an important role for human skin mast cells in DENV infection and identify a novel mechanism for systemic spread of DENV infection from the initial peripheral mosquito injection site. Copyright © 2016 by The American Association of Immunologists, Inc.

Spreading dynamics in complex networks

International Nuclear Information System (INIS)

Pei, Sen; Makse, Hernán A

2013-01-01

Searching for influential spreaders in complex networks is an issue of great significance for applications across various domains, ranging from epidemic control, innovation diffusion, viral marketing, and social movement to idea propagation. In this paper, we first display some of the most important theoretical models that describe spreading processes, and then discuss the problem of locating both the individual and multiple influential spreaders respectively. Recent approaches in these two topics are presented. For the identification of privileged single spreaders, we summarize several widely used centralities, such as degree, betweenness centrality, PageRank, k-shell, etc. We investigate the empirical diffusion data in a large scale online social community—LiveJournal. With this extensive dataset, we find that various measures can convey very distinct information of nodes. Of all the users in the LiveJournal social network, only a small fraction of them are involved in spreading. For the spreading processes in LiveJournal, while degree can locate nodes participating in information diffusion with higher probability, k-shell is more effective in finding nodes with a large influence. Our results should provide useful information for designing efficient spreading strategies in reality. (paper)

Spreading dynamics in complex networks

Science.gov (United States)

Pei, Sen; Makse, Hernán A.

2013-12-01

Searching for influential spreaders in complex networks is an issue of great significance for applications across various domains, ranging from epidemic control, innovation diffusion, viral marketing, and social movement to idea propagation. In this paper, we first display some of the most important theoretical models that describe spreading processes, and then discuss the problem of locating both the individual and multiple influential spreaders respectively. Recent approaches in these two topics are presented. For the identification of privileged single spreaders, we summarize several widely used centralities, such as degree, betweenness centrality, PageRank, k-shell, etc. We investigate the empirical diffusion data in a large scale online social community—LiveJournal. With this extensive dataset, we find that various measures can convey very distinct information of nodes. Of all the users in the LiveJournal social network, only a small fraction of them are involved in spreading. For the spreading processes in LiveJournal, while degree can locate nodes participating in information diffusion with higher probability, k-shell is more effective in finding nodes with a large influence. Our results should provide useful information for designing efficient spreading strategies in reality.

Governance by Diffusion: Transnational Municipal Networks and the Spread of Local Climate Strategies in Europe

OpenAIRE

Lukas Hakelberg

2014-01-01

Cities have become crucial actors for the global governance of climate change. Their increased activity in this field is reflected by the rising number of adoptions of local climate strategies in an original sample of 274 European cities from 1992 to 2009. Using event history analysis, I find that this spread is promoted by transnational municipal networks (TMNs) successfully deploying strategies for governance by diffusion, their impact exceeding that of most alternative explanatory factors ...

The Influence of Globalization on Turkish Sports

Science.gov (United States)

Sahin, Mehmet

2018-01-01

This paper addresses the phenomenon of globalization, which has also spread to sports, in terms of its economic, social and cultural aspects; while discussing the concept based on examples from the discipline of football in the premier league of Turkey. In this framework, sports labor emigration mobility is handled, and sponsorship and the effects…

Scale-free correlations in the geographical spreading of obesity

Science.gov (United States)

Gallos, Lazaros; Barttfeld, Pablo; Havlin, Shlomo; Sigman, Mariano; Makse, Hernan

2012-02-01

Obesity levels have been universally increasing. A crucial problem is to determine the influence of global and local drivers behind the obesity epidemic, to properly guide effective policies. Despite the numerous factors that affect the obesity evolution, we show a remarkable regularity expressed in a predictable pattern of spatial long-range correlations in the geographical spreading of obesity. We study the spatial clustering of obesity and a number of related health and economic indicators, and we use statistical physics methods to characterize the growth of the resulting clusters. The resulting scaling exponents allow us to broadly classify these indicators into two separate universality classes, weakly or strongly correlated. Weak correlations are found in generic human activity such as population distribution and the growth of the whole economy. Strong correlations are recovered, among others, for obesity, diabetes, and the food industry sectors associated with food consumption. Obesity turns out to be a global problem where local details are of little importance. The long-range correlations suggest influence that extends to large scales, hinting that the physical model of obesity clustering can be mapped to a long-range correlated percolation process.

Smooth muscle cell rigidity and extracellular matrix organization influence endothelial cell spreading and adhesion formation in coculture.

Science.gov (United States)

Wallace, Charles S; Strike, Sophie A; Truskey, George A

2007-09-01

Efforts to develop functional tissue-engineered blood vessels have focused on improving the strength and mechanical properties of the vessel wall, while the functional status of the endothelium within these vessels has received less attention. Endothelial cell (EC) function is influenced by interactions between its basal surface and the underlying extracellular matrix. In this study, we utilized a coculture model of a tissue-engineered blood vessel to evaluate EC attachment, spreading, and adhesion formation to the extracellular matrix on the surface of quiescent smooth muscle cells (SMCs). ECs attached to and spread on SMCs primarily through the alpha(5)beta(1)-integrin complex, whereas ECs used either alpha(5)beta(1)- or alpha(v)beta(3)-integrin to spread on fibronectin (FN) adsorbed to plastic. ECs in coculture lacked focal adhesions, but EC alpha(5)beta(1)-integrin bound to fibrillar FN on the SMC surface, promoting rapid fibrillar adhesion formation. As assessed by both Western blot analysis and quantitative real-time RT-PCR, coculture suppressed the expression of focal adhesion proteins and mRNA, whereas tensin protein and mRNA expression were elevated. When attached to polyacrylamide gels with similar elastic moduli as SMCs, focal adhesion formation and the rate of cell spreading increased relative to ECs in coculture. Thus, the elastic properties are only one factor contributing to EC spreading and focal adhesion formation in coculture. The results suggest that the softness of the SMCs and the fibrillar organization of FN inhibit focal adhesions and reduce cell spreading while promoting fibrillar adhesion formation. These changes in the type of adhesions may alter EC signaling pathways in tissue-engineered blood vessels.

An analytical study of the improved nonlinear tolerance of DFT-spread OFDM and its unitary-spread OFDM generalization.

Science.gov (United States)

Shulkind, Gal; Nazarathy, Moshe

2012-11-05

DFT-spread (DFT-S) coherent optical OFDM was numerically and experimentally shown to provide improved nonlinear tolerance over an optically amplified dispersion uncompensated fiber link, relative to both conventional coherent OFDM and single-carrier transmission. Here we provide an analytic model rigorously accounting for this numerical result and precisely predicting the optimal bandwidth per DFT-S sub-band (or equivalently the optimal number of sub-bands per optical channel) required in order to maximize the link non-linear tolerance (NLT). The NLT advantage of DFT-S OFDM is traced to the particular statistical dependency introduced among the OFDM sub-carriers by means of the DFT spreading operation. We further extend DFT-S to a unitary-spread generalized modulation format which includes as special cases the DFT-S scheme as well as a new format which we refer to as wavelet-spread (WAV-S) OFDM, replacing the spreading DFTs by Hadamard matrices which have elements +/-1 hence are multiplier-free. The extra complexity incurred in the spreading operation is almost negligible, however the performance improvement with WAV-S relative to plain OFDM is more modest than that achieved by DFT-S, which remains the preferred format for nonlinear tolerance improvement, outperforming both plain OFDM and single-carrier schemes.

Development of a hull-less pumpkin (Cucurbita pepo L.) seed oil press-cake spread.

Science.gov (United States)

Radočaj, Olga; Dimić, Etelka; Vujasinović, Vesna

2012-09-01

A stable, oil-based spread rich in the omega-3 (ω-3) and omega-6 (ω-6) fatty acids was developed using a hull-less pumpkin seed (Cucurbita pepo L.) oil press-cake, a by-product of the pumpkin oil pressing process, along with cold-pressed hemp oil. Response surface methodology (RSM) was applied to investigate the effects of two factors, as the formulation's compositional variables: a commercial stabilizer (X(1) ) and cold-pressed hemp oil (X(2) ) added to the pumpkin seed oil press-cake in the spread formulations. A central composite, 2-factorial experimental design on 5 levels was used to optimize the spreads where model responses were ω-3 fatty acids content, spreadability (hardness), oil separation, and sensory evaluation. The selected responses were significantly affected by both variables (P spreads resembled commercial peanut butter, both in appearance, texture and spreadability; were a source of ω-3 fatty acids and with no visual oil separation after 1 mo of storage. An optimum spread was produced using 1.25% (w/w) of stabilizer and 80% of hemp oil (w/w, of the total added oil) which had 0.97 g of ω-3 fatty acids per serving size; penetration depth of 68.4 mm; oil separation of 9.2% after 3 mo of storage; and a sensory score of 17.5. A use of by-products generated from different food processing technologies, where the edible waste is successfully incorporated as a value-added ingredient, has become a very important area of research to support global sustainability efforts. This study contributes to the knowledge of a product design process for oil-based spread development, where oil press-cake, a by-product of the oil pressing process of the naked pumpkin seeds, was used and where results have demonstrated that a new product can be successfully developed and potentially manufactured as a functional food. © 2012 Institute of Food Technologists®

Super-performance in a palm species

NARCIS (Netherlands)

Jansen, Merel

2016-01-01

The world is changing rapidly due to anthropogenic disturbance. Effects include: global warming, massive pollution, a changed global nitrogen cycle, high rates of land-use change, and exotic species spread. This has a tremendous impact on both natural and agricultural systems. To understand these

Effects of local and global network connectivity on synergistic epidemics

Science.gov (United States)

Broder-Rodgers, David; Pérez-Reche, Francisco J.; Taraskin, Sergei N.

2015-12-01

Epidemics in networks can be affected by cooperation in transmission of infection and also connectivity between nodes. An interplay between these two properties and their influence on epidemic spread are addressed in the paper. A particular type of cooperative effects (called synergy effects) is considered, where the transmission rate between a pair of nodes depends on the number of infected neighbors. The connectivity effects are studied by constructing networks of different topology, starting with lattices with only local connectivity and then with networks that have both local and global connectivity obtained by random bond-rewiring to nodes within a certain distance. The susceptible-infected-removed epidemics were found to exhibit several interesting effects: (i) for epidemics with strong constructive synergy spreading in networks with high local connectivity, the bond rewiring has a negative role in epidemic spread, i.e., it reduces invasion probability; (ii) in contrast, for epidemics with destructive or weak constructive synergy spreading on networks of arbitrary local connectivity, rewiring helps epidemics to spread; (iii) and, finally, rewiring always enhances the spread of epidemics, independent of synergy, if the local connectivity is low.

Spreading Culture on Quantum Entanglement and Consciousness

Science.gov (United States)

Nobili, G.; Teodorani, M.

The subject of "quantum entanglement" in general doesn't seem to be particularly considered in Europe in the form of popularizing books or of educational physics projects. These authors have started to spread out this kind of scientific culture in both forms, including popularizing seminars too. Concerning the entanglement phenomenon, recently, new thought experiments have been outlined, new laboratory results have come out in the form of real discoveries in quantum optics, new studies on "bio-entanglement" and 'global consciousness effects' have been carried out, and very sophisticated new ideas have been developed in the fields of quantum physics, biophysics, cosmology and epistemology. These authors intend to show their effort of diffusing widely this growing scientific knowledge. Beyond all this there is a long-term strategy aimed at inculcating new concepts in physics in order to trigger the interest of scholars at all levels, in that which is probably the most innovative and interdisciplinary subject of the human knowledge of this new millennium.

The Global People landscaping study: intercultural effectiveness in global education partnerships

OpenAIRE

Reid, S.; Stadler, Stefanie; Spencer-Oatey, Helen

2009-01-01

The Context\\ud The Higher Education sector in the UK is experiencing a period of rapid and competitive internationalisation. The market for higher education, at undergraduate and post graduate levels, is now truly global: many potential students can make choices about study destinations between an enormous range of institutions in any of the five continents. The audience for research is also global, with a proliferation of domestic and international journals, a multitude of international conf...

Resource Allocation with Adaptive Spread Spectrum OFDM Using 2D Spreading for Power Line Communications

Directory of Open Access Journals (Sweden)

Baudais Jean-Yves

2007-01-01

Full Text Available Bit-loading techniques based on orthogonal frequency division mutiplexing (OFDM are frequently used over wireline channels. In the power line context, channel state information can reasonably be obtained at both transmitter and receiver sides, and adaptive loading can advantageously be carried out. In this paper, we propose to apply loading principles to an spread spectrum OFDM (SS-OFDM waveform which is a multicarrier system using 2D spreading in the time and frequency domains. The presented algorithm handles the subcarriers, spreading codes, bits and energies assignment in order to maximize the data rate and the range of the communication system. The optimization is realized at a target symbol error rate and under spectral mask constraint as usually imposed. The analytical study shows that the merging principle realized by the spreading code improves the rate and the range of the discrete multitone (DMT system in single and multiuser contexts. Simulations have been run over measured power line communication (PLC channel responses and highlight that the proposed system is all the more interesting than the received signal-to-noise ratio (SNR is low.

Rapid response in psychological treatments for binge eating disorder.

Science.gov (United States)

Hilbert, Anja; Hildebrandt, Thomas; Agras, W Stewart; Wilfley, Denise E; Wilson, G Terence

2015-06-01

Analysis of short- and long-term effects of rapid response across 3 different treatments for binge eating disorder (BED). In a randomized clinical study comparing interpersonal psychotherapy (IPT), cognitive-behavioral therapy guided self-help (CBTgsh), and behavioral weight loss (BWL) treatment in 205 adults meeting Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV; APA, 1994) criteria for BED, the predictive value of rapid response, defined as ≥70% reduction in binge eating by Week 4, was determined for remission from binge eating and global eating disorder psychopathology at posttreatment, 6-, 12-, 18-, and 24-month follow-ups. Rapid responders in CBTgsh, but not in IPT or BWL, showed significantly greater rates of remission from binge eating than nonrapid responders, which was sustained over the long term. Rapid and nonrapid responders in IPT and rapid responders in CBTgsh showed a greater remission from binge eating than nonrapid responders in CBTgsh and BWL. Rapid responders in CBTgsh showed greater remission from binge eating than rapid responders in BWL. Although rapid responders in all treatments had lower global eating disorder psychopathology than nonrapid responders in the short term, rapid responders in CBTgsh and IPT were more improved than those in BWL and nonrapid responders in each treatment. Rapid responders in BWL did not differ from nonrapid responders in CBTgsh and IPT. Rapid response is a treatment-specific positive prognostic indicator of sustained remission from binge eating in CBTgsh. Regarding an evidence-based, stepped-care model, IPT, equally efficacious for rapid and nonrapid responders, could be investigated as a second-line treatment in case of nonrapid response to first-line CBTgsh. (c) 2015 APA, all rights reserved).

Spreading dynamics of power-law fluid droplets

International Nuclear Information System (INIS)

Liang Zhanpeng; Peng Xiaofeng; Wang Xiaodong; Lee, D-J; Su Ay

2009-01-01

This paper aims at providing a summary of the theoretical models available for non-Newtonian fluid spreading dynamics. Experimental findings and model predictions for a Newtonian fluid spreading test are briefly reviewed. Then how the complete wetting and partial wetting power-law fluids spread over a solid substrate is examined. The possible extension of Newtonian fluid models to power-law fluids is also discussed.

Asymmetrically interacting spreading dynamics on complex layered networks.

Science.gov (United States)

Wang, Wei; Tang, Ming; Yang, Hui; Younghae Do; Lai, Ying-Cheng; Lee, GyuWon

2014-05-29

The spread of disease through a physical-contact network and the spread of information about the disease on a communication network are two intimately related dynamical processes. We investigate the asymmetrical interplay between the two types of spreading dynamics, each occurring on its own layer, by focusing on the two fundamental quantities underlying any spreading process: epidemic threshold and the final infection ratio. We find that an epidemic outbreak on the contact layer can induce an outbreak on the communication layer, and information spreading can effectively raise the epidemic threshold. When structural correlation exists between the two layers, the information threshold remains unchanged but the epidemic threshold can be enhanced, making the contact layer more resilient to epidemic outbreak. We develop a physical theory to understand the intricate interplay between the two types of spreading dynamics.

Information spreading in Delay Tolerant Networks based on nodes' behaviors

Science.gov (United States)

Wu, Yahui; Deng, Su; Huang, Hongbin

2014-07-01

Information spreading in DTNs (Delay Tolerant Networks) adopts a store-carry-forward method, and nodes receive the message from others directly. However, it is hard to judge whether the information is safe in this communication mode. In this case, a node may observe other nodes' behaviors. At present, there is no theoretical model to describe the varying rule of the nodes' trusting level. In addition, due to the uncertainty of the connectivity in DTN, a node is hard to get the global state of the network. Therefore, a rational model about the node's trusting level should be a function of the node's own observing result. For example, if a node finds k nodes carrying a message, it may trust the information with probability p(k). This paper does not explore the real distribution of p(k), but instead presents a unifying theoretical framework to evaluate the performance of the information spreading in above case. This framework is an extension of the traditional SI (susceptible-infected) model, and is useful when p(k) conforms to any distribution. Simulations based on both synthetic and real motion traces show the accuracy of the framework. Finally, we explore the impact of the nodes' behaviors based on certain special distributions through numerical results.

The small world yields the most effective information spreading

International Nuclear Information System (INIS)

Lü Linyuan; Chen Duanbing; Zhou Tao

2011-01-01

The spreading dynamics of information and diseases are usually analyzed by using a unified framework and analogous models. In this paper, we propose a model to emphasize the essential difference between information spreading and epidemic spreading, where the memory effects, the social reinforcement and the non-redundancy of contacts are taken into account. Under certain conditions, the information spreads faster and broader in regular networks than in random networks, which to some extent supports the recent experimental observation of spreading in online society (Centola D 2010 Science 329 1194). At the same time, the simulation result indicates that the random networks tend to be favorable for effective spreading when the network size increases. This challenges the validity of the above-mentioned experiment for large-scale systems. More importantly, we show that the spreading effectiveness can be sharply enhanced by introducing a little randomness into the regular structure, namely the small-world networks yield the most effective information spreading. This work provides insights into the role of local clustering in information spreading. (paper)

Rapid Global River Flood Risk Assessment under Climate and Socioeconomic Scenarios: An Extreme Case of Eurasian region

Science.gov (United States)

Kwak, Young-joo; Magome, Jun; Hasegawa, Akira; Iwami, Yoichi

2017-04-01

Causing widespread devastation with massive economic damage and loss of human lives, flood disasters hamper economic growth and accelerate poverty particularly in developing countries. Globally, this trend will likely continue due to increase in flood magnitude and lack of preparedness for extreme events. In line with risk reduction efforts since the early 21st century, the monitors and governors of global river floods should pay attention to international scientific and policy communities for support to facilitate evidence-based policy making with a special interest in long-term changes due to climate change and socio-economic effects. Although advanced hydrological inundation models and risk models have been developed to reveal flood risk, hazard, exposure, and vulnerability at a river basin, it is obviously hard to identify the distribution and locations of continent-level flood risk based on national-level data. Therefore, we propose a methodological possibility for rapid global flood risk assessment with the results from its application to the two periods, i.e., Present (from 1980 to 2004) and Future (from 2075 to 2099). The method is particularly designed to effectively simplify complexities of a hazard area by calculating the differential inundation depth using GFID2M (global flood inundation depth 2-dimension model), despite low data availability. In this research, we addressed the question of which parts in the Eurasian region (8E to 180E, 0N to 60N) can be found as high-risk areas in terms of exposed population and economy in case of a 50-year return period flood. Economic losses were estimated according to the Shared Socioeconomic Pathways (SSP) scenario, and the flood scale was defined using the annual maximum daily river discharge under the extreme conditions of climate change simulated with MRI-AGCM3.2S based on the Representative Concentration Pathways (RCP8.5) emissions scenario. As a preliminary result, the total potential economic loss in the

Globalization and Technology

Directory of Open Access Journals (Sweden)

Traian-Alexandru Miu

2016-01-01

Full Text Available Globalization, very complex phenomenon, involves overcoming the barriers between different states, which allowed the rapid transfer of capital, technology, information, and the "toxins" from one country to another. First, the technology formed the basis of rapid expansion of great ideas promoted by globalization. Undeniable progress in the field of technology and science, has conferred to the man extraordinary powers that have been used most often to the detriment of his spiritual progress. We must not deny that science and technology have brought many benefits to human, and he could expand the knowledge horizon upon the world in which he lives, exploiting information acquired and share them with others. Science and technology must become for postmodern man ways of talk and communion between human and divinity, all to the praise of God and the perfection of the creature.

Credit Spreads Across the Business Cycle

DEFF Research Database (Denmark)

Nielsen, Mads Stenbo

This paper studies how corporate bond spreads vary with the business cycle. I show that both level and slope of empirical credit spread curves are correlated with the state of the economy, and I link this to variation in idiosyncratic jump risk. I develop a structural credit risk model...... that accounts for both business cycle and jump risk, and show by estimation that the model captures the counter-cyclical level and pro-cyclical slope of empirical credit spread curves. In addition, I provide a new procedure for estimation of idiosyncratic jump risk, which is consistent with observed shocks...

Colonic motility and enema spreading

International Nuclear Information System (INIS)

Hardy, J.G.; Wood, E.; Clark, A.G.; Reynolds, J.R.; Queen's Medical Centre, Nottingham

1986-01-01

Radiolabelled enema solution was administered to eight healthy subjects, both in fasted and fed states. Enema spreading was monitored over a 4-h period using gamma scintigraphy and colonic motility was recorded simultaneously using a pressure sensitive radiotelemetry capsule. The rate and extent of enema dispersion were unaffected by eating. Spreading could be correlated with colonic motility and was inhibited by aboral propulsion of the colonic contents. (orig.)

Is wartime mobilisation a suitable policy model for rapid national climate mitigation?

International Nuclear Information System (INIS)

Delina, Laurence L.; Diesendorf, Mark

2013-01-01

Climate science suggests that, to have a high probability of limiting global warming to an average temperature increase of 2 °C, global greenhouse gas emissions must peak by 2020 and be reduced to close to zero by 2040. However, the current trend is heading towards at least 4 °C by 2100 and little effective action is being taken. This paper commences the process of developing contingency plans for a scenario in which a sudden major global climate impact galvanises governments to implement emergency climate mitigation targets and programs. Climate activists assert that rapid mitigation is feasible, invoking the scale and scope of wartime mobilisation strategies. This paper draws upon historical accounts of social, technological and economic restructurings in several countries during World War 2 in order to investigate potential applications of wartime experience to radical, rigorous and rapid climate mitigation strategies. We focus on the energy sector, the biggest single contributor to global climate change, in developed and rapidly developing countries. We find that, while wartime experience suggests some potential strategies for rapid climate mitigation in the areas of finance and labour, it also has severe limitations, resulting from its lack of democratic processes. - Highlights: • The paper explores the strengths and weaknesses of using wartime experience as a model for rapid climate mitigation. • Wartime experience suggests some potential strategies for rapid climate mitigation in the areas of finance and labour. • Wartime experience also has severe limitations, resulting from its lack of democratic processes

LastQuake: a comprehensive strategy for rapid engagement of earthquake eyewitnesses, massive crowdsourcing and risk reduction

Science.gov (United States)

Bossu, R.; Roussel, F.; Mazet-Roux, G.; Steed, R.; Frobert, L.

2015-12-01

LastQuake is a smartphone app, browser add-on and the most sophisticated Twitter robot (quakebot) for earthquakes currently in operation. It fulfills eyewitnesses' needs by offering information on felt earthquakes and their effects within tens of seconds of their occurrence. Associated with an active presence on Facebook, Pinterest and on websites, this proves a very efficient engagement strategy. For example, the app was installed thousands of times after the Ghorka earthquake in Nepal. Language barriers have been erased by using visual communication; for example, felt reports are collected through a set of cartoons representing different shaking levels. Within 3 weeks of the magnitude 7.8 Ghorka earthquakes, 7,000 felt reports with thousands of comments were collected related to the mainshock and tens of its aftershocks as well as 100 informative geo-located pics. The QuakeBot was essential in allowing us to be identified so well and interact with those affected. LastQuake is also a risk reduction tool since it provides rapid information. Rapid information is similar to prevention since when it does not exist, disasters can happen. When no information is available after a felt earthquake, the public block emergency lines by trying to find out the cause of the shaking, crowds form potentially leading to unpredictable crowd movement, rumors spread. In its next release LastQuake will also provide people with guidance immediately after a shaking through a number of pop-up cartoons illustrating "do/don't do" items (go to open places, do not phone emergency services except if people are injured…). LastQuake's app design is simple and intuitive and has a global audience. It benefited from a crowdfunding campaign (and the support of the Fondation MAIF) and more improvements have been planned after an online feedback campaign organized in early June with the Ghorka earthquake eyewitnesses. LastQuake is also a seismic risk reduction tools thanks to its very rapid

Nanoscale dynamic wetting and spreading of molten Ti alloy on 6H-SiC

International Nuclear Information System (INIS)

Tanaka, Shun-Ichiro; Iwamoto, Chihiro

2008-01-01

We have investigated nanoscale features at the reactive wetting front of the molten Ag-27.4 wt.% Cu-4.9 wt.% Ti on 6H-SiC using video movies recorded in situ on a high-temperature stage of a high-resolution transmission electron microscope and also proposed a model of a chemical reaction at each tip. One of the features of reactive wetting and spreading at 1073 K in 4 x 10 -5 Pa was the discontinuous motion of the tip, and the halting time depended on the thickness of an amorphous Si-O layer on SiC, which can be explained by the time needed for the decomposition of the layer by Ti atoms to form TiC nanoparticles since Ti atoms in the molten alloy sufficiently rapidly diffuse to the tip on the SiC surface. Molten Ti and TiC nanolayers preceded the Ti 5 Si 3 nanolayer at the tip. The reaction required to form the TiC nanolayer is also the rate-determining step for spreading. The contact angle of the tip increased up to 60-80 deg. when the tip halted, whereas the tip decreased down to 10 deg. on the nonbasal plane and 20 deg. on the basal plane of SiC when it traveled rapidly. The high traveling angle of the molten tip on the basal polar plane of SiC indicates a high interfacial energy between Ti and SiC(0 0 0 1)

Drought Persistence Errors in Global Climate Models

Science.gov (United States)

Moon, H.; Gudmundsson, L.; Seneviratne, S. I.

2018-04-01

The persistence of drought events largely determines the severity of socioeconomic and ecological impacts, but the capability of current global climate models (GCMs) to simulate such events is subject to large uncertainties. In this study, the representation of drought persistence in GCMs is assessed by comparing state-of-the-art GCM model simulations to observation-based data sets. For doing so, we consider dry-to-dry transition probabilities at monthly and annual scales as estimates for drought persistence, where a dry status is defined as negative precipitation anomaly. Though there is a substantial spread in the drought persistence bias, most of the simulations show systematic underestimation of drought persistence at global scale. Subsequently, we analyzed to which degree (i) inaccurate observations, (ii) differences among models, (iii) internal climate variability, and (iv) uncertainty of the employed statistical methods contribute to the spread in drought persistence errors using an analysis of variance approach. The results show that at monthly scale, model uncertainty and observational uncertainty dominate, while the contribution from internal variability is small in most cases. At annual scale, the spread of the drought persistence error is dominated by the statistical estimation error of drought persistence, indicating that the partitioning of the error is impaired by the limited number of considered time steps. These findings reveal systematic errors in the representation of drought persistence in current GCMs and suggest directions for further model improvement.

Role of Atmospheric Cloud Radiative Effects in the Intermodal Spread in the Shift of Southern Hemispheric Eddy-driven Jet in Responses to Global Warming

Science.gov (United States)

Li, Y.; Thompson, D. W. J.; Bony, S.

2017-12-01

Observations and most climate models suggest storm track and extratropical eddy driven jet shifts poleward in a warmer climate, particularly in the Southern Hemisphere. However, the magnitude of such shifts remains uncertain. Even for a prescribed uniform SST changes, models produce large inter-model spread in the magnitude of jet shift, suggesting that a substantial part of these uncertainties are caused by the impact of cloud radiative effects on the atmospheric heating rate per se. In this study we will investigate 1) how much do clouds contribute to the spread of the circulation response in the absence of SST coupling? 2) how much do clouds contribute to the spread of the direct CO2 and SST-only response?

Apoptosis Triggers Specific, Rapid, and Global mRNA Decay with 3′ Uridylated Intermediates Degraded by DIS3L2

Directory of Open Access Journals (Sweden)

Marshall P. Thomas

2015-05-01

Full Text Available Apoptosis is a tightly coordinated cell death program that damages mitochondria, DNA, proteins, and membrane lipids. Little is known about the fate of RNA as cells die. Here, we show that mRNAs, but not noncoding RNAs, are rapidly and globally degraded during apoptosis. mRNA decay is triggered early in apoptosis, preceding membrane lipid scrambling, genomic DNA fragmentation, and apoptotic changes to translation initiation factors. mRNA decay depends on mitochondrial outer membrane permeabilization and is amplified by caspase activation. 3′ truncated mRNA decay intermediates with nontemplated uridylate-rich tails are generated during apoptosis. These tails are added by the terminal uridylyl transferases (TUTases ZCCHC6 and ZCCHC11, and the uridylated transcript intermediates are degraded by the 3′ to 5′ exonuclease DIS3L2. Knockdown of DIS3L2 or the TUTases inhibits apoptotic mRNA decay, translation arrest, and cell death, whereas DIS3L2 overexpression enhances cell death. Our results suggest that global mRNA decay is an overlooked hallmark of apoptosis.

Generation and reception of spread-spectrum signals

Science.gov (United States)

Moser, R.

1983-05-01

The term 'spread-spectrum' implies a technique whereby digitized information is added to a pseudo-random number sequence and the resultant bit stream changes some parameter of the carrier frequency in discrete increments. The discrete modulation of the carrier frequency is usually realized either as a multiple level phase shift keyed or frequency shift keyed signal. The resultant PSK-modulated frequency spectrum is referred to as direct sequence spread-spectrum, whereas the FSK-modulated carrier frequency is referred to as a frequency hopped spread spectrum. These can be considered the major subsets of the more general term 'spread-spectrum'. In discussing signal reception, it is pointed out that active correlation methods are used for channel synchronization when the psuedo random sequences are long or when the processing gain is large, whereas the passive methods may be used for either short pseudo-random noise generation codes or to assist in attaining initial synchronization in long sequence spread-spectrum systems.

ECONOMIC AND SOCIAL IMPLICATIONS OF GLOBALIZATION

Directory of Open Access Journals (Sweden)

Oana CHINDRIS-VASIOIU

2013-12-01

Full Text Available The confrontation between third millennium will not be between civilizations but between forces of globalization and global agents. Already live in a global economy, context in which it is necessary to understand by globalization the modernization process of life world by spreading economic means of production and communication at world level. Globalization produces a capitalism healthy whereas stimulates competition beneficial between an ever-increasing number of companies. Economic and political unification under the global financial corporate banner is accompanied by mixing spiritual values and return unique realm. After internationalism political correctness (multiculturalism, feminism, ecological radically administered Western individualism typical bruising, it seems that the ground is ready for the big toe-in. Globalization can be seen as a crucial stage of expansion and economic interdependence. This stage is completing a process of aggregation of relatively autonomous local economies whose element mainly in the past has been constant widening of the space for the exchange of each economic savings. Economic renewal based on knowledge of known but a contrary geospatial evolution. Advances in knowledge are favored and intimately linked to the possibility of communication. So, they are favored by communication infrastructure and communication technologies.

Surveying the global virome

DEFF Research Database (Denmark)

Scheel, Troels K H; Simmonds, Peter; Kapoor, Amit

2015-01-01

Recent advances in sequencing technologies have greatly enhanced our abilities to identify novel microbial sequences. Thus, our understanding of the global virome and the virome of specific host species in particular is rapidly expanding. Identification of animal viruses is important for understa......Recent advances in sequencing technologies have greatly enhanced our abilities to identify novel microbial sequences. Thus, our understanding of the global virome and the virome of specific host species in particular is rapidly expanding. Identification of animal viruses is important....... Much remains to be learned on the novel hepaciviruses, including their association with disease, and thereby how relevant they will become as HCV model systems and for studies of animal disease. This review discusses how virome analysis led to identification of novel hepaci- and pegiviruses...

rapid increase in precaution The global financial crisis: origin ...

African Journals Online (AJOL)

user

2010-05-01

May 1, 2010 ... provoked a global flight on quality, caused firms to cut back on ... despite coordinated easing of monetary policy by governments and trillions ... indicated in the scope of the study, the discussions will be based on financial .... financial investors in decision making, which would overvalue asset prices in.

Climate impact on spreading of airborne infectious diseases. Complex network based modeling of climate influences on influenza like illnesses

Science.gov (United States)

Brenner, Frank; Marwan, Norbert; Hoffmann, Peter

2017-06-01

In this study we combined a wide range of data sets to simulate the outbreak of an airborne infectious disease that is directly transmitted from human to human. The basis is a complex network whose structures are inspired by global air traffic data (from openflights.org) containing information about airports, airport locations, direct flight connections and airplane types. Disease spreading inside every node is realized with a Susceptible-Exposed-Infected-Recovered (SEIR) compartmental model. Disease transmission rates in our model are depending on the climate environment and therefore vary in time and from node to node. To implement the correlation between water vapor pressure and influenza transmission rate [J. Shaman, M. Kohn, Proc. Natl. Acad. Sci. 106, 3243 (2009)], we use global available climate reanalysis data (WATCH-Forcing-Data-ERA-Interim, WFDEI). During our sensitivity analysis we found that disease spreading dynamics are strongly depending on network properties, the climatic environment of the epidemic outbreak location, and the season during the year in which the outbreak is happening.

Heterogeneous incidence and propagation of spreading depolarizations

Science.gov (United States)

Kaufmann, Dan; Theriot, Jeremy J; Zyuzin, Jekaterina; Service, C Austin; Chang, Joshua C; Tang, Y Tanye; Bogdanov, Vladimir B; Multon, Sylvie; Schoenen, Jean; Ju, Y Sungtaek

2016-01-01

Spreading depolarizations are implicated in a diverse set of neurologic diseases. They are unusual forms of nervous system activity in that they propagate very slowly and approximately concentrically, apparently not respecting the anatomic, synaptic, functional, or vascular architecture of the brain. However, there is evidence that spreading depolarizations are not truly concentric, isotropic, or homogeneous, either in space or in time. Here we present evidence from KCl-induced spreading depolarizations, in mouse and rat, in vivo and in vitro, showing the great variability that these depolarizations can exhibit. This variability can help inform the mechanistic understanding of spreading depolarizations, and it has implications for their phenomenology in neurologic disease. PMID:27562866

Epidemic spreading in time-varying community networks

Energy Technology Data Exchange (ETDEWEB)

Ren, Guangming, E-mail: wangxy@dlut.edu.cn, E-mail: ren-guang-ming@163.com [School of Electronic and Information, Guangdong Polytechnic Normal University, Guangzhou 510665 (China); Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116024 (China); Wang, Xingyuan, E-mail: wangxy@dlut.edu.cn, E-mail: ren-guang-ming@163.com [Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116024 (China)

2014-06-15

The spreading processes of many infectious diseases have comparable time scale as the network evolution. Here, we present a simple networks model with time-varying community structure, and investigate susceptible-infected-susceptible epidemic spreading processes in this model. By both theoretic analysis and numerical simulations, we show that the efficiency of epidemic spreading in this model depends intensively on the mobility rate q of the individuals among communities. We also find that there exists a mobility rate threshold q{sub c}. The epidemic will survive when q > q{sub c} and die when q < q{sub c}. These results can help understanding the impacts of human travel on the epidemic spreading in complex networks with community structure.

Epidemic spreading in time-varying community networks

International Nuclear Information System (INIS)

Ren, Guangming; Wang, Xingyuan

2014-01-01

The spreading processes of many infectious diseases have comparable time scale as the network evolution. Here, we present a simple networks model with time-varying community structure, and investigate susceptible-infected-susceptible epidemic spreading processes in this model. By both theoretic analysis and numerical simulations, we show that the efficiency of epidemic spreading in this model depends intensively on the mobility rate q of the individuals among communities. We also find that there exists a mobility rate threshold q c . The epidemic will survive when q > q c and die when q  c . These results can help understanding the impacts of human travel on the epidemic spreading in complex networks with community structure

Trading Quality across Borders: Colonial Discourse and International Quality Assurance Policies in Higher Education

Science.gov (United States)

Blanco Ramírez, Gerardo

2014-01-01

Accountability and quality assurance have become central discourses in higher education policy throughout the world. However, accountability and quality assurance involve power and control. Practices and ideas about quality developed in the Global North are spreading rapidly across the Global South, leading to increased uniformity in the…

Peculiarities of spreading separatist trends in the Modern World in the context of development of the global processes

Directory of Open Access Journals (Sweden)

Bostan Sergii Ivanovich

2016-04-01

Full Text Available The international collaboration is entering the new era of globalization revealing not only the new ways of development and quantum growth for humanity but also new threats, problems and global conflicts. There is now doubt that humanity is facing new global range of problems, agenda of the 21st century and urgent issues of global organization of the world order and systems of global administration acceptable for all states. Preventing distribution of international confrontation between the major political players through advancement of separatist and terrorist trends must become the main priority for the international system of collective security, which should be changed according to the realities of the modern global processes.

High-temperature spreading kinetics of metals

Energy Technology Data Exchange (ETDEWEB)

Rauch, N.

2005-05-15

In this PhD work a drop transfer setup combined with high speed photography has been used to analyze the spreading of Ag on polished polycrystalline Mo and single crystalline Mo (110) and (100) substrates. The objective of this work was to unveil the basic phenomena controlling spreading in metal-metal systems. The observed spreading kinetics were compared with current theories of low and high temperature spreading such as a molecular kinetic model and a fluid flow model. Analyses of the data reveal that the molecular model does describe the fastest velocity data well for all the investigated systems. Therefore, the energy which is dissipated during the spreading process is a dissipation at the triple line rather than dissipation due to the viscosity in the liquid. A comparison of the determined free activation energy for wetting of {delta}G95{approx}145kJ/mol with literature values allows the statement that the rate determining step seems to be a surface diffusion of the Ag atoms along the triple line. In order to investigate possible ridge formation, due to local atomic diffusion of atoms of the substrate at the triple during the spreading process, grooving experiments of the polycrystalline Mo were performed to calculate the surface diffusities that will control ridge evolution. The analyses of this work showed that a ridge formation at the fastest reported wetting velocities was not possible if there is no initial perturbation for a ridge. If there was an initial perturbation for a ridge the ridge had to be much smaller than 1 nm in order to be able to move with the liquid font. Therefore ridge formation does not influence the spreading kinetics for the studied system and the chosen conditions. SEM, AFM and TEM investigations of the triple line showed that ridge formation does also not occur at the end of the wetting experiment when the drop is close to equilibrium and the wetting velocity is slow. (orig.)

An Exploration of Iranian EFL Teachers' Perceptions on the Globalization and Hegemony of English

Science.gov (United States)

Safari, Parvin; Razmjoo, Seyyed Ayatollah

2016-01-01

Globalization as an increasingly influencing force has led English language to become the lingua franca of the world. However, the global spread of English is considered as linguistic and cultural imperialism of English speaking countries to exert their dominance, power, culture, ideology and language over the periphery countries. The devastating…

Non-isothermal spreading of liquid drops on horizontal plates

International Nuclear Information System (INIS)

Ehrhard, P.; Davis, S.H.

1990-05-01

A viscous-liquid drop spreads on a smooth horizontal surface, which is uniformly heated or cooled. Lubrication theory is used to study thin drops subject to capillary, thermocapillary and gravity forces, and a variety of contact-angle-versus-speed conditions. It is found for isothermal drops that gravity is very important at large times and determines the power law for unlimited spreading. Predictions compare well with the experimental data on isothermal spreading for both two-dimensional and axisymmetric configurations. It is found that heating (cooling) retards (augments) the spreading process. When the advancing contact angle is zero, heating will cause the drop to spread only finitely far. For positive advancing contact angles, sufficient cooling will cause unlimited spreading. Thus, the heat transfer serves as a sentitive control on the spreading. (orig.) [de

CSL Issue Paper. March 2008, Volume 3-08. New Media and the Warfighter. Workshop Initial Impressions

National Research Council Canada - National Science Library

Murphy, Dennis

2008-01-01

.... The global information revolution and rapid spread of the internet and other digital media have leveled the playing field between nation-states, non-state actors, multinational corporations and individuals...

A study of the spreading scheme for viral marketing based on a complex network model

Science.gov (United States)

Yang, Jianmei; Yao, Canzhong; Ma, Weicheng; Chen, Guanrong

2010-02-01

Buzzword-based viral marketing, known also as digital word-of-mouth marketing, is a marketing mode attached to some carriers on the Internet, which can rapidly copy marketing information at a low cost. Viral marketing actually uses a pre-existing social network where, however, the scale of the pre-existing network is believed to be so large and so random, so that its theoretical analysis is intractable and unmanageable. There are very few reports in the literature on how to design a spreading scheme for viral marketing on real social networks according to the traditional marketing theory or the relatively new network marketing theory. Complex network theory provides a new model for the study of large-scale complex systems, using the latest developments of graph theory and computing techniques. From this perspective, the present paper extends the complex network theory and modeling into the research of general viral marketing and develops a specific spreading scheme for viral marking and an approach to design the scheme based on a real complex network on the QQ instant messaging system. This approach is shown to be rather universal and can be further extended to the design of various spreading schemes for viral marketing based on different instant messaging systems.

Pathways of Prion Spread during Early Chronic Wasting Disease in Deer.

Science.gov (United States)

Hoover, Clare E; Davenport, Kristen A; Henderson, Davin M; Denkers, Nathaniel D; Mathiason, Candace K; Soto, Claudio; Zabel, Mark D; Hoover, Edward A

2017-05-15

Among prion infections, two scenarios of prion spread are generally observed: (i) early lymphoid tissue replication or (ii) direct neuroinvasion without substantial antecedent lymphoid amplification. In nature, cervids are infected with chronic wasting disease (CWD) prions by oral and nasal mucosal exposure, and studies of early CWD pathogenesis have implicated pharyngeal lymphoid tissue as the earliest sites of prion accumulation. However, knowledge of chronological events in prion spread during early infection remains incomplete. To investigate this knowledge gap in early CWD pathogenesis, we exposed white-tailed deer to CWD prions by mucosal routes and performed serial necropsies to assess PrP CWD tissue distribution by real-time quaking-induced conversion (RT-QuIC) and tyramide signal amplification immunohistochemistry (TSA-IHC). Although PrP CWD was not detected by either method in the initial days (1 and 3) postexposure, we observed PrP CWD seeding activity and follicular immunoreactivity in oropharyngeal lymphoid tissues at 1 and 2 months postexposure (MPE). At 3 MPE, PrP CWD replication had expanded to all systemic lymphoid tissues. By 4 MPE, the PrP CWD burden in all lymphoid tissues had increased and approached levels observed in terminal disease, yet there was no evidence of nervous system invasion. These results indicate the first site of CWD prion entry is in the oropharynx, and the initial phase of prion amplification occurs in the oropharyngeal lymphoid tissues followed by rapid dissemination to systemic lymphoid tissues. This lymphoid replication phase appears to precede neuroinvasion. IMPORTANCE Chronic wasting disease (CWD) is a universally fatal transmissible spongiform encephalopathy affecting cervids, and natural infection occurs through oral and nasal mucosal exposure to infectious prions. Terminal disease is characterized by PrP CWD accumulation in the brain and lymphoid tissues of affected animals. However, the initial sites of prion

Hotel chains of the global South: The internationalization of South African hotel brands

OpenAIRE

Rogerson, Jayne M.

2016-01-01

The global hotel industry is at the heart of the tourism production system and dominated by chain affiliated hotels. Understanding the international spread of hotel chains is a critical issue in contemporary tourism scholarship. Although the internationalization of hotel chains based in the global North is extensively researched, limited work exists on hotel chains based in the global South. This paper addresses the internationalization and destination choice in Africa of South African based ...

The global spread of Zika virus: is public and media concern justified in regions currently unaffected?

Institute of Scientific and Technical Information of China (English)

Narayan Gyawali; Richard S.Bradbury; Andrew W.Taylor-Robinson

2016-01-01

Background:Zika virus,an Aedes mosquito-borne flavivirus,is fast becoming a worldwide public health concern following its suspected association with over 4000 recent cases of microcephaly among newborn infants in Brazil.Discussion:Prior to its emergence in Latin America in 2015-2016,Zika was known to exist at a relatively low prevalence in parts of Africa,Asia and the Pacific islands.An extension of its apparent global dispersion may be enabled by climate conditions suitable to support the population growth ofA.aegypti and A.albopictus mosquitoes over an expanding geographical range.In addition,increased globalisation continues to pose a risk for the spread of infection.Further,suspicions of alternative modes of virus transmission (sexual and vertical),if proven,provide a platform for outbreaks in mosquito non-endemic regions as well.Since a vaccine or anti-viral therapy is not yet available,current means of disease prevention involve protection from mosquito bites,excluding pregnant females from travelling to Zika-endemic territories,and practicing safe sex in those countries.Importantly,in countries where Zika is reported as endemic,caution is advised in planning to conceive a baby until such time as the apparent association between infection with the virus and microcephaly is either confirmed or refuted.The question arises as to what advice is appropriate to give in more economically developed countries distant to the current epidemic and in which Zika has not yet been reported.Summary:Despite understandable concern among the general public that has been fuelled by the media,in regions where Zika is not present,such as North America,Europe and Australia,at this time any outbreak (initiated by an infected traveler returning from an endemic area) would very probably be contained locally.Since Aedes spp.has very limited spatial dispersal,overlapping high population densities of mosquitoes and humans would be needed to sustain a focus of infection.However,as A

The global spread of Zika virus: is public and media concern justified in regions currently unaffected?

Science.gov (United States)

Gyawali, Narayan; Bradbury, Richard S; Taylor-Robinson, Andrew W

2016-04-19

Zika virus, an Aedes mosquito-borne flavivirus, is fast becoming a worldwide public health concern following its suspected association with over 4000 recent cases of microcephaly among newborn infants in Brazil. Prior to its emergence in Latin America in 2015-2016, Zika was known to exist at a relatively low prevalence in parts of Africa, Asia and the Pacific islands. An extension of its apparent global dispersion may be enabled by climate conditions suitable to support the population growth of A. aegypti and A. albopictus mosquitoes over an expanding geographical range. In addition, increased globalisation continues to pose a risk for the spread of infection. Further, suspicions of alternative modes of virus transmission (sexual and vertical), if proven, provide a platform for outbreaks in mosquito non-endemic regions as well. Since a vaccine or anti-viral therapy is not yet available, current means of disease prevention involve protection from mosquito bites, excluding pregnant females from travelling to Zika-endemic territories, and practicing safe sex in those countries. Importantly, in countries where Zika is reported as endemic, caution is advised in planning to conceive a baby until such time as the apparent association between infection with the virus and microcephaly is either confirmed or refuted. The question arises as to what advice is appropriate to give in more economically developed countries distant to the current epidemic and in which Zika has not yet been reported. Despite understandable concern among the general public that has been fuelled by the media, in regions where Zika is not present, such as North America, Europe and Australia, at this time any outbreak (initiated by an infected traveler returning from an endemic area) would very probably be contained locally. Since Aedes spp. has very limited spatial dispersal, overlapping high population densities of mosquitoes and humans would be needed to sustain a focus of infection. However, as A

Disruption of the novel gene fad104 causes rapid postnatal death and attenuation of cell proliferation, adhesion, spreading and migration

International Nuclear Information System (INIS)

Nishizuka, Makoto; Kishimoto, Keishi; Kato, Ayumi; Ikawa, Masahito; Okabe, Masaru; Sato, Ryuichiro; Niida, Hiroyuki; Nakanishi, Makoto; Osada, Shigehiro; Imagawa, Masayoshi

2009-01-01

The molecular mechanisms at the beginning of adipogenesis remain unknown. Previously, we identified a novel gene, fad104 (factor for adipocyte differentiation 104), transiently expressed at the early stage of adipocyte differentiation. Since the knockdown of the expression of fad104 dramatically repressed adipogenesis, it is clear that fad104 plays important roles in adipocyte differentiation. However, the physiological roles of fad104 are still unknown. In this study, we generated fad104-deficient mice by gene targeting. Although the mice were born in the expected Mendelian ratios, all died within 1 day of birth, suggesting fad104 to be crucial for survival after birth. Furthermore, analyses of mouse embryonic fibroblasts (MEFs) prepared from fad104-deficient mice provided new insights into the functions of fad104. Disruption of fad104 inhibited adipocyte differentiation and cell proliferation. In addition, cell adhesion and wound healing assays using fad104-deficient MEFs revealed that loss of fad104 expression caused a reduction in stress fiber formation, and notably delayed cell adhesion, spreading and migration. These results indicate that fad104 is essential for the survival of newborns just after birth and important for cell proliferation, adhesion, spreading and migration

Stable genetic diversity despite parasite and pathogen spread in honey bee colonies

Science.gov (United States)

Jara, Laura; Muñoz, Irene; Cepero, Almudena; Martín-Hernández, Raquel; Serrano, José; Higes, Mariano; De la Rúa, Pilar

2015-10-01

In the last decades, the rapid spread of diseases, such as varroosis and nosemosis, associated with massive honey bee colonies mortality around the world has significantly decreased the number and size of honey bee populations and possibly their genetic diversity. Here, we compare the genetic diversity of Iberian honey bee colonies in two samplings performed in 2006 and 2010 in relation to the presence of the pathogenic agents Nosema apis, Nosema ceranae, and Varroa destructor in order to determine whether parasite and pathogen spread in honey bee colonies reflects changes in genetic diversity. We found that the genetic diversity remained similar, while the incidence of N. ceranae increased and the incidence of N. apis and V. destructor decreased slightly. These results indicate that the genetic diversity was not affected by the presence of these pathogenic agents in the analyzed period. However, the two groups of colonies with and without Nosema/Varroa detected showed significant genetic differentiation (G test). A detailed analysis of the allelic segregation of microsatellite loci in Nosema/Varroa-negative colonies and parasitized ones revealed two outlier loci related to genes involved in immune response.

Stable genetic diversity despite parasite and pathogen spread in honey bee colonies.

Science.gov (United States)

Jara, Laura; Muñoz, Irene; Cepero, Almudena; Martín-Hernández, Raquel; Serrano, José; Higes, Mariano; De la Rúa, Pilar

2015-10-01

In the last decades, the rapid spread of diseases, such as varroosis and nosemosis, associated with massive honey bee colonies mortality around the world has significantly decreased the number and size of honey bee populations and possibly their genetic diversity. Here, we compare the genetic diversity of Iberian honey bee colonies in two samplings performed in 2006 and 2010 in relation to the presence of the pathogenic agents Nosema apis, Nosema ceranae, and Varroa destructor in order to determine whether parasite and pathogen spread in honey bee colonies reflects changes in genetic diversity. We found that the genetic diversity remained similar, while the incidence of N. ceranae increased and the incidence of N. apis and V. destructor decreased slightly. These results indicate that the genetic diversity was not affected by the presence of these pathogenic agents in the analyzed period. However, the two groups of colonies with and without Nosema/Varroa detected showed significant genetic differentiation (G test). A detailed analysis of the allelic segregation of microsatellite loci in Nosema/Varroa-negative colonies and parasitized ones revealed two outlier loci related to genes involved in immune response.

Human mobility and time spent at destination: impact on spatial epidemic spreading.

Science.gov (United States)

Poletto, Chiara; Tizzoni, Michele; Colizza, Vittoria

2013-12-07

Host mobility plays a fundamental role in the spatial spread of infectious diseases. Previous theoretical works based on the integration of network theory into the metapopulation framework have shown that the heterogeneities that characterize real mobility networks favor the propagation of epidemics. Nevertheless, the studies conducted so far assumed the mobility process to be either Markovian (in which the memory of the origin of each traveler is lost) or non-Markovian with a fixed traveling time scale (in which individuals travel to a destination and come back at a constant rate). Available statistics however show that the time spent by travelers at destination is characterized by wide fluctuations, ranging from a single day up to several months. Such varying length of stay crucially affects the chance and duration of mixing events among hosts and may therefore have a strong impact on the spread of an emerging disease. Here, we present an analytical and a computational study of epidemic processes on a complex subpopulation network where travelers have memory of their origin and spend a heterogeneously distributed time interval at their destination. Through analytical calculations and numerical simulations we show that the heterogeneity of the length of stay alters the expression of the threshold between local outbreak and global invasion, and, moreover, it changes the epidemic behavior of the system in case of a global outbreak. Additionally, our theoretical framework allows us to study the effect of changes in the traveling behavior in response to the infection, by considering a scenario in which sick individuals do not leave their home location. Finally, we compare the results of our non-Markovian framework with those obtained with a classic Markovian approach and find relevant differences between the two, in the estimate of the epidemic invasion potential, as well as of the timing and the pattern of its spatial spread. These results highlight the importance of

The birth and spread of IWRM - A case study of global policy diffusion and translation

Directory of Open Access Journals (Sweden)

Jeremy Allouche

2016-10-01

Full Text Available How did the idea of IWRM emerge at the global level? Why has IWRM become so popular and so resilient, at least in discourse and policy? What has caused IWRM policies to diffuse across time and space? The principal goal of this article is to identify a set of concepts and mechanisms to study the global diffusion and translation of IWRM through coercion, cooperation, or learning from the ground. The article will also highlight the extent to which this global diffusion was contested and translated into different meanings in terms of policy orientation. Overall, IWRM was a mindset of a particular period where the water policy paradigm was evolving in the same direction as sustainable development and other related paradigms in a post-Rio moment. There were no clear alternatives at the time but now IWRM is being questioned. This IWRM fatigue is leading to other framings and discourses around the water-food-energy nexus and the green economy.

Formation and spreading of Red Sea Outflow Water in the Red Sea

Science.gov (United States)

Zhai, Ping; Bower, Amy S.; Smethie, William M.; Pratt, Larry J.

2015-09-01

Hydrographic data, chlorofluorocarbon-12 (CFC-12) and sulfur hexafluoride (SF6) measurements collected in March 2010 and September-October 2011 in the Red Sea, as well as an idealized numerical experiment are used to study the formation and spreading of Red Sea Outflow Water (RSOW) in the Red Sea. Analysis of inert tracers, potential vorticity distributions, and model results confirm that RSOW is formed through mixed-layer deepening caused by sea surface buoyancy loss in winter in the northern Red Sea and reveal more details on RSOW spreading rates, pathways, and vertical structure. The southward spreading of RSOW after its formation is identified as a layer with minimum potential vorticity and maximum CFC-12 and SF6. Ventilation ages of seawater within the RSOW layer, calculated from the partial pressure of SF6 (pSF6), range from 2 years in the northern Red Sea to 15 years at 17°N. The distribution of the tracer ages is in agreement with the model circulation field which shows a rapid transport of RSOW from its formation region to the southern Red Sea where there are longer circulation pathways and hence longer residence time due to basin wide eddies. The mean residence time of RSOW within the Red Sea estimated from the pSF6 age is 4.7 years. This time scale is very close to the mean transit time (4.8 years) for particles from the RSOW formation region to reach the exit at the Strait of Bab el Mandeb in the numerical experiment.

A seawater desalination scheme for global hydrological models

Science.gov (United States)

Hanasaki, Naota; Yoshikawa, Sayaka; Kakinuma, Kaoru; Kanae, Shinjiro

2016-10-01

Seawater desalination is a practical technology for providing fresh water to coastal arid regions. Indeed, the use of desalination is rapidly increasing due to growing water demand in these areas and decreases in production costs due to technological advances. In this study, we developed a model to estimate the areas where seawater desalination is likely to be used as a major water source and the likely volume of production. The model was designed to be incorporated into global hydrological models (GHMs) that explicitly include human water usage. The model requires spatially detailed information on climate, income levels, and industrial and municipal water use, which represent standard input/output data in GHMs. The model was applied to a specific historical year (2005) and showed fairly good reproduction of the present geographical distribution and national production of desalinated water in the world. The model was applied globally to two periods in the future (2011-2040 and 2041-2070) under three distinct socioeconomic conditions, i.e., SSP (shared socioeconomic pathway) 1, SSP2, and SSP3. The results indicate that the usage of seawater desalination will have expanded considerably in geographical extent, and that production will have increased by 1.4-2.1-fold in 2011-2040 compared to the present (from 2.8 × 109 m3 yr-1 in 2005 to 4.0-6.0 × 109 m3 yr-1), and 6.7-17.3-fold in 2041-2070 (from 18.7 to 48.6 × 109 m3 yr-1). The estimated global costs for production for each period are USD 1.1-10.6 × 109 (0.002-0.019 % of the total global GDP), USD 1.6-22.8 × 109 (0.001-0.020 %), and USD 7.5-183.9 × 109 (0.002-0.100 %), respectively. The large spreads in these projections are primarily attributable to variations within the socioeconomic scenarios.

Slowing global warming

International Nuclear Information System (INIS)

Flavin, C.

1990-01-01

According to the authors, global warming promises to be one of the central environmental issues of the nineties. After a decade of scientific concern but popular neglect, the eighties ended with a growing political as well as scientific consensus that the world can no longer afford to procrastinate about this issue. This paper reports on coping with global warming which, according to the author, will force societies to move rapidly into uncharted terrain, reversing powerful trends that have dominated the industrial age. This challenge cannot be met without a strong commitment on the part of both individual consumers and governments. In terms of the earth's carbon balance, the unprecedented policy changes that have now become urgent include a new commitment to greater energy efficiency and renewable energy sources, a carbon tax on fossil fuels, a reversal of deforestation in tropical countries, and the rapid elimination of CFCs

Dynamical Model about Rumor Spreading with Medium

Directory of Open Access Journals (Sweden)

Xiaxia Zhao

2013-01-01

Full Text Available Rumor is a kind of social remark, that is untrue, and not be confirmed, and spreads on a large scale in a short time. Usually, it can induce a cloud of pressure, anxiety, and panic. Traditionally, it is propagated by word of mouth. Nowadays, with the emergence of the internet, rumors can be spread by instant messengers, emails, or publishing. With this new pattern of spreading, an ISRW dynamical model considering the medium as a subclass is established. Beside the dynamical analysis of the model, we mainly explore the mechanism of spreading of individuals-to-individuals and medium-to-individual. By numerical simulation, we find that if we want to control the rumor spreading, it will not only need to control the rate of change of the spreader subclass, but also need to control the change of the information about rumor in medium which has larger influence. Moreover, to control the effusion of rumor is more important than deleting existing information about rumor. On the one hand, government should enhance the management of internet. On the other hand, relevant legal institutions for punishing the rumor creator and spreader on internet who can be tracked should be established. Using this way, involved authorities can propose efficient measures to control the rumor spreading to keep the stabilization of society and development of economy.

Spreading in online social networks: the role of social reinforcement.

Science.gov (United States)

Zheng, Muhua; Lü, Linyuan; Zhao, Ming

2013-07-01

Some epidemic spreading models are usually applied to analyze the propagation of opinions or news. However, the dynamics of epidemic spreading and information or behavior spreading are essentially different in many aspects. Centola's experiments [Science 329, 1194 (2010)] on behavior spreading in online social networks showed that the spreading is faster and broader in regular networks than in random networks. This result contradicts with the former understanding that random networks are preferable for spreading than regular networks. To describe the spreading in online social networks, a unknown-known-approved-exhausted four-status model was proposed, which emphasizes the effect of social reinforcement and assumes that the redundant signals can improve the probability of approval (i.e., the spreading rate). Performing the model on regular and random networks, it is found that our model can well explain the results of Centola's experiments on behavior spreading and some former studies on information spreading in different parameter space. The effects of average degree and network size on behavior spreading process are further analyzed. The results again show the importance of social reinforcement and are accordant with Centola's anticipation that increasing the network size or decreasing the average degree will enlarge the difference of the density of final approved nodes between regular and random networks. Our work complements the former studies on spreading dynamics, especially the spreading in online social networks where the information usually requires individuals' confirmations before being transmitted to others.

Global achievements in soil and water conservation: The case of Conservation Agriculture

Directory of Open Access Journals (Sweden)

A. Kassam

2014-03-01

In 2011, CA had spread over 125 million hectares (9% of the global cropped land across all continents and most agro-ecologies, including small and large farms. In addition, there is a significant area of CA orchards in the Mediterranean countries. CA is now considered to be a practical agro-ecological approach to achieving sustainable agriculture intensification. It offers environmental, economic and social advantages that are not fully possible with tillage-based production systems, as well as improved productivity and resilience, and improved ecosystem services while minimizing the excessive use of agrochemicals, energy and heavy machinery. While there are challenges to the adoption of CA, there is also increasing interest from producers, the civil society, donors and private sector institutions to further promote and service the uptake and spread of CA globally.

Social Distancing Strategies against Disease Spreading

Science.gov (United States)

Valdez, L. D.; Buono, C.; Macri, P. A.; Braunstein, L. A.

2013-12-01

The recurrent infectious diseases and their increasing impact on the society has promoted the study of strategies to slow down the epidemic spreading. In this review we outline the applications of percolation theory to describe strategies against epidemic spreading on complex networks. We give a general outlook of the relation between link percolation and the susceptible-infected-recovered model, and introduce the node void percolation process to describe the dilution of the network composed by healthy individual, i.e., the network that sustain the functionality of a society. Then, we survey two strategies: the quenched disorder strategy where an heterogeneous distribution of contact intensities is induced in society, and the intermittent social distancing strategy where health individuals are persuaded to avoid contact with their neighbors for intermittent periods of time. Using percolation tools, we show that both strategies may halt the epidemic spreading. Finally, we discuss the role of the transmissibility, i.e., the effective probability to transmit a disease, on the performance of the strategies to slow down the epidemic spreading.

Disease spreading in real-life networks

Science.gov (United States)

Gallos, Lazaros; Argyrakis, Panos

2002-08-01

In recent years the scientific community has shown a vivid interest in the network structure and dynamics of real-life organized systems. Many such systems, covering an extremely wide range of applications, have been recently shown to exhibit scale-free character in their connectivity distribution, meaning that they obey a power law. Modeling of epidemics on lattices and small-world networks suffers from the presence of a critical infection threshold, above which the entire population is infected. For scale-free networks, the original assumption was that the formation of a giant cluster would lead to an epidemic spreading in the same way as in simpler networks. Here we show that modeling epidemics on a scale-free network can greatly improve the predictions on the rate and efficiency of spreading, as compared to lattice models and small-world networks. We also show that the dynamics of a disease are greatly influenced by the underlying population structure. The exact same model can describe a plethora of networks, such as social networks, virus spreading in the Web, rumor spreading, signal transmission etc.

Energy spread in ion beam analysis

International Nuclear Information System (INIS)

Szilagyi, E.

2000-01-01

In ion beam analysis (IBA) the depth profiles are extracted from the experimentally determined energy profiles. The spectra, however, are subject to finite energy resolution of both extrinsic and intrinsic origin. Calculation of those effects such as instrumental beam, geometry and detection-related energy and angular spreads as well as energy straggling, multiple scattering and Doppler effects in the sample itself is not trivial, especially since it involves treatment of non-independent random processes. A proper account for energy spread is vital in IBA not only for correct extraction of elemental and isotopic depth profiles from the measured spectra, but already prior to data acquisition, in optimising experimental conditions to reach the required depth resolution at a certain depth. After a short review of the literature on the different energy spread contributions experimental examples are given from resonance, RBS, elastic BS and ERDA practice in which an account for energy spread contributions is essential. Some further examples illustrate extraction of structural information (roughness, pore size, etc.) from elaborated depth resolution calculation for such layer structures

Energy spread in ion beam analysis

Energy Technology Data Exchange (ETDEWEB)

Szilagyi, E. E-mail: szilagyi@rmki.kkfki.hu

2000-03-01

In ion beam analysis (IBA) the depth profiles are extracted from the experimentally determined energy profiles. The spectra, however, are subject to finite energy resolution of both extrinsic and intrinsic origin. Calculation of those effects such as instrumental beam, geometry and detection-related energy and angular spreads as well as energy straggling, multiple scattering and Doppler effects in the sample itself is not trivial, especially since it involves treatment of non-independent random processes. A proper account for energy spread is vital in IBA not only for correct extraction of elemental and isotopic depth profiles from the measured spectra, but already prior to data acquisition, in optimising experimental conditions to reach the required depth resolution at a certain depth. After a short review of the literature on the different energy spread contributions experimental examples are given from resonance, RBS, elastic BS and ERDA practice in which an account for energy spread contributions is essential. Some further examples illustrate extraction of structural information (roughness, pore size, etc.) from elaborated depth resolution calculation for such layer structures.

Globalization of healthcare.

Science.gov (United States)

2012-05-01

Globalization-the increasing transnational circulation of money, goods, people, ideas, and information worldwide-is generally recognized as one of the most powerful forces shaping our current and future history. How is it affecting healthcare, and in that context, what is the purpose and significance of Global Advances in Health and Medicine (GAHM), publisher of this journal? Our goal is not homogenization but rather to provide an opportunity for integration, convergence, and collaboration across cultures. By respecting and conserving the richness and diversity of each new medicine, we embrace globalization. Globalization is of course not new; it began in the Renaissance and particularly with the 15th- and 16th-century voyages of exploration by Columbus, Magellan, and others. Since the beginning of time, there have been interactions and exchanges among different peoples and cultures. However, the current magnitude of globalization is unprecedented and yet still expanding rapidly.

A Global Computing Grid for LHC; Una red global de computacion para LHC

Energy Technology Data Exchange (ETDEWEB)

Hernandez Calama, J. M.; Colino Arriero, N.

2013-06-01

An innovative computing infrastructure has played an instrumental role in the recent discovery of the Higgs boson in the LHC and has enabled scientists all over the world to store, process and analyze enormous amounts of data in record time. The Grid computing technology has made it possible to integrate computing center resources spread around the planet, including the CIEMAT, into a distributed system where these resources can be shared and accessed via Internet on a transparent, uniform basis. A global supercomputer for the LHC experiments. (Author)

Linear theory of equatorial spread F

International Nuclear Information System (INIS)

Hudson, M.K.; Kennel, C.F.

1975-01-01

A fluid dispersion relation for the drift and interchange (Rayleigh-Taylor) modes in a collisional plasma forms the basis for a linear theory of equatorial spread F. The collisional drift mode growth rate will exceed the growth rate of the Rayleigh-Taylor mode at short perpendicular wavelengths and density gradient scale lengths, and the drift mode can grow on top side as well as on bottom side density gradients. However, below the F peak, where spread F predominates, it is concluded that both the drift and the Rayleigh-Taylor modes contribute to the total spread F spectrum, the Rayleigh-Taylor mode dominating at long and the drift mode at short perpendicular wavelengths above the ion Larmor radius

Millennium Ecosystem Assessment: MA Rapid Land Cover Change

Data.gov (United States)

National Aeronautics and Space Administration — The Millennium Ecosystem Assessment: MA Rapid Land Cover Change provides data and information on global and regional land cover change in raster format for...

Epidemic spreading in a hierarchical social network.

Science.gov (United States)

Grabowski, A; Kosiński, R A

2004-09-01

A model of epidemic spreading in a population with a hierarchical structure of interpersonal interactions is described and investigated numerically. The structure of interpersonal connections is based on a scale-free network. Spatial localization of individuals belonging to different social groups, and the mobility of a contemporary community, as well as the effectiveness of different interpersonal interactions, are taken into account. Typical relations characterizing the spreading process, like a range of epidemic and epidemic curves, are discussed. The influence of preventive vaccinations on the spreading process is investigated. The critical value of preventively vaccinated individuals that is sufficient for the suppression of an epidemic is calculated. Our results are compared with solutions of the master equation for the spreading process and good agreement of the character of this process is found.

Flame spread along thermally thick horizontal rods

Science.gov (United States)

Higuera, F. J.

2002-06-01

An analysis is carried out of the spread of a flame along a horizontal solid fuel rod, for which a weak aiding natural convection flow is established in the underside of the rod by the action of the axial gradient of the pressure variation that gravity generates in the warm gas surrounding the flame. The spread rate is determined in the limit of infinitely fast kinetics, taking into account the effect of radiative losses from the solid surface. The effect of a small inclination of the rod is discussed, pointing out a continuous transition between upward and downward flame spread. Flame spread along flat-bottomed solid cylinders, for which the gradient of the hydrostatically generated pressure drives the flow both along and across the direction of flame propagation, is also analysed.

Target-Specific Assay for Rapid and Quantitative Detection of Mycobacterium chimaera DNA.

Science.gov (United States)

Zozaya-Valdés, Enrique; Porter, Jessica L; Coventry, John; Fyfe, Janet A M; Carter, Glen P; Gonçalves da Silva, Anders; Schultz, Mark B; Seemann, Torsten; Johnson, Paul D R; Stewardson, Andrew J; Bastian, Ivan; Roberts, Sally A; Howden, Benjamin P; Williamson, Deborah A; Stinear, Timothy P

2017-06-01

Mycobacterium chimaera is an opportunistic environmental mycobacterium belonging to the Mycobacterium avium - M. intracellulare complex. Although most commonly associated with pulmonary disease, there has been growing awareness of invasive M. chimaera infections following cardiac surgery. Investigations suggest worldwide spread of a specific M. chimaera clone, associated with contaminated hospital heater-cooler units used during the surgery. Given the global dissemination of this clone, its potential to cause invasive disease, and the laboriousness of current culture-based diagnostic methods, there is a pressing need to develop rapid and accurate diagnostic assays specific for M. chimaera Here, we assessed 354 mycobacterial genome sequences and confirmed that M. chimaera is a phylogenetically coherent group. In silico comparisons indicated six DNA regions present only in M. chimaera We targeted one of these regions and developed a TaqMan quantitative PCR (qPCR) assay for M. chimaera with a detection limit of 100 CFU/ml in whole blood spiked with bacteria. In vitro screening against DNA extracted from 40 other mycobacterial species and 22 bacterial species from 21 diverse genera confirmed the in silico -predicted specificity for M. chimaera Screening 33 water samples from heater-cooler units with this assay highlighted the increased sensitivity of PCR compared to culture, with 15 of 23 culture-negative samples positive by M. chimaera qPCR. We have thus developed a robust molecular assay that can be readily and rapidly deployed to screen clinical and environmental specimens for M. chimaera . Copyright © 2017 American Society for Microbiology.

Rapidly Progressive Spontaneous Spinal Epidural Abscess

Directory of Open Access Journals (Sweden)

Abdurrahman Aycan

2016-01-01

Full Text Available Spinal epidural abscess (SEA is a rare disease which is often rapidly progressive. Delayed diagnosis of SEA may lead to serious complications and the clinical findings of SEA are generally nonspecific. Paraspinal abscess should be considered in the presence of local low back tenderness, redness, and pain with fever, particularly in children. In case of delayed diagnosis and treatment, SEA may spread to the epidural space and may cause neurological deficits. Magnetic resonance imaging (MRI remains the method of choice in the diagnosis of SEA. Treatment of SEA often consists of both medical and surgical therapy including drainage with percutaneous entry, corpectomy, and instrumentation.

The burden of non-communicable diseases in Nigeria; in the context of globalization.

Science.gov (United States)

Maiyaki, Musa Baba; Garbati, Musa Abubakar

2014-01-01

This paper highlights the tenets of globalization and how its elements have spread to sub-Saharan Africa, and Nigeria in particular. It assesses the growing burden of non-communicable diseases (NCDs) in Nigeria and its relationship with globalization. It further describes the conceptual framework on which to view the impact of globalization on NCDs in Nigeria. It assesses the Nigerian dimension of the relationship between the risk factors of NCDs and globalization. Appropriate recommendations on tackling the burden of NCDs in Nigeria based on cost-effective, culturally sensitive, and evidence-based interventions are highlighted.

Global warming and mycoflora in the Baltic Region

Directory of Open Access Journals (Sweden)

Hanns Kreisel

2013-12-01

Full Text Available The author discusses possible effects of global warming on distribution and ecology of larger fungi, and presents examples of suggested indicator species which apparently are spreading from south to north. Only Basidiomycetes are corncerned, while actually no case of non-lichenized Ascomycetes is known. A continued monitoring of the mentioned species is recommended.

A Tri-Country Marketing Project--Preparing Students for the Realities of a Global Marketplace

Science.gov (United States)

Freeman, Ina; Knight, Peter; Butt, Irfan

2011-01-01

With rapidly increasing globalization, business students are required to understand complex global markets and adapt to the rapid changes in the global landscape. This paper discusses a project where students from International Marketing courses in Pakistan, the United States, and France used an interactive platform as a base to jointly explore…

Assimilative and non-assimilative color spreading in the watercolor configuration

Directory of Open Access Journals (Sweden)

Eiji eKimura

2014-09-01

Full Text Available A colored line flanking a darker contour will appear to spread its color onto an area enclosed by the line (watercolor effect. The watercolor effect has been characterized as an assimilative effect, but non-assimilative color spreading has also been demonstrated in the same spatial configuration; e.g., when a black inner contour (IC is paired with a blue outer contour (OC, yellow color spreading can be observed. To elucidate visual mechanisms underlying these different color spreading effects, this study investigated the effects of luminance ratio between the double contours on the induced color by systematically manipulating the IC and OC luminances (Experiment 1 as well as the background luminance (Experiment 2. The results showed that the luminance conditions suitable for assimilative and non-assimilative color spreading were nearly opposite. When the Weber contrast of the IC to the background luminances (IC contrast was smaller than that of the OC (OC contrast, the induced color became similar to the IC color (assimilative spreading. In contrast, when the OC contrast was smaller than or equal to the IC contrast, the induced color became yellow (non-assimilative spreading. Extending these findings, Experiment 3 showed that bilateral color spreading, e.g., assimilative spreading on one side and non-assimilative spreading on the other side, can also be observed in the watercolor configuration. These results suggest that the assimilative and non-assimilative spreading were mediated by different visual mechanisms. The properties of the assimilative spreading are consistent with the model proposed to account for neon color spreading [Grossberg, S. & Mingolla, E. (1985 Percept. Psychophys., 38, 141-171] and extended for the watercolor effect [Pinna, B., & Grossberg, S. (2005 J. Opt. Soc. Am. A, 22, 2207-2221]. However, the present results suggest that additional mechanisms are needed to account for the non-assimilative color spreading.

Assimilative and non-assimilative color spreading in the watercolor configuration.

Science.gov (United States)

Kimura, Eiji; Kuroki, Mikako

2014-01-01

A colored line flanking a darker contour will appear to spread its color onto an area enclosed by the line (watercolor effect). The watercolor effect has been characterized as an assimilative effect, but non-assimilative color spreading has also been demonstrated in the same spatial configuration; e.g., when a black inner contour (IC) is paired with a blue outer contour (OC), yellow color spreading can be observed. To elucidate visual mechanisms underlying these different color spreading effects, this study investigated the effects of luminance ratio between the double contours on the induced color by systematically manipulating the IC and the OC luminance (Experiment 1) as well as the background luminance (Experiment 2). The results showed that the luminance conditions suitable for assimilative and non-assimilative color spreading were nearly opposite. When the Weber contrast of the IC to the background luminance (IC contrast) was smaller in size than that of the OC (OC contrast), the induced color became similar to the IC color (assimilative spreading). In contrast, when the OC contrast was smaller than or equal to the IC contrast, the induced color became yellow (non-assimilative spreading). Extending these findings, Experiment 3 showed that bilateral color spreading, i.e., assimilative spreading on one side and non-assimilative spreading on the other side, can also be observed in the watercolor configuration. These results suggest that the assimilative and the non-assimilative spreading were mediated by different visual mechanisms. The properties of the assimilative spreading are consistent with the model proposed to account for neon color spreading (Grossberg and Mingolla, 1985) and extended for the watercolor effect (Pinna and Grossberg, 2005). However, the present results suggest that additional mechanisms are needed to account for the non-assimilative color spreading.

Global warming causes sinkhole collapse – Case study in Florida, USA

OpenAIRE

Meng, Yan; Jia, Long

2018-01-01

The occurrence frequency and intensity of many natural geohazards, such as landslides, debris flows and earthquakes, have increased in response to global warming. However, the effects of such on development and spread of sinkholes has been largely overlooked. Most research shows that water pumping and related drawdown is the most important factor in sinkhole development, but in this paper evidence is presented which highlights the role played by global warming in causing sinkholes. The state ...

Global Transcriptome Analysis of Aedes aegypti Mosquitoes in Response to Zika Virus Infection.

Science.gov (United States)

Etebari, Kayvan; Hegde, Shivanand; Saldaña, Miguel A; Widen, Steven G; Wood, Thomas G; Asgari, Sassan; Hughes, Grant L

2017-01-01

Zika virus (ZIKV) of the Flaviviridae family is a recently emerged mosquito-borne virus that has been implicated in the surge of the number of microcephaly instances in South America. The recent rapid spread of the virus led to its declaration as a global health emergency by the World Health Organization. The virus is transmitted mainly by the mosquito Aedes aegypti , which is also the vector of dengue virus; however, little is known about the interactions of the virus with the mosquito vector. In this study, we investigated the transcriptome profiles of whole A. aegypti mosquitoes in response to ZIKV infection at 2, 7, and 14 days postinfection using transcriptome sequencing. Results showed changes in the abundance of a large number of transcripts at each time point following infection, with 18 transcripts commonly changed among the three time points. Gene ontology analysis revealed that most of the altered genes are involved in metabolic processes, cellular processes, and proteolysis. In addition, 486 long intergenic noncoding RNAs that were altered upon ZIKV infection were identified. Further, we found changes of a number of potential mRNA target genes correlating with those of altered host microRNAs. The outcomes provide a basic understanding of A. aegypti responses to ZIKV and help to determine host factors involved in replication or mosquito host antiviral response against the virus. IMPORTANCE Vector-borne viruses pose great risks to human health. Zika virus has recently emerged as a global threat, rapidly expanding its distribution. Understanding the interactions of the virus with mosquito vectors at the molecular level is vital for devising new approaches in inhibiting virus transmission. In this study, we embarked on analyzing the transcriptional response of Aedes aegypti mosquitoes to Zika virus infection. Results showed large changes in both coding and long noncoding RNAs. Analysis of these genes showed similarities with other flaviviruses, including

Managing the Global Supply Chain

DEFF Research Database (Denmark)

Skjøtt-Larsen, Tage; Schary, Philip B.; Mikkola, Juliana Hsuan

The world today faces global competition. The supply chain is vital part of the globalization process. Presenting a global view of the scope and complexity of supply chain management, this book reflects the rapid change that has taken place within the supply chain and its environment. This new...... edition has been fully updated with recent changes in concepts, technology and practice. Integration and collaboration are keywords in future competition. Firms must be agile and lean at the same time. The book gives an insightful overview of the conceptual foundations of the global supply chain, as...... well as current examples of best practice of managing supply chains in a global context....

Managing the Global Supply Chain

DEFF Research Database (Denmark)

Hsuan, Juliana; Skjøtt-Larsen, Tage; Kinra, Aseem

The world today faces global competition. The supply chain is vital part of the globalization process. Presenting a global view of the scope and complexity of supply chain management, this book reflects the rapid change that has taken place within the supply chain and its environment. This new...... well as current examples of best practice of managing supply chains in a global context....... edition has been fully updated with recent changes in concepts, technology and practice. Integration and collaboration are keywords in future competition. Firms must be agile and lean at the same time. The book gives an insightful overview of the conceptual foundations of the global supply chain, as...

Beyond EFL : Globalizing Education in Japan

OpenAIRE

Smith, Michael

2017-01-01

Current approaches to education are not providing students in Japan with the skills necessary to become global human resources. How can skills such as effective communication, problem solving, cultural awareness, and leadership, all necessary in a rapidly globalizing world, be developed and nurtured in Japan’s schools？ National public education must begin to play a more prominent role in the development of these important global skills. This paper will describe first year university students’...

Lexical Ambiguity: Making a Case against Spread

Science.gov (United States)

Kaplan, Jennifer J.; Rogness, Neal T.; Fisher, Diane G.

2012-01-01

We argue for decreasing the use of the word "spread" when describing the statistical idea of dispersion or variability in introductory statistics courses. In addition, we argue for increasing the use of the word "variability" as a replacement for "spread."

A review of recent results on spread F theory

International Nuclear Information System (INIS)

Ossakow, S.L.

1979-01-01

Ionospheric Spread F was discovered some four decades ago. Yet only in the past few years has significant progress been made in the theoretical explanation of such phenomena. In particular, considerable effort has been expended to explain equatorial Spread F and the attendant satellite signal propagation scintillation phenomena. The present review dwells mainly in this low latitude area. The various linear plasma instabilities thought to initiate equatorial Spread F are discussed. Recent theoretical and numerical simulation studies of the nonlinear evolution of the collisional Rayleigh-Taylor instability in equatorial Spread F are reviewed. Also, analytical studies of rising equatorial Spread F bubbles in the collisional and collisionless Rayleigh-Taylor regime are discussed, as well as the nohlinear saturation of instabilities in these two regimes. Current theories on very small scale (< approx 10 meters) size irregularities observed by radar backscatter during equatorial Spread F and their relation to the larger wavelength scintillation causing irregularities are discussed. Application of turbulence theory to equatorial Spread F phenomena is reviewed. Remaining problems to be dealt with at equatorial latitudes are summarized. (Auth.)

Spread of Zika virus in the Americas.

Science.gov (United States)

Zhang, Qian; Sun, Kaiyuan; Chinazzi, Matteo; Pastore Y Piontti, Ana; Dean, Natalie E; Rojas, Diana Patricia; Merler, Stefano; Mistry, Dina; Poletti, Piero; Rossi, Luca; Bray, Margaret; Halloran, M Elizabeth; Longini, Ira M; Vespignani, Alessandro

2017-05-30

We use a data-driven global stochastic epidemic model to analyze the spread of the Zika virus (ZIKV) in the Americas. The model has high spatial and temporal resolution and integrates real-world demographic, human mobility, socioeconomic, temperature, and vector density data. We estimate that the first introduction of ZIKV to Brazil likely occurred between August 2013 and April 2014 (90% credible interval). We provide simulated epidemic profiles of incident ZIKV infections for several countries in the Americas through February 2017. The ZIKV epidemic is characterized by slow growth and high spatial and seasonal heterogeneity, attributable to the dynamics of the mosquito vector and to the characteristics and mobility of the human populations. We project the expected timing and number of pregnancies infected with ZIKV during the first trimester and provide estimates of microcephaly cases assuming different levels of risk as reported in empirical retrospective studies. Our approach represents a modeling effort aimed at understanding the potential magnitude and timing of the ZIKV epidemic and it can be potentially used as a template for the analysis of future mosquito-borne epidemics.

Epidemic spread over networks with agent awareness and social distancing

KAUST Repository

Paarporn, Keith

2016-04-20

We study an SIS epidemic model over an arbitrary connected network topology when the agents receive personalized information about the current epidemic state. The agents utilize their available information to either reduce interactions with their neighbors (social distancing) when they believe the epidemic is currently prevalent or resume normal interactions when they believe there is low risk of becoming infected. The information is a weighted combination of three sources: 1) the average states of nodes in contact neighborhoods 2) the average states of nodes in an information network 3) a global broadcast of the average epidemic state of the network. A 2n-state Markov Chain is first considered to model the disease dynamics with awareness, from which a mean-field discrete-time n-state dynamical system is derived, where each state corresponds to an agent\\'s probability of being infected. The nonlinear model is a lower bound of its linearized version about the origin. Hence, global stability of the origin (the diseasefree equilibrium) in the linear model implies global stability in the nonlinear model. When the origin is not stable, we show the existence of a nontrivial fixed point in the awareness model, which obeys a strict partial order in relation to the nontrivial fixed point of the dynamics without distancing. In simulations, we define two performance metrics to understand the effectiveness agent awareness has in reducing the spread of an epidemic. © 2015 IEEE.

Crustal accretion along the global mid-ocean ridge system based on basaltic glass and olivine-hosted melt inclusion compositions

Science.gov (United States)

Wanless, V. D.; Behn, M. D.

2015-12-01

The depth and distribution of crystallization at mid-ocean ridges controls the overall architecture of the oceanic crust, influences hydrothermal circulation, and determines geothermal gradients in the crust and uppermost mantle. Despite this, there is no overall consensus on how crystallization is distributed within the crust/upper mantle or how this varies with spreading rate. Here, we examine crustal accretion at mid-ocean ridges by combining crystallization pressures calculated from major element barometers on mid-ocean ridge basalt (MORB) glasses with vapor-saturation pressures from melt inclusions to produce a detailed map of crystallization depths and distributions along the global ridge system. We calculate pressures of crystallization from >11,500 MORB glasses from the global ridge system using two established major element barometers (1,2). Additionally, we use vapor-saturation pressures from >400 olivine-hosted melt inclusions from five ridges with variable spreading rates to constrain pressures and distributions of crystallization along the global ridge system. We show that (i) crystallization depths from MORB glasses increase and become less focused with decreasing spreading rate, (ii) maximum glass pressures are greater than the maximum melt inclusion pressure, which indicates that the melt inclusions do not record the deepest crystallization at mid-ocean ridges, and (iii) crystallization occurs in the lower crust/upper mantle at all ridges, indicating accretion is distributed throughout the crust at all spreading rates, including those with a steady-state magma lens. Finally, we suggest that the remarkably similar maximum vapor-saturation pressures (~ 3000 bars) in melt inclusion from all spreading rates reflects the CO2 content of the depleted upper mantle feeding the global mid-ocean ridge system. (1) Michael, P. & W. Cornell (1998), Journal of Geophysical Research, 103(B8), 18325-18356; (2) Herzberg, C. (2004), Journal of Petrology, 45(12), 2389.

Relationship between attenuation coefficients and dose-spread kernels

International Nuclear Information System (INIS)

Boyer, A.L.

1988-01-01

Dose-spread kernels can be used to calculate the dose distribution in a photon beam by convolving the kernel with the primary fluence distribution. The theoretical relationships between various types and components of dose-spread kernels relative to photon attenuation coefficients are explored. These relations can be valuable as checks on the conservation of energy by dose-spread kernels calculated by analytic or Monte Carlo methods

Theoretical and experimental analysis of the impacts of removable storage media and antivirus software on viral spread

Science.gov (United States)

Gan, Chenquan; Yang, Xiaofan

2015-05-01

In this paper, a new computer virus propagation model, which incorporates the effects of removable storage media and antivirus software, is proposed and analyzed. The global stability of the unique equilibrium of the model is independent of system parameters. Numerical simulations not only verify this result, but also illustrate the influences of removable storage media and antivirus software on viral spread. On this basis, some applicable measures for suppressing virus prevalence are suggested.

Effects of rewiring strategies on information spreading in complex dynamic networks

Science.gov (United States)

Ally, Abdulla F.; Zhang, Ning

2018-04-01

Recent advances in networks and communication services have attracted much interest to understand information spreading in social networks. Consequently, numerous studies have been devoted to provide effective and accurate models for mimicking information spreading. However, knowledge on how to spread information faster and more widely remains a contentious issue. Yet, most existing works are based on static networks which limit the reality of dynamism of entities that participate in information spreading. Using the SIR epidemic model, this study explores and compares effects of two rewiring models (Fermi-Dirac and Linear functions) on information spreading in scale free and small world networks. Our results show that for all the rewiring strategies, the spreading influence replenishes with time but stabilizes in a steady state at later time-steps. This means that information spreading takes-off during the initial spreading steps, after which the spreading prevalence settles toward its equilibrium, with majority of the population having recovered and thus, no longer affecting the spreading. Meanwhile, rewiring strategy based on Fermi-Dirac distribution function in one way or another impedes the spreading process, however, the structure of the networks mimic the spreading, even with a low spreading rate. The worst case can be when the spreading rate is extremely small. The results emphasize that despite a big role of such networks in mimicking the spreading, the role of the parameters cannot be simply ignored. Apparently, the probability of giant degree neighbors being informed grows much faster with the rewiring strategy of linear function compared to that of Fermi-Dirac distribution function. Clearly, rewiring model based on linear function generates the fastest spreading across the networks. Therefore, if we are interested in speeding up the spreading process in stochastic modeling, linear function may play a pivotal role.

Individual stock-option prices and credit spreads

NARCIS (Netherlands)

Cremers, M.; Driessen, J.; Maenhout, P.; Weinbaum, D.

2008-01-01

This paper introduces measures of volatility and jump risk that are based on individual stock options to explain credit spreads on corporate bonds. Implied volatilities of individual options are shown to contain useful information for credit spreads and improve on historical volatilities when

"Global Cities" and "Globalization" in East Asia: Empirical Realities and Conceptual Questions

OpenAIRE

Smith, David; Timberlake, Michael

2002-01-01

For most of the Twentieth Century, East Asia was among the least urbanized parts of the world; now it is a region where cities are growing the most rapidly and becoming increasingly important centers regionally and in terms of the global urban hierarchy. Tokyo is unquestionably a key "global city," with Hong Kong probably following not far behind, and Seoul and Taipei also moving up in the world city ranks as crucial national articulates of highly successful newly industrialized countries (N...

The genomic signatures of Shigella evolution, adaptation and geographical spread.

Science.gov (United States)

The, Hao Chung; Thanh, Duy Pham; Holt, Kathryn E; Thomson, Nicholas R; Baker, Stephen

2016-04-01

Shigella spp. are some of the key pathogens responsible for the global burden of diarrhoeal disease. These facultative intracellular bacteria belong to the family Enterobacteriaceae, together with other intestinal pathogens, such as Escherichia coli and Salmonella spp. The genus Shigella comprises four different species, each consisting of several serogroups, all of which show phenotypic similarity, including invasive pathogenicity. DNA sequencing suggests that this similarity results from the convergent evolution of different Shigella spp. founders. Here, we review the evolutionary relationships between Shigella spp. and E . coli, and we highlight how the genomic plasticity of these bacteria and their acquisition of a distinctive virulence plasmid have enabled the development of such highly specialized pathogens. Furthermore, we discuss the insights that genotyping and whole-genome sequencing have provided into the phylogenetics and intercontinental spread of Shigella spp.

Influence of trust in the spreading of information

Science.gov (United States)

Wu, Hongrun; Arenas, Alex; Gómez, Sergio

2017-01-01

The understanding and prediction of information diffusion processes on networks is a major challenge in network theory with many implications in social sciences. Many theoretical advances occurred due to stochastic spreading models. Nevertheless, these stochastic models overlooked the influence of rational decisions on the outcome of the process. For instance, different levels of trust in acquaintances do play a role in information spreading, and actors may change their spreading decisions during the information diffusion process accordingly. Here, we study an information-spreading model in which the decision to transmit or not is based on trust. We explore the interplay between the propagation of information and the trust dynamics happening on a two-layer multiplex network. Actors' trustable or untrustable states are defined as accumulated cooperation or defection behaviors, respectively, in a Prisoner's Dilemma setup, and they are controlled by a memory span. The propagation of information is abstracted as a threshold model on the information-spreading layer, where the threshold depends on the trustability of agents. The analysis of the model is performed using a tree approximation and validated on homogeneous and heterogeneous networks. The results show that the memory of previous actions has a significant effect on the spreading of information. For example, the less memory that is considered, the higher is the diffusion. Information is highly promoted by the emergence of trustable acquaintances. These results provide insight into the effect of plausible biases on spreading dynamics in a multilevel networked system.

The recent activities of nuclear power globalization. Our provision against global warming by global deployment of our own technologies as integrated nuclear power plant supply company'

International Nuclear Information System (INIS)

Yamauchi, Kiyoshi; Suzuki, Shigemitsu

2008-01-01

Mitsubishi Heavy Industries, Ltd. (MHI) is striving to expand and spread nuclear power plants as an 'Integrated Nuclear Power Plant Supply Company' based on its engineering, manufacturing, and technological support capabilities. The company also has ample experience in the export of major components. MHI is accelerating its global deployment through the market introduction of large-sized strategic reactor US-APWR, the joint development of a mid-sized strategic reactor ATMEA1 with AREVA, and a small strategic reactor PBMR. The company also plans to internationally deploy technologies for the nuclear fuel cycle. We present here the leading-edge trends in the global deployment of these nuclear businesses, all of which help to solve the energy and environmental issues in the world. (author)

Attenuating the alcohol allure: attentional broadening reduces rapid motivational response to alcohol pictures.

Science.gov (United States)

Ryerson, Nicole C; Neal, Lauren B; Gable, Philip A

2017-04-01

Past research has found that exposure to alcohol cues causes a narrowing of attentional scope and enhances the neural responses associated with approach motivation. The current research sought to determine if a manipulated broadened (global) attentional scope would reduce approach-motivated neural reactivity to alcohol pictures. In the current study, participants (n = 82) were exposed to alcohol and neutral pictures following either a global or local attentional scope manipulation. Early motivated attentional processing was assessed using the N1 event-related potential (ERP), a neurophysiological marker of rapid motivated attention. A global attentional scope reduced N1 amplitudes to alcohol pictures as compared to a local attentional scope. Self-reported binge drinking related to larger N1 amplitudes to alcohol pictures, but not to neutral pictures. Individuals with greater binge drinking experience demonstrated increased rapid motivated attentional processing to alcohol pictures. These results suggest that enhancing a global (vs. local) attentional scope attenuates rapid motivated attentional processing of alcohol pictures in comparison to neutral pictures. Graphical abstract ᅟ.

Managing Geographically Dispersed Teams: From Temporary to Permanent Global Virtual Teams

DEFF Research Database (Denmark)

Svane Hansen, Tine; Hope, Alexander John; Moehler, Robert C.

2012-01-01

for organisations to move towards establishing permanent Global Virtual Teams in order to leverage knowledge sharing and cooperation across distance. To close this gap, this paper will set the scene for a research project investigating the changed preconditions for organisations. As daily face-to-face communication......The rise and spread of information communication technologies (ICT) has enabled increasing use of geographically dispersed work teams (Global Virtual Teams). Originally, Global Virtual Teams were mainly organised into temporary projects. Little research has focused on the emergent challenge...... generation of self-lead digital natives, who are already practising virtual relationships and a new approach to work, and currently joining the global workforce; and improved communication technologies. Keywords: Global Virtual teams, ICT, leadership, motivation, self-management, millenials....

Minimizing Energy Spread In The REX/HIE-ISOLDE Linac

CERN Document Server

Yucemoz, Mert

2017-01-01

This report tries to minimize the energy spread of the beam at the end of the REX-HIE-ISOLDE Linac using the last RF cavity as a buncher. Beams with very low energy spread are often required by the users of the facility In addition, one of the main reason to have minimum energy spread in longitudinal phase space is that higher beam energy spread translates in to a position spread after interacting with target. This causes an overlap in the position of different particles that makes it difficult to distinguish them. Hence, in order to find the operation settings for minimum energy spread at the end of the REX-HIE-ISOLDE linac and to inspect the ongoing physics, several functions on Matlab were created that runs beam dynamics program called “TRACKV39” that provides some graphs and values as a result for analysis.

The role of spatial heterogeneity in the evolution of local and global infections of viruses.

Directory of Open Access Journals (Sweden)

Koich Saeki

2018-01-01

Full Text Available Viruses have two modes spread in a host body, one is to release infectious particles from infected cells (global infection and the other is to infect directly from an infected cell to an adjacent cell (local infection. Since the mode of spread affects the evolution of life history traits, such as virulence, it is important to reveal what level of global and local infection is selected. Previous studies of the evolution of global and local infection have paid little attention to its dependency on the measures of spatial configuration. Here we show the evolutionarily stable proportion of global and local infection, and how it depends on the distribution of target cells. Using an epidemic model on a regular lattice, we consider the infection dynamics by pair approximation and check the evolutionarily stable strategy. We also conduct the Monte-Carlo simulation to observe evolutionary dynamics. We show that a higher local infection is selected as target cells become clustered. Surprisingly, the selected strategy depends not only on the degree of clustering but also the abundance of target cells per se.

Drop spreading and penetration into pre-wetted powders

KAUST Repository

Marston, Jeremy

2013-05-01

We present results from an experimental study of the impact of liquid drops onto powder beds which are pre-wetted with the impacting liquid. Using high-speed video imaging, we study both the dynamics of the initial spreading regime and drainage times once the drop has reached its maximum spread on the surface. During the initial spreading stage, we compare our experimental data to a previously developed model which incorporates imbibition into the spreading dynamics and observe reasonable agreement. We find that the maximum spread is a strong function of the moisture content in the powder bed and that the total time from impact to complete drainage is always shorter than that for dry powder. Our results indicate that there is an optimum moisture content (or saturation) which leads to the fastest penetration. We use simple scaling arguments which also identify an optimum moisture content for fastest penetration, which agrees very well with the experimental result. © 2013 Elsevier B.V.

The spreading time in SIS epidemics on networks

Science.gov (United States)

He, Zhidong; Van Mieghem, Piet

2018-03-01

In a Susceptible-Infected-Susceptible (SIS) process, we investigate the spreading time Tm, which is the time when the number of infected nodes in the metastable state is first reached, starting from the outbreak of the epidemics. We observe that the spreading time Tm resembles a lognormal-like distribution, though with different deep tails, both for the Markovian and the non-Markovian infection process, which implies that the spreading time can be very long with a relatively high probability. In addition, we show that a stronger virus, with a higher effective infection rate τ or an earlier timing of the infection attempts, does not always lead to a shorter average spreading time E [Tm ] . We numerically demonstrate that the average spreading time E [Tm ] in the complete graph and the star graph scales logarithmically as a function of the network size N for a fixed fraction of infected nodes in the metastable state.

The VULCANO VE-U7 Corium spreading benchmark

Energy Technology Data Exchange (ETDEWEB)

Journeau, Christophe; Haquet, Jean-Francois [CEA Cadarache, Severe Accident Mastering experimental Laboratory (DEN/DTN/STRI/LMA), 13108 St Paul lez Durance (France); Spindler, Bertrand [CEA Grenoble, Physicochemistry and Multiphasic Thermalhydraulics Laboratory (DEN/DTN/SE2T/LPTM), 17 rue des Martyrs, F-38054 Grenoble CEDEX 9 (France); Spengler, Claus [Gesellschaft fuer Reaktorsicherheit mbH, Department for Thermohydraulics/Process Engineering, Schwertnergasse 1, D-50667 Koeln (Germany); Foit, Jerzy [Forschungszentrum Karlsruhe GmbH, Institut fuer Kern nd Energietechnik (IKET), P.O. Box 3640, D-76021 Karlsruhe (Germany)

2006-07-01

In a hypothetical nuclear reactor severe accident, corium spreading is one possible mitigation measure that has been selected for the EPR design. A post-test benchmark exercise has been organized on the VULCANO VE-U7 corium spreading experiment. In this test, a prototypic corium mixture representative of what could be expected at the opening of EPR reactor-pit gate has been spread on siliceous concrete and on a reference channel in inert refractory ceramic. The spreading progression was not much affected by the presence of concrete and sparging gases. The procedure used to estimate the corium physical properties from its composition and temperature provided a satisfactory data set. The CORFLOW, LAVA and THEMA codes provide satisfactory calculations of the spreading front evolution and of its final length. LAVA and THEMA estimations of the substrate temperatures, which are the initial conditions for longer term Molten Core Concrete Interaction or Corium Ceramic Interaction computations, are also close to the measured data, within the experimental uncertainties. (authors)

The VULCANO VE-U7 Corium spreading benchmark

International Nuclear Information System (INIS)

Journeau, Christophe; Haquet, Jean-Francois; Spindler, Bertrand; Spengler, Claus; Foit, Jerzy

2006-01-01

In a hypothetical nuclear reactor severe accident, corium spreading is one possible mitigation measure that has been selected for the EPR design. A post-test benchmark exercise has been organized on the VULCANO VE-U7 corium spreading experiment. In this test, a prototypic corium mixture representative of what could be expected at the opening of EPR reactor-pit gate has been spread on siliceous concrete and on a reference channel in inert refractory ceramic. The spreading progression was not much affected by the presence of concrete and sparging gases. The procedure used to estimate the corium physical properties from its composition and temperature provided a satisfactory data set. The CORFLOW, LAVA and THEMA codes provide satisfactory calculations of the spreading front evolution and of its final length. LAVA and THEMA estimations of the substrate temperatures, which are the initial conditions for longer term Molten Core Concrete Interaction or Corium Ceramic Interaction computations, are also close to the measured data, within the experimental uncertainties. (authors)

Modelling unidirectional liquid spreading on slanted microposts

DEFF Research Database (Denmark)

Cavalli, Andrea; Blow, Matthew L.; Yeomans, Julia M.

2013-01-01

A lattice Boltzmann algorithm is used to simulate the slow spreading of drops on a surface patterned with slanted micro-posts. Gibb's pinning of the interface on the sides or top of the posts leads to unidirectional spreading over a wide range of contact angles and inclination angles of the posts....... Regimes for spreading in no, one or two directions are identified, and shown to agree well with a two-dimensional theory proposed in Chu, Xiao and Wang. A more detailed numerical analysis of the contact line shapes allows us to understand deviations from the two dimensional model, and to identify...

Slip of Spreading Viscoplastic Droplets.

Science.gov (United States)

Jalaal, Maziyar; Balmforth, Neil J; Stoeber, Boris

2015-11-10

The spreading of axisymmetric viscoplastic droplets extruded slowly on glass surfaces is studied experimentally using shadowgraphy and swept-field confocal microscopy. The microscopy furnishes vertical profiles of the radial velocity using particle image velocimetry (PIV) with neutrally buoyant tracers seeded in the fluid. Experiments were conducted for two complex fluids: aqueous solutions of Carbopol and xanthan gum. On untreated glass surfaces, PIV demonstrates that both fluids experience a significant amount of effective slip. The experiments were repeated on glass that had been treated to feature positive surface charges, thereby promoting adhesion between the negatively charged polymeric constituents of the fluids and the glass surface. The Carbopol and xanthan gum droplets spread more slowly on the treated surface and to a smaller radial distance. PIV demonstrated that this reduced spreading was associated with a substantial reduction in slip. For Carbopol, the effective slip could be eliminated entirely to within the precision of the PIV measurements; the reduction in slip was less effective for xanthan gum, with a weak slip velocity remaining noticeable.

The Emerging Amphibian Fungal Disease, Chytridiomycosis: A Key Example of the Global Phenomenon of Wildlife Emerging Infectious Diseases.

Science.gov (United States)

Kolby, Jonathan E; Daszak, Peter

2016-06-01

The spread of amphibian chytrid fungus, Batrachochytrium dendrobatidis, is associated with the emerging infectious wildlife disease chytridiomycosis. This fungus poses an overwhelming threat to global amphibian biodiversity and is contributing toward population declines and extinctions worldwide. Extremely low host-species specificity potentially threatens thousands of the 7,000+ amphibian species with infection, and hosts in additional classes of organisms have now also been identified, including crayfish and nematode worms.Soon after the discovery of B. dendrobatidis in 1999, it became apparent that this pathogen was already pandemic; dozens of countries and hundreds of amphibian species had already been exposed. The timeline of B. dendrobatidis's global emergence still remains a mystery, as does its point of origin. The reason why B. dendrobatidis seems to have only recently increased in virulence to catalyze this global disease event remains unknown, and despite 15 years of investigation, this wildlife pandemic continues primarily uncontrolled. Some disease treatments are effective on animals held in captivity, but there is currently no proven method to eradicate B. dendrobatidis from an affected habitat, nor have we been able to protect new regions from exposure despite knowledge of an approaching "wave" of B. dendrobatidis and ensuing disease.International spread of B. dendrobatidis is largely facilitated by the commercial trade in live amphibians. Chytridiomycosis was recently listed as a globally notifiable disease by the World Organization for Animal Health, but few countries, if any, have formally adopted recommended measures to control its spread. Wildlife diseases continue to emerge as a consequence of globalization, and greater effort is urgently needed to protect global health.

Global nuclear cleanout initiative 2004

International Nuclear Information System (INIS)

Edlow, J.; Gruber, G.

2004-01-01

Full text: During more than 50 years of Atoms for Peace programmes nuclear materials were spread out worldwide. Stranded nuclear materials from nuclear research are left over without any safe back-end solution. 'Dirty Bombs' or so-called 'Radioactive Dispersal Devices (RDD)' are no longer science fiction since the world experienced the 9/11 attack. Governmental, NGO's and private industry organizations having discussed Global Nuclear Cleanout since then and start to take actions. The US Department of Energy (DOE) has announced to establish a dedicated organization in cooperation with IAEA and start the 'Global Threat Reduction Initiative (GTRI)'. The US government will allocate to that program USD 450 M over the next 10 years. Besides the historical development the paper will focus on the progress of the different initiatives and perspectives to threat reduction. (author)

The influence of low air pressure on horizontal flame spread over flexible polyurethane foam and correlative smoke productions

International Nuclear Information System (INIS)

Tu, Ran; Zeng, Yi; Fang, Jun; Zhang, Yongming

2016-01-01

Highlights: • Quasi two-dimensional flame spreading behavior of flexible polyurethane (FPU) foam was investigated. • Theoretical correlation of pressure effects on global burning rate was proposed. • The influence of pressure on plume and ceiling jet temperatures was studied theoretically. • Pressure effects on soot formation and CO concentration were analyzed. - Abstract: Pressure effects on quasi two-dimensional flexible polyurethane (FPU) foam flame spreading behavior, typical product concentrations, and smoke detector responses were investigated by comparative experiments under different ambient pressures of 99.8 kPa (in Hefei) and 66.5 kPa (in Lhasa), respectively. First, significant decreases of flame spreading velocity and burning rate were observed under low pressure condition. Averaged global burning rate was found to be dependent on pressure, with an exponential factor of 4/3 theoretically based on pressure modeling. Second, the maximum temperature at a given position in axial thermal plume showed insensitivity to pressure, yet the maximum temperature in ceiling jet was obviously higher. Third, the low pressure was shown to have no effect on soot particles size distribution by scan electron microscopy (SEM) imaging. However, the soot number concentration decreased with reduced pressure attributed to the much slower soot formation rate under low pressure. This result would further have an interesting influence on the response signals of photoelectric detector and ionization detector. Finally, the pressure effects on variation of CO and O_2 volume concentration were discussed. Considering the relatively small heat release rate for FPU foam selected, the CO concentration in the far-field ceiling jet low under low pressure was found to be lower for the enhanced diffusive effect.

Mapping the Spread of Mounted Warfare

Directory of Open Access Journals (Sweden)

Peter Turchin

2016-12-01

Full Text Available Military technology is one of the most important factors affecting the evolution of complex societies. In particular, mounted warfare, the use of horse-riders in military operations, revolutionized war as it spread to different parts of Eurasia and Africa during the Ancient and Medieval eras, and to the Americas during the Early Modern period. Here we use a variety of sources to map this spread.

The joint estimation of term structures and credit spreads

NARCIS (Netherlands)

Houweling, P.; Hoek, J.; Kleibergen, F.R.

1999-01-01

We present a new framework for the joint estimation of the default-free government term structure and corporate credit spread curves. By using a data set of liquid, German mark denominated bonds, we show that this yields more realistic spreads than traditionally obtained spread curves that result

Exploring the agency of global environmental consultancy firms in earth system governance

NARCIS (Netherlands)

Bouteligier, S.

2011-01-01

In contemporary global environmental governance, private companies are both recipients of as well as contributors to the development and spread of environmental practices, norms, standards, and legislation. One sector that seems to be of particular significance is the environmental consultancy

Economic Globalization and a Nuclear Renaissance

Energy Technology Data Exchange (ETDEWEB)

Wood, Thomas W; Johnson, Wayne L; Parker, Brian M

2001-10-22

The phenomenon of globalization has become increasingly well recognized, documented, and analyzed in the last several years. Globalization, the integration of markets and intra-firm competition on a worldwide basis, involves complex behavioral and mindset changes within a firm that facilitate global competition. The changes revolve around efficient information flow and rapid deployment of technology. The objective of this report is to examine the probable characteristics of a global nuclear renaissance and its broad implications for industry structure and export control relative to nuclear technology. The question of how a modern renaissance would affect the trend toward globalization of the nuclear industry is addressed.

Economic Globalization and a Nuclear Renaissance

International Nuclear Information System (INIS)

Wood, Thomas W.; Johnson, Wayne L.; Parker, Brian M.

2001-01-01

The phenomenon of globalization has become increasingly well recognized, documented, and analyzed in the last several years. Globalization, the integration of markets and intra-firm competition on a worldwide basis, involves complex behavioral and mindset changes within a firm that facilitate global competition. The changes revolve around efficient information flow and rapid deployment of technology. The objective of this report is to examine the probable characteristics of a global nuclear renaissance and its broad implications for industry structure and export control relative to nuclear technology. The question of how a modern renaissance would affect the trend toward globalization of the nuclear industry is addressed

Classical spreading-fractionation, hyperfractionation, hypofractionation: let us attempt to be practical

International Nuclear Information System (INIS)

Cosset, J.M.; Baillet, F.

1986-01-01

The so-called classical spreading-fractionation (5 sessions of 2 Gy per week) was elaborated originally by the first generation of radiotherapists at the beginning of the century. It is a remarkable fact that even today the most up-to-date radiobiologists are in agreement that this regimen usually represents the best possible compromise between antitumoral efficacy and toxicity to healthy tissue. Hyperfractionation is still in the clinical trial stage with the aim of defining its precise place in clinical practice. At the present there is only one formal indication apart from within this framework: tumors with very rapid times for doubling in size, since hyperfractionation alone can deliver a high dose in a short period of time (accelerated treatment). Hypofractionation can be highly recommended for palliative treatment, because of its simplicity and efficacy. In contrast, when large size tumours (particularly digestive) are treated in patients with an elevated expected rate of recovery, this technique may provoke late complications and should, a priori, be avoided. For small size tumours however (ENT, breast) it would appear possible to elaborate hypofractio - nation protocols allowing local control to a similar degree to that obtained with the classical regimen, without significantly increasing late complications, on the condition that radiation parameters (dose, spread, fractionation) be cho - sen with the greatest care [fr

Dynamic properties of epidemic spreading on finite size complex networks

Science.gov (United States)

Li, Ying; Liu, Yang; Shan, Xiu-Ming; Ren, Yong; Jiao, Jian; Qiu, Ben

2005-11-01

The Internet presents a complex topological structure, on which computer viruses can easily spread. By using theoretical analysis and computer simulation methods, the dynamic process of disease spreading on finite size networks with complex topological structure is investigated. On the finite size networks, the spreading process of SIS (susceptible-infected-susceptible) model is a finite Markov chain with an absorbing state. Two parameters, the survival probability and the conditional infecting probability, are introduced to describe the dynamic properties of disease spreading on finite size networks. Our results can help understanding computer virus epidemics and other spreading phenomena on communication and social networks. Also, knowledge about the dynamic character of virus spreading is helpful for adopting immunity policy.

Modelling the introduction and spread of non-native species: international trade and climate change drive ragweed invasion.

Science.gov (United States)

Chapman, Daniel S; Makra, László; Albertini, Roberto; Bonini, Maira; Páldy, Anna; Rodinkova, Victoria; Šikoparija, Branko; Weryszko-Chmielewska, Elżbieta; Bullock, James M

2016-09-01

Biological invasions are a major driver of global change, for which models can attribute causes, assess impacts and guide management. However, invasion models typically focus on spread from known introduction points or non-native distributions and ignore the transport processes by which species arrive. Here, we developed a simulation model to understand and describe plant invasion at a continental scale, integrating repeated transport through trade pathways, unintentional release events and the population dynamics and local anthropogenic dispersal that drive subsequent spread. We used the model to simulate the invasion of Europe by common ragweed (Ambrosia artemisiifolia), a globally invasive plant that causes serious harm as an aeroallergen and crop weed. Simulations starting in 1950 accurately reproduced ragweed's current distribution, including the presence of records in climatically unsuitable areas as a result of repeated introduction. Furthermore, the model outputs were strongly correlated with spatial and temporal patterns of ragweed pollen concentrations, which are fully independent of the calibration data. The model suggests that recent trends for warmer summers and increased volumes of international trade have accelerated the ragweed invasion. For the latter, long distance dispersal because of trade within the invaded continent is highlighted as a key invasion process, in addition to import from the native range. Biosecurity simulations, whereby transport through trade pathways is halted, showed that effective control is only achieved by early action targeting all relevant pathways. We conclude that invasion models would benefit from integrating introduction processes (transport and release) with spread dynamics, to better represent propagule pressure from native sources as well as mechanisms for long-distance dispersal within invaded continents. Ultimately, such integration may facilitate better prediction of spatial and temporal variation in invasion

Three Eras in Global Tobacco Control: How Global Governance Processes Influenced Online Tobacco Control Networking.

Science.gov (United States)

Wipfli, Heather; Chu, Kar-Hai; Lancaster, Molly; Valente, Thomas

2016-01-01

Online networks can serve as a platform to diffuse policy innovations and enhance global health governance. This study focuses on how shifts in global health governance may influence related online networks. We compare social network metrics (average degree centrality [AVGD], density [D] and clustering coefficient [CC]) of Globalink, an online network of tobacco control advocates, across three eras in global tobacco control governance; pre-Framework Convention on Tobacco Control (FCTC) policy transfer (1992-1998), global regime formation through the FCTC negotiations (1999-2005), and philanthropic funding through the Bloomberg Initiative (2006-2012). Prior to 1999, Globalink was driven by a handful of high-income countries (AVGD=1.908 D=0.030, CC=0.215). The FCTC negotiations (1999-2005) corresponded with a rapid uptick in the number of countries represented within Globalink and new members were most often brought into the network through relationships with regional neighbors (AVGD=2.824, D=0.021, CC=0.253). Between 2006 and 2012, the centrality of the US in the network increases significantly (AVGD=3.414, D=0.023, CC=0.310). The findings suggest that global institutionalization through WHO, as with the FCTC, can lead to the rapid growth of decentralized online networks. Alternatively, private initiatives, such as the Bloomberg Initiative, can lead to clustering in which a single source of information gains increasing influence over an online network.

The Theoretical Aspects of the Development of Global Production Networks and Value Chains: the New Paradigm of Globalization

Directory of Open Access Journals (Sweden)

Cherkas Nataliia I.

2018-03-01

Full Text Available The article is aimed at systematizing the contemporary perceptions of the changing paradigms of globalization and international competition as a result of the spread of global networks and value chains. The development of global value chains (GVC occurred as a result of two distributions of globalization: (1 global competition is manifested at the level of sectors and companies (from the mid-nineteenth century (2 the concept of trade in tasks arises (at the end of XX century. The publication analyzes the impact of globalization on the international competitiveness of both the EU and the developing countries in the trade of final products and tasks. The model takes into consideration differences in wages, technology gap and trade costs, and provides for assessing the comparative advantages of individual sectors or segments of GVC. Features of the conception of global production networks have been identified as: «imports for production» and «imports for exports», which define international competitiveness on the basis of creation of the intrinsic value added. It is determined that the competitiveness of the economy is determined by the country’s positions in the GVC, and the increase in productivity of companies depends on their involvement in the segments (tasks with a high level of value added.

Epidemic spread in bipartite network by considering risk awareness

Science.gov (United States)

Han, She; Sun, Mei; Ampimah, Benjamin Chris; Han, Dun

2018-02-01

Human awareness plays an important role in the spread of infectious diseases and the control of propagation patterns. Exploring the interplay between human awareness and epidemic spreading is a topic that has been receiving increasing attention. Considering the fact, some well-known diseases only spread between different species we propose a theoretical analysis of the Susceptible-Infected-Susceptible (SIS) epidemic spread from the perspective of bipartite network and risk aversion. Using mean field theory, the epidemic threshold is calculated theoretically. Simulation results are consistent with the proposed analytic model. The results show that, the final infection density is negative linear with the value of individuals' risk awareness. Therefore, the epidemic spread could be effectively suppressed by improving individuals' risk awareness.

China's Overseas M&A in Global Economic Crisis

Institute of Scientific and Technical Information of China (English)

Han Kang

2009-01-01

@@ verseas Merger and Acquisition (M&A) is not only the major means for the enterprises to expand rapid-ly and operate globally, but also the significant stra-tegic tools for acquiring advanced technotegy from other companies and seizing the market and other resources.

On entanglement spreading from holography

Energy Technology Data Exchange (ETDEWEB)

Mezei, Márk [Princeton Center for Theoretical Science, Princeton University,Princeton, NJ 08544 (United States)

2017-05-11

A global quench is an interesting setting where we can study thermalization of subsystems in a pure state. We investigate entanglement entropy (EE) growth in global quenches in holographic field theories and relate some of its aspects to quantities characterizing chaos. More specifically we obtain four key results: We prove holographic bounds on the entanglement velocity v{sub E} and the butterfly effect speed v{sub B} that arises in the study of chaos. We obtain the EE as a function of time for large spherical entangling surfaces analytically. We show that the EE is insensitive to the details of the initial state or quench protocol. In a thermofield double state we determine analytically the two-sided mutual information between two large concentric spheres separated in time. We derive a bound on the rate of growth of EE for arbitrary shapes, and develop an expansion for EE at early times. In a companion paper https://arxiv.org/abs/1608.05101, these results are put in the broader context of EE growth in chaotic systems: we relate EE growth to the chaotic spreading of operators, derive bounds on EE at a given time, and compare the holographic results to spin chain numerics and toy models. In this paper, we perform holographic calculations that provide the basis of arguments presented in that paper. We prove holographic bounds on the entanglement velocity v{sub E} and the butterfly effect speed v{sub B} that arises in the study of chaos. We obtain the EE as a function of time for large spherical entangling surfaces analytically. We show that the EE is insensitive to the details of the initial state or quench protocol. In a thermofield double state we determine analytically the two-sided mutual information between two large concentric spheres separated in time. We derive a bound on the rate of growth of EE for arbitrary shapes, and develop an expansion for EE at early times.

How We Got to the Northern Hemisphere Ice Ages: Late Miocene Global Cooling and Plate Tectonic CO2 Forcing

Science.gov (United States)

Herbert, T.; Dalton, C. A.; Carchedi, C.

2017-12-01

The evolution of Earth's climate between "refrigeration" of East Antarctica and the onset of cyclic Northern Hemisphere glaciation spanned more than 11 Myr. In the latest Miocene (Messinian) time, approximately half way on this journey, changes on land, ranging from the expansion of arid zones to major floral and faunal ecosystem shifts, accelerated. Recent compilations of marine surface temperatures reveal that global cooling from the Miocene Optimum (14-16Ma) also accelerated in late Miocene (7-5.35 Ma) time to reach temperatures not much above Holocene conditions. Both hemispheres cooled in parallel, with the changes amplified at higher latitudes in comparison to the tropics. Despite the strong circumstantial case for CO2 decline as the dominant cause of late Miocene climatic and evolutionary change, proxy indicators of CO2concentrations paint an equivocal picture of greenhouse forcing. Here we provide evidence that global sea floor spreading (SFS) rates decelerated at exactly the times of major climatic cooling, linking a decline in tectonic degassing (at both subduction zones and mid-ocean ridges) to fundamental shifts in the global carbon cycle. Our work utilizes newly available global compilations of seafloor fabric and marine magnetic anomalies provided by the NSF-funded Global Seafloor Fabric and Magnetic Lineation Data Base Project. Previous global compilations of SFS typically binned estimates over 10 Myr increments, losing critical resolution on the timescale of late Neogene climate changes. We further improve the signal:noise of SFS estimates by incorporating recent advances in the astronomical calibration of the Miocene geomagnetic polarity timescale. We use two approaches to compile spreading rate estimates over the past 20 Myr at each spreading system: optimized finite rotation calculations, and averages of sea floor-spreading derived from the distances of magnetic lineations along flow lines on the sea floor. Weighted by ridge length, we find an 25

Note on numerical study of the beam energy spread in NDCX-I

International Nuclear Information System (INIS)

Vay, J.-L.; Seidl, P.A.; Friedman, A.

2011-01-01

). The energy spread starts at 0.1 eV at the source and rapidly rises to a few eV, then fluctuates between a fraction of an eV and tens of eV, ending near the exit in a range of a few eV at the outer edge of the beam to a few tens of eV near the axis. The higher value on-axis is associated with greater numerical noise there, due to the axisymmetric geometry of the calculation, resulting in poorer simulation-particle statistics at small radius. A scatter plot of the macroparticles kinetic energy (KE) versus radius (R) and longitudinal position (0.28 m < z < 3 m) colored by local energy spread is shown in Fig. 2 (b). As expected, there is a correlation of the kinetic energy with radius that is clearly visible at z = 2.8 m and vanishes at the metal plate at z = 3 m. More snapshots from simulations varying the time step, grid resolution and number of macroparticles are given in Appendix II. The macro-particles were collected at the exit plate and their kinetic energy history is plotted in Fig. 3 (left) and contrasted to an experimental measurement using a streak camera shown in Fig. 3. For some types of measurements, averaging over several pulses to improve signal-to-noise will contribute an additional spread that may not be present on any single beam pulse. The upper bound for the energy spread is in the range of a few 100 eV for the experiment while in the range of a few eV for the reported Warp simulations. The Marx voltage exhibits variations in the range of up to several hundreds of volts, playing a significant role in the experimentally measured energy spread, which may account for the difference between the experimental and the simulated bounds.

Seasonal variations of equatorial spread-F

Directory of Open Access Journals (Sweden)

B. V. Krishna Murthy

Full Text Available The occurrence of spread-F at Trivandrum (8.5°N, 77°E, dip 0.5°N has been investigated on a seasonal basis in sunspot maximum and minimum years in terms of the growth rate of irregularities by the generalized collisional Rayleigh-Taylor (GRT instability mechanism which includes the gravitational and cross-field instability terms. The occurrence statistics of spread-F at Trivandrum have been obtained using quarter hourly ionograms. The nocturnal variations of the growth rate of irregularities by the GRT mechanism have been estimated for different seasons in sunspot maximum and minimum years at Trivandrum using h'F values and vertical drift velocities obtained from ionograms. It is found that the seasonal variation of spread-F occurrence at Trivandrum can, in general, be accounted for on the basis of the GRT mechanism.

Seasonal variations of equatorial spread-F

Directory of Open Access Journals (Sweden)

K. S. V. Subbarao

1994-01-01

Full Text Available The occurrence of spread-F at Trivandrum (8.5°N, 77°E, dip 0.5°N has been investigated on a seasonal basis in sunspot maximum and minimum years in terms of the growth rate of irregularities by the generalized collisional Rayleigh-Taylor (GRT instability mechanism which includes the gravitational and cross-field instability terms. The occurrence statistics of spread-F at Trivandrum have been obtained using quarter hourly ionograms. The nocturnal variations of the growth rate of irregularities by the GRT mechanism have been estimated for different seasons in sunspot maximum and minimum years at Trivandrum using h'F values and vertical drift velocities obtained from ionograms. It is found that the seasonal variation of spread-F occurrence at Trivandrum can, in general, be accounted for on the basis of the GRT mechanism.

Of Asian forests and European fields: Eastern U.S. plant invasions in a global floristic context.

Directory of Open Access Journals (Sweden)

Jason D Fridley

Full Text Available BACKGROUND: Biogeographic patterns of species invasions hold important clues to solving the recalcitrant 'who', 'where', and 'why' questions of invasion biology, but the few existing studies make no attempt to distinguish alien floras (all non-native occurrences from invasive floras (rapidly spreading species of significant management concern, nor have invasion biologists asked whether particular habitats are consistently invaded by species from particular regions. METHODOLOGY/PRINCIPAL FINDINGS: Here I describe the native floristic provenances of the 2629 alien plant taxa of the Eastern Deciduous Forest of the Eastern U.S. (EUS, and contrast these to the subset of 449 taxa that EUS management agencies have labeled 'invasive'. Although EUS alien plants come from all global floristic regions, nearly half (45% have native ranges that include central and northern Europe or the Mediterranean (39%. In contrast, EUS invasive species are most likely to come from East Asia (29%, a pattern that is magnified when the invasive pool is restricted to species that are native to a single floristic region (25% from East Asia, compared to only 11% from northern/central Europe and 2% from the Mediterranean. Moreover, East Asian invaders are mostly woody (56%, compared to just 23% of the total alien flora and are significantly more likely to invade intact forests and riparian areas than European species, which dominate managed or disturbed ecosystems. CONCLUSIONS/SIGNIFICANCE: These patterns suggest that the often-invoked 'imperialist dogma' view of global invasions equating invasion events with the spread of European colonialism is at best a restricted framework for invasion in disturbed ecosystems. This view must be superseded by a biogeographic invasion theory that is explicitly habitat-specific and can explain why particular world biotas tend to dominate particular environments.

Globalization of Healthcare

Science.gov (United States)

2012-01-01

Globalization—the increasing transnational circulation of money, goods, people, ideas, and information worldwide—is generally recognized as one of the most powerful forces shaping our current and future history. How is it affecting healthcare, and in that context, what is the purpose and significance of Global Advances in Health and Medicine (GAHM), publisher of this journal? Our goal is not homogenization but rather to provide an opportunity for integration, convergence, and collaboration across cultures. By respecting and conserving the richness and diversity of each new medicine, we embrace globalization. Globalization is of course not new; it began in the Renaissance and particularly with the 15th- and 16th-century voyages of exploration by Columbus, Magellan, and others. Since the beginning of time, there have been interactions and exchanges among different peoples and cultures. However, the current magnitude of globalization is unprecedented and yet still expanding rapidly. PMID:24278809

Global initiatives to prevent nuclear terrorism

International Nuclear Information System (INIS)

2010-01-01

The fight against nuclear and radiological terrorism - someone to blow up a nuclear weapon or spread radioactive material as a 'dirty bomb' that act of terrorism - is one of the most serious threats to international security. The Global Initiative to prevent nuclear terrorism is a Norwegian-sponsored initiative that is aimed directly at combating terrorism by non-state actors. NRPA follow up Norwegian measures, including in Kazakhstan, and verifies that they are implemented and functioning as intended. (AG)

The global establishment of a highly-fluoroquinolone resistant Salmonella enterica serotype Kentucky ST198 strain

Directory of Open Access Journals (Sweden)

Simon eLe Hello

2013-12-01

Full Text Available While the spread of Salmonella enterica serotype Kentucky resistant to ciprofloxacin across Africa and the Middle-East has been described recently, the presence of this strain in humans, food, various animal species (livestock, pets, and wildlife and in environment is suspected in other countries of different continents. Here, we report results of an in-depth molecular epidemiological study on a global human and non-human collection of S. Kentucky (n=70.We performed XbaI-pulsed field gel electrophoresis and multilocus sequence typing, assessed mutations in the quinolone resistance-determining regions, detected β-lactam resistance mechanisms, and screened the presence of the Salmonella genomic island 1 (SGI1. In this study, we highlight the rapid and extensive worldwide dissemination of the ciprofloxacin-resistant S. Kentucky ST198-X1-SGI1 strain since the mid-2000s in an increasingly large number of contaminated sources, including the environment. This strain has accumulated an increasing number of chromosomal and plasmid resistance determinants and has been identified in the Indian subcontinent, Southeast Asia and Europe since 2010. The second substitution at position 87 in GyrA (replacing the amino acid Asp appeared helpful for epidemiological studies to track the origin of contamination.This global study provides evidence leading to the conclusion that high-level resistance to ciprofloxacin in S. Kentucky is a simple microbiological trait that facilitates the identification of the epidemic clone of interest, ST198-X1-SGI1. Taking this into account is essential in order to detect and monitor it easily and to take rapid measures in livestock to ensure control of this infection.

Dielectric fluid directional spreading under the action of corona discharge

Science.gov (United States)

Zhou, Shangru; Liu, Jie; Hu, Qun; Jiang, Teng; Yang, Jinchu; Liu, Sheng; Zheng, Huai

2018-01-01

Liquid spreading is a very common nature phenomenon and of significant importance for a broad range of applications. In this study, a dielectric fluid directional spreading phenomenon is presented. Under the action of corona discharge, a dielectric fluid, here a typical silicone directionally spreads along conductive patterns on conductive/nonconductive substrates. Directional spreading behaviors of silicone were experimentally observed on different conductive patterns in detail. Spreading speeds were analyzed at different driving voltages, which induced the corona discharge. The presented phenomenon may be useful to inspire several techniques of manipulating liquid transportation and fabricating micropatterns.

Avian Influenza: a global threat needing a global solution

Directory of Open Access Journals (Sweden)

Koh GCH

2008-11-01

Full Text Available Abstract There have been three influenza pandemics since the 1900s, of which the 1919–1919 flu pandemic had the highest mortality rates. The influenza virus infects both humans and birds, and mutates using two mechanisms: antigenic drift and antigenic shift. Currently, the H5N1 avian flu virus is limited to outbreaks among poultry and persons in direct contact to infected poultry, but the mortality rate among infected humans is high. Avian influenza (AI is endemic in Asia as a result of unregulated poultry rearing in rural areas. Such birds often live in close proximity to humans and this increases the chance of genetic re-assortment between avian and human influenza viruses which may produce a mutant strain that is easily transmitted between humans. Once this happens, a global pandemic is likely. Unlike SARS, a person with influenza infection is contagious before the onset of case-defining symptoms which limits the effectiveness of case isolation as a control strategy. Researchers have shown that carefully orchestrated of public health measures could potentially limit the spread of an AI pandemic if implemented soon after the first cases appear. To successfully contain and control an AI pandemic, both national and global strategies are needed. National strategies include source surveillance and control, adequate stockpiles of anti-viral agents, timely production of flu vaccines and healthcare system readiness. Global strategies such as early integrated response, curbing the disease outbreak at source, utilization of global resources, continuing research and open communication are also critical.

Farm-retail price spread for pork in Malaysia

OpenAIRE

Tey, (John) Yeong-Sheng; Randy, Stringer; Wendy, Umberger

2009-01-01

The price difference between farm and retail levels is called price spread, which is constituted mostly by marketing costs and profits. From the price spread, this paper intends to estimate elasticities of price transmission for pork in Malaysia via different empirical model specifications of markup pricing model. Using data from January 1997 to December 2007, a quantitative analysis of farm-to-retail price spreads was undertaken for pork in Malaysia. It was found that retail price is the onl...

Beam-width spreading of vortex beams in free space

Science.gov (United States)

Wang, Weiwei; Li, Jinhong; Duan, Meiling

2018-01-01

Based on the extended Huygens-Fresnel principle and the definition of second-order moments of the Wigner distribution function, the analytical expression for the beam-width spreading of Gaussian Schell-model (GSM) vortex beams in free space are derived, and used to study the influence of beam parameters on the beam-width spreading of GSM vortex beams. With the increment of the propagation distance, the beam-width spreading of GSM vortex beams will increase; the bigger the topological charge, spatial correlation length, wavelength and waist width are, the smaller the beam-width spreading is.

Depletion of fossil fuels and the impacts of global warming

International Nuclear Information System (INIS)

Hoel, M.; Kverndokk, S.

1996-01-01

This paper combines the theory of optimal extraction of exhaustible resources with the theory of greenhouse externalities, to analyze problems of global warming when the supply side is considered. The optimal carbon tax will initially rise but eventually fall when the externality is positively related to the stock of carbon in the atmosphere. It is shown that the tax will start falling before the stock of carbon in the atmosphere reaches its maximum. If there exists a non-polluting backstop technology, it will be optimal to extract and consume fossil fuels even when the price of fossil fuels is equal to the price of the backstop. The total extraction is the same as when the externality is ignored, but in the presence of the greenhouse effect, it will be optimal to slow the extraction and spread it over a longer period. If, on the other hand, the greenhouse externality depends on the rate of change in the atmospheric stock of carbon, the evolution of the optimal carbon tax is more complex. It can even be optimal to subsidize carbon emissions to avoid future rapid changes in the stock of carbon, and therefore future damages. 22 refs., 3 figs

On the global distribution of hydrothermal vent fields: One decade later

Science.gov (United States)

Beaulieu, S. E.; Baker, E. T.; German, C. R.

2012-12-01

Since the last global compilation one decade ago, the known number of active submarine hydrothermal vent fields has almost doubled. At the end of 2009, a total of 518 active vent fields was catalogued, with about half (245) visually confirmed and others (273) inferred active at the seafloor. About half (52%) of these vent fields are at mid-ocean ridges (MORs), 25% at volcanic arcs, 21% at back-arc spreading centers (BASCs), and 2% at intra-plate volcanoes and other settings. One third are in high seas, and the nations with the most known active vent fields within EEZs are Tonga, USA, Japan, and New Zealand. The increase in known vent fields reflects a number of factors, including increased national and commercial interests in seafloor hydrothermal deposits as mineral resources. Here, we have comprehensively documented the percentage of strike length at MORs and BASCs that has been systematically explored for hydrothermal activity. As of the end of 2009, almost 30% of the ~60,000 km of MORs had been surveyed at least with spaced vertical profiles to detect hydrothermal plumes. A majority of the vents discovered at MORs in the past decade occurred at segments with vs. weighted-average full spreading rate (u_s), we predicted 676 vent fields remaining to be discovered at MORs. Even accounting for the lower F_s at slower spreading rates, almost half of the vents that are predicted remaining to be discovered at MORs are at ultra-slow to slow spreading rates (explored tend to be at high latitudes, such as the ultra-slow to slow spreading Arctic MORs (e.g., Kolbeinsey and Mohns Ridges), the ultra-slow American-Antarctic Ridge, and the intermediate spreading Pacific-Antarctic Ridge. Although a greater percentage of the ~11,000 km of BASCs has been surveyed for hydrothermal activity, the discoveries at BASCs in the past decade were mainly at segments with intermediate to fast spreading rates. Using the same equation for F_s vs. u_s, we predicted 71 vent fields remaining to

Spreading paths in partially observed social networks

Science.gov (United States)

Onnela, Jukka-Pekka; Christakis, Nicholas A.

2012-03-01

Understanding how and how far information, behaviors, or pathogens spread in social networks is an important problem, having implications for both predicting the size of epidemics, as well as for planning effective interventions. There are, however, two main challenges for inferring spreading paths in real-world networks. One is the practical difficulty of observing a dynamic process on a network, and the other is the typical constraint of only partially observing a network. Using static, structurally realistic social networks as platforms for simulations, we juxtapose three distinct paths: (1) the stochastic path taken by a simulated spreading process from source to target; (2) the topologically shortest path in the fully observed network, and hence the single most likely stochastic path, between the two nodes; and (3) the topologically shortest path in a partially observed network. In a sampled network, how closely does the partially observed shortest path (3) emulate the unobserved spreading path (1)? Although partial observation inflates the length of the shortest path, the stochastic nature of the spreading process also frequently derails the dynamic path from the shortest path. We find that the partially observed shortest path does not necessarily give an inflated estimate of the length of the process path; in fact, partial observation may, counterintuitively, make the path seem shorter than it actually is.

Spreading paths in partially observed social networks.

Science.gov (United States)

Onnela, Jukka-Pekka; Christakis, Nicholas A

2012-03-01

Understanding how and how far information, behaviors, or pathogens spread in social networks is an important problem, having implications for both predicting the size of epidemics, as well as for planning effective interventions. There are, however, two main challenges for inferring spreading paths in real-world networks. One is the practical difficulty of observing a dynamic process on a network, and the other is the typical constraint of only partially observing a network. Using static, structurally realistic social networks as platforms for simulations, we juxtapose three distinct paths: (1) the stochastic path taken by a simulated spreading process from source to target; (2) the topologically shortest path in the fully observed network, and hence the single most likely stochastic path, between the two nodes; and (3) the topologically shortest path in a partially observed network. In a sampled network, how closely does the partially observed shortest path (3) emulate the unobserved spreading path (1)? Although partial observation inflates the length of the shortest path, the stochastic nature of the spreading process also frequently derails the dynamic path from the shortest path. We find that the partially observed shortest path does not necessarily give an inflated estimate of the length of the process path; in fact, partial observation may, counterintuitively, make the path seem shorter than it actually is.

Assessment of thema code against spreading experiments

International Nuclear Information System (INIS)

Spindler, B.; Veteau, J.M.; Cecco, L. de; Montanelli, P.; Pineau, D.

2000-01-01

In the frame work of severe accident research, the spreading code THEMA, developed at CEA/DRN, aims at predicting the spreading extent of molten core after a vessel melt-through. The code solves fluid balance equations integrated over the fluid depth for oxidic and/or metallic phases under the shallow water assumption, using a finite difference scheme. Solidification is taken into account through crust formation on the substrate and at contact with the surroundings, as well as increase of fluid viscosity with solid fraction in the melt. A separate energy equation is solved for the solid substrate, including possible ablation. The assessment of THEMA code against the spreading experiments performed in the framework of the corium spreading and coolability project of the European Union is presented. These experiments use either simulating materials at medium (RIT), or at high temperature (KATS), or corium (VULCANO, FARO), conducted at different mass flow rates and with large or low solidification interval. THEMA appears to be able to simulate the whole set of the experiments investigated. Comparison between experimental and computed spreading lengths and substrate temperatures are quite satisfactory. The results show a rather large sensitivity at mass flow rate and inlet temperature, indicating that, generally, efforts should be made to improve the accuracy of the measurements of such parameters in the experiments. (orig.)

Transmission loss patterns from acoustic harassment and deterrent devices do not always follow geometrical spreading predictions

DEFF Research Database (Denmark)

Shapiro, A.D.; Tougaard, J.; Jørgensen, P.B.

2009-01-01

and cylindrical spreading models and conflicted with the classic concept of concentric zones of increasing disturbance with decreasing range. Under such conditions, animals may encounter difficulties when trying to determine the direction to and location of a sound source, which may complicate or jeopardize...... level for all sources in each of the environments. This variability was likely caused by source directionality, inter-ping source level variation and multipath interference. Rapid and unpredictable variations in the sound level as a function of range deviated from expectations derived from spherical...

Charged-particle multiplicity at mid-rapidity in Au–Au collisions at ...

Indian Academy of Sciences (India)

The particle density at mid-rapidity is an essential global variable for the characterization of nuclear collisions at ultra-relativistic energies. It provides information about the initial conditions and energy density reached in these collisions. The pseudorapidity densities of charged particles at mid-rapidity in Au + Au collisions at ...

Mapping Pn amplitude spreading and attenuation in Asia

Energy Technology Data Exchange (ETDEWEB)

Yang, Xiaoning [Los Alamos National Laboratory; Phillips, William S [Los Alamos National Laboratory; Stead, Richard J [Los Alamos National Laboratory

2010-12-06

Pn travels most of its path in the mantle lid. Mapping the lateral variation of Pn amplitude attenuation sheds light on material properties and dynamics of the uppermost region of the mantle. Pn amplitude variation depends on the wavefront geometric spreading as well as material attenuation. We investigated Pn geometric spreading, which is much more complex than a traditionally assumed power-law spreading model, using both synthetic and observed amplitude data collected in Asia. We derived a new Pn spreading model based on the formulation that was proposed previously to account for the spherical shape of the Earth (Yang et. al., BSSA, 2007). New parameters derived for the spreading model provide much better correction for Pn amplitudes in terms of residual behavior. Because we used observed Pn amplitudes to construct the model, the model incorporates not only the effect of the Earth's spherical shape, but also the effect of potential upper-mantle velocity gradients in the region. Using the new spreading model, we corrected Pn amplitudes measured at 1, 2, 4 and 6 Hz and conducted attenuation tomography. The resulting Pn attenuation model correlates well with the regional geology. We see high attenuation in regions such as northern Tibetan Plateau and the western Pacific subduction zone, and low attenuation for stable blocks such as Sichuan and Tarim basins.

Using isotopes for global warming observation

International Nuclear Information System (INIS)

Namata, K.

2002-01-01

This paper, based on a literature review, discusses the main aspects of using isotopic techniques to obtain information about global warming. The rapid increase concentration of carbon dioxide (CO 2 ) and methane (CH 4 ) in the atmosphere will result in global warming by the greenhouse effect, and the isotopic techniques constitute an efficient tool to explain this complex environmental phenomenon. (author)

Did vaccination slow the spread of bluetongue in France?

Directory of Open Access Journals (Sweden)

Maryline Pioz

Full Text Available Vaccination is one of the most efficient ways to control the spread of infectious diseases. Simulations are now widely used to assess how vaccination can limit disease spread as well as mitigate morbidity or mortality in susceptible populations. However, field studies investigating how much vaccines decrease the velocity of epizootic wave-fronts during outbreaks are rare. This study aimed at investigating the effect of vaccination on the propagation of bluetongue, a vector-borne disease of ruminants. We used data from the 2008 bluetongue virus serotype 1 (BTV-1 epizootic of southwest France. As the virus was newly introduced in this area, natural immunity of livestock was absent. This allowed determination of the role of vaccination in changing the velocity of bluetongue spread while accounting for environmental factors that possibly influenced it. The average estimated velocity across the country despite restriction on animal movements was 5.4 km/day, which is very similar to the velocity of spread of the bluetongue virus serotype 8 epizootic in France also estimated in a context of restrictions on animal movements. Vaccination significantly reduced the propagation velocity of BTV-1. In comparison to municipalities with no vaccine coverage, the velocity of BTV-1 spread decreased by 1.7 km/day in municipalities with immunized animals. For the first time, the effect of vaccination has been quantified using data from a real epizootic whilst accounting for environmental factors known to modify the velocity of bluetongue spread. Our findings emphasize the importance of vaccination in limiting disease spread across natural landscape. Finally, environmental factors, specifically those related to vector abundance and activity, were found to be good predictors of the velocity of BTV-1 spread, indicating that these variables need to be adequately accounted for when evaluating the role of vaccination on bluetongue spread.

International travel between global urban centres vulnerable to yellow fever transmission.

Science.gov (United States)

Brent, Shannon E; Watts, Alexander; Cetron, Martin; German, Matthew; Kraemer, Moritz Ug; Bogoch, Isaac I; Brady, Oliver J; Hay, Simon I; Creatore, Maria I; Khan, Kamran

2018-05-01

To examine the potential for international travel to spread yellow fever virus to cities around the world. We obtained data on the international flight itineraries of travellers who departed yellow fever-endemic areas of the world in 2016 for cities either where yellow fever was endemic or which were suitable for viral transmission. Using a global ecological model of dengue virus transmission, we predicted the suitability of cities in non-endemic areas for yellow fever transmission. We obtained information on national entry requirements for yellow fever vaccination at travellers' destination cities. In 2016, 45.2 million international air travellers departed from yellow fever-endemic areas of the world. Of 11.7 million travellers with destinations in 472 cities where yellow fever was not endemic but which were suitable for virus transmission, 7.7 million (65.7%) were not required to provide proof of vaccination upon arrival. Brazil, China, India, Mexico, Peru and the United States of America had the highest volumes of travellers arriving from yellow fever-endemic areas and the largest populations living in cities suitable for yellow fever transmission. Each year millions of travellers depart from yellow fever-endemic areas of the world for cities in non-endemic areas that appear suitable for viral transmission without having to provide proof of vaccination. Rapid global changes in human mobility and urbanization make it vital for countries to re-examine their vaccination policies and practices to prevent urban yellow fever epidemics.

The global environment: An overview

International Nuclear Information System (INIS)

Tolba, M.K.

1992-01-01

Global environmental chemistry today involves a rapidly expanding need both for new research and for the development of an interdiciplinary approach to the multiplicity of interconnected environmental problems. Every ecosystem shows signs of damage: growing quantities of wastes; decreasing water supplies; soil degradation; coastal zone deterioration; deforestation and climatic change; global warming due to ozone depletion. Solutions must involve a cooperative and holistic global effort in three areas: scientific understanding of how the interactive physical, chemical and biological processes regulate the total Earth system; public policy implications including closer liaison between scientists and policymakers;and understanding of the state of the global environment, what is going wrong, why, and whether it is getting worse

Pleiades rapid rotators - evidence for an evolutionary sequence

International Nuclear Information System (INIS)

Butler, R.P.; Marcy, G.W.; Cohen, R.D.; Duncan, D.K.; California Univ., La Jolla; Space Telescope Science Institute, Baltimore, MD)

1987-01-01

Four rapidly rotating early-K dwarfs in the Pleiades are shown to contain an order of magnitude more Li than four slow rotators of the same spectral type, as would be expected if they were systematically younger. This supports the idea that late-type stars first arrive on the main sequence with V(rot) greater than about 100 km/s, that they spin down to V(rot) less than about 10 km/s in 10 to the 7th to 10 to the 8th yr, and that the Pleiades lower main sequence shows such an age spread. 14 references

Enhancing Student Collaboration in Global Virtual Teams

Science.gov (United States)

Kohut, Gary F.

2012-01-01

With the growth in the global economy and the rapid development of communication and information technologies, global virtual teams are quickly becoming the norm in the workplace. Research indicates, however, that many students have little or no experience working in such teams. Students who learn through these experiences benefit from higher task…

Globalization and the Changing Epidemiology of Hepatitis A Virus.

Science.gov (United States)

Jacobsen, Kathryn H

2018-03-02

Increased economic interdependence, social integration, and other aspects of globalization are contributing to significant changes in hepatitis A epidemiology. Globally, the incidence of hepatitis A virus (HAV) infection is decreasing, the age at midpoint of population immunity (AMPI) is increasing, and the proportion of symptomatic cases is increasing as the average age at infection increases. In low-income countries, HAV remains endemic but improved water and sanitation systems are reducing transmission rates among young children. In high-income countries, most adults remain susceptible to HAV and foodborne outbreaks are becoming more frequent. Middle-income countries have diverse epidemiological profiles, and they play important roles in the global spread of HAV through international trade and travel. Future changes in the epidemiology of hepatitis A will be heavily influenced by globalization processes. Copyright © 2018 Cold Spring Harbor Laboratory Press; all rights reserved.

Crystal mosaic spread determination by slow neutron scattering

International Nuclear Information System (INIS)

Adib, M.; Naguib, K.; Abdel Kawy, A.; Ashry, A.; Abbas, Y.; Wahba, M.; Maayouf, M.A.

1988-01-01

A method has been established for determination of the crystal mosaic spread. The method is based on recording all neutron-reflected, under bragg condition, from a certain crystal plane. A computer code was developed especially in order to fit the measured wavelength's distribution of the reflected neutrons with the calculated one, assuming that the crystal mosaic spread has a Gaussian shape. The code accounts for the parameters of the time of flight spectrometer used during the present measurements, as well as divergence of the incident neutron beam. The developed method has been applied for determination of the mosaic spread of both zinc and pyrolytic graphite (P.G.) crystals. The mosaic spread values deduced from the present measurements, are 10'+-6' and 3.60 0 +-0.16 0 respectively for Zn and P.G. crystals

SPREADING LAYERS IN ACCRETING OBJECTS: ROLE OF ACOUSTIC WAVES FOR ANGULAR MOMENTUM TRANSPORT, MIXING, AND THERMODYNAMICS

Energy Technology Data Exchange (ETDEWEB)

Philippov, Alexander A.; Rafikov, Roman R.; Stone, James M., E-mail: sashaph@princeton.edu [Department of Astrophysical Sciences, Princeton University, Ivy Lane, Princeton, NJ 08540 (United States)

2016-01-20

Disk accretion at a high rate onto a white dwarf (WD) or a neutron star has been suggested to result in the formation of a spreading layer (SL)—a belt-like structure on the object's surface, in which the accreted matter steadily spreads in the poleward (meridional) direction while spinning down. To assess its basic characteristics, we perform two-dimensional hydrodynamic simulations of supersonic SLs in the relevant morphology with a simple prescription for cooling. We demonstrate that supersonic shear naturally present at the base of the SL inevitably drives sonic instability that gives rise to large-scale acoustic modes governing the evolution of the SL. These modes dominate the transport of momentum and energy, which is intrinsically global and cannot be characterized via some form of local effective viscosity (e.g., α-viscosity). The global nature of the wave-driven transport should have important implications for triggering Type I X-ray bursts in low-mass X-ray binaries. The nonlinear evolution of waves into a system of shocks drives effective rearrangement (sensitively depending on thermodynamical properties of the flow) and deceleration of the SL, which ultimately becomes transonic and susceptible to regular Kelvin–Helmholtz instability. We interpret this evolution in terms of the global structure of the SL and suggest that mixing of the SL material with the underlying stellar fluid should become effective only at intermediate latitudes on the accreting object's surface, where the flow has decelerated appreciably. In the near-equatorial regions the transport is dominated by acoustic waves and mixing is less efficient. We speculate that this latitudinal nonuniformity of mixing in accreting WDs may be linked to the observed bipolar morphology of classical nova ejecta.

Unidirectional spreading of oil under solid ice

International Nuclear Information System (INIS)

Weerasuriya, S.A.; Yapa, P.D.

1993-01-01

Equations are presented to describe the unidirectional spreading of oil under solid ice covers floating in calm water. These spreading equations are derived using a simplified form of the Navier-Stokes equations, and cover both the constant discharge and the constant volume modes. An equation for computing final slick length is also given. Laboratory experiments using physical models were conducted to verify the equations. The experiments used oils of different viscosities, ice cover roughnesses varying from smooth to rough, and a variety of discharge conditions. The emphasis of the study was on the dominant spreading mechanism for oil under ice, which is the buoyancy-viscous phase. The laboratory results agree closely with the theoretical predictions. Discrepancies can be attributed to the experimental difficulties and errors introduced from the assumptions made in deriving the theory. The equations presented will be useful in computing spreading rate during an accidental oil spill or in contingency planning. The equations are simple to use, suitable for hand calculations or for incorporation into numerical models for oil spill simulation. 24 refs., 10 figs., 1 tab

Global shortage of neonatal and paediatric antibiotic trials: rapid review.

Science.gov (United States)

Thompson, Georgina; Barker, Charlotte I; Folgori, Laura; Bielicki, Julia A; Bradley, John S; Lutsar, Irja; Sharland, Mike

2017-10-13

There have been few clinical trials (CTs) on antibiotics that inform neonatal and paediatric drug labelling. The rate of unlicensed and off-label prescribing in paediatrics remains high. It is unclear whether the current neonatal and paediatric antibiotic research pipeline is adequate to inform optimal drug dosing. Using the ClinicalTrials.gov registry, this review aims to establish the current global status of antibiotic CTs in children up to 18 years of age. Studies were identified using key word searches of the ClinicalTrials.gov registry and were manually filtered using prespecified inclusion/exclusion criteria. 76 registered open CTs of antibiotics in children were identified globally; 23 (30%) were recruiting newborns (only 8 (11%) included preterm neonates), 52 (68%) infants and toddlers, 58 (76%) children and 54 (71%) adolescents. The majority of registered trials were late phase (10 (15%) phase 3 and 23 (35%) phase 4/pharmacovigilance). Two-thirds were sponsored by non-profit organisations, compared with pharmaceutical companies (50 (66%) vs 26 (34%), respectively). A greater proportion of non-profit funded trials were efficacy-based strategic trials (n=34, 68%), in comparison with industry-led trials, which were most often focused on safety or pharmacokinetic data (n=17, 65%). Only 2 of the 37 antibiotics listed on the May 2016 Pew Charitable Trusts antibiotic development pipeline, currently being studied in adults, appear to be currently recruiting in open paediatric CTs. This review highlights that very few paediatric antibiotic CTs are being conducted globally, especially in neonates. There is a striking disparity noted between antibiotic drug development programmes in adults and children. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

The spread of scientific information: insights from the web usage statistics in PLoS article-level metrics.

Directory of Open Access Journals (Sweden)

Koon-Kiu Yan

Full Text Available The presence of web-based communities is a distinctive signature of Web 2.0. The web-based feature means that information propagation within each community is highly facilitated, promoting complex collective dynamics in view of information exchange. In this work, we focus on a community of scientists and study, in particular, how the awareness of a scientific paper is spread. Our work is based on the web usage statistics obtained from the PLoS Article Level Metrics dataset compiled by PLoS. The cumulative number of HTML views was found to follow a long tail distribution which is reasonably well-fitted by a lognormal one. We modeled the diffusion of information by a random multiplicative process, and thus extracted the rates of information spread at different stages after the publication of a paper. We found that the spread of information displays two distinct decay regimes: a rapid downfall in the first month after publication, and a gradual power law decay afterwards. We identified these two regimes with two distinct driving processes: a short-term behavior driven by the fame of a paper, and a long-term behavior consistent with citation statistics. The patterns of information spread were found to be remarkably similar in data from different journals, but there are intrinsic differences for different types of web usage (HTML views and PDF downloads versus XML. These similarities and differences shed light on the theoretical understanding of different complex systems, as well as a better design of the corresponding web applications that is of high potential marketing impact.

The spread of scientific information: insights from the web usage statistics in PLoS article-level metrics.

Science.gov (United States)

Yan, Koon-Kiu; Gerstein, Mark

2011-01-01

The presence of web-based communities is a distinctive signature of Web 2.0. The web-based feature means that information propagation within each community is highly facilitated, promoting complex collective dynamics in view of information exchange. In this work, we focus on a community of scientists and study, in particular, how the awareness of a scientific paper is spread. Our work is based on the web usage statistics obtained from the PLoS Article Level Metrics dataset compiled by PLoS. The cumulative number of HTML views was found to follow a long tail distribution which is reasonably well-fitted by a lognormal one. We modeled the diffusion of information by a random multiplicative process, and thus extracted the rates of information spread at different stages after the publication of a paper. We found that the spread of information displays two distinct decay regimes: a rapid downfall in the first month after publication, and a gradual power law decay afterwards. We identified these two regimes with two distinct driving processes: a short-term behavior driven by the fame of a paper, and a long-term behavior consistent with citation statistics. The patterns of information spread were found to be remarkably similar in data from different journals, but there are intrinsic differences for different types of web usage (HTML views and PDF downloads versus XML). These similarities and differences shed light on the theoretical understanding of different complex systems, as well as a better design of the corresponding web applications that is of high potential marketing impact.

Altitudinal Barrier to the Spread of an Invasive Species: Could the Pyrenean Chain Slow the Natural Spread of the Pinewood Nematode?

Directory of Open Access Journals (Sweden)

Julien Haran

Full Text Available Mountain ranges may delimit the distribution of native species as well as constitute potential barriers to the spread of invasive species. The invasive pinewood nematode, Bursaphelenchus xylophilus, is a severe forest pest inducing pine wilt disease. It is vectored in Europe by a native long-horned beetle, Monochamus galloprovincialis. This study explored the potential of the Pyrenean chain to slow or prevent the natural spread of nematode-infested beetles from the Iberian Peninsula, where the nematode is established and is expanding its range, towards France and the rest of Europe. An analysis of the genetic structure and migration patterns of the beetle populations throughout the Pyrenean mountain range was combined with a spread model simulating the potential movements of nematode-infested beetles across it. The central part of the Pyrenees, which corresponds to the highest elevation zone, was shown to prevent gene flow between the French and Spanish populations of M. galloprovincialis on each side of the mountains. Conversely, strong admixture was detected between populations located on both sides of low elevation hills, and especially at the east and west extremities of the mountain range. Simulations of the spread of nematode-infested beetles under various thresholds of beetle survival and pine wilt disease expression gave results consistent with the variation in genetic make-up, suggesting that western and eastern hillsides may represent corridors favoring natural spread of the nematode from the Iberian Peninsula to France. Simulations also showed that temperature rise due to climate change may significantly reduce the extent of the barrier formed by highest elevations. Our results support the hypothesis that the Pyrenean chain represents a partial barrier to the natural spread of nematode-infested beetles. These results, which have to be considered together with potential human-assisted long-distance spread of the nematode, highlight

DataSpread: Unifying Databases and Spreadsheets.

Science.gov (United States)

Bendre, Mangesh; Sun, Bofan; Zhang, Ding; Zhou, Xinyan; Chang, Kevin ChenChuan; Parameswaran, Aditya

2015-08-01

Spreadsheet software is often the tool of choice for ad-hoc tabular data management, processing, and visualization, especially on tiny data sets. On the other hand, relational database systems offer significant power, expressivity, and efficiency over spreadsheet software for data management, while lacking in the ease of use and ad-hoc analysis capabilities. We demonstrate DataSpread, a data exploration tool that holistically unifies databases and spreadsheets. It continues to offer a Microsoft Excel-based spreadsheet front-end, while in parallel managing all the data in a back-end database, specifically, PostgreSQL. DataSpread retains all the advantages of spreadsheets, including ease of use, ad-hoc analysis and visualization capabilities, and a schema-free nature, while also adding the advantages of traditional relational databases, such as scalability and the ability to use arbitrary SQL to import, filter, or join external or internal tables and have the results appear in the spreadsheet. DataSpread needs to reason about and reconcile differences in the notions of schema, addressing of cells and tuples, and the current "pane" (which exists in spreadsheets but not in traditional databases), and support data modifications at both the front-end and the back-end. Our demonstration will center on our first and early prototype of the DataSpread, and will give the attendees a sense for the enormous data exploration capabilities offered by unifying spreadsheets and databases.

Infections Unlikely to be Spread Through Swimming Pools

Science.gov (United States)

... Water Home Infections Unlikely to be Spread Through Swimming Pools Language: English (US) Español (Spanish) Recommend on ... included below. Infections Unlikely to be Spread by Swimming Pools Head Lice Head lice are unlikely to ...

How Global Science has yet to Bridge Global Differences - A Status Report of the IUGS Taskforce on Global Geoscience Workforce

Science.gov (United States)

Keane, C. M.; Gonzales, L. M.

2010-12-01

The International Union of Geological Sciences, with endorsement by UNESCO, has established a taskforce on global geosciences workforce and has tasked the American Geological Institute to take a lead. Springing from a session on global geosciences at the IGC33 in Oslo, Norway, the taskforce is to address three issues on a global scale: define the geosciences, determine the producers and consumers of geoscientists, and frame the understandings to propose pathways towards improved global capacity building in the geosciences. With the combination of rapid retirements in the developed world, and rapid economic expansion and impact of resource and hazard issues in the developing world, the next 25 years will be a dynamic time for the geosciences. However, to date there has been little more than a cursory sense of who and what the geosciences are globally and whether we will be able to address the varied needs and issues in the developed and the developing worlds. Based on prior IUGS estimates, about 50% of all working geoscientists reside in the Unites States, and the US was also producing about 50% of all new geosciences graduate degrees globally. Work from the first year of the taskforce has elucidated the immense complexity of the issue of defining the geosciences, as it bring is enormous cultural and political frameworks, but also shed light on the status of the geosciences in each country. Likewise, this leads to issues of who is actually producing and consuming geoscience talent, and whether countries are meeting domestic demand, and if not, is external talent available to import. Many US-based assumptions about the role of various countries in the geosciences’ global community of people, namely China and India, appear to have been misplaced. In addition, the migration of geoscientists between countries raised enormous questions about what is nationality and if there is an ideal ‘global geoscientist.’ But more than anything, the taskforce is revealing clear

GLOBALIZATION AND ITS IMPACT ON INDIAN ECONOMY

OpenAIRE

Raghunath

2017-01-01

Globalization means different things to different people. It can be defined simply as an expansion of economic activities across political boundaries of nation states. More importantly it refers to a process of deepening economic integration, increasing economic openness and growing economic interdependence between countries in the world economy. It is associated not only with a phenomenal spread and volume of cross-border economic transactions but also with an organization of economic activi...

Empowering global software development with business intelligence

OpenAIRE

Maté Morga, Alejandro; Trujillo Mondéjar, Juan Carlos; García, Félix; Serrano Martín, Manuel; Piattini, Mario

2016-01-01

Context: Global Software Development (GSD) allows companies to take advantage of talent spread across the world. Most research has been focused on the development aspect. However, little if any attention has been paid to the management of GSD projects. Studies report a lack of adequate support for management’s decisions made during software development, further accentuated in GSD since information is scattered throughout multiple factories, stored in different formats and standards. Objective...

A global reference model of Curie-point depths based on EMAG2

Science.gov (United States)

Li, Chun-Feng; Lu, Yu; Wang, Jian

2017-03-01

In this paper, we use a robust inversion algorithm, which we have tested in many regional studies, to obtain the first global model of Curie-point depth (GCDM) from magnetic anomaly inversion based on fractal magnetization. Statistically, the oceanic Curie depth mean is smaller than the continental one, but continental Curie depths are almost bimodal, showing shallow Curie points in some old cratons. Oceanic Curie depths show modifications by hydrothermal circulations in young oceanic lithosphere and thermal perturbations in old oceanic lithosphere. Oceanic Curie depths also show strong dependence on the spreading rate along active spreading centers. Curie depths and heat flow are correlated, following optimal theoretical curves of average thermal conductivities K = ~2.0 W(m°C)-1 for the ocean and K = ~2.5 W(m°C)-1 for the continent. The calculated heat flow from Curie depths and large-interval gridding of measured heat flow all indicate that the global heat flow average is about 70.0 mW/m2, leading to a global heat loss ranging from ~34.6 to 36.6 TW.

Global teaching of global seismology

Science.gov (United States)

Stein, S.; Wysession, M.

2005-12-01

Our recent textbook, Introduction to Seismology, Earthquakes, & Earth Structure (Blackwell, 2003) is used in many countries. Part of the reason for this may be our deliberate attempt to write the book for an international audience. This effort appears in several ways. We stress seismology's long tradition of global data interchange. Our brief discussions of the science's history illustrate the contributions of scientists around the world. Perhaps most importantly, our discussions of earthquakes, tectonics, and seismic hazards take a global view. Many examples are from North America, whereas others are from other areas. Our view is that non-North American students should be exposed to North American examples that are type examples, and that North American students should be similarly exposed to examples elsewhere. For example, we illustrate how the Euler vector geometry changes a plate boundary from spreading, to strike-slip, to convergence using both the Pacific-North America boundary from the Gulf of California to Alaska and the Eurasia-Africa boundary from the Azores to the Mediterranean. We illustrate diffuse plate boundary zones using western North America, the Andes, the Himalayas, the Mediterranean, and the East Africa Rift. The subduction zone discussions examine Japan, Tonga, and Chile. We discuss significant earthquakes both in the U.S. and elsewhere, and explore hazard mitigation issues in different contexts. Both comments from foreign colleagues and our experience lecturing overseas indicate that this approach works well. Beyond the specifics of our text, we believe that such a global approach is facilitated by the international traditions of the earth sciences and the world youth culture that gives students worldwide common culture. For example, a video of the scene in New Madrid, Missouri that arose from a nonsensical earthquake prediction in 1990 elicits similar responses from American and European students.

A fundamental look at fire spread in California chaparral

Science.gov (United States)

David R. Weise; Thomas Fletcher; Larry Baxter; Shankar Mahalingam; Xiangyang Zhou; Patrick Pagni; Rod Linn; Bret Butler

2004-01-01

The USDA Forest Service National Fire Plan funded a research program to study fire spread in live fuels of the southwestern United States. In the U.S. current operational fire spread models do not distinguish between live and dead fuels in a sophisticated manner because the study of live fuels has been limited. The program is experimentally examining fire spread at 3...

Flame spread over inclined electrical wires with AC electric fields

KAUST Repository

Lim, Seung J.

2017-07-21

Flame spread over polyethylene-insulated electrical wires was studied experimentally with applied alternating current (AC) by varying the inclination angle (θ), applied voltage (VAC), and frequency (fAC). For the baseline case with no electric field applied, the flame spread rate and the flame width of downwardly spreading flames (DSFs) decreased from the horizontal case for −20° ≤ θ < 0° and maintained near constant values for −90° ≤ θ < −20°, while the flame spread rate increased appreciably as the inclination angle of upwardly spreading flames (USFs) increased. When an AC electric field was applied, the behavior of flame spread rate in DSFs (USFs) could be classified into two (three) sub-regimes characterized by various functional dependences on VAC, fAC, and θ. In nearly all cases of DSFs, a globular molten polyethylene formed ahead of the spreading flame edge, occasionally dripping onto the ground. In these cases, an effective flame spread rate was defined to represent the burning rate by measuring the mass loss due to dripping. This effective spread rate was independent of AC frequency, while it decreased linearly with voltage and was independent of the inclination angle. In DSFs, when excessively high voltage and frequency were applied, the dripping led to flame extinction during propagation and the extinction frequency correlated well with applied voltage. In USFs, when high voltage and frequency were applied, multiple globular molten PEs formed at several locations, leading to ejections of multiple small flame segments from the main flame, thereby reducing the flame spread rate, which could be attributed to the electrospray phenomenon.

A model of spreading of sudden events on social networks

Science.gov (United States)

Wu, Jiao; Zheng, Muhua; Zhang, Zi-Ke; Wang, Wei; Gu, Changgui; Liu, Zonghua

2018-03-01

Information spreading has been studied for decades, but its underlying mechanism is still under debate, especially for those ones spreading extremely fast through the Internet. By focusing on the information spreading data of six typical events on Sina Weibo, we surprisingly find that the spreading of modern information shows some new features, i.e., either extremely fast or slow, depending on the individual events. To understand its mechanism, we present a susceptible-accepted-recovered model with both information sensitivity and social reinforcement. Numerical simulations show that the model can reproduce the main spreading patterns of the six typical events. By this model, we further reveal that the spreading can be speeded up by increasing either the strength of information sensitivity or social reinforcement. Depending on the transmission probability and information sensitivity, the final accepted size can change from continuous to discontinuous transition when the strength of the social reinforcement is large. Moreover, an edge-based compartmental theory is presented to explain the numerical results. These findings may be of significance on the control of information spreading in modern society.

Spreading depolarisations and outcome after traumatic brain injury

DEFF Research Database (Denmark)

Hartings, Jed A; Bullock, M Ross; Okonkwo, David O

2011-01-01

Pathological waves of spreading mass neuronal depolarisation arise repeatedly in injured, but potentially salvageable, grey matter in 50-60% of patients after traumatic brain injury (TBI). We aimed to ascertain whether spreading depolarisations are independently associated with unfavourable...

Global, regional, and national burden of neurological disorders during 1990-2015

DEFF Research Database (Denmark)

2017-01-01

BACKGROUND: Comparable data on the global and country-specific burden of neurological disorders and their trends are crucial for health-care planning and resource allocation. The Global Burden of Diseases, Injuries, and Risk Factors (GBD) Study provides such information but does not routinely...... aggregate results that are of interest to clinicians specialising in neurological conditions. In this systematic analysis, we quantified the global disease burden due to neurological disorders in 2015 and its relationship with country development level. METHODS: We estimated global and country......-specific prevalence, mortality, disability-adjusted life-years (DALYs), years of life lost (YLLs), and years lived with disability (YLDs) for various neurological disorders that in the GBD classification have been previously spread across multiple disease groupings. The more inclusive grouping of neurological...

[SPREADING OF NCTC CLONE 929 CELLS AFTER RESEEDING].

Science.gov (United States)

Petrov, Yu P; Negulyaev, Yu A; Tsupkina, N V

2015-01-01

The period (1 h after reseeding) of behaviour of mouse NCTC clone 929 cells to the conditions of artificial cultivation was studied. The time-lapse imaging followed the processing of the cells with ImageJ program was applied. To characterize the parametres cell status we used the cell area (projection of the cell on substrate) and Rp/Ra ratio introduced earlier as a spreading coefficient (Kuz'minykh, Petrov, 2004). After attaching a substratum, cells have a form of sphere (the phase "sphere") as the daughter cells after a mitosis. We revealed however that after this phase the reseeded cells do not start usual spreading and migration along substratum. They pass a phase of equally spreading in all directions and shaping their area as a circle (phase "circle"). This phase is absent of the daughter cells spreading after mitosis. We assume that the phase "circle" is a result of adaptation of the cells to reseedings at artificial cultivation. It is necessary for formation of a substrate composed of own extracellular matrix components (ECM) of the cells. Own ECM facilitates transition of the cells to their usual spreading and migration along substratum.

Simulation spread sheet of Angra-1 secondary circuit

International Nuclear Information System (INIS)

Futuro, F.L.; Rucos, J.; Ogando, A.; Maprelian, E.; Bassel, W.S.; Baptista Filho, B.D.

2000-01-01

The efficient operation of a Nuclear Power Plant (NPP) requires the continuous identification of derivations in the main operating parameters. The identification and analysis of those derivations allow someone to detect the degradation of instruments or even of any equipment. In order to study this problem the group of thermal generation of Angra 1 NPP, devised the use of a Microsoft Excel spread sheet for the automation of Angra 1 thermal balance. In the set of simulation spread sheets, measured values of the secondary system main parameters were compared with project values for a given reactor power level and condenser pressure. The spread sheets provide the turbines power and efficiency and do the plant thermal balance. This work presents a general description of the spread sheets set and a real case analysis of Angra 1 NPP, showing its precision and use easiness. (author)

Epidemic Spreading with Heterogeneous Awareness on Human Networks

Directory of Open Access Journals (Sweden)

Yanling Lu

2017-01-01

Full Text Available The spontaneous awareness behavioral responses of individuals have a significant impact on epidemic spreading. In this paper, a modified Susceptible-Alert-Infected-Susceptible (SAIS epidemic model with heterogeneous awareness is presented to study epidemic spreading in human networks and the impact of heterogeneous awareness on epidemic dynamics. In this model, when susceptible individuals receive awareness information about the presence of epidemic from their infected neighbor nodes, they will become alert individuals with heterogeneous awareness rate. Theoretical analysis and numerical simulations show that heterogeneous awareness can enhance the epidemic threshold with certain conditions and reduce the scale of virus outbreaks compared with no awareness. What is more, for the same awareness parameter, it also shows that heterogeneous awareness can slow effectively the spreading size and does not delay the arrival time of epidemic spreading peak compared with homogeneous awareness.

Airborne spread of disease--the implications for dentistry.

Science.gov (United States)

Harrel, Stephen K

2004-11-01

The potential for the airborne spread of disease has been recognized for many years. Recent studies have shown that this mode for disease transmission is capable of spreading a fatal disease such as Severe Acute Respiratory Syndrome over a wide area. Many dental procedures produce extensive aerosols and splatter that are routinely contaminated with bacteria, viruses, and blood. In the past, the potential for these aerosols and splatter to be a vector for disease spread has not been emphasized in dental infection control. Recently published data shows a need to reassess the potential for dental aerosols and splatter to spread disease and the need for their control. Simple and inexpensive methods for the control of dental aerosols and splatter are given. Dental personnel are urged to make the control of aerosols a standard part of their infection control procedures.

Market Channels of Technology Startups that Internationalize Rapidly from Inception

Directory of Open Access Journals (Sweden)

Simar Yoos

2012-10-01

Full Text Available The study of technology startups that internationalize rapidly from inception has increased in recent years. However, little is known about their channels to market. This article addresses a gap in the "born global" literature by examining the channels used by six startups that internationalized rapidly from inception as well as the programs they used to support their channel partners and customers. The six startups examined combined the use of the Internet with: i a relationship with a multi-national, ii distributors, iii re-sellers, or iv a direct sales force. They also delivered programs to support partners and customers that focused on communications, alliance and network development, education, marketing and promotion, and financial incentives. This article informs entrepreneurs who need to design go-to-market channels to exploit global opportunities about decisions made by other entrepreneurs who launched born-global companies. Normative rules and practitioner-oriented approaches are needed to help entrepreneurs explain and apply the results presented in this article.

Effect of network topology on the spreading of technologies

International Nuclear Information System (INIS)

Kocsis, G.; Kun, F.

2007-01-01

Complete text of publication follows. Technological evolution of socio-economic systems has two major components: (i) Innovation New products, ideas, paradigms emerge as a result of innovations which are then tested by the market. (ii) Spreading Successful technologies spread over the system resulting in an overall technological progress. In the present project we study the spreading of new technological achievements, searching for the conditions of technological development. One of the key components of the spreading of successful technologies is the copying, i.e. members of the system adopt technologies used by other individuals according to certain decision mechanisms. Decision making is usually based on a cost-benefit balance so that a technology gets adopted by a large number of individuals if the upgrading provides enough benefits. The gradual adaptation of high level technologies leads to spreading of technologies and an overall technological progress of the socio-economic system. We proposed an agent based model for the spreading process of such technologies in which the interaction of individuals plays a crucial role. Agents of the model use products of different technologies to collaborate with each other which induce costs proportional to the difference of technological levels. Additional costs arise when technologies of different providers are used. Agents can adopt technologies and providers of their interacting partners in order to reduce their costs leading to microscopic rearrangements of the system. Starting from a random configuration of different technological levels a complex time evolution emerges where the spreading of advanced technologies and the overall technological progress of the system are determined by the amount of advantages more advanced technologies provide, and by the structure of the social environment of agents. When technological progress arises, the spreading of technologies in the system can be described by extreme order

Population genetic structure of a common host predicts the spread of white-nose syndrome, an emerging infectious disease in bats.

Science.gov (United States)

Wilder, Aryn P; Kunz, Thomas H; Sorenson, Michael D

2015-11-01

Landscape complexity influences patterns of animal dispersal, which in turn may affect both gene flow and the spread of pathogens. White-nose syndrome (WNS) is an introduced fungal disease that has spread rapidly throughout eastern North America, causing massive mortality in bat populations. We tested for a relationship between the population genetic structure of the most common host, the little brown myotis (Myotis lucifugus), and the geographic spread of WNS to date by evaluating logistic regression models of WNS risk among hibernating colonies in eastern North America. We hypothesized that risk of WNS to susceptible host colonies should increase with both geographic proximity and genetic similarity, reflecting historical connectivity, to infected colonies. Consistent with this hypothesis, inclusion of genetic distance between infected and susceptible colonies significantly improved models of disease spread, capturing heterogeneity in the spatial expansion of WNS despite low levels of genetic differentiation among eastern populations. Expanding our genetic analysis to the continental range of little brown myotis reveals strongly contrasting patterns of population structure between eastern and western North America. Genetic structure increases markedly moving westward into the northern Great Plains, beyond the current distribution of WNS. In western North America, genetic differentiation of geographically proximate populations often exceeds levels observed across the entire eastern region, suggesting infrequent and/or locally restricted dispersal, and thus relatively limited opportunities for pathogen introduction in western North America. Taken together, our analyses suggest a possibly slower future rate of spread of the WNS pathogen, at least as mediated by little brown myotis. © 2015 John Wiley & Sons Ltd.

Modeling universal dynamics of cell spreading on elastic substrates.

Science.gov (United States)

Fan, Houfu; Li, Shaofan

2015-11-01

A three-dimensional (3D) multiscale moving contact line model is combined with a soft matter cell model to study the universal dynamics of cell spreading over elastic substrates. We have studied both the early stage and the late stage cell spreading by taking into account the actin tension effect. In this work, the cell is modeled as an active nematic droplet, and the substrate is modeled as a St. Venant Kirchhoff elastic medium. A complete 3D simulation of cell spreading has been carried out. The simulation results show that the spreading area versus spreading time at different stages obeys specific power laws, which is in good agreement with experimental data and theoretical prediction reported in the literature. Moreover, the simulation results show that the substrate elasticity may affect force dipole distribution inside the cell. The advantage of this approach is that it combines the hydrodynamics of actin retrograde flow with moving contact line model so that it can naturally include actin tension effect resulting from actin polymerization and actomyosin contraction, and thus it might be capable of simulating complex cellular scale phenomenon, such as cell spreading or even crawling.

INNOVATION PROCESS FOR HALAL PRODUCT DEVELOPMENT: AN EMPIRICAL ANALYSIS OF ITALIAN FIRMS

OpenAIRE

Giacomo DI FOGGIA; Stefano FERRARI; Valentina LAZZAROTTI; Emanuele PIZZURNO

2011-01-01

The Halal global market is promising a rapid and sustained growth (Berry 2008; Sungkar et al., 2008). In fact, only for Halal food industry, the amount of international trade has exceeded 2.1 trillion USD in 2006 (Berry 2008; Riaz and Chaudry 2004). The reasons of the prompt growing are multiple, but mainly due to (1) the rapid spread of the Islamic faithful worldwide, (2) the increasing spending power of the Islamic people. Despite the importance this market has on the global scene, few stud...

Perineural spread of nasopharyngeal carcinoma: Radiological and CT demonstration

Energy Technology Data Exchange (ETDEWEB)

Pandolfo, I.; Gaeta, M.; Longo, M.; Faranda, C.; Blandino, A.

1988-11-01

Perineural spread is well known to be the most insidious form of tumour spread of a number of head and neck malignancies. However, perineural extension of nasopharyngeal carcinoma (NC) is a poorly recognized event. Four cases of perineural metastases from NC have been detected with pluridirectional tomography and CT. In 3 cases involvement of the Vidian nerve (nervus canalis pterygoidei) and pterygoid canal was observed. In a fourth patient, invasion of one pterygopalatine fossa and perineural spread along ipsilateral maxillary nerve with enlargement and erosion of the foramen rotundum was demonstrated. Radiological diagnosis of clinically unsuspected perineural tumour spread is important because it markedly influences treatment planning and prognosis of NC.

Spread spectrum image steganography.

Science.gov (United States)

Marvel, L M; Boncelet, C R; Retter, C T

1999-01-01

In this paper, we present a new method of digital steganography, entitled spread spectrum image steganography (SSIS). Steganography, which means "covered writing" in Greek, is the science of communicating in a hidden manner. Following a discussion of steganographic communication theory and review of existing techniques, the new method, SSIS, is introduced. This system hides and recovers a message of substantial length within digital imagery while maintaining the original image size and dynamic range. The hidden message can be recovered using appropriate keys without any knowledge of the original image. Image restoration, error-control coding, and techniques similar to spread spectrum are described, and the performance of the system is illustrated. A message embedded by this method can be in the form of text, imagery, or any other digital signal. Applications for such a data-hiding scheme include in-band captioning, covert communication, image tamperproofing, authentication, embedded control, and revision tracking.

GENDER AND GLOBALIZATION: FEMALE LABOR AND WOMEN'S MOBILIZATION

Directory of Open Access Journals (Sweden)

Val Moghadam

2015-08-01

Full Text Available This paper casts a gender perspective on globalization to illuminate the contradictory effects on women workers and on women's activism. The scope of the paper is global. The sources of data are UN publications, country-based data and newsletters from women's organizations as well as the author's fieldwork. The paper begins by examining the various dimensions of globalization-economic, political and cultural, with a focus on their contradictory social-gender effects. These include inequalities in the global economy and the continued hegemony of the core, the feminization of labor, the withering away of the developmentalist/welfarist state, the rise of identity politics and other forms of particularism, the spread of concepts of human rights and women's rights, and the proliferation of women's organizations and transnational feminist networks. I argue that, although globalization has had dire economic effects, the process has created a new constituency-working women and organizing women who may herald a potent anti-systemic movement. World-systems theory, social movement theory, and development studies should take account of female labor and of oppositional transnational feminist networks.

Economic liberalization and globalization vs. India's poor

OpenAIRE

Oschinski, Matthias

2003-01-01

Today, many in the national and international NGO community perceive globalization and economic liberalization as a threat claiming that it widens inequalities and increases overall poverty. While it is true that inequality is on the rise in a rapidly globalizing world the real culprit is not globalization itself but rather a lack of economic reforms and economic liberalization. This paper aims to show that many in the international NGO community confuse cause and effect. The root cause of po...

Globalization and Social Justice in OECD Countries

OpenAIRE

Björn Kauder; Niklas Potrafke

2015-01-01

Social justice is a topic of importance to social scientists and also political decision makers. We examine the relationship between globalization and social justice as measured by a new indicator for 31 OECD countries. The results show that countries that experienced rapid globalization enjoy social justice. When the KOF index of globalization increases by one standard deviation, the social justice indicator increases by about 0.4 points (on a scale from 1 to 10). The policy implication is t...

Nuclear stockpiles globalization

International Nuclear Information System (INIS)

Jouffray, Fabien

2016-01-01

For technological reasons, but more importantly political ones, the spread of nuclear weapons is foreseen as inevitable especially with the multiplication of so-called 'threshold states'. On the one hand, technological barriers will gradually disappear with globalization and information sharing in our societies. Furthermore, becoming a threshold power appears today as key to get freedom of action, a tool of counter-deterrence or blackmail according to the camp you belong to, like in the Iranian and north Korean cases. For proliferant countries, it will now consist in an enforcement of an embryonic, even though rather deterrent or even threatening, nuclear program thanks to new technologies, reducing completion times and even allowing to skip the final nuclear test

Spreading of a granular droplet

Science.gov (United States)

Clement, Eric; Sanchez, Ivan; Raynaud, Franck; Lanuza, Jose; Andreotti, Bruno; Aranson, Igor

2008-03-01

The influence of controlled vibrations on the granular rheology is investigated in a specifically designed experiment in which a granular film spreads under the action of horizontal vibrations. A nonlinear diffusion equation is derived theoretically that describes the evolution of the deposit shape. A self-similar parabolic shape (the``granular droplet'') and a spreading dynamics are predicted that both agree quantitatively with the experimental results. The theoretical analysis is used to extract effective friction coefficients between the base and the granular layer under sustained and controlled vibrations. A shear thickening regime characteristic of dense granular flows is evidenced at low vibration energy, both for glass beads and natural sand. Conversely, shear thinning is observed at high agitation.

Dynamic wetting and spreading and the role of topography

International Nuclear Information System (INIS)

McHale, Glen; Newton, Michael I; Shirtcliffe, Neil J

2009-01-01

The spreading of a droplet of a liquid on a smooth solid surface is often described by the Hoffman-de Gennes law, which relates the edge speed, v e , to the dynamic and equilibrium contact angles θ and θ e through v e ∝θ(θ 2 -θ e 2 ). When the liquid wets the surface completely and the equilibrium contact angle vanishes, the edge speed is proportional to the cube of the dynamic contact angle. When the droplets are non-volatile this law gives rise to simple power laws with time for the contact angle and other parameters in both the capillary and gravity dominated regimes. On a textured surface, the equilibrium state of a droplet is strongly modified due to the amplification of the surface chemistry induced tendencies by the topography. The most common example is the conversion of hydrophobicity into superhydrophobicity. However, when the surface chemistry favors partial wetting, topography can result in a droplet spreading completely. A further, frequently overlooked consequence of topography is that the rate at which an out-of-equilibrium droplet spreads should also be modified. In this report, we review ideas related to the idea of topography induced wetting and consider how this may relate to dynamic wetting and the rate of droplet spreading. We consider the effect of the Wenzel and Cassie-Baxter equations on the driving forces and discuss how these may modify power laws for spreading. We relate the ideas to both the hydrodynamic viscous dissipation model and the molecular-kinetic theory of spreading. This suggests roughness and solid surface fraction modified Hoffman-de Gennes laws relating the edge speed to the dynamic and equilibrium contact angle. We also consider the spreading of small droplets and stripes of non-volatile liquids in the capillary regime and large droplets in the gravity regime. In the case of small non-volatile droplets spreading completely, a roughness modified Tanner's law giving the dependence of dynamic contact angle on time is

The global and Canadian energy outlook

International Nuclear Information System (INIS)

Stewart, M.J.

2006-01-01

The global energy situation is rapidly changing. Global oil and gas trade is increasing, in an environment of rising prices, higher costs, greater environmental concerns, and growing security uncertainties. While predictions of shortages through depletion of oil and gas reserves are unfounded, the world must adapt to higher prices and changing trade patterns, as conventional reserves are increasingly being replaced un-conventional resources. Canada, drawing upon its vast natural resources and technological innovation, is positioned to be an even more important global energy leader in the 21st century. (author)

HIV-associated disruption of tight and adherens junctions of oral epithelial cells facilitates HSV-1 infection and spread.

Directory of Open Access Journals (Sweden)

Irna Sufiawati

Full Text Available Herpes simplex virus (HSV types 1 and 2 are the most common opportunistic infections in HIV/AIDS. In these immunocompromised individuals, HSV-1 reactivates and replicates in oral epithelium, leading to oral disorders such as ulcers, gingivitis, and necrotic lesions. Although the increased risk of HSV infection may be mediated in part by HIV-induced immune dysfunction, direct or indirect interactions of HIV and HSV at the molecular level may also play a role. In this report we show that prolonged interaction of the HIV proteins tat and gp120 and cell-free HIV virions with polarized oral epithelial cells leads to disruption of tight and adherens junctions of epithelial cells through the mitogen-activated protein kinase signaling pathway. HIV-induced disruption of oral epithelial junctions facilitates HSV-1 paracellular spread between the epithelial cells. Furthermore, HIV-associated disruption of adherens junctions exposes sequestered nectin-1, an adhesion protein and critical receptor for HSV envelope glycoprotein D (gD. Exposure of nectin-1 facilitates binding of HSV-1 gD, which substantially increases HSV-1 infection of epithelial cells with disrupted junctions over that of cells with intact junctions. Exposed nectin-1 from disrupted adherens junctions also increases the cell-to-cell spread of HSV-1 from infected to uninfected oral epithelial cells. Antibodies to nectin-1 and HSV-1 gD substantially reduce HSV-1 infection and cell-to-cell spread, indicating that HIV-promoted HSV infection and spread are mediated by the interaction of HSV gD with HIV-exposed nectin-1. Our data suggest that HIV-associated disruption of oral epithelial junctions may potentiate HSV-1 infection and its paracellular and cell-to-cell spread within the oral mucosal epithelium. This could be one of the possible mechanisms of rapid development of HSV-associated oral lesions in HIV-infected individuals.

Global Governance Mechanisms to Address Antimicrobial Resistance.