WorldWideScience

Sample records for rapid global spread

  1. Asian origin and rapid global spread of the destructive dry rot fungus Serpula lacrymans.

    Science.gov (United States)

    Kauserud, Håvard; Svegården, Ingeborg Bjorvand; Saetre, Glenn-Peter; Knudsen, Henning; Stensrud, Øyvind; Schmidt, Olaf; Doi, Shuichi; Sugiyama, Tomoaki; Högberg, Nils

    2007-08-01

    The dry rot fungus Serpula lacrymans (Basidiomycota) is the most damaging destroyer of wood construction materials in temperate regions. While being a widespread aggressive indoor biodeterioration agent, it is only found in a few natural environments. The geographical source of spread and colonization by this fungus in human environments is thus somewhat of an enigma. Employing genetic markers (amplified fragment length polymorphisms, DNA sequences and microsatellites) on a worldwide sample of specimens, we show that the dry rot fungus is divided into two main lineages; one nonaggressive residing naturally in North America and Asia (var. shastensis), and another aggressive lineage including specimens from all continents, both from natural environments and buildings (var. lacrymans). Our genetic analyses indicate that the two lineages represent well-differentiated cryptic species. Genetic analyses pinpoint mainland Asia as the origin of the aggressive form var. lacrymans. A few aggressive genotypes have migrated worldwide from Asia to Europe, North and South America and Oceania followed by local population expansions. The very low genetic variation in the founder populations indicate that they have established through recent founder events, for example by infected wood materials transported over land or sea. A separate colonization has happened from mainland Asia to Japan. Our data also indicate that independent immigration events have happened to Oceania from different continents followed by admixture.

  2. Facing Two Rapidly Spreading Internet Worms

    CERN Multimedia

    IT Department

    2009-01-01

    The Internet is currently facing a growing number of computer infections due to two rapidly spreading worms. The "Conficker" and "Downadup" worms have infected an estimated 1.1 million PCs in a 24-hour period, bringing the total number of infected computers to 3.5 million [1]. Via a single USB stick, these worms were also responsible for the infection of about 40 laptops at the last EGEE conference in Istanbul. In order to reduce the impact of these worms on CERN Windows computers, the Computer Security Team has suggested several preventive measures described here. Disabling the Windows AutoRun and AutoPlay Features The Computer Security Team and the IT/IS group have decided to disable the "AutoRun" and "AutoPlay" functionality on all centrally-managed Windows computers at CERN. When inserting CDs, DVDs or USB sticks into a PC, "AutoRun" and "AutoPlay" are responsible for automatically playing music or films stored on these media, or ...

  3. Rapidly spreading seagrass invades the Caribbean with unknown ecological consequences

    Science.gov (United States)

    Rogers, Caroline S.; Willette, Demian A; Miller, Jeff

    2014-01-01

    The non-native seagrass Halophila stipulacea has spread rapidly throughout the Caribbean Sea (Willette et al. 2014); without additional research, the ecological ramifications of this invasion are difficult to predict. Biodiversity, connectivity of marine ecosystems, and recovery of degraded coral reefs could all be affected. The invasive seagrass, native to the Red Sea and Indian Ocean, has taken over sand bottoms and intermixed with or replaced native seagrasses, including Thalassia testudinum, Syringodium filiforme, and Halodule wrightii.

  4. Global transport networks and infectious disease spread.

    Science.gov (United States)

    Tatem, A J; Rogers, D J; Hay, S I

    2006-01-01

    Air, sea and land transport networks continue to expand in reach, speed of travel and volume of passengers and goods carried. Pathogens and their vectors can now move further, faster and in greater numbers than ever before. Three important consequences of global transport network expansion are infectious disease pandemics, vector invasion events and vector-borne pathogen importation. This review briefly examines some of the important historical examples of these disease and vector movements, such as the global influenza pandemics, the devastating Anopheles gambiae invasion of Brazil and the recent increases in imported Plasmodium falciparum malaria cases. We then outline potential approaches for future studies of disease movement, focussing on vector invasion and vector-borne disease importation. Such approaches allow us to explore the potential implications of international air travel, shipping routes and other methods of transport on global pathogen and vector traffic.

  5. Predicting the global spread range via small subnetworks

    Science.gov (United States)

    Sun, Jiachen; Dong, Junyou; Ma, Xiao; Feng, Ling; Hu, Yanqing

    2017-04-01

    Modern online social network platforms are replacing traditional media due to their effectiveness in both spreading information and communicating opinions. One of the key problems in these online platforms is to predict the global spread range of any given information. Due to its gigantic size as well as time-varying dynamics, an online social network's global structure, however, is usually inaccessible to most researchers. Thus, it raises the very important issue of how to use solely small subnetworks to predict the global influence. In this paper, based on percolation theory, we show that the global spread range can be predicted well from only two small subnetworks. We test our methods in an artificial network and three empirical online social networks, such as the full Sina Weibo network with 99546027 nodes.

  6. ANTIMICROBIAL RESISTANCE AND ITS GLOBAL SPREAD

    Directory of Open Access Journals (Sweden)

    R P Sharma

    2010-06-01

    Full Text Available Since their discovery during the 20th century, antimicrobial agents (antibiotics and related medicinal drugs have substantially reduced the threat posed by infectious diseases. The use of these “wonder drugs”, combined with improvements in sanitation, housing, and nutrition, and the advent of widespread immunization programmes, has led to a dramatic drop in deaths from diseases that were previously widespread, untreatable, and frequently fatal. Over the years, antimicrobials have saved the lives and eased the suffering of millions of people. By helping to bring many serious infectious diseases under control, these drugs hav also contributed to the major gains in life expectancy experienced during the latter part of the last century. These gains are now seriously jeopardized by another recent development: the emergence and spread of microbes that are resistant to cheap and effective first-choice, or “first- line” drugs. The bacterial infections which contribute most to human disease are also those in which emerging microbial resistance is most evident: diarrhoeal diseases, respiratory tract infections, meningitis, sexually transmitted infections, and hospital-acquired infections. Some important examples include penicillin-resistant Streptococcus pneumoniae, vancomycin-resistant enterococci, methicillin-resistant Staphylococcus aureus, multi-resistant salmonellae, and multi-resistant Mycobacterium tuberculosis. The development of resistance to drugs commonly used to treat malaria is of particular concern, as is the emerging resistance to anti-HIV drugs. Treatment, resu.lting in prolonged illness and greater risk of death, Treatment failures also lead to longer periods of infectivity, which increase the numbers of infected people moving in the community and thus expose the general population to the risk of contracting a resistant strain of infection. When infections become resistant to first-line antimicrobials, treatment has to be switched

  7. Emergence and global spread of epidemic healthcare-associated Clostridium difficile.

    Science.gov (United States)

    He, Miao; Miyajima, Fabio; Roberts, Paul; Ellison, Louise; Pickard, Derek J; Martin, Melissa J; Connor, Thomas R; Harris, Simon R; Fairley, Derek; Bamford, Kathleen B; D'Arc, Stephanie; Brazier, Jon; Brown, Derek; Coia, John E; Douce, Gill; Gerding, Dale; Kim, Hee Jung; Koh, Tse Hsien; Kato, Haru; Senoh, Mitsutoshi; Louie, Tom; Michell, Stephen; Butt, Emma; Peacock, Sharon J; Brown, Nick M; Riley, Tom; Songer, Glen; Wilcox, Mark; Pirmohamed, Munir; Kuijper, Ed; Hawkey, Peter; Wren, Brendan W; Dougan, Gordon; Parkhill, Julian; Lawley, Trevor D

    2013-01-01

    Epidemic C. difficile (027/BI/NAP1) has rapidly emerged in the past decade as the leading cause of antibiotic-associated diarrhea worldwide. However, the key events in evolutionary history leading to its emergence and the subsequent patterns of global spread remain unknown. Here, we define the global population structure of C. difficile 027/BI/NAP1 using whole-genome sequencing and phylogenetic analysis. We show that two distinct epidemic lineages, FQR1 and FQR2, not one as previously thought, emerged in North America within a relatively short period after acquiring the same fluoroquinolone resistance-conferring mutation and a highly related conjugative transposon. The two epidemic lineages showed distinct patterns of global spread, and the FQR2 lineage spread more widely, leading to healthcare-associated outbreaks in the UK, continental Europe and Australia. Our analysis identifies key genetic changes linked to the rapid transcontinental dissemination of epidemic C. difficile 027/BI/NAP1 and highlights the routes by which it spreads through the global healthcare system.

  8. The global spread of HIV-1 subtype B epidemic.

    Science.gov (United States)

    Magiorkinis, Gkikas; Angelis, Konstantinos; Mamais, Ioannis; Katzourakis, Aris; Hatzakis, Angelos; Albert, Jan; Lawyer, Glenn; Hamouda, Osamah; Struck, Daniel; Vercauteren, Jurgen; Wensing, Annemarie; Alexiev, Ivailo; Åsjö, Birgitta; Balotta, Claudia; Gomes, Perpétua; Camacho, Ricardo J; Coughlan, Suzie; Griskevicius, Algirdas; Grossman, Zehava; Horban, Anders; Kostrikis, Leondios G; Lepej, Snjezana J; Liitsola, Kirsi; Linka, Marek; Nielsen, Claus; Otelea, Dan; Paredes, Roger; Poljak, Mario; Puchhammer-Stöckl, Elizabeth; Schmit, Jean Claude; Sönnerborg, Anders; Staneková, Danica; Stanojevic, Maja; Stylianou, Dora C; Boucher, Charles A B; Nikolopoulos, Georgios; Vasylyeva, Tetyana; Friedman, Samuel R; van de Vijver, David; Angarano, Gioacchino; Chaix, Marie-Laure; de Luca, Andrea; Korn, Klaus; Loveday, Clive; Soriano, Vincent; Yerly, Sabine; Zazzi, Mauricio; Vandamme, Anne-Mieke; Paraskevis, Dimitrios

    2016-12-01

    Human immunodeficiency virus type 1 (HIV-1) was discovered in the early 1980s when the virus had already established a pandemic. For at least three decades the epidemic in the Western World has been dominated by subtype B infections, as part of a sub-epidemic that traveled from Africa through Haiti to United States. However, the pattern of the subsequent spread still remains poorly understood. Here we analyze a large dataset of globally representative HIV-1 subtype B strains to map their spread around the world over the last 50years and describe significant spread patterns. We show that subtype B travelled from North America to Western Europe in different occasions, while Central/Eastern Europe remained isolated for the most part of the early epidemic. Looking with more detail in European countries we see that the United Kingdom, France and Switzerland exchanged viral isolates with non-European countries than with European ones. The observed pattern is likely to mirror geopolitical landmarks in the post-World War II era, namely the rise and the fall of the Iron Curtain and the European colonialism. In conclusion, HIV-1 spread through specific migration routes which are consistent with geopolitical factors that affected human activities during the last 50years, such as migration, tourism and trade. Our findings support the argument that epidemic control policies should be global and incorporate political and socioeconomic factors. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  9. Emergence and global spread of epidemic healthcare-associated Clostridium difficile

    OpenAIRE

    He, Miao; Miyajima, Fabio; Roberts, Paul; Ellison, Louise; Pickard, Derek J.; Martin, Melissa J.; Connor, Thomas R.; Harris, Simon R.; Fairley, Derek; Bamford, Kathleen B.; D?Arc, Stephanie; Brazier, Jon; Brown, Derek; Coia, John E.; Douce, Gill

    2012-01-01

    Epidemic C. difficile (027/BI/NAP1) has rapidly emerged in the past decade as the leading cause of antibiotic-associated diarrhea worldwide. However, the key events in evolutionary history leading to its emergence and the subsequent patterns of global spread remain unknown. Here, we define the global population structure of C. difficile 027/BI/NAP1 using whole-genome sequencing and phylogenetic analysis. We show that two distinct epidemic lineages, FQR1 and FQR2, not one as previously thought...

  10. Subduction, back-arc spreading and global mantle flow

    Science.gov (United States)

    Hager, B. H.; Oconnell, R. J.; Raefsky, A.

    1983-01-01

    It is pointed out that the subducted lithosphere associated with Benioff zones provides the only direct evidence about the flow in the earth's interior associated with plate motions. It is the primary objective of the present investigation to study the relation between the orientation of subducting lithosphere and the flow patterns (both local and global) near subduction zones. Most of the calculations conducted are based on simple flow models for radially symmetric, Newtonian viscous spheres. The investigation is concerned with the possibility that a simple model of global mantle flow could account for some features of subduction zones. It is found that such a model can account for the orientation of the seismic zones, and, in addition, also for features related to back-arc spreading and perhaps the maximum earthquake size.

  11. Forced Spreading of Aqueous Solutions on Zwitterionic Sulfobetaine Surfaces for Rapid Evaporation and Solute Separation.

    Science.gov (United States)

    Wu, Cyuan-Jhang; Singh, Vickramjeet; Sheng, Yu-Jane; Tsao, Heng-Kwong

    2017-08-01

    Solute separation of aqueous mixtures is mainly dominated by water vaporization. The evaporation rate of an aqueous drop grows with increasing the liquid-gas interfacial area. The spontaneous spreading behavior of a water droplet on a total wetting surface provides huge liquid-gas interfacial area per unit volume; however, it is halted by the self-pinning phenomenon upon addition of nonvolatile solutes. In this work, it is shown that the solute-induced self-pinning can be overcome by gravity, leading to anisotropic spreading much faster than isotropic spreading. The evaporation rate of anisotropic spreading on a zwitterionic sulfobetaine surface is 25 times larger as that on a poly(methyl methacrylate) surface. Dramatic enhancement of evaporation is demonstrated by simultaneous formation of fog atop liquid film. During anisotropic spreading, the solutes are quickly precipitated out within 30 s, showing the rapid solute-water separation. After repeated spreading process for the dye-containing solution, the mean concentration of the collection is doubled, revealing the concentration efficiency as high as 100%. Gravity-enhanced spreading on total wetting surfaces at room temperature is easy to scale-up with less energy consumption, and thus it has great potentials for the applications of solute separation and concentration.

  12. Global Spread of Leprosy Tied to Human Migration

    National Research Council Canada - National Science Library

    David Grimm

    2005-01-01

    ... of how leprosy spread and indicate that colonialism and the slave trade helped bring the sickness to West Africa and much of the New World. "It's very interesting work that should help us fill in the picture of how human migration is tied to the dissemination of leprosy," says Daniel Hartl, a population geneticist at Harvard Universit...

  13. The contribution of rapid intraoperative cytology in the evaluation of endometrial cancer spread.

    Science.gov (United States)

    Anastasiadis, Panagiotis; Koutlaki, Nikoleta; Liberis, Vasilios; Tsikouras, Panagiotis; Dimitraki, Marina; Liberis, Anastasios; Galazios, George

    2011-02-01

    Peritoneal washing cytology and imprint cytology of pelvic lymph nodes samples were used to evaluate the rapid cytologic detection of peritoneal and retroperitoneal spread of endometrial cancer. We undertook a study on 194 endometrial cancer patients who underwent primary treatment in the Gynecologic Clinic, Democritus University of Thrace. All patients were subjected to peritoneal washing (PW) cytology and imprint cytology performed on lymph node sampling. The cytologic specimens were stained by May-Grünwald Giemsa (MGG) and Haematoxylin eosin (HE) techniques. Cell-blocks prepared from peritoneal washings (PWs) and the lymph node samples were sent for histologic examination. The cytologic fi ndings were correlated to histologic results. Rapid intraoperative cytology provides a useful diagnostic technique for the assessment of endometrial cancer spread. HE and MGG stain presented different values of sensitivity and specifi city in the detection of peritoneal and retroperitoneal spread of endometrial cancer. Cytologic assessment of intraperitoneal and retroperitoneal spread of endometrial cancer is a rapid, intraoperative procedure, which provides the surgeon with useful information regarding the stage of the disease and the subsequent therapeutic approach.

  14. A passerine spreads its tail to facilitate a rapid recovery of its body posture during hovering

    Science.gov (United States)

    Su, Jian-Yuan; Ting, Shang-Chieh; Chang, Yu-Hung; Yang, Jing-Tang

    2012-01-01

    We demonstrate experimentally that a passerine exploits tail spreading to intercept the downward flow induced by its wings to facilitate the recovery of its posture. The periodic spreading of its tail by the White-eye bird exhibits a phase correlation with both wingstroke motion and body oscillation during hovering flight. During a downstroke, a White-eye's body undergoes a remarkable pitch-down motion, with the tail undergoing an upward swing. This pitch-down motion becomes appropriately suppressed at the end of the downstroke; the bird's body posture then recovers gradually to its original status. Employing digital particle-image velocimetry, we show that the strong downward flow induced by downstroking the wings serves as an external jet flow impinging upon the tail, providing a depressing force on the tail to counteract the pitch-down motion of the bird's body. Spreading of the tail enhances a rapid recovery of the body posture because increased forces are experienced. The maximum force experienced by a spread tail is approximately 2.6 times that of a non-spread tail. PMID:22258552

  15. A passerine spreads its tail to facilitate a rapid recovery of its body posture during hovering.

    Science.gov (United States)

    Su, Jian-Yuan; Ting, Shang-Chieh; Chang, Yu-Hung; Yang, Jing-Tang

    2012-07-07

    We demonstrate experimentally that a passerine exploits tail spreading to intercept the downward flow induced by its wings to facilitate the recovery of its posture. The periodic spreading of its tail by the White-eye bird exhibits a phase correlation with both wingstroke motion and body oscillation during hovering flight. During a downstroke, a White-eye's body undergoes a remarkable pitch-down motion, with the tail undergoing an upward swing. This pitch-down motion becomes appropriately suppressed at the end of the downstroke; the bird's body posture then recovers gradually to its original status. Employing digital particle-image velocimetry, we show that the strong downward flow induced by downstroking the wings serves as an external jet flow impinging upon the tail, providing a depressing force on the tail to counteract the pitch-down motion of the bird's body. Spreading of the tail enhances a rapid recovery of the body posture because increased forces are experienced. The maximum force experienced by a spread tail is approximately 2.6 times that of a non-spread tail.

  16. Rapidly Tunable Dual-Comb RF Photonic Filter for Ultrabroadband RF Spread Spectrum Applications

    OpenAIRE

    Kim, Hyoung-Jun; Leaird, Daniel E.; Weiner, Andrew M.

    2016-01-01

    IEEE Transactions on Microwave Theory and Techniques The article of record as published may be found at http://dx.doi.org/10.1109/tmtt.2016.2599162 We demonstrate a rapidly frequency-tunable radio frequency (RF) filter using microwave photonics technology for ultrawideband RF spread spectrum applications. A pair of electro-optic frequency combs is arranged as a dispersive tapped delay line in a differential detection configuration to implement a programmable finite impulse response RF f...

  17. Propagation of capillary waves and ejection of small droplets in rapid droplet spreading

    KAUST Repository

    Ding, Hang

    2012-03-12

    A new regime of droplet ejection following the slow deposition of drops onto a near-complete wetting solid substrate is identified in experiments and direct numerical simulations; a coalescence cascade subsequent to pinch-off is also observed for the first time. Results of numerical simulations indicate that the propagation of capillary waves that lead to pinch-off is closely related to the self-similar behaviour observed in the inviscid recoil of droplets, and that motions of the crests and troughs of capillary waves along the interface do not depend on the wettability and surface tension (or Ohnesorge number). The simulations also show that a self-similar theory for universal pinch-off can be used for the time evolution of the pinching neck. However, although good agreement is also found with the double-cone shape of the pinching neck for droplet ejection in drop deposition on a pool of the same liquid, substantial deviations are observed in such a comparison for droplet ejection in rapid drop spreading (including the newly identified regime). This deviation is shown to result from interference by the solid substrate, a rapid downwards acceleration of the top of the drop surface and the rapid spreading process. The experiments also confirm non-monotonic spreading behaviour observed previously only in numerical simulations, and suggest substantial inertial effects on the relation between an apparent contact angle and the dimensionless contact-line speed. © 2012 Cambridge University Press.

  18. Globalization and the spread of ICT’s

    OpenAIRE

    Jean-Michel LEDJOU

    2010-01-01

    In Africa, technological innovation has helped to uncover dynamics in contrast with the frozen image that some might have of the continent. Information and communication technologies (ICTs) are a challenge for international operators. What are the consequences of ICTs diffusion policies? In a context of globalization, how do people appropriate those technologies?

  19. Impact of the topology of global macroeconomic network on the spreading of economic crises.

    Science.gov (United States)

    Lee, Kyu-Min; Yang, Jae-Suk; Kim, Gunn; Lee, Jaesung; Goh, Kwang-Il; Kim, In-mook

    2011-03-31

    Throughout economic history, the global economy has experienced recurring crises. The persistent recurrence of such economic crises calls for an understanding of their generic features rather than treating them as singular events. The global economic system is a highly complex system and can best be viewed in terms of a network of interacting macroeconomic agents. In this regard, from the perspective of collective network dynamics, here we explore how the topology of the global macroeconomic network affects the patterns of spreading of economic crises. Using a simple toy model of crisis spreading, we demonstrate that an individual country's role in crisis spreading is not only dependent on its gross macroeconomic capacities, but also on its local and global connectivity profile in the context of the world economic network. We find that on one hand clustering of weak links at the regional scale can significantly aggravate the spread of crises, but on the other hand the current network structure at the global scale harbors higher tolerance of extreme crises compared to more "globalized" random networks. These results suggest that there can be a potential hidden cost in the ongoing globalization movement towards establishing less-constrained, trans-regional economic links between countries, by increasing vulnerability of the global economic system to extreme crises.

  20. The effects of global awareness on the spreading of epidemics in multiplex networks

    Science.gov (United States)

    Zang, Haijuan

    2018-02-01

    It is increasingly recognized that understanding the complex interplay patterns between epidemic spreading and human behavioral is a key component of successful infection control efforts. In particular, individuals can obtain the information about epidemics and respond by altering their behaviors, which can affect the spreading dynamics as well. Besides, because the existence of herd-like behaviors, individuals are very easy to be influenced by the global awareness information. Here, in this paper, we propose a global awareness controlled spreading model (GACS) to explore the interplay between the coupled dynamical processes. Using the global microscopic Markov chain approach, we obtain the analytical results for the epidemic thresholds, which shows a high accuracy by comparison with lots of Monte Carlo simulations. Furthermore, considering other classical models used to describe the coupled dynamical processes, including the local awareness controlled contagion spreading (LACS) model, Susceptible-Infected-Susceptible-Unaware-Aware-Unaware (SIS-UAU) model and the single layer occasion, we make a detailed comparisons between the GACS with them. Although the comparisons and results depend on the parameters each model has, the GACS model always shows a strong restrain effects on epidemic spreading process. Our results give us a better understanding of the coupled dynamical processes and highlights the importance of considering the spreading of global awareness in the control of epidemics.

  1. Impact of the Topology of Global Macroeconomic Network on the Spreading of Economic Crises

    Science.gov (United States)

    Lee, Kyu-Min; Yang, Jae-Suk; Kim, Gunn; Lee, Jaesung; Goh, Kwang-Il; Kim, In-mook

    2011-01-01

    Throughout economic history, the global economy has experienced recurring crises. The persistent recurrence of such economic crises calls for an understanding of their generic features rather than treating them as singular events. The global economic system is a highly complex system and can best be viewed in terms of a network of interacting macroeconomic agents. In this regard, from the perspective of collective network dynamics, here we explore how the topology of the global macroeconomic network affects the patterns of spreading of economic crises. Using a simple toy model of crisis spreading, we demonstrate that an individual country's role in crisis spreading is not only dependent on its gross macroeconomic capacities, but also on its local and global connectivity profile in the context of the world economic network. We find that on one hand clustering of weak links at the regional scale can significantly aggravate the spread of crises, but on the other hand the current network structure at the global scale harbors higher tolerance of extreme crises compared to more “globalized” random networks. These results suggest that there can be a potential hidden cost in the ongoing globalization movement towards establishing less-constrained, trans-regional economic links between countries, by increasing vulnerability of the global economic system to extreme crises. PMID:21483794

  2. Rapid spread of complex change: a case study in inpatient palliative care

    Directory of Open Access Journals (Sweden)

    Filipski Marta I

    2009-12-01

    Full Text Available Abstract Background Based on positive findings from a randomized controlled trial, Kaiser Permanente's national executive leadership group set an expectation that all Kaiser Permanente and partner hospitals would implement a consultative model of interdisciplinary, inpatient-based palliative care (IPC. Within one year, the number of IPC consultations program-wide increased almost tenfold from baseline, and the number of teams nearly doubled. We report here results from a qualitative evaluation of the IPC initiative after a year of implementation; our purpose was to understand factors supporting or impeding the rapid and consistent spread of a complex program. Methods Quality improvement study using a case study design and qualitative analysis of in-depth semi-structured interviews with 36 national, regional, and local leaders. Results Compelling evidence of impacts on patient satisfaction and quality of care generated 'pull' among adopters, expressed as a remarkably high degree of conviction about the value of the model. Broad leadership agreement gave rise to sponsorship and support that permeated the organization. A robust social network promoted knowledge exchange and built on an existing network with a strong interest in palliative care. Resource constraints, pre-existing programs of a different model, and ambiguous accountability for implementation impeded spread. Conclusions A complex, hospital-based, interdisciplinary intervention in a large health care organization spread rapidly due to a synergy between organizational 'push' strategies and grassroots-level pull. The combination of push and pull may be especially important when the organizational context or the practice to be spread is complex.

  3. Observations on the Global Spread of Physician Assistant Education.

    Science.gov (United States)

    Ballweg, Ruth M; Hooker, Roderick S

    2017-10-01

    The physician assistant concept was developed in the 1960s as a response to the shortage and uneven distribution of generalist doctors. The goal was to increase the public's access to health care. After a half century of development and implementation, the PA model has become a global strategy to augment medical service delivery. In many instances the introduction of the PA was successful. Elsewhere it is in the early stages of development. The name may be modified depending on the country: "physician associate," "clinical assistant," "associate physician" are alternatives. While not all PA start-ups have been successful, where the PA model is thriving and growing, the concept provides rich examples of adaptation and evolution. The notion of including a PA is based on the concept of a medical team model and modified depending on the needs of the nation's health structure, regulation, and policy. Along the way, the education process undergoes modification, depending on the needs of the nation, but what emerges is a strategy for augmenting a stretched physician cadre. The reasons for success and failure are multifactorial, and the early implementation of a PA program can be a daunting task. This article examines the PA education experience in 15 countries. Successful use of PAs suggests that flexible adaptation to health care demand, generalist education, physician acceptance, and cost-effectiveness analysis may be keys that influence policy and their retention. In the end, success, adaptation, and failures are the lessons learned.

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

    Science.gov (United States)

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

    2017-11-01

    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 of the downgoing plate and accreted below the overlying suprasubduction zone lithosphere immediately following ophiolite formation. Paleomagnetic analyses of ophiolites can provide important insights into the enigmatic geodynamic processes operating in this setting via identification of tectonic rotations related to upper plate extension. Here we present net tectonic rotation results from the Late Cretaceous Mersin ophiolite of southern Turkey that document rapid and progressive rotation of ophiolitic rocks and their associated metamorphic sole. Specifically, we demonstrate that lower crustal cumulate rocks and early dykes intruded into the underlying mantle section have undergone extreme rotation around ridge-parallel, shallowly-plunging axes, consistent with oceanic detachment faulting during spreading. Importantly, later dykes cutting the metamorphic sole experienced rotation around the same axis but with a lower magnitude. We show that these rotations occurred via a common mechanism in a pre-obduction, fore-arc setting, and are best explained by combining (hyper)extension resulting from detachment-mode, amagmatic suprasubduction zone spreading in a fore-arc environment with a recently proposed mechanism for exhumation of metamorphic soles driven by upper plate extension. Available age constraints demonstrate that extreme rotation of these units was accommodated rapidly by these processes over a time period of <∼3 Myr, comparable with rates of rotation seen in oceanic core complexes in the modern oceans.

  5. Global stability of a two-mediums rumor spreading model with media coverage

    Science.gov (United States)

    Huo, Liang'an; Wang, Li; Song, Guoxiang

    2017-09-01

    Rumor spreading is a typical form of social communication and plays a significant role in social life, and media coverage has a great influence on the spread of rumor. In this paper, we present a new model with two media coverage to investigate the impact of the different mediums on rumor spreading. Then, we calculate the equilibria of the model and construct the reproduction number ℜ0. And we prove the global asymptotic stability of equilibria by using Lyapunov functions. Finally, we can conclude that the transition rate of the ignorants between two mediums has a direct effect on the scale of spreaders, and different media coverage has significant effects on the dynamics behaviors of rumor spreading.

  6. Modeling the potential of different countries for pandemic spread over the global air network

    Science.gov (United States)

    Sun, Zhe; Lv, Baolei; Xu, Bing

    2017-04-01

    Air network plays an important role in the spread of global epidemics due to its superior speed and range. Understanding the disease transmission pattern via network is the foundation for the prevention and control of future pandemics. In this study, we measured the potential of different countries for the pandemic spread by using a disease transmission model which integrated inter-country air traffic flow and geographic distance. The model was verified on the spread pattern of 2003 SARS, 2009 H1N1 influenza and 2014 Ebola by setting starting point at China, Mexico and Guinea respectively. Results showed that the model well reproduced the spread direction during the early stage as the time course were in good agreement with the reported arrival dates. Then the model was used to simulate the potential risk of each country in spreading the disease as the origin country. We observed that countries in North America, Europe and East Asia had the highest risk of transmission considering their high degree in the air network. We also found that for most starting countries, United States, United Kingdom, Germany and France would become the most-important spreading cores. Compared with empirical Susceptible-Infectious-Recover model, this model could respond much faster to the disease spread with no need for empirical disease transmission parameters.

  7. Global Stability of a Variation Epidemic Spreading Model on Complex Networks

    Directory of Open Access Journals (Sweden)

    De-gang Xu

    2015-01-01

    Full Text Available Epidemic spreading on networks becomes a hot issue of nonlinear systems, which has attracted many researchers’ attention in recent years. A novel epidemic spreading model with variant factors in complex networks is proposed and investigated in this paper. One main feature of this model is that virus variation is investigated in the process of epidemic dynamical spreading. The global dynamics of this model involving an endemic equilibrium and a disease-free equilibrium are, respectively, discussed. Some sufficient conditions are given for the existence of the endemic equilibrium. In addition, the global asymptotic stability problems of the disease-free equilibrium and the endemic equilibrium are also investigated by the Routh-Hurwitz stability criterion and Lyapunov stability criterion. And the uniform persistence condition of the new system is studied. Finally, numerical simulations are provided to illustrate obtained theoretical results.

  8. Predictive study on the risk of malaria spreading due to global warming

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Masaji [National Inst. for Environmental Studies, Tsukuba, Ibaraki (Japan)

    1996-12-31

    Global warming will bring about a temperature elevation, and the habitat of vectors of infectious diseases, such as malaria and dengue fever, will spread into subtropical or temperate zone. The purpose of this study is to simulate the spreading of these diseases through reexamination of existing data and collection of some additional information by field survey. From these data, the author will establish the relationship between meteorological conditions, vector density and malaria occurrence. And then he will simulate and predict the malaria epidemics in case of temperature elevation in southeast Asia and Japan.

  9. Genome scale evolution of myxoma virus reveals host-pathogen adaptation and rapid geographic spread.

    Science.gov (United States)

    Kerr, Peter J; Rogers, Matthew B; Fitch, Adam; Depasse, Jay V; Cattadori, Isabella M; Twaddle, Alan C; Hudson, Peter J; Tscharke, David C; Read, Andrew F; Holmes, Edward C; Ghedin, Elodie

    2013-12-01

    The evolutionary interplay between myxoma virus (MYXV) and the European rabbit (Oryctolagus cuniculus) following release of the virus in Australia in 1950 as a biological control is a classic example of host-pathogen coevolution. We present a detailed genomic and phylogeographic analysis of 30 strains of MYXV, including the Australian progenitor strain Standard Laboratory Strain (SLS), 24 Australian viruses isolated from 1951 to 1999, and three isolates from the early radiation in Britain from 1954 and 1955. We show that in Australia MYXV has spread rapidly on a spatial scale, with multiple lineages cocirculating within individual localities, and that both highly virulent and attenuated viruses were still present in the field through the 1990s. In addition, the detection of closely related virus lineages at sites 1,000 km apart suggests that MYXV moves freely in geographic space, with mosquitoes, fleas, and rabbit migration all providing means of transport. Strikingly, despite multiple introductions, all modern viruses appear to be ultimately derived from the original introductions of SLS. The rapidity of MYXV evolution was also apparent at the genomic scale, with gene duplications documented in a number of viruses. Duplication of potential virulence genes may be important in increasing the expression of virulence proteins and provides the basis for the evolution of novel functions. Mutations leading to loss of open reading frames were surprisingly frequent and in some cases may explain attenuation, but no common mutations that correlated with virulence or attenuation were identified.

  10. Spreading vs. Rifting as modes of extensional tectonics on the globally expanded Ganymede

    Science.gov (United States)

    Pizzi, Alberto; di Domenica, Alessandra; Komatsu, Goro; Cofano, Alessandra; Mitri, Giuseppe; Bruzzone, Lorenzo

    2017-05-01

    The formation of Ganymede's sulci is likely related to extensional tectonics that affected this largest icy satellite of Jupiter. Through geometric and structural analyses we reconstructed the pre-deformed terrains and we recognized two different modes of extension associated with sulci. In the first mode, smooth sulci constitute spreading centers between two dark terrain plates, similar to the fast oceanic spreading centers on Earth. Here extension is primarily accommodated by crustal accretion of newly formed icy crust. In the second mode, dark terrain extension is mainly accommodated by swaths of normal fault systems analogous to Earth's continental crustal rifts. A comparison with terrestrial extensional analogues, based on the fault displacement/length (Dmax/L) ratio, spacing and morphology, showed that magmato-tectonic spreading centers and continental crustal rifts on Earth follow the same relative patterns observed on Ganymede. Our results suggest that the amount of extensional strain may have previously been underestimated since the occurrence of spreading centers may have played a major role in the tectonic evolution of the globally expanded Ganymede. We also discuss a possible model for the origin of the different modes of extension in the context of the global expansion of the satellite.

  11. The rise of global corporate social responsibility: mining and the spread of global norms

    National Research Council Canada - National Science Library

    Dashwood, Hevina S

    2012-01-01

    "The Rise of Global Corporate Social Responsibility Combining insights from international relations theory with institutional approaches from organization theory and public policy, this book provides...

  12. Rapid spread of mouse mammary tumor virus in cultured human breast cells

    Directory of Open Access Journals (Sweden)

    Günzburg Walter H

    2007-10-01

    Full Text Available Abstract Background The role of mouse mammary tumor virus (MMTV as a causative agent in human breast carcinogenesis has recently been the subject of renewed interest. The proposed model is based on the detection of MMTV sequences in human breast cancer but not in healthy breast tissue. One of the main drawbacks to this model, however, was that until now human cells had not been demonstrated to sustain productive MMTV infection. Results Here, we show for the first time the rapid spread of mouse mammary tumor virus, MMTV(GR, in cultured human mammary cells (Hs578T, ultimately leading to the infection of every cell in culture. The replication of the virus was monitored by quantitative PCR, quantitative RT-PCR and immunofluorescence imaging. The infected human cells expressed, upon cultivation with dexamethasone, MMTV structural proteins and released spiked B-type virions, the infectivity of which could be neutralized by anti-MMTV antibody. Replication of the virus was efficiently blocked by an inhibitor of reverse transcription, 3'-azido-3'-deoxythymidine. The human origin of the infected cells was confirmed by determining a number of integration sites hosting the provirus, which were unequivocally identified as human sequences. Conclusion Taken together, our results show that human cells can support replication of mouse mammary tumor virus.

  13. Non-global and rapidity logarithms in narrow jet broadening

    Science.gov (United States)

    Becher, Thomas; Rahn, Rudi; Shao, Ding Yu

    2017-10-01

    We derive an all-order factorization theorem for the narrow jet broadening event shape, a measure of the transverse momentum in jet events. This is a non-global observable which receives logarithmically enhanced contributions associated with the large rapidity difference between soft and collinear radiation and which is also sensitive to soft recoil effects. Our work is the first factorization analysis of an observable of this type and we show that with regard to the non-global nature, the rapidity logarithms do not constitute an essential complication since they can be tied to the jet function, which is the same as for global observables. As a consequence, the leading non-global logarithms in narrow jet broadening are encoded in the same overall factor relevant for the hemisphere soft function and light jet mass.

  14. [Rapid spread of the HIV-1 circular recombinant CRF02-AG in Russia and neighboring countries].

    Science.gov (United States)

    Moskaleychik, F F; Laga, V Yu; Delgado, E; Vega, Y; Fernandez-Garcia, A; Perez-Alvarez; Kornilaeva, G V; Pronin, A Yu; Zhernov, Yu V; Thomson, M M; Bobkova, M R; Karamov, E V

    2015-01-01

    The spread of the HIV-1circular recombinant CRF02-AG in countries of the former Soviet union (Commonwealth of Independent States, CIS) was studies using partial and full genome sequences. The full-genome sequence of the CRF02-AG recombinant circulating in Russia was obtained for the first time. A Global phylogenetic tree of CRF02-AG full-genome sequences was constructed. Three distinct groups of the sequences were detected as clustered by the geographical location (CIS, South Korea, and France), which is indicative of the single-virus introduction in each of the regions mentioned above. The CIS cluster exhibiting minimum genetic diversity was, therefore, relatively young. The phylogenetic analysis of the env gene sequences within the CIS cluster made it possible to clearly discriminate three branches: two of Russian and one of Uzbek origin. The low genetic diversity within the two Russian subclusters provides evidence of at least two recent independent introductions of the CRF02-AG recombinant from Central Asia into Russia. This work was performed within the framework of the 7th Federal Research Program (FP&), Project EURIPRED (European Research Infrastructures for Poverty Related Diseases), grant agreement No.312661.

  15. Rapid spread and diversification of respiratory syncytial virus genotype ON1, Kenya.

    Science.gov (United States)

    Agoti, Charles N; Otieno, James R; Gitahi, Caroline W; Cane, Patricia A; Nokes, D James

    2014-06-01

    Respiratory syncytial virus genotype ON1, which is characterized by a 72-nt duplication in the attachment protein gene, has been detected in >10 countries since first identified in Ontario, Canada, in 2010. We describe 2 waves of genotype ON1 infections among children admitted to a rural hospital in Kenya during 2012. Phylogenetic analysis of attachment protein gene sequences showed multiple introductions of genotype ON1; variants distinct from the original Canadian viruses predominated in both infection waves. The genotype ON1 dominated over the other group A genotypes during the second wave, and some first wave ON1 variants reappeared in the second wave. An analysis of global genotype ON1 sequences determined that this genotype has become considerably diversified and has acquired signature coding mutations within immunogenic regions, and its most recent common ancestor dates to ≈2008-2009. Surveillance of genotype ON1 contributes to an understanding of the mechanisms of rapid emergence of respiratory viruses.

  16. Rapid Spread of Zika Virus in The Americas - Implications for Public Health Preparedness for Mass Gatherings at the 2016 Brazil Olympic Games

    Directory of Open Access Journals (Sweden)

    Eskild Petersen

    2016-03-01

    Full Text Available Mass gatherings at major international sporting events put millions of international travelers and local host-country residents at risk of acquiring infectious diseases, including locally endemic infectious diseases. The mosquito-borne Zika virus (ZIKV has recently aroused global attention due to its rapid spread since its first detection in May 2015 in Brazil to 22 other countries and other territories in the Americas. The ZIKV outbreak in Brazil, has also been associated with a significant rise in the number of babies born with microcephaly and neurological disorders, and has been declared a ‘Global Emergency by the World Health Organization. This explosive spread of ZIKV in Brazil poses challenges for public health preparedness and surveillance for the Olympics and Paralympics which are due to be held in Rio De Janeiro in August, 2016. We review the epidemiology and clinical features of the current ZIKV outbreak in Brazil, highlight knowledge gaps, and review the public health implications of the current ZIKV outbreak in the Americas. We highlight the urgent need for a coordinated collaborative response for prevention and spread of infectious diseases with epidemic potential at mass gatherings events.

  17. Global warming and the potential spread of vector-borne diseases

    Energy Technology Data Exchange (ETDEWEB)

    Patz, J. [Johns Hopkins School of Hygiene and Public Health, Baltimore, MD (United States). Dept. of Microbiology and Immunology

    1996-12-31

    Climatic factors influence many vector-borne infectious diseases, in addition to demographic, biological, and ecological determinants. The United Nation`s Intergovernmental Panel on Climate Change (IPCC) estimates an unprecedented global rise of 2.0 C by the year 2100. Of major concern is that these changes can affect the spread of many serious infectious diseases, including malaria and dengue fever. Global warming would directly affect disease transmission by shifting the mosquito`s geographic range, increasing reproductive and biting rates, and shortening pathogen incubation period. Human migration and damage to health infrastructures from the projected increase in climate variability and sea level rise could indirectly contribute to disease transmission. A review of this literature, as well as preliminary data from ongoing studies will be presented.

  18. Tracking the global spread of vaccine sentiments: the global response to Japan's suspension of its HPV vaccine recommendation.

    Science.gov (United States)

    Larson, Heidi J; Wilson, Rose; Hanley, Sharon; Parys, Astrid; Paterson, Pauline

    2014-01-01

    In June 2013 the Japanese Ministry of Health, Labor, and Welfare (MHLW) suspended its HPV vaccination recommendation after a series of highly publicized alleged adverse events following immunization stoked public doubts about the vaccine's safety. This paper examines the global spread of the news of Japan's HPV vaccine suspension through online media, and takes a retrospective look at non-Japanese media sources that were used to support those claiming HPV vaccine injury in Japan. Two searches were conducted. One searched relevant content in an archive of Google Alerts on vaccines and vaccine preventable diseases. The second search was conducted using Google Search on January 6th 2014 and on July 18th 2014, using the keywords, "HPV vaccine Japan" and "cervical cancer vaccine Japan." Both searches were used as Google Searches render more (and some different) results than Google Alerts. Online media collected and analyzed totalled 57. Sixty 3 percent were published in the USA, 23% in Japan, 5% in the UK, 2% in France, 2% in Switzerland, 2% in the Philippines, 2% in Kenya and 2% in Denmark. The majority took a negative view of the HPV vaccine, the primary concern being vaccine safety. The news of Japan's suspension of the HPV vaccine recommendation has traveled globally through online media and social media networks, being applauded by anti-vaccination groups but not by the global scientific community. The longer the uncertainty around the Japanese HPV vaccine recommendation persists, the further the public concerns are likely to travel.

  19. 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.|info:eu-repo/dai/nl/269263624

    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

  20. Complementary Factors Contributing To The Rapid Spread Of HIV-I ...

    African Journals Online (AJOL)

    Conclusions: 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, ...

  1. Limited Geographical Origin and Global Spread of Sulfadoxine-Resistant dhps Alleles in Plasmodium falciparum Populations

    Science.gov (United States)

    Venkatesan, Meera; Ohashi, Jun; Culleton, Richard; Takahashi, Nobuyuki; Tsukahara, Takahiro; Ndounga, Mathieu; Dysoley, Lek; Endo, Hiroyoshi; Hombhanje, Francis; Ferreira, Marcelo U.; Plowe, Christopher V.; Tanabe, Kazuyuki

    2011-01-01

    Background. Plasmodium falciparum malaria resistant to chloroquine and pyrimethamine originated in limited foci and migrated to Africa. It remains unresolved whether P. falciparum resistance to sulfadoxine, which is conferred by mutations in dihydropteroate synthase (DHPS), evolved following a similar pattern. Methods. The dhps locus of 893 P. falciparum isolates from 12 countries in Asia, the Pacific Islands, Africa, and South America was sequenced. Haplotypes of 6 microsatellite loci flanking the dhps locus were determined to define the genetic relationships among sulfadoxine-resistant lineages. Results. Six distinct sulfadoxine-resistant lineages were identified. Highly resistant lineages appear to have originated only in Southeast Asia and South America. Two resistant lineages found throughout Southeast Asia have been introduced to East Africa, where they appear to have spread. Conclusions. The infrequent selection of parasites highly resistant to sulfadoxine and the subsequent migration of resistant lineages from Asia to Africa are similar to the patterns observed in chloroquine and pyrimethamine resistance. These findings strongly suggest that the global migration of resistant parasites has played a decisive role in the establishment of drug-resistant P. falciparum parasites, and that similar patterns may be anticipated for the spread of artemisinin resistance. PMID:22021623

  2. 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.

  3. A method for assessing the global spread of HIV-1 infection based on air travel.

    Science.gov (United States)

    Flahault, A; Valleron, A

    1992-01-01

    "The paper presents a methodology aimed at quantifying the impact of regular air traffic on the global spread of AIDS. A compartmental approach is used to represent the fluxes of infective passengers between 52 major cities. The impact of these fluxes on the pandemic is assessed by using a methodology which has been applied in the past for studying the dynamic of an influenza pandemic. In its present version, under simplified assumptions, the model reproduces qualitatively the three world patterns of HIV-1 infection in 1988. The methodology developed in this paper does not provide a detailed past history of the virus, and does not take into account the possibility of multifoci sporadic cases in the past. However it provides evidence that the significant start of the pandemic...was by the end of the 60's in Central Africa." (SUMMARY IN FRE) excerpt

  4. A decade of plague in Mahajanga, Madagascar: insights into the global maritime spread of pandemic plague.

    Science.gov (United States)

    Vogler, Amy J; Chan, Fabien; Nottingham, Roxanne; Andersen, Genevieve; Drees, Kevin; Beckstrom-Sternberg, Stephen M; Wagner, David M; Chanteau, Suzanne; Keim, Paul

    2013-02-12

    A cluster of human plague cases occurred in the seaport city of Mahajanga, Madagascar, from 1991 to 1999 following 62 years with no evidence of plague, which offered insights into plague pathogen dynamics in an urban environment. We analyzed a set of 44 Mahajanga isolates from this 9-year outbreak, as well as an additional 218 Malagasy isolates from the highland foci. We sequenced the genomes of four Mahajanga strains, performed whole-genome sequence single-nucleotide polymorphism (SNP) discovery on those strains, screened the discovered SNPs, and performed a high-resolution 43-locus multilocus variable-number tandem-repeat analysis of the isolate panel. Twenty-two new SNPs were identified and defined a new phylogenetic lineage among the Malagasy isolates. Phylogeographic analysis suggests that the Mahajanga lineage likely originated in the Ambositra district in the highlands, spread throughout the northern central highlands, and was then introduced into and became transiently established in Mahajanga. Although multiple transfers between the central highlands and Mahajanga occurred, there was a locally differentiating and dominant subpopulation that was primarily responsible for the 1991-to-1999 Mahajanga outbreaks. Phylotemporal analysis of this Mahajanga subpopulation revealed a cycling pattern of diversity generation and loss that occurred during and after each outbreak. This pattern is consistent with severe interseasonal genetic bottlenecks along with large seasonal population expansions. The ultimate extinction of plague pathogens in Mahajanga suggests that, in this environment, the plague pathogen niche is tenuous at best. However, the temporary large pathogen population expansion provides the means for plague pathogens to disperse and become ecologically established in more suitable nonurban environments. Maritime spread of plague led to the global dissemination of this disease and affected the course of human history. Multiple historical plague waves

  5. Early-phase transmission of Yersinia pestis by unblocked fleas as a mechanism explaining rapidly spreading plague epizootics.

    Science.gov (United States)

    Eisen, Rebecca J; Bearden, Scott W; Wilder, Aryn P; Montenieri, John A; Antolin, Michael F; Gage, Kenneth L

    2006-10-17

    Plague is a highly virulent disease believed to have killed millions during three historic human pandemics. Worldwide, it remains a threat to humans and is a potential agent of bioterrorism. Dissemination of Yersinia pestis, the etiological agent of plague, by blocked fleas has been the accepted paradigm for flea-borne transmission. However, this mechanism, which requires a lengthy extrinsic incubation period before a short infectious window often followed by death of the flea, cannot sufficiently explain the rapid rate of spread that typifies plague epidemics and epizootics. Inconsistencies between the expected rate of spread by blocked rat fleas and that observed during the Black Death has even caused speculation that plague was not the cause of this medieval pandemic. We used the primary vector to humans in North America, Oropsylla montana, which rarely becomes blocked, as a model for studying alternative flea-borne transmission mechanisms. Our data revealed that, in contrast to the classical blocked flea model, O. montana is immediately infectious, transmits efficiently for at least 4 d postinfection (early phase) and may remain infectious for a long time because the fleas do not suffer block-induced mortality. These factors match the criteria required to drive plague epizootics as defined by recently published mathematical models. The scenario of efficient early-phase transmission by unblocked fleas described in our study calls for a paradigm shift in concepts of how Y. pestis is transmitted during rapidly spreading epizootics and epidemics, including, perhaps, the Black Death.

  6. Rapid northward spread of a zooxanthellate coral enhanced by artificial structures and sea warming in the western Mediterranean.

    Directory of Open Access Journals (Sweden)

    Eduard Serrano

    Full Text Available The hermatypic coral Oculina patagonica can drive a compositional shift in shallow water benthic marine communities in the northwestern Mediterranean. Here, we analyze a long-term, large-scale observational dataset to characterize the dynamics of the species' recent northward range shift along the coast of Catalonia and examine the main factors that could have influenced this spread. The variation in the distributional range of Oculina patagonica was examined by monitoring 223 locations including natural and artificial habitats along >400 km of coastline over the last 19 years (1992-2010. Abundance of the species increased from being present in one location in 1992 to occur on 19% of the locations in 2010, and exhibited an acceleration of its spreading over time driven by the join action of neighborhood and long-distance dispersal. However, the pattern of spread diverged between artificial and natural habitats. A short lag phase and a high slope on the exponential phase characterized the temporal pattern of spread on artificial habitats in contrast to that observed on natural ones. Northward expansion has occurred at the fastest rate (22 km year(-1 reported for a coral species thus far, which is sufficiently fast to cope with certain climate warming predictions. The pattern of spread suggests that this process is mediated by the interplay of (i the availability of open space provided by artificial habitats, (ii the seawater temperature increase with the subsequent extension of the growth period, and (iii the particular biological features of O. patagonica (current high growth rates, early reproduction, and survival to low temperature and in polluted areas. These results are indicative of an ongoing fundamental modification of temperate shallow water assemblages, which is consistent with the predictions indicating that the Mediterranean Sea is one of the most sensitive regions to global change.

  7. 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

  8. Congener diversity, topographic heterogeneity and human-assisted dispersal predict spread rates of alien herpetofauna at a global scale.

    Science.gov (United States)

    Liu, Xuan; Li, Xianping; Liu, Zetian; Tingley, Reid; Kraus, Fred; Guo, Zhongwei; Li, Yiming

    2014-07-01

    Understanding the factors that determine rates of range expansion is not only crucial for developing risk assessment schemes and management strategies for invasive species, but also provides important insight into the ability of species to disperse in response to climate change. However, there is little knowledge on why some invasions spread faster than others at large spatiotemporal scales. Here, we examine the effects of human activities, species traits and characteristics of the invaded range on spread rates using a global sample of alien reptile and amphibian introductions. We show that spread rates vary remarkably among invaded locations within a species, and differ across biogeographical realms. Spread rates are positively related to the richness of native congeneric species and human-assisted dispersal in the invaded range but are negatively correlated with topographic heterogeneity. Our findings highlight the importance of environmental characteristics and human-assisted dispersal in developing robust frameworks for predicting species' range shifts. © 2014 John Wiley & Sons Ltd/CNRS.

  9. 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.

  10. FOREST DISTURBANCE LEADS TO THE RAPID SPREAD OF THE INVASIVE LEUCAENA LEUCOCEPHALA IN TAIWAN

    Directory of Open Access Journals (Sweden)

    J. C. Chen

    2012-07-01

    Full Text Available This study, based on different investigative documents and analytical methods, elucidates spatial distribution of habitats for major invasive exotic plants, Leucaena leucocephala, in Taiwan. Results show that Leucaena leucocephala is most harmful to broad-leaved trees and its invasion directly relates to changes in the physical environment. Leucaena leucocephala can bloom and bear fruits all year round and during the period of seeds sprouting and saplings, the invasion varies greatly among different soil types. Leucaena leucocephala prefers weakly acidic soil, though it grows well with other soil textures and nutrients as well. The average spreading rate of Leucaena leucocephala is 3.55 ha year−1 on abandoned farm land calculated from the aerial photographs taken in 1982, 1992, 2003, and 2007.

  11. 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.

  12. Aedes albopictus in the United States: rapid spread of a potential disease vector.

    Science.gov (United States)

    Moore, C G; Francy, D B; Eliason, D A; Monath, T P

    1988-09-01

    Aedes albopictus, the Asian "tiger mosquito," was found in Houston, Texas, in 1985. Aedes albopictus is primarily a forest edge inhabiting species that has readily adapted to the container habitats produced by humans. Although not yet incriminated in the spread of any disease in the Americas, it has been repeatedly implicated in epidemic dengue and dengue hemorrhagic fever transmission in Asia. It is a competent laboratory vector of La Crosse, yellow fever and other viruses, and can transovarially transmit at least 15 viruses. In 1986, Ae. albopictus was found in many other Texas counties, and in Alabama, Arkansas, Florida, Georgia, Illinois, Indiana, Louisiana, Mississippi, Missouri, Ohio, and Tennessee. In 1987, infestations were discovered in Delaware, Kentucky, Maryland, and North Carolina. Aedes albopictus and other exotic species were intercepted in shipments of used tires entering the United States from Asia. All such tires must now be free of mosquitoes before entering the country. Control over the movement and storage of tires, a strong source reduction program, and intensive public education can solve the albopictus problem.

  13. Emerging infectious diseases and pandemic potential: status quo and reducing risk of global spread.

    Science.gov (United States)

    McCloskey, Brian; Dar, Osman; Zumla, Alimuddin; Heymann, David L

    2014-10-01

    Emerging infectious diseases are an important public health threat and infections with pandemic potential are a major global risk. Although much has been learned from previous events the evidence for mitigating actions is not definitive and pandemic preparedness remains a political and scientific challenge. A need exists to develop trust and effective meaningful collaboration between countries to help with rapid detection of potential pandemic infections and initiate public health actions. This collaboration should be within the framework of the International Health Regulations. Collaboration between countries should be encouraged in a way that acknowledges the benefits that derive from sharing biological material and establishing equitable collaborative research partnerships. The focus of pandemic preparedness should include upstream prevention through better collaboration between human and animal health sciences to enhance capacity to identify potential pathogens before they become serious human threats, and to prevent their emergence where possible. The one-health approach provides a means to develop this and could potentially enhance alignment of global health and trade priorities. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Differentially expressed genes in Bordetella pertussis strains belonging to a lineage which recently spread globally.

    Directory of Open Access Journals (Sweden)

    Daan de Gouw

    Full Text Available Pertussis is a highly contagious, acute respiratory disease in humans caused by the Gram-negative pathogen Bordetella pertussis. Pertussis has resurged in the face of intensive vaccination and this has coincided with the emergence of strains carrying a particular allele for the pertussis toxin promoter, ptxP3, which is associated with higher levels of pertussis toxin (Ptx production. Within 10 to 20 years, ptxP3 strains have nearly completely replaced the previously dominant ptxP1 strains resulting in a worldwide selective sweep. In order to identify B. pertussis genes associated with the selective sweep, we compared the expression of genes in ptxP1 and ptxP3 strains that are under control of the Bordetella master virulence regulatory locus (bvgASR. The BvgAS proteins comprise a two component sensory transduction system which is regulated by temperature, nicotinic acid and sulfate. By increasing the sulfate concentration, it is possible to change the phase of B. pertussis from virulent to avirulent. Until recently, the only distinctive phenotype of ptxP3 strains was a higher Ptx production. Here we identify additional phenotypic differences between ptxP1 and ptxP3 strains which may have contributed to its global spread by comparing global transcriptional responses under sulfate-modulating conditions. We show that ptxP3 strains are less sensitive to sulfate-mediated gene suppression, resulting in an increased production of the vaccine antigens pertactin (Prn and Ptx and a number of other virulence genes, including a type III secretion toxin, Vag8, a protein involved in complement resistance, and lpxE involved in lipid A modification. Furthermore, enhanced expression of the vaccine antigens Ptx and Prn by ptxP3 strains was confirmed at the protein level. Identification of genes differentially expressed between ptxP1 and ptxP3 strains may elucidate how B. pertussis has adapted to vaccination and allow the improvement of pertussis vaccines by

  15. Rapid conversion of an oceanic spreading center to a subduction zone inferred from high-precision geochronology.

    Science.gov (United States)

    Keenan, Timothy E; Encarnación, John; Buchwaldt, Robert; Fernandez, Dan; Mattinson, James; Rasoazanamparany, Christine; Luetkemeyer, P Benjamin

    2016-11-22

    Where and how subduction zones initiate is a fundamental tectonic problem, yet there are few well-constrained geologic tests that address the tectonic settings and dynamics of the process. Numerical modeling has shown that oceanic spreading centers are some of the weakest parts of the plate tectonic system [Gurnis M, Hall C, Lavier L (2004) Geochem Geophys Geosys 5:Q07001], but previous studies have not favored them for subduction initiation because of the positive buoyancy of young lithosphere. Instead, other weak zones, such as fracture zones, have been invoked. Because these models differ in terms of the ages of crust that are juxtaposed at the site of subduction initiation, they can be tested by dating the protoliths of metamorphosed oceanic crust that is formed by underthrusting at the beginning of subduction and comparing that age with the age of the overlying lithosphere and the timing of subduction initiation itself. In the western Philippines, we find that oceanic crust was less than ∼1 My old when it was underthrust and metamorphosed at the onset of subduction in Palawan, Philippines, implying forced subduction initiation at a spreading center. This result shows that young and positively buoyant, but weak, lithosphere was the preferred site for subduction nucleation despite the proximity of other potential weak zones with older, denser lithosphere and that plate motion rapidly changed from divergence to convergence.

  16. Role of the Insect Supervectors Bemisia tabaci and Frankliniella occidentalis in the Emergence and Global Spread of Plant Viruses.

    Science.gov (United States)

    Gilbertson, Robert L; Batuman, Ozgur; Webster, Craig G; Adkins, Scott

    2015-11-01

    Emergence of insect-transmitted plant viruses over the past 10-20 years has been disproportionately driven by two so-called supervectors: the whitefly, Bemisia tabaci, and the Western flower thrips, Frankliniella occidentalis. High rates of reproduction and dispersal, extreme polyphagy, and development of insecticide resistance, together with human activities, have made these insects global pests. These supervectors transmit a diversity of plant viruses by different mechanisms and mediate virus emergence through local evolution, host shifts, mixed infections, and global spread. Associated virus evolution involves reassortment, recombination, and component capture. Emergence of B. tabaci-transmitted geminiviruses (begomoviruses), ipomoviruses, and torradoviruses has led to global disease outbreaks as well as multiple paradigm shifts. Similarly, F. occidentalis has mediated tospovirus host shifts and global dissemination and the emergence of pollen-transmitted ilarviruses. The plant virus-supervector interaction offers exciting opportunities for basic research and global implementation of generalized disease management strategies to reduce economic and environmental impacts.

  17. Global spread of vancomycin-resistant Enterococcus faecium from distinct nosocomial genetic complex

    National Research Council Canada - National Science Library

    Willems, Rob J L; Top, Janetta; van Santen, Marga; Robinson, D Ashley; Coque, Teresa M; Baquero, Fernando; Grundmann, Hajo; Bonten, Marc J M

    2005-01-01

    ...) has crossed genus boundaries to methicillin-resistant Staphylococcus aureus. Spread of VRE, therefore, represents an immediate threat for patient care and creates a reservoir of mobile resistance genes for other, more virulent pathogens...

  18. "Global Imbalances, the U.S. Dollar, and How the Crisis at the Core of Global Finance Spread to "Self-insuring" Emerging Market Economies"

    OpenAIRE

    Bibow, Jörg

    2010-01-01

    This paper investigates the spread of what started as a crisis at the core of the global financial system to emerging economies. While emerging economies had exhibited some resilience through the early stages of the financial turmoil that began in the summer of 2007, they have been hit hard since mid-2008. Their deteriorating fortunes are only partly attributable to the collapse in world trade and sharp drop in commodity prices. Things were made worse by emerging markets' exposure to the turm...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    African Journals Online (AJOL)

    user

    2010-05-01

    May 1, 2010 ... Abstract. The financial crisis that erupted in September 2008—following more than two years of financial turmoil has become global crisis for the world economy. An attempt is made in this study to assess the possible causes of the origin, contagion and impact of the current global financial crisis with ...

  1. Rapid spread of tomato yellow leaf curl virus in China is aided differentially by two invasive whiteflies.

    Directory of Open Access Journals (Sweden)

    Huipeng Pan

    Full Text Available BACKGROUND: Tomato yellow leaf curl virus (TYLCV was introduced into China in 2006, approximately 10 years after the introduction of an invasive whitefly, Bemisia tabaci (Genn. B biotype. Even so the distribution and prevalence of TYLCV remained limited, and the economic damage was minimal. Following the introduction of Q biotype into China in 2003, the prevalence and spread of TYLCV started to accelerate. This has lead to the hypothesis that the two biotypes might not be equally competent vectors of TYLCV. METHODOLOGY/PRINCIPAL FINDINGS: The infection frequency of TYLCV in the field-collected B. tabaci populations was investigated, the acquisition and transmission capability of TYLCV by B and Q biotypes were compared under the laboratory conditions. Analysis of B. tabaci populations from 55 field sites revealed the existence of 12 B and 43 Q biotypes across 18 provinces in China. The acquisition and transmission experiments showed that both B and Q biotypes can acquire and transmit the virus, however, Q biotype demonstrated superior acquisition and transmission capability than its B counterparts. Specifically, Q biotype acquired significantly more viral DNA than the B biotype, and reached the maximum viral load in a substantially shorter period of time. Although TYLCV was shown to be transmitted horizontally by both biotypes, Q biotype exhibited significantly higher viral transmission frequency than B biotype. Vertical transmission result, on the other hand, indicated that TYLCV DNA can be detected in eggs and nymphs, but not in pupae and adults of the first generation progeny. CONCLUSIONS/SIGNIFICANCE: These combined results suggested that the epidemiology of TYLCV was aided differentially by the two invasive whiteflies (B and Q biotypes through horizontal but not vertical transmission of the virus. This is consistent with the concomitant eruption of TYLCV in tomato fields following the recent rapid invasion of Q biotype whitefly in China.

  2. The global spread of hepatitis C virus 1a and 1b: a phylodynamic and phylogeographic analysis.

    Directory of Open Access Journals (Sweden)

    Gkikas Magiorkinis

    2009-12-01

    Full Text Available BACKGROUND: Hepatitis C virus (HCV is estimated to affect 130-180 million people worldwide. Although its origin is unknown, patterns of viral diversity suggest that HCV genotype 1 probably originated from West Africa. Previous attempts to estimate the spatiotemporal parameters of the virus, both globally and regionally, have suggested that epidemic HCV transmission began in 1900 and grew steadily until the late 1980s. However, epidemiological data suggest that the expansion of HCV may have occurred after the Second World War. The aim of our study was to elucidate the timescale and route of the global spread of HCV. METHODS AND FINDINGS: We show that the rarely sequenced HCV region (E2P7NS2 is more informative for molecular epidemiology studies than the more commonly used NS5B region. We applied phylodynamic methods to a substantial set of new E2P7NS2 and NS5B sequences, together with all available global HCV sequences with information in both of these genomic regions, in order to estimate the timescale and nature of the global expansion of the most prevalent HCV subtypes, 1a and 1b. We showed that transmission of subtypes 1a and 1b "exploded" between 1940 and 1980, with the spread of 1b preceding that of 1a by at least 16 y (95% confidence interval 15-17. Phylogeographic analysis of all available NS5B sequences suggests that HCV subtypes 1a and 1b disseminated from the developed world to the developing countries. CONCLUSIONS: The evolutionary rate of HCV appears faster than previously suggested. The global spread of HCV coincided with the widespread use of transfused blood and blood products and with the expansion of intravenous drug use but slowed prior to the wide implementation of anti-HCV screening. Differences in the transmission routes associated with subtypes 1a and 1b provide an explanation of the relatively earlier expansion of 1b. Our data show that the most plausible route of the HCV dispersal was from developed countries to the

  3. The temporal evolution and global spread of Cauliflower mosaic virus, a plant pararetrovirus.

    Directory of Open Access Journals (Sweden)

    Ryosuke Yasaka

    Full Text Available Cauliflower mosaic virus (CaMV is a plant pararetrovirus with a double-stranded DNA genome. It is the type member of the genus Caulimovirus in the family Caulimoviridae. CaMV is transmitted by sap inoculation and in nature by aphids in a semi-persistent manner. To investigate the patterns and timescale of CaMV migration and evolution, we sequenced and analyzed the genomes of 67 isolates of CaMV collected mostly in Greece, Iran, Turkey, and Japan together with nine published sequences. We identified the open-reading frames (ORFs in the genomes and inferred their phylogeny. After removing recombinant sequences, we estimated the substitution rates, divergence times, and phylogeographic patterns of the virus populations. We found that recombination has been a common feature of CaMV evolution, and that ORFs I-V have a different evolutionary history from ORF VI. The ORFs have evolved at rates between 1.71 and 5.81×10(-4 substitutions/site/year, similar to those of viruses with RNA or ssDNA genomes. We found four geographically confined lineages. CaMV probably spread from a single population to other parts of the world around 400-500 years ago, and is now widely distributed among Eurasian countries. Our results revealed evidence of frequent gene flow between populations in Turkey and those of its neighboring countries, with similar patterns observed for Japan and the USA. Our study represents the first report on the spatial and temporal spread of a plant pararetrovirus.

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

    African Journals Online (AJOL)

    user

    2010-05-01

    May 1, 2010 ... The financial crisis that erupted in September 2008—following more than two years of financial turmoil .... The study begins with a brief historical description of financial crises from the Great Depression of ... financial crisis of 1997/98 and the current global economic crisis (2008/09). [. The Great Depression.

  5. 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.

  6. Detecting a signal in the noise: monitoring the global spread of novel psychoactive substances using media and other open-source information.

    Science.gov (United States)

    Young, Matthew M; Dubeau, Chad; Corazza, Ornella

    2015-07-01

    To determine the feasibility and utility of using media reports and other open-source information collected by the Global Public Health Intelligence Network (GPHIN), an event-based surveillance system operated by the Public Health Agency of Canada, to rapidly detect clusters of adverse drug events associated with 'novel psychoactive substances' (NPS) at the international level. Researchers searched English media reports collected by the GPHIN between 1997 and 2013 for references to synthetic cannabinoids. They screened the resulting reports for relevance and content (i.e., reports of morbidity and arrest), plotted and compared with other available indicators (e.g., US poison control center exposures). The pattern of results from the analysis of GPHIN reports resembled the pattern seen from the other indicators. The results of this study indicate that using media and other open-source information can help monitor the presence, usage, local policy, law enforcement responses, and spread of NPS in a rapid effective way. Further, modifying GPHIN to actively track NPS would be relatively inexpensive to implement and would be highly complementary to current national and international monitoring efforts. © 2015 The Authors. Human Psychopharmacology published by John Wiley & Sons, Ltd.

  7. 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.

  8. 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)....

  9. Global Navigation Satellite System (GNSS) Ultra-Rapid Earth Rotation Product from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This derived product set consists of Global Navigation Satellite System Ultra-Rapid Earth Rotation Product (ERP) from the NASA Crustal Dynamics Data Information...

  10. Global Navigation Satellite System (GNSS) Rapid Orbit/Clock/ERP 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 Orbit/Reference Frame Product Summary from the NASA Crustal Dynamics Data Information...

  11. Global Navigation Satellite System (GNSS) Rapid Earth Rotation Product from NASA CDDIS

    Data.gov (United States)

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

  12. Rapid global fitting of large fluorescence lifetime imaging microscopy datasets.

    Directory of Open Access Journals (Sweden)

    Sean C Warren

    Full Text Available Fluorescence lifetime imaging (FLIM is widely applied to obtain quantitative information from fluorescence signals, particularly using Förster Resonant Energy Transfer (FRET measurements to map, for example, protein-protein interactions. Extracting FRET efficiencies or population fractions typically entails fitting data to complex fluorescence decay models but such experiments are frequently photon constrained, particularly for live cell or in vivo imaging, and this leads to unacceptable errors when analysing data on a pixel-wise basis. Lifetimes and population fractions may, however, be more robustly extracted using global analysis to simultaneously fit the fluorescence decay data of all pixels in an image or dataset to a multi-exponential model under the assumption that the lifetime components are invariant across the image (dataset. This approach is often considered to be prohibitively slow and/or computationally expensive but we present here a computationally efficient global analysis algorithm for the analysis of time-correlated single photon counting (TCSPC or time-gated FLIM data based on variable projection. It makes efficient use of both computer processor and memory resources, requiring less than a minute to analyse time series and multiwell plate datasets with hundreds of FLIM images on standard personal computers. This lifetime analysis takes account of repetitive excitation, including fluorescence photons excited by earlier pulses contributing to the fit, and is able to accommodate time-varying backgrounds and instrument response functions. We demonstrate that this global approach allows us to readily fit time-resolved fluorescence data to complex models including a four-exponential model of a FRET system, for which the FRET efficiencies of the two species of a bi-exponential donor are linked, and polarisation-resolved lifetime data, where a fluorescence intensity and bi-exponential anisotropy decay model is applied to the analysis

  13. Rapid global fitting of large fluorescence lifetime imaging microscopy datasets.

    Science.gov (United States)

    Warren, Sean C; Margineanu, Anca; Alibhai, Dominic; Kelly, Douglas J; Talbot, Clifford; Alexandrov, Yuriy; Munro, Ian; Katan, Matilda; Dunsby, Chris; French, Paul M W

    2013-01-01

    Fluorescence lifetime imaging (FLIM) is widely applied to obtain quantitative information from fluorescence signals, particularly using Förster Resonant Energy Transfer (FRET) measurements to map, for example, protein-protein interactions. Extracting FRET efficiencies or population fractions typically entails fitting data to complex fluorescence decay models but such experiments are frequently photon constrained, particularly for live cell or in vivo imaging, and this leads to unacceptable errors when analysing data on a pixel-wise basis. Lifetimes and population fractions may, however, be more robustly extracted using global analysis to simultaneously fit the fluorescence decay data of all pixels in an image or dataset to a multi-exponential model under the assumption that the lifetime components are invariant across the image (dataset). This approach is often considered to be prohibitively slow and/or computationally expensive but we present here a computationally efficient global analysis algorithm for the analysis of time-correlated single photon counting (TCSPC) or time-gated FLIM data based on variable projection. It makes efficient use of both computer processor and memory resources, requiring less than a minute to analyse time series and multiwell plate datasets with hundreds of FLIM images on standard personal computers. This lifetime analysis takes account of repetitive excitation, including fluorescence photons excited by earlier pulses contributing to the fit, and is able to accommodate time-varying backgrounds and instrument response functions. We demonstrate that this global approach allows us to readily fit time-resolved fluorescence data to complex models including a four-exponential model of a FRET system, for which the FRET efficiencies of the two species of a bi-exponential donor are linked, and polarisation-resolved lifetime data, where a fluorescence intensity and bi-exponential anisotropy decay model is applied to the analysis of live cell

  14. Rapid Global Imagery Management and Generation In Action

    Science.gov (United States)

    Huang, T.; Alarcon, C.; Thompson, C. K.; Roberts, J. T.; Hall, J. R.; Cechini, M. F.; Schmaltz, J. E.; McGann, J. M.; Boller, R. A.; Murphy, K. J.; Bingham, A. W.

    2013-12-01

    NASA's Global Imagery Browse Services (GIBS) project has positioned itself to be the global imagery solution for the Earth Observation System (EOS), delivering global, full-resolution satellite imagery in a highly responsive manner. This is an ambitious goal for supporting a growing a collection of distributed archives consist of heterogeneous near real-time (NRT) and science products with varied and often disparate provenance pertaining to source platforms and instruments, spatial resolutions, processing algorithms, metadata models and packaging specifications. GIBS consists of two major subsystems, OnEarth and The Imagery Exchange (TIE). OnEarth is the Open Geospatial Consortium (OGC)-compliant Web Map Tile Service (WMTS), which efficiently serves multi-resolution imagery to clients (e.g., http://podaac-tools.jpl.nasa.gov/soto/ and http://earthdata.nasa.gov/labs/worldview/). TIE is the GIBS imagery workflow management solution that is a specialization of the horizontally scaled Data Management and Archive System (DMAS) developed at the Jet Propulsion Laboratory. Like DMAS, TIE is an Open Archival Information System (OAIS) responsible for orchestrating the workflow for acquisition, preparation, generation, and archiving of imagery to be served by OnEarth. The workflow collects imagery provenance throughout a product's lifecycle by leveraging the EOS Clearing House (ECHO) and other long-term metadata repositories in order to promote reproducibility and retain lineage with source observational artifacts. This talk focuses on the current TIE development activities and some of the patterns and architectures that have proven successful in building a horizontal-scaling workflow data systems. As a data solution developed using open source technologies. This talk also discusses current activities in getting DMAS and TIE to the open source community.

  15. Global interference during early visual processing:ERP evidence from a rapid global/local selective task

    Directory of Open Access Journals (Sweden)

    Virginie eBeaucousin

    2013-08-01

    Full Text Available Visual perception depends on the integration of local elements of a visual scene into a global frame. Evidence from behavioral studies shows that (1 the detection of the global frame is faster than the detection of the local parts, a phenomenon called the global advantage, and that (2 an interference of the global shape is also present during local processing. Together, these effects are called the global precedence effect. Even if the global advantage appears to impact neural processing as early as the first 100 msec post-stimulus, previous studies failed to find a global interference effect before 200 msec post-stimulus. Using for the first time a rapid display of letter component stimuli during a global/local selective task in which conditions with perceptual conflict, congruent and incongruent conditions were considered, the present event-related potential study shows a global interference effect occurring as early as the time range of the N1 component. In particular, only congruent stimuli elicited similar N1 amplitude during the global and local tasks, whereas an increased of the N1 amplitude during the global task was observed (as compared to the local task for both stimuli with perceptual conflict and incongruent stimuli. This finding corroborates the recent neural models of human visual perception.

  16. Rapid, global demographic expansions after the origins of agriculture.

    Science.gov (United States)

    Gignoux, Christopher R; Henn, Brenna M; Mountain, Joanna L

    2011-04-12

    The invention of agriculture is widely assumed to have driven recent human population growth. However, direct genetic evidence for population growth after independent agricultural origins has been elusive. We estimated population sizes through time from a set of globally distributed whole mitochondrial genomes, after separating lineages associated with agricultural populations from those associated with hunter-gatherers. The coalescent-based analysis revealed strong evidence for distinct demographic expansions in Europe, southeastern Asia, and sub-Saharan Africa within the past 10,000 y. Estimates of the timing of population growth based on genetic data correspond neatly to dates for the initial origins of agriculture derived from archaeological evidence. Comparisons of rates of population growth through time reveal that the invention of agriculture facilitated a fivefold increase in population growth relative to more ancient expansions of hunter-gatherers.

  17. A genomic portrait of the emergence, evolution, and global spread of a methicillin-resistant Staphylococcus aureus pandemic

    DEFF Research Database (Denmark)

    Holden, Matthew T G; Hsu, Li-Yang; Kurt, Kevin

    2013-01-01

    The widespread use of antibiotics in association with high-density clinical care has driven the emergence of drug-resistant bacteria that are adapted to thrive in hospitalized patients. Of particular concern are globally disseminated methicillin-resistant Staphylococcus aureus (MRSA) clones...... to analyze the genome sequences for 193 S. aureus isolates, we were able to show that the current pandemic population of EMRSA-15 descends from a health-care-associated MRSA epidemic that spread throughout England in the 1980s, which had itself previously emerged from a primarily community...... of pathogen genome sequencing as a diagnostic tool. We document the genetic changes associated with adaptation to the hospital environment and with increasing drug resistance over time, and how MRSA evolution likely has been influenced by country-specific drug use regimens....

  18. Rapid spread of the invasive yellow-legged hornet in France: the role of human-mediated dispersal and the effects of control measures

    OpenAIRE

    Robinet, Christelle; Suppo, Christelle; Darrouzet, Eric

    2017-01-01

    1.The invasive yellow-legged hornet was first discovered in Europe, in south-western France, in 2004. It has since spread very rapidly and has caused significant mortality among honey bees and native entomofauna. It also poses a risk to humans because its sting provokes allergic reactions. The objectives of this study were the following: (i) to disentangle the roles played by human-mediated dispersal and self-mediated dispersal in the species’ rapid range expansion and (ii) to estimate the in...

  19. South Asia as a Reservoir for the Global Spread of Ciprofloxacin-Resistant Shigella sonnei: A Cross-Sectional Study.

    Directory of Open Access Journals (Sweden)

    Hao Chung The

    2016-08-01

    Full Text Available Antimicrobial resistance is a major issue in the Shigellae, particularly as a specific multidrug-resistant (MDR lineage of Shigella sonnei (lineage III is becoming globally dominant. Ciprofloxacin is a recommended treatment for Shigella infections. However, ciprofloxacin-resistant S. sonnei are being increasingly isolated in Asia and sporadically reported on other continents. We hypothesized that Asia is a primary hub for the recent international spread of ciprofloxacin-resistant S. sonnei.We performed whole-genome sequencing on a collection of 60 contemporaneous ciprofloxacin-resistant S. sonnei isolated in four countries within Asia (Vietnam, n = 11; Bhutan, n = 12; Thailand, n = 1; Cambodia, n = 1 and two outside of Asia (Australia, n = 19; Ireland, n = 16. We reconstructed the recent evolutionary history of these organisms and combined these data with their geographical location of isolation. Placing these sequences into a global phylogeny, we found that all ciprofloxacin-resistant S. sonnei formed a single clade within a Central Asian expansion of lineage III. Furthermore, our data show that resistance to ciprofloxacin within S. sonnei may be globally attributed to a single clonal emergence event, encompassing sequential gyrA-S83L, parC-S80I, and gyrA-D87G mutations. Geographical data predict that South Asia is the likely primary source of these organisms, which are being regularly exported across Asia and intercontinentally into Australia, the United States and Europe. Our analysis was limited by the number of S. sonnei sequences available from diverse geographical areas and time periods, and we cannot discount the potential existence of other unsampled reservoir populations of antimicrobial-resistant S. sonnei.This study suggests that a single clone, which is widespread in South Asia, is likely driving the current intercontinental surge of ciprofloxacin-resistant S. sonnei and is capable of establishing endemic transmission in new

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

    Science.gov (United States)

    Van den Broeck, Wouter; Gioannini, Corrado; Gonçalves, Bruno; Quaggiotto, Marco; Colizza, Vittoria; Vespignani, Alessandro

    2011-02-02

    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. 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. The user-friendly graphical interface of the GLEaMviz tool, along with its high level of detail and the realism of its embedded modeling approach

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

    Directory of Open Access Journals (Sweden)

    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

  2. How reproductive ecology contributes to the spread of a globally invasive fish.

    Directory of Open Access Journals (Sweden)

    Amy E Deacon

    Full Text Available Invasive freshwater fish represent a major threat to biodiversity. Here, we first demonstrate the dramatic, human-mediated range expansion of the Trinidadian guppy (Poecilia reticulata, an invasive fish with a reputation for negatively impacting native freshwater communities. Next, we explore possible mechanisms that might explain successful global establishment of this species. Guppies, along with some other notable invasive fish species such as mosquitofish (Gambusia spp., have reproductive adaptations to ephemeral habitats that may enable introductions of very small numbers of founders to succeed. The remarkable ability of single pregnant guppies to routinely establish viable populations is demonstrated using a replicated mesocosm set up. In 86% of cases, these populations persisted for two years (the duration of the experiment. Establishment success was independent of founder origin (high and low predation habitats, and there was no loss of behavioural performance amongst mesocosm juveniles. Behavioural "signatures" of the founding locality were, however, evident in mesocosm fish. Our results demonstrate that introductions consisting of a single individual can lead to thriving populations of this invasive fish and suggest that particular caution should be exercised when introducing this species, or other livebearers, to natural water bodies.

  3. How Reproductive Ecology Contributes to the Spread of a Globally Invasive Fish

    Science.gov (United States)

    Deacon, Amy E.; Ramnarine, Indar W.; Magurran, Anne E.

    2011-01-01

    Invasive freshwater fish represent a major threat to biodiversity. Here, we first demonstrate the dramatic, human-mediated range expansion of the Trinidadian guppy (Poecilia reticulata), an invasive fish with a reputation for negatively impacting native freshwater communities. Next, we explore possible mechanisms that might explain successful global establishment of this species. Guppies, along with some other notable invasive fish species such as mosquitofish (Gambusia spp.), have reproductive adaptations to ephemeral habitats that may enable introductions of very small numbers of founders to succeed. The remarkable ability of single pregnant guppies to routinely establish viable populations is demonstrated using a replicated mesocosm set up. In 86% of cases, these populations persisted for two years (the duration of the experiment). Establishment success was independent of founder origin (high and low predation habitats), and there was no loss of behavioural performance amongst mesocosm juveniles. Behavioural “signatures” of the founding locality were, however, evident in mesocosm fish. Our results demonstrate that introductions consisting of a single individual can lead to thriving populations of this invasive fish and suggest that particular caution should be exercised when introducing this species, or other livebearers, to natural water bodies. PMID:21957449

  4. The global spread of English, scientific communication and ESP: questions of equity, access and domain loss

    Directory of Open Access Journals (Sweden)

    Gibson Ferguson

    2007-04-01

    Full Text Available The emergence of English as the international language of scientific communication has been so amply documented (e.g. see Sano, 2002; Ammon, 2003 that its dominance is hardly disputed empirically even by those most critical of this state of affairs. More contested, however, are the effects of this dominance: with two sets of concerns particularly salient: (i the potential detrimental impact on other languages –even standardised national languages, which are at risk, so it is argued, of being relegated to a lesser role in an incipient global diglossia and of losing domains; and (ii the communicative inequality produced by the dominance of English between, in particular, native-speaking scientists/academics and non-native scientists, the latter experiencing relative disadvantage, it is sometimes claimed, when it comes to placing their work in high prestige international journals. This paper investigates both these concerns drawing on a combination of bibliometric data, literature survey and conceptual analysis, the purpose being to determine the extent which criticisms relating to domain loss and inequity can be sustained. The paper argues that the risk of domain loss is very real, but that recent language planning interventions may help avert the danger. As regards inequality, we argue that while language is still a barrier for some scholars, it seems to be diminishing in importance, with non-language factors surpassing them as sources of disadvantage. At the end of the paper some tentative suggestions are made for the amelioration of language-based disadvantage in academic publication.

  5. 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

  6. Fluid Spatial Dynamics of West Nile Virus in the United States: Rapid Spread in a Permissive Host Environment.

    Science.gov (United States)

    Di Giallonardo, Francesca; Geoghegan, Jemma L; Docherty, Douglas E; McLean, Robert G; Zody, Michael C; Qu, James; Yang, Xiao; Birren, Bruce W; Malboeuf, Christine M; Newman, Ruchi M; Ip, Hon S; Holmes, Edward C

    2015-10-28

    The introduction of West Nile virus (WNV) into North America in 1999 is a classic example of viral emergence in a new environment, with its subsequent dispersion across the continent having a major impact on local bird populations. Despite the importance of this epizootic, the pattern, dynamics, and determinants of WNV spread in its natural hosts remain uncertain. In particular, it is unclear whether the virus encountered major barriers to transmission, or spread in an unconstrained manner, and if specific viral lineages were favored over others indicative of intrinsic differences in fitness. To address these key questions in WNV evolution and ecology, we sequenced the complete genomes of approximately 300 avian isolates sampled across the United States between 2001 and 2012. Phylogenetic analysis revealed a relatively star-like tree structure, indicative of explosive viral spread in the United States, although with some replacement of viral genotypes through time. These data are striking in that viral sequences exhibit relatively limited clustering according to geographic region, particularly for those viruses sampled from birds, and no strong phylogenetic association with well-sampled avian species. The genome sequence data analyzed here also contain relatively little evidence for adaptive evolution, particularly of structural proteins, suggesting that most viral lineages are of similar fitness and that WNV is well adapted to the ecology of mosquito vectors and diverse avian hosts in the United States. In sum, the molecular evolution of WNV in North America depicts a largely unfettered expansion within a permissive host and geographic population with little evidence of major adaptive barriers. How viruses spread in new host and geographic environments is central to understanding the emergence and evolution of novel infectious diseases and for predicting their likely impact. The emergence of the vector-borne West Nile virus (WNV) in North America in 1999

  7. Ecosystem-level effects of a globally spreading invertebrate invader are not moderated by a functionally similar native.

    Science.gov (United States)

    Penk, Marcin; Irvine, Kenneth; Donohue, Ian

    2015-11-01

    Biological invasions are a key element of human-induced global environmental change. However, lack of knowledge of the indirect consequences of invasions, combined with poor understanding of how their ecological effects depend upon competitive attributes of the receiving community, hinders our ability to manage and predict the effects of invasive species on ecosystems. We established an experiment using a combination of both additive and substitutive experimental designs to explore the effects of the globally spreading mysid shrimp Hemimysis anomala on the biological structure of outdoor pond mesocosms in the absence and presence of a functionally similar native competitor, Mysis salemaai. The naturally smaller H. anomala had considerably stronger effects on primary producers, multiple aspects of consumer assemblages and overall biological structure of the ponds in comparison with the functionally similar native. Moreover, the magnitude of these effects was generally independent of the presence of M. salemaai and even total mysid density. Hemimysis anomala reduced both the abundance and diversity of zooplankton assemblages significantly, triggering a strong trophic cascade on phytoplankton and a simultaneous increase of benthic invertebrate biomass. These findings indicate that invasion by H. anomala may exacerbate the effects of nutrient enrichment on lakes. Our results demonstrate that introduced species can, irrespective of the presence of functionally similar natives, induce complex changes to ecosystems that reach beyond direct consumptive effects. Moreover, the cascading indirect effects of invasion can exacerbate the impacts of other stressors. Disregarding the complexity of indirect effects therefore risks underestimating significantly the global ecological footprint of biological invasions. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

  8. Fluid spatial dynamics of West Nile virus in the USA: Rapid spread in a permissive host environment

    Science.gov (United States)

    Di Giallonardo , Francesca; Geoghegan, Jemma L.; Docherty, Douglas E.; McLean, Robert G.; Zody, Michael C.; Qu, James; Yang, Xiao; Birren, Bruce W.; Malboeuf, Christine M.; Newman, R.; Ip, Hon S.; Holmes, Edward C.

    2016-01-01

    The introduction of West Nile virus (WNV) into North America in 1999 is a classical example of viral emergence in a new environment, with its subsequent dispersion across the continent having a major impact on local bird populations. Despite the importance of this epizootic, the pattern, dynamics and determinants of WNV spread in its natural hosts remain uncertain. In particular, it is unclear whether the virus encountered major barriers to transmission, or spread in an unconstrained manner, and if specific viral lineages were favored over others indicative of intrinsic differences in fitness. To address these key questions in WNV evolution and ecology we sequenced the complete genomes of approximately 300 avian isolates sampled across the USA between 2001-2012. Phylogenetic analysis revealed a relatively ‘star-like' tree structure, indicative of explosive viral spread in US, although with some replacement of viral genotypes through time. These data are striking in that viral sequences exhibit relatively limited clustering according to geographic region, particularly for those viruses sampled from birds, and no strong phylogenetic association with well sampled avian species. The genome sequence data analysed here also contain relatively little evidence for adaptive evolution, particularly on structural proteins, suggesting that most viral lineages are of similar fitness, and that WNV is well adapted to the ecology of mosquito vectors and diverse avian hosts in the USA. In sum, the molecular evolution of WNV in North America depicts a largely unfettered expansion within a permissive host and geographic population with little evidence of major adaptive barriers.

  9. 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

  10. What Technology Startups Must Get Right to Globalize Early and Rapidly

    Directory of Open Access Journals (Sweden)

    Tony Bailetti

    2012-10-01

    Full Text Available Upon or shortly after inception, growth-oriented technology startups must operate in a market that is global. Management teams and investors of technology startups can benefit from approaches and models that can help them operate in a global market early and rapidly. How well a technology startup addresses the realities of globalization will determine its success. A better understanding of what management teams and investors of technology startups must get right to globalize their startups is needed. This article is an attempt to meet this need. In this article, lessons that have been extracted from six literature streams and from information on 21 startups founded in 12 countries are used to identify the six elements that a startup must get right to globalize early and rapidly. These six elements are: i Problem scope, ii Stakeholders’ commitments, iii Collaborative entrepreneurship, iv Relational capital, v Legitimacy, and vi Global capability. The main contribution of this article is that it throws the spotlight on the need to develop prescriptive rules and practitioner-oriented models that can help a technology startup operate globally from an early stage.

  11. 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.

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

    Science.gov (United States)

    Bowers, Jolene R; Kitchel, Brandon; Driebe, Elizabeth M; MacCannell, Duncan R; Roe, Chandler; Lemmer, Darrin; de Man, Tom; Rasheed, J Kamile; Engelthaler, David M; Keim, Paul; Limbago, Brandi M

    2015-01-01

    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.

  13. Global Navigation Satellite System (GNSS) Rapid Clock Product (30 second resolution, daily files, generated daily) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This derived product set consists of Global Navigation Satellite System Rapid Satellite and Receiver Clock Product (30-second granularity, daily files, generated...

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

    Science.gov (United States)

    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.

  15. Global Expression-Based Classification of Lymph Node Metastasis and Extracapsular Spread of Oral Tongue Squamous Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Xiaofeng Zhou

    2006-11-01

    Full Text Available Regional lymph node metastasis is a critical event in oral tongue squamous cell carcinoma (OTSCC progression. The identification of biomarkers associated with the metastatic process would provide critical prognostic information to facilitate clinical decision making for improved management of OTSCC patients. Global expressional profiles were obtained for 25 primary OTSCCs, where 11 cases showed lymph node metastasis (pN+ histologically and 14 cases were nonmetastatic (pN-. Seven of pN+ cases also exhibited extracapsular spread (ECS of metastatic nodes. Multiple expression indices were used to generate signature gene sets for pN+/- and ECS+/- cases. Selected genes from signature gene sets were validated using quantitative reverse transcription-polymerase chain reaction (qRT-PCR. The classification powers of these genes were then evaluated using a logistic model, receiver operating characteristic curve analysis, leave-oneout cross-validation. qRT-PCR validation data showed that differences at RNA levels are either statistically significant (P<.05 or suggestive (P< .1 for six of eight genes tested (BMP2, CTTN, EEF1A1, GTSE1, MMP9, EGFR for pN+/- cases, for five of eight genes tested (BMP2, CTTN, EEF1A1, MMP9, EGFR for ECS+/- cases. Logistic models with specific combinations of genes (CTTN+MMP9+EGFR for pN and CTTN+EEFIA1+MMP9 for ECS achieved perfect specificity and sensitivity. Leave-one-out cross-validation showed overall accuracy rates of 85% for both pN and ECS prediction models. Our results demonstrated that the pN and the ECS of OTSCCs can be predicted by gene expression analyses of primary tumors.

  16. Early and rapid globalization as part of innovation and growth strategies

    DEFF Research Database (Denmark)

    Zijdemans, Erik; Azimi, Zohreh; Tanev, Stoyan

    of technology start-ups as a specific growth strategy (Zijdemans & Tanev, 2014). Our research adopts a dynamic resource perspective according to which the distinction between ex-ante and ex-post value of resources (Schmidt & Keil, 2012) complements the effectual entrepreneurial approach, which is typical...... for start-ups that globalize rapidly in an environment with a high degree of uncertainty (Sarasvathy, Kumar, York, & Bhagavatula, 2014). The ex-ante valuation of resources (Schmidt & Keil, 2012) is related to the ex-post characteristics of BG firms (Tanev, 2012) resulting in a Global Value Generator (GVG......) – 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...

  17. Leuna methods of rapid emptying and pressure release of operating equipment filled with combustible liquids and gases, as means of prevention of spreading fires

    Energy Technology Data Exchange (ETDEWEB)

    1944-12-14

    At times, the considerable amounts of combustible liquids in the equipment during distillation, gas separation, scrubbing, etc. required special precautionary measures even under normal conditions. Obviously, such amounts of combustibles carried the danger of spreading fires from any disturbance, such as breaks in the piping, of the slides, explosions, and small fires. The past precautions taken in this matter had been fire extinguishers, construction of localizing compartments, spray systems, reduction of the amount of liquids, and other similar measures. However, such measures were of little use in case of an attack. Leuna decided to provide a means of rapid emptying with a simultaneous rapid exhausting of all equipment under danger. Releasing the pressure would prevent the formation of sharp-pointed flames with their devastating consequences. The installation consisted essentially of groups of valves (easily accessible), long pipe lines, storage farms for liquids, and a discharge into the air. Provisions were made for returning the materials under atmospheric pressure to prevent losses. The figures showed rapid emptying of scrubbers for circulating gas under high pressure, gasoline catchpot still, and pressure release of gas separation unit. These installations proved worthy and became a necessary part of operations. Four diagrams are given showing this installation. 4 diagrams

  18. Delaying the international spread of pandemic influenza.

    Science.gov (United States)

    Cooper, Ben S; Pitman, Richard J; Edmunds, W John; Gay, Nigel J

    2006-06-01

    The recent emergence of hypervirulent subtypes of avian influenza has underlined the potentially devastating effects of pandemic influenza. Were such a virus to acquire the ability to spread efficiently between humans, control would almost certainly be hampered by limited vaccine supplies unless global spread could be substantially delayed. Moreover, the large increases that have occurred in international air travel might be expected to lead to more rapid global dissemination than in previous pandemics. To evaluate the potential of local control measures and travel restrictions to impede global dissemination, we developed stochastic models of the international spread of influenza based on extensions of coupled epidemic transmission models. These models have been shown to be capable of accurately forecasting local and global spread of epidemic and pandemic influenza. We show that under most scenarios restrictions on air travel are likely to be of surprisingly little value in delaying epidemics, unless almost all travel ceases very soon after epidemics are detected. Interventions to reduce local transmission of influenza are likely to be more effective at reducing the rate of global spread and less vulnerable to implementation delays than air travel restrictions. Nevertheless, under the most plausible scenarios, achievable delays are small compared with the time needed to accumulate substantial vaccine stocks.

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

    OpenAIRE

    Bostan Sergii Ivanovich

    2016-01-01

    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 m...

  20. 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.

  1. Evolution of the East Pacific Rise at 16° 19° S since 5 Ma: Bisection of overlapping spreading centers by new, rapidly propagating ridge segments

    Science.gov (United States)

    Cormier, Marie-Helene; Scheirer, Daniel S.; MacDonald, Ken C.

    1996-02-01

    Nearly complete side-scan, bathymetry and magnetic coverage documents the evolution of the geometry of the East Pacific Rise (EPR) between 16° and 19° S since 5 Ma. Lineaments visible in SeaMARC II, H-MR1 and Sea Beam 2000 side-scan data correspond dominantly to normal fault scarps which have developed in the axial region perpendicular to the least compressive stress. Except near overlapping spreading centers (OSCs), the lineament orientations are taken to represent the perpendicular to the instantaneous Pacific-Nazca spreading direction. Their dominant orientation in the axial region is 012°, in good agreement with the prediction of the current model of relative plate motion (DeMets et al., 1994). However, the variations of the lineament azimuths with age show that there has been a small (3° 5°) clockwise change in the Nazca-Pacific relative motion since 5 Ma. There is also a distinct population of lineaments which strike counterclockwise to the ambient orientation. These discordant lineaments form somewhat coherent patterns on the seafloor and represent the past migration tracks of several left-stepping OSCs. Concurrent analysis of these discordant zones and the magnetic anomalies, reveals that up to 1 Ma, the EPR was offset by a few large, left-stepping OSCs. These OSCs were bisected into smaller OSCs by new spreading segments forming within their overlap basins. The smaller OSCs proceeded to migrate rapidly and were further bisected by newly spawned ridge segments until the present staircase of small, left-stepping OSCs was achieved. By transferring lithosphere from one plate to the other, these migration events account remarkably well for the variable spreading asymmetry in the area. Between 16° and 19° S, the present EPR is magmatically very “robust”, as evidenced by its inflated morphology, the profuse volcanic and hydrothermal activity observed from submerisbles and towed cameras, the geochemistry of axial basalts, and seismic and gravity data

  2. Rapid Processing of a Global Feature in the ON Visual Pathways of Behaving Monkeys

    Directory of Open Access Journals (Sweden)

    Jun Huang

    2017-08-01

    Full Text Available Visual objects are recognized by their features. Whereas, some features are based on simple components (i.e., local features, such as orientation of line segments, some features are based on the whole object (i.e., global features, such as an object having a hole in it. Over the past five decades, behavioral, physiological, anatomical, and computational studies have established a general model of vision, which starts from extracting local features in the lower visual pathways followed by a feature integration process that extracts global features in the higher visual pathways. This local-to-global model is successful in providing a unified account for a vast sets of perception experiments, but it fails to account for a set of experiments showing human visual systems' superior sensitivity to global features. Understanding the neural mechanisms underlying the “global-first” process will offer critical insights into new models of vision. The goal of the present study was to establish a non-human primate model of rapid processing of global features for elucidating the neural mechanisms underlying differential processing of global and local features. Monkeys were trained to make a saccade to a target in the black background, which was different from the distractors (white circle in color (e.g., red circle target, local features (e.g., white square target, a global feature (e.g., white ring with a hole target or their combinations (e.g., red square target. Contrary to the predictions of the prevailing local-to-global model, we found that (1 detecting a distinction or a change in the global feature was faster than detecting a distinction or a change in color or local features; (2 detecting a distinction in color was facilitated by a distinction in the global feature, but not in the local features; and (3 detecting the hole was interfered by the local features of the hole (e.g., white ring with a squared hole. These results suggest that monkey ON

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

    OpenAIRE

    Michela Viale; Elena Ferrero

    2012-01-01

    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 ...

  4. Multilocus sequence analysis of xanthomonads causing bacterial spot of tomato and pepper plants reveals strains generated by recombination among species and recent global spread of Xanthomonas gardneri.

    Science.gov (United States)

    Timilsina, Sujan; Jibrin, Mustafa O; Potnis, Neha; Minsavage, Gerald V; Kebede, Misrak; Schwartz, Allison; Bart, Rebecca; Staskawicz, Brian; Boyer, Claudine; Vallad, Gary E; Pruvost, Olivier; Jones, Jeffrey B; Goss, Erica M

    2015-02-01

    Four Xanthomonas species are known to cause bacterial spot of tomato and pepper, but the global distribution and genetic diversity of these species are not well understood. A collection of bacterial spot-causing strains from the Americas, Africa, Southeast Asia, and New Zealand were characterized for genetic diversity and phylogenetic relationships using multilocus sequence analysis of six housekeeping genes. By examining strains from different continents, we found unexpected phylogeographic patterns, including the global distribution of a single multilocus haplotype of X. gardneri, possible regional differentiation in X. vesicatoria, and high species diversity on tomato in Africa. In addition, we found evidence of multiple recombination events between X. euvesicatoria and X. perforans. Our results indicate that there have been shifts in the species composition of bacterial spot pathogen populations due to the global spread of dominant genotypes and that recombination between species has generated genetic diversity in these populations.

  5. 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.

  6. Metofluthrin: investigations into the use of a volatile spatial pyrethroid in a global spread of dengue, chikungunya and Zika viruses

    OpenAIRE

    Buhagiar, Tamara S.; Gregor J Devine; Scott A. Ritchie

    2017-01-01

    Background Metofluthrin reduces biting activity in Aedes aegypti through the confusion, knockdown, and subsequent kill of a mosquito. A geographical spread in dengue, chikungunya, and Zika viruses, increases intervention demands. Response to a Zika outbreak may require a different strategy than dengue, as high-risk individuals, specifically pregnant women, need to be targeted. Methods In semi-field conditions within a residential property in Cairns, Queensland, the impacts of metofluthrin on ...

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Global Navigation Satellite System (GNSS) Ultra-Rapid Orbit/Clock/ERP Product Comparison Summary from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This derived product set consists of Global Navigation Satellite System Rapid Orbit/Reference Frame Product Summary from the NASA Crustal Dynamics Data Information...

  9. Global Navigation Satellite System (GNSS) Ultra-Rapid Orbit/Clock/ERP 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 Orbit/Reference Frame Product Summary from the NASA Crustal Dynamics Data Information...

  10. 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.

  11. 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.

  12. Rapid global expansion of the fungal disease chytridiomycosis into declining and healthy amphibian populations.

    Directory of Open Access Journals (Sweden)

    Timothy Y James

    2009-05-01

    Full Text Available The fungal disease chytridiomycosis, caused by Batrachochytrium dendrobatidis, is enigmatic because it occurs globally in both declining and apparently healthy (non-declining amphibian populations. This distribution has fueled debate concerning whether, in sites where it has recently been found, the pathogen was introduced or is endemic. In this study, we addressed the molecular population genetics of a global collection of fungal strains from both declining and healthy amphibian populations using DNA sequence variation from 17 nuclear loci and a large fragment from the mitochondrial genome. We found a low rate of DNA polymorphism, with only two sequence alleles detected at each locus, but a high diversity of diploid genotypes. Half of the loci displayed an excess of heterozygous genotypes, consistent with a primarily clonal mode of reproduction. Despite the absence of obvious sex, genotypic diversity was high (44 unique genotypes out of 59 strains. We provide evidence that the observed genotypic variation can be generated by loss of heterozygosity through mitotic recombination. One strain isolated from a bullfrog possessed as much allelic diversity as the entire global sample, suggesting the current epidemic can be traced back to the outbreak of a single clonal lineage. These data are consistent with the current chytridiomycosis epidemic resulting from a novel pathogen undergoing a rapid and recent range expansion. The widespread occurrence of the same lineage in both healthy and declining populations suggests that the outcome of the disease is contingent on environmental factors and host resistance.

  13. 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.

  14. Genomic epidemiology of the Haitian cholera outbreak: a single introduction followed by rapid, extensive, and continued spread characterized the onset of the epidemic.

    Science.gov (United States)

    Eppinger, Mark; Pearson, Talima; Koenig, Sara S K; Pearson, Ofori; Hicks, Nathan; Agrawal, Sonia; Sanjar, Fatemeh; Galens, Kevin; Daugherty, Sean; Crabtree, Jonathan; Hendriksen, Rene S; Price, Lance B; Upadhyay, Bishnu P; Shakya, Geeta; Fraser, Claire M; Ravel, Jacques; Keim, Paul S

    2014-11-04

    For centuries, cholera has been one of the most feared diseases. The causative agent Vibrio cholerae is a waterborne Gram-negative enteric pathogen eliciting a severe watery diarrheal disease. In October 2010, the seventh pandemic reached Haiti, a country that had not experienced cholera for more than a century. By using whole-genome sequence typing and mapping strategies of 116 serotype O1 strains from global sources, including 44 Haitian genomes, we present a detailed reconstructed evolutionary history of the seventh pandemic with a focus on the Haitian outbreak. We catalogued subtle genomic alterations at the nucleotide level in the genome core and architectural rearrangements from whole-genome map comparisons. Isolates closely related to the Haitian isolates caused several recent outbreaks in southern Asia. This study provides evidence for a single-source introduction of cholera from Nepal into Haiti followed by rapid, extensive, and continued clonal expansion. The phylogeographic patterns in both southern Asia and Haiti argue for the rapid dissemination of V. cholerae across the landscape necessitating real-time surveillance efforts to complement the whole-genome epidemiological analysis. As eradication efforts move forward, phylogeographic knowledge will be important for identifying persistent sources and monitoring success at regional levels. The results of molecular and epidemiological analyses of this outbreak suggest that an indigenous Haitian source of V. cholerae is unlikely and that an indigenous source has not contributed to the genomic evolution of this clade. In this genomic epidemiology study, we have applied high-resolution whole-genome-based sequence typing methodologies on a comprehensive set of genome sequences that have become available in the aftermath of the Haitian cholera epidemic. These sequence resources enabled us to reassess the degree of genomic heterogeneity within the Vibrio cholerae O1 serotype and to refine boundaries and

  15. What are the implications of rapid global warming for landslide-triggered turbidity current activity?

    Science.gov (United States)

    Clare, Michael; Peter, Talling; James, Hunt

    2014-05-01

    arithmetic mean recurrence, λ, for the full records (λ=0.007 and 0.0125 Myr). This period of inactivity is coincident with a dramatic carbon isotopic excursion (i.e. warmest part of the IETM) and heavily skews statistical analyses for both records. Dramatic global warming appears to exert a strong control on inhibiting turbidity current activity; whereas the effects of sea level change are not shown to be statistically significant. Rapid global warming is often implicated as a potential landslide trigger, due to dissociation of gas hydrates in response to elevated ocean temperatures. Other studies have suggested that intense global warming may actually be attributed to the atmospheric release of gas hydrates following catastrophic failure of large parts of a continental slope. Either way, a greater intensity of landslide and resultant turbidity current activity would be expected during the IETM; however, our findings are to the contrary. We offer some explanations in relation to potential triggers. Our work suggests that previous rapid global warming at the IETM did not trigger more frequent turbidity currents. This has direct relevance to future assessments relating to landslide-triggered tsunami hazard, and breakage of subsea cables by turbidity currents.

  16. 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.

    2013-01-01

    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.

  17. Sustaining global agriculture through rapid detection and deployment of genetic resistance to deadly crop diseases.

    Science.gov (United States)

    Periyannan, Sambasivam

    2017-12-04

    Contents I. II. III. IV. V. VI. VII. VIII. References SUMMARY: Genetically encoded resistance is a major component of crop disease management. Historically, gene loci conferring resistance to pathogens have been identified through classical genetic methods. In recent years, accelerated gene cloning strategies have become available through advances in sequencing, gene capture and strategies for reducing genome complexity. Here, I describe these approaches with key emphasis on the isolation of resistance genes to the cereal crop diseases that are an ongoing threat to global food security. Rapid gene isolation enables their efficient deployment through marker-assisted selection and transgenic technology. Together with innovations in genome editing and progress in pathogen virulence studies, this creates further opportunities to engineer long-lasting resistance. These approaches will speed progress towards a future of farming using fewer pesticides. © 2017 Commonwealth of Australia. New Phytologist © 2017 New Phytologist Trust.

  18. Global patent landscape of programmed cell death 1: implications of the rapid expansion.

    Science.gov (United States)

    Kong, Xiangjun; Zhang, Qianru; Lai, Yunfeng; Hu, Hao; Chen, Xin; Hu, Yuanjia

    2018-01-01

    Inhibitors of programmed cell death 1 (PD-1) and its ligands are producing a paradigm shift in cancer treatment. The promising clinical outcomes and a multi-billion dollar market have prompted active research and development and resulted in relentless patent protection. However, the global patent landscape in this field remains unclear. Areas covered: The patent landscape encompassing global patenting activities and developing trends in the field is discussed based on a data set of 1287 patent families. Patenting activities have expanded rapidly in the past three years. Specific trends in relevant aspects are presented, including patent filing countries, patent ownership, co-patents, technical areas, and technological connections in terms of patent citation relationships. Expert opinion: Together with patenting momentum in recent years, fragmented ownership and dense technological connections of PD-1-related inventions raise the possibility of a patent thicket. The explosion of patent applications and complex citation relationships could also lead to considerable patent conflicts and disputes on overlapping intellectual property rights, in addition to existing legal uncertainties. Patent applicants in this field are encouraged to be aware of these concerns when developing valid patent strategies.

  19. Travelling Policies and Global Buzzwords: How International Non-Governmental Organizations and Charities Spread the Word about Early Childhood in the Global South

    Science.gov (United States)

    Penn, Helen

    2011-01-01

    This article is based on a web-search commissioned by an international charity to review the work of international non-governmental organizations (INGOs) and charities which promote and support early childhood education and care (ECEC) in the global South. The article examines examples of such initiatives. It is suggested that there is…

  20. Genomic analysis of globally diverse Mycobacterium tuberculosis strains provides insights into emergence and spread of multidrug resistance

    Science.gov (United States)

    Manson, Abigail L.; Cohen, Keira A.; Abeel, Thomas; Desjardins, Christopher A.; Armstrong, Derek T.; Barry, Clifton E.; Brand, Jeannette; Chapman, Sinéad B.; Cho, Sang-Nae; Gabrielian, Andrei; Gomez, James; Jodals, Andreea M.; Joloba, Moses; Jureen, Pontus; Lee, Jong Seok; Malinga, Lesibana; Maiga, Mamoudou; Nordenberg, Dale; Noroc, Ecaterina; Romancenco, Elena; Salazar, Alex; Ssengooba, Willy; Velayati, A. A.; Winglee, Kathryn; Zalutskaya, Aksana; Via, Laura E.; Cassell, Gail H.; Dorman, Susan E.; Ellner, Jerrold; Farnia, Parissa; Galagan, James E.; Rosenthal, Alex; Crudu, Valeriu; Homorodean, Daniela; Hsueh, Po-Ren; Narayanan, Sujatha; Pym, Alexander S.; Skrahina, Alena; Swaminathan, Soumya; Van der Walt, Martie; Alland, David; Bishai, William R.; Cohen, Ted; Hoffner, Sven; Birren, Bruce W.; Earl, Ashlee M.

    2017-01-01

    Multidrug-resistant tuberculosis (MDR-TB), caused by drug resistant strains of Mycobacterium tuberculosis, is an increasingly serious problem worldwide. In this study, we examined a dataset of 5,310 M. tuberculosis whole genome sequences from five continents. Despite great diversity with respect to geographic point of isolation, genetic background and drug resistance, patterns of drug resistance emergence were conserved globally. We have identified harbinger mutations that often precede MDR. In particular, the katG S315T mutation, conferring resistance to isoniazid, overwhelmingly arose before rifampicin resistance across all lineages, geographic regions, and time periods. Molecular diagnostics that include markers for rifampicin resistance alone will be insufficient to identify pre-MDR strains. Incorporating knowledge of pre-MDR polymorphisms, particularly katG S315, into molecular diagnostics will enable targeted treatment of patients with pre-MDR-TB to prevent further development of MDR-TB. PMID:28092681

  1. A global airport-based risk model for the spread of dengue infection via the air transport network.

    Science.gov (United States)

    Gardner, Lauren; Sarkar, Sahotra

    2013-01-01

    The number of travel-acquired dengue infections has seen a consistent global rise over the past decade. An increased volume of international passenger air traffic originating from regions with endemic dengue has contributed to a rise in the number of dengue cases in both areas of endemicity and elsewhere. This paper reports results from a network-based risk assessment model which uses international passenger travel volumes, travel routes, travel distances, regional populations, and predictive species distribution models (for the two vector species, Aedes aegypti and Aedes albopictus) to quantify the relative risk posed by each airport in importing passengers with travel-acquired dengue infections. Two risk attributes are evaluated: (i) the risk posed by through traffic at each stopover airport and (ii) the risk posed by incoming travelers to each destination airport. The model results prioritize optimal locations (i.e., airports) for targeted dengue surveillance. The model is easily extendible to other vector-borne diseases.

  2. A global airport-based risk model for the spread of dengue infection via the air transport network.

    Directory of Open Access Journals (Sweden)

    Lauren Gardner

    Full Text Available The number of travel-acquired dengue infections has seen a consistent global rise over the past decade. An increased volume of international passenger air traffic originating from regions with endemic dengue has contributed to a rise in the number of dengue cases in both areas of endemicity and elsewhere. This paper reports results from a network-based risk assessment model which uses international passenger travel volumes, travel routes, travel distances, regional populations, and predictive species distribution models (for the two vector species, Aedes aegypti and Aedes albopictus to quantify the relative risk posed by each airport in importing passengers with travel-acquired dengue infections. Two risk attributes are evaluated: (i the risk posed by through traffic at each stopover airport and (ii the risk posed by incoming travelers to each destination airport. The model results prioritize optimal locations (i.e., airports for targeted dengue surveillance. The model is easily extendible to other vector-borne diseases.

  3. 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.

  4. Hydrological and associated biogeochemical consequences of rapid global warming during the Paleocene-Eocene Thermal Maximum

    Science.gov (United States)

    Carmichael, Matthew J.; Inglis, Gordon N.; Badger, Marcus P. S.; Naafs, B. David A.; Behrooz, Leila; Remmelzwaal, Serginio; Monteiro, Fanny M.; Rohrssen, Megan; Farnsworth, Alexander; Buss, Heather L.; Dickson, Alexander J.; Valdes, Paul J.; Lunt, Daniel J.; Pancost, Richard D.

    2017-10-01

    The Paleocene-Eocene Thermal Maximum (PETM) hyperthermal, 56 million years ago (Ma), is the most dramatic example of abrupt Cenozoic global warming. During the PETM surface temperatures increased between 5 and 9 °C and the onset likely took < 20 kyr. The PETM provides a case study of the impacts of rapid global warming on the Earth system, including both hydrological and associated biogeochemical feedbacks, and proxy data from the PETM can provide constraints on changes in warm climate hydrology simulated by general circulation models (GCMs). In this paper, we provide a critical review of biological and geochemical signatures interpreted as direct or indirect indicators of hydrological change at the PETM, explore the importance of adopting multi-proxy approaches, and present a preliminary model-data comparison. Hydrological records complement those of temperature and indicate that the climatic response at the PETM was complex, with significant regional and temporal variability. This is further illustrated by the biogeochemical consequences of inferred changes in hydrology and, in fact, changes in precipitation and the biogeochemical consequences are often conflated in geochemical signatures. There is also strong evidence in many regions for changes in the episodic and/or intra-annual distribution of precipitation that has not widely been considered when comparing proxy data to GCM output. Crucially, GCM simulations indicate that the response of the hydrological cycle to the PETM was heterogeneous - some regions are associated with increased precipitation - evaporation (P - E), whilst others are characterised by a decrease. Interestingly, the majority of proxy data come from the regions where GCMs predict an increase in PETM precipitation. We propose that comparison of hydrological proxies to GCM output can be an important test of model skill, but this will be enhanced by further data from regions of model-simulated aridity and simulation of extreme precipitation

  5. Correlating Global Precipitation Measurement satellite data with karst spring hydrographs for rapid catchment delineation

    Science.gov (United States)

    Longenecker, Jake; Bechtel, Timothy; Chen, Zhao; Goldscheider, Nico; Liesch, Tanja; Walter, Robert

    2017-05-01

    To protect karst spring water resources, catchments must be known. We have developed a method for correlating spring hydrographs with newly available, high-resolution, satellite-based Global Precipitation Measurement data to rapidly and remotely locate recharge areas. We verify the method using a synthetic comparison of ground-based rain gage data with the satellite precipitation data set. Application to karst springs is proven by correlating satellite data with hydrographs from well-known springs with published catchments in Europe and North America. Application to an unknown-catchment spring in Pennsylvania suggests distant recharge, requiring a flow path that crosses topographic divides, as well as multiple lithologies, physiographic provinces, and tectonic boundaries. Although surprising, this latter result is consistent with published geologic/geophysical, monitoring well, and stream gage data. We conclude that the method has considerable potential to improve the speed and accuracy of catchment identification and hydrodynamic characterization, with applications to water resource protection and groundwater exploration, among others.

  6. Imagining Possibilities in a Global World: Music, Learning and Rapid Change

    Science.gov (United States)

    Allsup, Randall Everett

    2004-01-01

    This essay examines the shift toward a globally interdependent world, starting with the ontological premise that thinking, identity and action are subsumed by culture. The author explores the view that globalism, with its break from modernist constraints, may enable liberation. The post-Soviet borderless economy implies a shift of rule and a new…

  7. Eigen Spreading

    Science.gov (United States)

    2008-02-27

    effort the LMAC was fully specified and characterized. The first order VHDL code was written up for the block and simulated, but it was not taken to the...combination of high performance FPGAs and DSPs are needed in the digital baseband portion. There are a number of vendors that specialize in providing...the main features of this board are: •600 MHz TI TMS320C6416 DSP ; Status Report: Eigen Spreading 18 Silvus Communication Systems, Inc. DARPA ATO

  8. Genomic analysis of an emerging multiresistant Staphylococcus aureus strain rapidly spreading in cystic fibrosis patients revealed the presence of an antibiotic inducible bacteriophage

    Directory of Open Access Journals (Sweden)

    Boniface Stephanie

    2009-01-01

    Full Text Available Abstract Background Staphylococcus aureus is a major human pathogen responsible for a variety of nosocomial and community-acquired infections. Recent reports show that the prevalence of Methicillin-Resistant S. aureus (MRSA infections in cystic fibrosis (CF patients is increasing. In 2006 in Marseille, France, we have detected an atypical MRSA strain with a specific antibiotic susceptibility profile and a unique growth phenotype. Because of the clinical importance of the spread of such strain among CF patients we decided to sequence the genome of one representative isolate (strain CF-Marseille to compare this to the published genome sequences. We also conducted a retrospective epidemiological analysis on all S. aureus isolated from 2002 to 2007 in CF patients from our institution. Results CF-Marseille is multidrug resistant, has a hetero-Glycopeptide-Intermediate resistance S. aureus phenotype, grows on Cepacia agar with intense orange pigmentation and has a thickened cell wall. Phylogenetic analyses using Complete Genome Hybridization and Multi Locus VNTR Assay showed that CF-Marseille was closely related to strain Mu50, representing vancomycin-resistant S. aureus. Analysis of CF-Marseille shows a similar core genome to that of previously sequenced MRSA strains but with a different genomic organization due to the presence of specific mobile genetic elements i.e. a new SCCmec type IV mosaic cassette that has integrated the pUB110 plasmid, and a new phage closely related to phiETA3. Moreover this phage could be seen by electron microscopy when mobilized with several antibiotics commonly used in CF patients including, tobramycin, ciprofloxacin, cotrimoxazole, or imipenem. Phylogenetic analysis of phenotypically similar h-GISA in our study also suggests that CF patients are colonized by polyclonal populations of MRSA that represents an incredible reservoir for lateral gene transfer. Conclusion In conclusion, we demonstrated the emergence and

  9. The gravity wave Doppler spread theory applied in a numerical spectral model of the middle atmosphere. 1. Model and global scale seasonal variations

    Science.gov (United States)

    Mayer, H. G.; Mengel, J. G.; Hines, C. O.; Chan, K. L.; Arnold, N. F.; Reddy, C. A.; Porter, H. S.

    1997-11-01

    Hines [1997a, b] has developed a Doppler spread parameterization (DSP) for the deposition of small-scale gravity wave (GW) momentum and energy in the middle atmosphere. We have incorporated this DSP into the two-dimensional (2-D) version of the numerical spectral model (NSM) of Chan et al [1994a, b] which is applied to the Earth's middle atmosphere. With a globally uniform flux of (quasi) isotropically propagating GW emanating from the troposphere, the NSM has been integrated for several model years to describe seasonal variations and equatorial oscillations. Here, after a review of the NSM and DSP, we discuss numerical results that describe the temperature and wind fields during solstice and equinox conditions, emphasizing the role played by the GW spectrum. That spectrum is filtered as it ascends through the stratosphere and provides, at the solstices, a highly anisotropic wave and momentum flux at mesospheric heights. Upon further filtering there, with attendant momentum deposition, the waves decelerate and then reverse the zonal circulation. In quasi-geostrophic balance latitudinally, this reversal is accompanied by a reversal of the latitudinal temperature gradient, one that leads to a temperature minimum in the summer polar mesopause region, as is observed. Corresponding results for equinox are obtained, and all are discussed. Our results differ only in detail from those of similar analyses that employ other GW parameterizations. They are presented here in part to exhibit the success of the DSP at this elementary level and in part to provide a point of departure against which future refinements may be judged. Our first extension of the modeling concerns the semiannual and quasi-biennial oscillations that are produced by the DSP in the NSM at equatorial latitudes with the same, constant and uniform, incident GW flux. Initial results are presented in the companion paper and are compared there with observations.

  10. Genomic epidemiology of the haitian cholera outbreak: a single introduction followed by rapid, extensive, and continued spread characterized the onset of the epidemic

    DEFF Research Database (Denmark)

    Eppinger, Mark; Pearson, Talima; Koenig, Sara S. K.

    2014-01-01

    In this genomic epidemiology study, we have applied high-resolution whole-genome-based sequence typing methodologies on a comprehensive set of genome sequences that have become available in the aftermath of the Haitian cholera epidemic. These sequence resources enabled us to reassess the degree...... of genomic heterogeneity within the Vibrio cholerae O1 serotype and to refine boundaries and evolutionary relationships. The established phylogenomic framework showed how outbreak isolates fit into the global phylogeographic patterns compared to a comprehensive globally and temporally diverse strain...... collection and provides strong molecular evidence that points to a nonindigenous source of the 2010 Haitian cholera outbreak and refines epidemiological standards used in outbreak investigations for outbreak inclusion/exclusion following the concept of genomic epidemiology. The generated phylogenomic data...

  11. A Global Comparative Evaluation of Commercial Immunochromatographic Rapid Diagnostic Tests for Visceral Leishmaniasis

    NARCIS (Netherlands)

    Cunningham, Jane; Hasker, Epco; Das, Pradeep; El Safi, Sayda; Goto, Hiro; Mondal, Dinesh; Mbuchi, Margaret; Mukhtar, Maowia; Rabello, Ana; Rijal, Suman; Sundar, Shyam; Wasunna, Monique; Adams, Emily; Menten, Joris; Peeling, Rosanna; Boelaert, Marleen; Khanal, Basudha; Das, Murari; Oliveira, Edward; de Assis, Tália Machado; Costa, Dorcas Lamounier; Bhaskar, Khondaker Rifathassan; Huda, M. Mamun; Hassan, Mukidul; Abdoun, Asim Osman; Awad, Aymen; Osman, Mohamed; Prajapati, Dinesh Kumar; Gidwani, Kamlesh; Tiwary, Puja; Paniago, Anamaria Mello Miranda; Sanchez, Maria Carmen Arroyo; Celeste, Beatriz Julieta; Jacquet, Diane; Magiri, Charles; Muia, A.; Kesusu, J.; Ageed, Al Farazdag; Galal, Nuha; Osman, Osman Salih; Gupta, A. K.; Bimal, Afrad S.; Das, V. N. R.

    2012-01-01

    Background. Poor access to diagnosis stymies control of visceral leishmaniasis (VL). Antibody-detecting rapid diagnostic tests (RDTs) can be performed in peripheral health settings. However, there are many brands available and published reports of variable accuracy. Methods. Commercial VL RDTs

  12. Surveying Geology Concepts in Education Standards for a Rapidly Changing Global Context

    Science.gov (United States)

    Guffey, Sarah K.; Slater, Stephanie J.; Schleigh, Sharon P.; Slater, Timothy F.; Heyer, Inge

    2016-01-01

    Internationally much attention is being paid to which of a seemingly endless list of scientific concepts should be taught to schoolchildren to enable them to best participate in the global economy of the 21st Century. In regards to science education, the concepts framing the subject of geology holds exalted status as core scientific principles in…

  13. Rapid changes in the geomagnetic field: from global to regional scales

    OpenAIRE

    Mandea, M.; Olsen, N; Monika Korte; Verbanac, G.; Y. Yahiat

    2008-01-01

    A large part of the Earth's magnetic field is generated by fluid motion in the molten outer core. Its temporal change, called secular variation, is characterized by occasional rapid changes known as geomagnetic jerks, sudden change in the second time derivative of the magnetic field. For a while, detailed studies of these phenomena suffered from the sparse distribution of geomagnetic observatories over many parts of the Earth. Recent studies on magnetic data provided by magnetic satellites, w...

  14. Plasmatocyte spreading peptide induces spreading of plasmatocytes but represses spreading of granulocytes.

    Science.gov (United States)

    Strand, M R; Clark, K D

    1999-11-01

    In most Lepidoptera, plasmatocytes and granulocytes are the two hemocyte classes capable of adhering to foreign targets. Previously, we identified plasmatocyte spreading peptide (PSP1) from the moth Pseudoplusia includens and reported that it induced plasmatocytes to rapidly spread on foreign surfaces. Here we examine whether the response of plasmatocytes to PSP1 was influenced by cell density or culture conditions, and whether PSP1 affected the adhesive state of granulocytes. Plasmatocyte spreading rates were clearly affected by cell density in the absence of PSP1 but spreading was density independent in the presence of PSP1. PSP1 also induced plasmatocytes in agarose-coated culture wells to form homotypic aggregations rather than spread on the surface of culture wells. In contrast, granulocytes rapidly spread in a density independent manner in the absence of PSP1, but were dose-dependently inhibited from spreading by the addition of peptide. An anti-PSP1 polyclonal antibody neutralized the spreading activity of synthetic PSP1. This antibody also neutralized the plasmatocyte spreading activity of granulocyte-conditioned medium, and significantly delayed plasmatocyte spreading when cells were cultured at a high density in unconditioned medium. These results suggested that the spreading activity derived from granulocytes is due in part to PSP1. Pretreatment of plasmatocytes with trypsin had no effect on PSP1-induced aggregation but PSP1-induced aggregations were readily dissociated by trypsin. This suggested that PSP1 is not an adhesion factor but induces adhesion by stimulating a change in the cell surface of plasmatocytes. Synthetic PSP1 also induced aggregation of plasmatocytes from other Lepidoptera indicating that regulation of hemocyte activity by PSP1-related peptides may be widespread. Arch. Copyright 1999 Wiley-Liss, Inc.

  15. Global Navigation Satellite System (GNSS) Ultra-Rapid Orbit Product (sub-daily files, generated 4 times/day) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This derived product set consists of Global Navigation Satellite System Ultra-Rapid Orbit Product (daily files, generated daily) from the NASA Crustal Dynamics Data...

  16. Rapid Training of Information Extraction with Local and Global Data Views

    Science.gov (United States)

    2012-05-01

    while the global classifier produces a similar- ity distribution. So we first use the following formula to transform similarities to probabilities. p...of 50 runs are performed (5 subsets times 10 experiments). We report 4http://nlp.stanford.edu/software/lex-parser.shtml 5http://ilk.uvt.nl/team/ sabine ...are high-precision patterns then the name pair has a high confidence. The confidence is computed by the following formula . Conf(Ni) = 1− k∏ j=1 (1− Prec

  17. The Rapid Intensification of Hurricane Karl (2010): New Remote Sensing Observations of Convective Bursts from the Global Hawk Platform

    Science.gov (United States)

    Guimond, Stephen R.; Heymsfield, Gerald M.; Reasor, Paul; Didlake, Anthony C., Jr.

    2016-01-01

    The evolution of rapidly intensifying Hurricane Karl (2010) is examined from a suite of remote sensing observations during the NASA Genesis and Rapid Intensification Processes (GRIP) field experiment. The novelties of this study are in the analysis of data from the airborne Doppler radar HIWRAP and the new Global Hawk airborne platform that allows long endurance sampling of hurricanes. Supporting data from the HAMSR microwave sounder coincident with HIWRAP and coordinated flights with the NOAA WP-3D aircraft help to provide a comprehensive understanding of the storm. The focus of the analysis is on documenting and understanding the structure, evolution and role of small scale, deep convective forcing in the storm intensification process. Deep convective bursts are sporadically initiated in the downshear quadrants of the storm and rotate into the upshear quadrants for a period of 12 h during the rapid intensification. The aircraft data analysis indicates that the bursts are being formed and maintained through a combination of two main processes: (1) convergence generated from counter-rotating mesovortex circulations and the larger vortex-scale flow and (2) the turbulent (scales of 25 km) transport of anomalously warm, buoyant air from the eye to the eyewall at low levels. The turbulent mixing across the eyewall interface and forced convective descent adjacent to the bursts assists in carving out the eye of Karl, which leads to an asymmetric enhancement of the warm core. The mesovortices play a key role in the evolution of the features described above.The Global Hawk aircraft allowed an examination of the vortex response and axisymmetrization period in addition to the burst pulsing phase. A pronounced axisymmetric development of the vortex is observed following the pulsing phase that includes a sloped eyewall structure and formation of a clear, wide eye.

  18. Rapid Detection Strategies for the Global Threat of Zika Virus: Current State, New Hypotheses and Limitations

    Directory of Open Access Journals (Sweden)

    Shruti Shukla

    2016-10-01

    Full Text Available The current scenario regarding the widespread Zika virus (ZIKV has resulted in numerous diagnostic studies, specifically in South America and in locations where there is frequent entry of travelers returning from ZIKV-affected areas, including pregnant women with or without clinical symptoms of ZIKV infection. The World Health Organization, WHO, announced that millions of cases of ZIKV are likely to occur in the United States of America in the near future. This situation has created an alarming public health emergency of international concern requiring the detection of this life-threatening viral candidate due to increased cases of newborn microcephaly associated with ZIKV infection. Hence, this review reports possible methods and strategies for the fast and reliable detection of ZIKV with particular emphasis on current updates, knowledge and new hypotheses that might be helpful for medical professionals in poor and developing countries that urgently need to address this problem. In particular, we emphasize liposome-based biosensors. Although these biosensors are currently among the less popular tools for human disease detection, they have become useful tools for the screening and detection of pathogenic bacteria, fungi and viruses because of their versatile advantageous features compared to other sensing devices. This review summarizes the currently available methods employed for the rapid detection of ZIKV and suggests an innovative approach involving the application of a liposome-based hypothesis for the development of new strategies for ZIKV detection and their use as effective biomedicinal tools.

  19. Rapid molecular TB diagnosis: evidence, policy making and global implementation of Xpert MTB/RIF.

    Science.gov (United States)

    Weyer, Karin; Mirzayev, Fuad; Migliori, Giovanni Battista; Van Gemert, Wayne; D'Ambrosio, Lia; Zignol, Matteo; Floyd, Katherine; Centis, Rosella; Cirillo, Daniela M; Tortoli, Enrico; Gilpin, Chris; de Dieu Iragena, Jean; Falzon, Dennis; Raviglione, Mario

    2013-07-01

    If tuberculosis (TB) is to be eliminated as a global health problem in the foreseeable future, improved detection of patients, earlier diagnosis and timely identification of rifampicin resistance will be critical. New diagnostics released in recent years have improved this perspective but they require investments in laboratory infrastructure, biosafety and staff specialisation beyond the means of many resource-constrained settings where most patients live. Xpert MTB/RIF, a new assay employing automated nucleic acid amplification to detect Mycobacterium tuberculosis, as well as mutations that confer rifampicin resistance, holds the promise to largely overcome these operational challenges. In this article we position Xpert MTB/RIF in today's TB diagnostic landscape and describe its additional potential as an adjunct to surveillance and surveys, taking into account considerations of pricing and ethics. In what could serve as a model for the future formulation of new policy on diagnostics, we trace the unique process by which the World Health Organization consulted international expertise and systematically assessed published evidence and freshly emerging experience from the field ahead of its endorsement of the Xpert MTB/RIF technology in 2010, summarise subsequent research findings and guidance on who to test and how, and provide perspectives on scaling up the new technology.

  20. Thumbnail‐based questionnaires for the rapid and efficient collection of macroseismic data from global earthquakes

    Science.gov (United States)

    Bossu, Remy; Landes, Matthieu; Roussel, Frederic; Steed, Robert; Mazet-Roux, Gilles; Martin, Stacey S.; Hough, Susan E.

    2017-01-01

    The collection of earthquake testimonies (i.e., qualitative descriptions of felt shaking) is essential for macroseismic studies (i.e., studies gathering information on how strongly an earthquake was felt in different places), and when done rapidly and systematically, improves situational awareness and in turn can contribute to efficient emergency response. In this study, we present advances made in the collection of testimonies following earthquakes around the world using a thumbnail‐based questionnaire implemented on the European‐Mediterranean Seismological Centre (EMSC) smartphone app and its website compatible for mobile devices. In both instances, the questionnaire consists of a selection of thumbnails, each representing an intensity level of the European Macroseismic Scale 1998. We find that testimonies are collected faster, and in larger numbers, by way of thumbnail‐based questionnaires than by more traditional online questionnaires. Responses were received from all seismically active regions of our planet, suggesting that thumbnails overcome language barriers. We also observed that the app is not sufficient on its own, because the websites are the main source of testimonies when an earthquake strikes a region for the first time in a while; it is only for subsequent shocks that the app is widely used. Notably though, the speed of the collection of testimonies increases significantly when the app is used. We find that automated EMSC intensities as assigned by user‐specified thumbnails are, on average, well correlated with “Did You Feel It?” (DYFI) responses and with the three independently and manually derived macroseismic datasets, but there is a tendency for EMSC to be biased low with respect to DYFI at moderate and large intensities. We address this by proposing a simple adjustment that will be verified in future earthquakes.

  1. Global Imagery Browse Services (GIBS) - Rapidly Serving NASA Imagery for Applications and Science Users

    Science.gov (United States)

    Schmaltz, J. E.; Ilavajhala, S.; Plesea, L.; Hall, J. R.; Boller, R. A.; Chang, G.; Sadaqathullah, S.; Kim, R.; Murphy, K. J.; Thompson, C. K.

    2012-12-01

    Expedited processing of imagery from NASA satellites for near-real time use by non-science applications users has a long history, especially since the beginning of the Terra and Aqua missions. Several years ago, the Land Atmosphere Near-real-time Capability for EOS (LANCE) was created to greatly expand the range of near-real time data products from a variety of Earth Observing System (EOS) instruments. NASA's Earth Observing System Data and Information System (EOSDIS) began exploring methods to distribute these data as imagery in an intuitive, geo-referenced format, which would be available within three hours of acquisition. Toward this end, EOSDIS has developed the Global Imagery Browse Services (GIBS, http://earthdata.nasa.gov/gibs) to provide highly responsive, scalable, and expandable imagery services. The baseline technology chosen for GIBS was a Tiled Web Mapping Service (TWMS) developed at the Jet Propulsion Laboratory. Using this, global images and mosaics are divided into tiles with fixed bounding boxes for a pyramid of fixed resolutions. Initially, the satellite imagery is created at the existing data systems for each sensor, ensuring the oversight of those most knowledgeable about the science. There, the satellite data is geolocated and converted to an image format such as JPEG, TIFF, or PNG. The GIBS ingest server retrieves imagery from the various data systems and converts them into image tiles, which are stored in a highly-optimized raster format named Meta Raster Format (MRF). The image tiles are then served to users via HTTP by means of an Apache module. Services are available for the entire globe (lat-long projection) and for both polar regions (polar stereographic projection). Requests to the services can be made with the non-standard, but widely known, TWMS format or via the well-known OGC Web Map Tile Service (WMTS) standard format. Standard OGC Web Map Service (WMS) access to the GIBS server is also available. In addition, users may request a

  2. Lack of global population genetic differentiation in thearbuscular mycorrhizal fungus Glomus mosseae suggestsa recent range expansion which may have coincided withthe spread of agriculture

    DEFF Research Database (Denmark)

    Rosendahl, Søren; McGee, Peter; Morton, Joseph B

    2009-01-01

    The arbuscular mycorrhizal fungus Glomus mosseae is commonly found in agricultural fields. The cosmopolitan species is found in Africa, Europe, America, Asia and Australia. Three hypotheses may explain this worldwide distribution: First, speciation occurred before the continents separated 120 Ma;...... happened much later than continental spread and that human activity may have had a major impact on the dispersal and the population structure of the fungus....

  3. 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

  4. Visual working memory modulates low-level saccade target selection: evidence from rapidly generated saccades in the global effect paradigm.

    Science.gov (United States)

    Hollingworth, Andrew; Matsukura, Michi; Luck, Steven J

    2013-11-04

    In three experiments, we examined the influence of visual working memory (VWM) on the metrics of saccade landing position in a global effect paradigm. Participants executed a saccade to the more eccentric object in an object pair appearing on the horizontal midline, to the left or right of central fixation. While completing the saccade task, participants maintained a color in VWM for an unrelated memory task. Either the color of the saccade target matched the memory color (target match), the color of the distractor matched the memory color (distractor match), or the colors of neither object matched the memory color (no match). In the no-match condition, saccades tended to land at the midpoint between the two objects: the global, or averaging, effect. However, when one of the two objects matched VWM, the distribution of landing position shifted toward the matching object, both for target match and for distractor match. VWM modulation of landing position was observed even for the fastest quartile of saccades, with a mean latency as low as 112 ms. Effects of VWM on such rapidly generated saccades, with latencies in the express-saccade range, indicate that VWM interacts with the initial sweep of visual sensory processing, modulating perceptual input to oculomotor systems and thereby biasing oculomotor selection. As a result, differences in memory match produce effects on landing position similar to the effects generated by differences in physical salience.

  5. Think globally, act locally: Phylodynamic reconstruction of infectious bronchitis virus (IBV QX genotype (GI-19 lineage reveals different population dynamics and spreading patterns when evaluated on different epidemiological scales.

    Directory of Open Access Journals (Sweden)

    Giovanni Franzo

    testifies that animal transportation and indirect transmission routes rather than local airborne diffusion contribute to the QX success and persistence at local scale. Globally, the spreading dynamics and evolution of the QX genotype were reconstructed from its very origin to nowadays, demonstrating the need of more effective direct control measures, particularly within each country. Unfortunately, the incompleteness of available molecular epidemiology data represents an insurmountable limit which leaves many questions currently unsolved, thus highlighting the compulsoriness of a structured monitoring and data sharing system implementation.

  6. A new approach to stopping the spread of invasive insects and pathogens: early detection and rapid response via a global network of sentinel plantings

    Science.gov (United States)

    K.O. Britton; P. White; A. Kramer; G. Hudler

    2010-01-01

    The Sanitary and Phytosanitary Agreement of the World Trade Organisation specifies that countries cannot regulate against unknown pests, yet many alien invasive forest pests are unknown to science prior to discovery in a new land. Many of these pests are introduced via nursery stock, but lack of pest information makes this pathway difficult to mitigate. Botanic gardens...

  7. Globalization

    Directory of Open Access Journals (Sweden)

    Tulio Rosembuj

    2006-12-01

    Full Text Available There is no singular globalization, nor is the result of an individual agent. We could start by saying that global action has different angles and subjects who perform it are different, as well as its objectives. The global is an invisible invasion of materials and immediate effects.

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

    Directory of Open Access Journals (Sweden)

    Z. Lai

    2013-08-01

    Full Text Available The 11 March 2011 tsunami triggered by the M9 and M7.9 earthquakes off the Tōhoku coast destroyed facilities at the Fukushima Dai-ichi Nuclear Power Plant (FNPP leading to a significant long-term flow of the radionuclide 137Cs 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 137Cs over the eastern shelf of Japan. The 137Cs 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 137Cs discharge, the model-predicted spreading of 137Cs 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 137Cs 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 137Cs spreading in the inner shelf where in situ measurements were made at 30 km off the coast. The overestimation of 137Cs 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 137Cs 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 137Cs in the ocean.

  9. The spread of inequality.

    Directory of Open Access Journals (Sweden)

    Deborah S Rogers

    Full Text Available The causes of socioeconomic inequality have been debated since the time of Plato. Many reasons for the development of stratification have been proposed, from the need for hierarchical control over large-scale irrigation systems to the accumulation of small differences in wealth over time via inheritance processes. However, none of these explains how unequal societies came to completely displace egalitarian cultural norms over time. Our study models demographic consequences associated with the unequal distribution of resources in stratified societies. Agent-based simulation results show that in constant environments, unequal access to resources can be demographically destabilizing, resulting in the outward migration and spread of such societies even when population size is relatively small. In variable environments, stratified societies spread more and are also better able to survive resource shortages by sequestering mortality in the lower classes. The predictions of our simulation are provided modest support by a range of existing empirical studies. In short, the fact that stratified societies today vastly outnumber egalitarian societies may not be due to the transformation of egalitarian norms and structures, but may instead reflect the more rapid migration of stratified societies and consequent conquest or displacement of egalitarian societies over time.

  10. The Spread of Inequality

    Science.gov (United States)

    Rogers, Deborah S.; Deshpande, Omkar; Feldman, Marcus W.

    2011-01-01

    The causes of socioeconomic inequality have been debated since the time of Plato. Many reasons for the development of stratification have been proposed, from the need for hierarchical control over large-scale irrigation systems to the accumulation of small differences in wealth over time via inheritance processes. However, none of these explains how unequal societies came to completely displace egalitarian cultural norms over time. Our study models demographic consequences associated with the unequal distribution of resources in stratified societies. Agent-based simulation results show that in constant environments, unequal access to resources can be demographically destabilizing, resulting in the outward migration and spread of such societies even when population size is relatively small. In variable environments, stratified societies spread more and are also better able to survive resource shortages by sequestering mortality in the lower classes. The predictions of our simulation are provided modest support by a range of existing empirical studies. In short, the fact that stratified societies today vastly outnumber egalitarian societies may not be due to the transformation of egalitarian norms and structures, but may instead reflect the more rapid migration of stratified societies and consequent conquest or displacement of egalitarian societies over time. PMID:21957457

  11. Infectious diseases epidemic threats and mass gatherings: Refocusing global attention on the continuing spread of the Middle East Respiratory syndrome coronavirus (MERS-CoV)

    NARCIS (Netherlands)

    Zumla, A. (Alimuddin); Alagaili, A.N. (Abdulaziz N.); Cotten, M. (Matthew); Azhar, E.I. (Esam I.)

    2016-01-01

    textabstractMedia and World Health Organization (WHO) attention on Zika virus transmission at the 2016 Rio Olympic Games and the 2015 Ebola virus outbreak in West Africa diverted the attention of global public health authorities from other lethal infectious diseases with epidemic potential. Mass

  12. Prompt Assessment of Global Earthquakes for Response (PAGER): A System for Rapidly Determining the Impact of Earthquakes Worldwide

    Science.gov (United States)

    Earle, Paul S.; Wald, David J.; Jaiswal, Kishor S.; Allen, Trevor I.; Hearne, Michael G.; Marano, Kristin D.; Hotovec, Alicia J.; Fee, Jeremy

    2009-01-01

    Within minutes of a significant earthquake anywhere on the globe, the U.S. Geological Survey (USGS) Prompt Assessment of Global Earthquakes for Response (PAGER) system assesses its potential societal impact. PAGER automatically estimates the number of people exposed to severe ground shaking and the shaking intensity at affected cities. Accompanying maps of the epicentral region show the population distribution and estimated ground-shaking intensity. A regionally specific comment describes the inferred vulnerability of the regional building inventory and, when available, lists recent nearby earthquakes and their effects. PAGER's results are posted on the USGS Earthquake Program Web site (http://earthquake.usgs.gov/), consolidated in a concise one-page report, and sent in near real-time to emergency responders, government agencies, and the media. Both rapid and accurate results are obtained through manual and automatic updates of PAGER's content in the hours following significant earthquakes. These updates incorporate the most recent estimates of earthquake location, magnitude, faulting geometry, and first-hand accounts of shaking. PAGER relies on a rich set of earthquake analysis and assessment tools operated by the USGS and contributing Advanced National Seismic System (ANSS) regional networks. A focused research effort is underway to extend PAGER's near real-time capabilities beyond population exposure to quantitative estimates of fatalities, injuries, and displaced population.

  13. Ecological ethics in captivity: balancing values and responsibilities in zoo and aquarium research under rapid global change.

    Science.gov (United States)

    Minteer, Ben A; Collins, James P

    2013-01-01

    Ethical obligations to animals in conservation research and management are manifold and often conflicting. Animal welfare concerns often clash with the ethical imperative to understand and conserve a population or ecosystem through research and management intervention. The accelerating pace and impact of global environmental change, especially climate change, complicates our understanding of these obligations. One example is the blurring of the distinction between ex situ (zoo- and aquarium-based) conservation and in situ (field-based) approaches as zoos and aquariums become more active in field conservation work and as researchers and managers consider more intensive interventions in wild populations and ecosystems to meet key conservation goals. These shifts, in turn, have consequences for our traditional understanding of the ethics of wildlife research and management, including our relative weighting of animal welfare and conservation commitments across rapidly evolving ex situ and in situ contexts. Although this changing landscape in many ways supports the increased use of captive wildlife in conservation-relevant research, it raises significant ethical concerns about human intervention in populations and ecosystems, including the proper role of zoos and aquariums as centers for animal research and conservation in the coming decades. Working through these concerns requires a pragmatic approach to ethical analysis, one that is able to make trade-offs among the many goods at stake (e.g., animal welfare, species viability, and ecological integrity) as we strive to protect species from further decline and extinction in this century.

  14. The Agile Rapid Global Combat Support (ARGCS) System: A Cost and Benefit Analysis of Including the ARGCS Technologies in the Acquisition of the Enhanced Consolidated Support System (ECASS)

    Science.gov (United States)

    2007-12-01

    Franck and Carmelita Troy in January 2007. Revised in May of 2007, this interim BCA, based on the data then available, offered an assessment of the...www.drivedemand.com/roipart1.html Franck, Raymond and Carmelita Troy, Agile Rapid Global Combat Support, Business Case Analysis, Version 1.0. Naval

  15. Multilocus Sequence Analysis of Xanthomonads Causing Bacterial Spot of Tomato and Pepper Plants Reveals Strains Generated by Recombination among Species and Recent Global Spread of Xanthomonas gardneri

    OpenAIRE

    Timilsina, Sujan; Jibrin, Mustafa O.; Potnis, Neha; Minsavage, Gerald V.; Kebede, Misrak; Schwartz, Allison; Bart, Rebecca; Staskawicz, Brian; Boyer, Claudine; Vallad, Gary E.; Pruvost, Olivier; Jones, Jeffrey B; Goss, Erica M.

    2014-01-01

    Four Xanthomonas species are known to cause bacterial spot of tomato and pepper, but the global distribution and genetic diversity of these species are not well understood. A collection of bacterial spot-causing strains from the Americas, Africa, Southeast Asia, and New Zealand were characterized for genetic diversity and phylogenetic relationships using multilocus sequence analysis of six housekeeping genes. By examining strains from different continents, we found unexpected phylogeographic ...

  16. What happened after the initial global spread of pandemic human influenza virus A (H1N1? A population genetics approach

    Directory of Open Access Journals (Sweden)

    Martinez-Hernandez Fernando

    2010-08-01

    Full Text Available Abstract Viral population evolution dynamics of influenza A is crucial for surveillance and control. In this paper we analyzed viral genetic features during the recent pandemic caused by the new influenza human virus A H1N1, using a conventional population genetics approach based on 4689 hemagglutinin (HA and neuraminidase (NA sequences available in GenBank submitted between March and December of 2009. This analysis showed several relevant aspects: a a scarce initial genetic variability within the viral isolates from some countries that increased along 2009 when influenza was dispersed around the world; b a worldwide virus polarized behavior identified when comparing paired countries, low differentiation and high gene flow were found in some pairs and high differentiation and moderate or scarce gene flow in others, independently of their geographical closeness, c lack of positive selection in HA and NA due to increase of the population size of virus variants, d HA and NA variants spread in a few months all over the world being identified in the same countries in different months along 2009, and e containment of viral variants in Mexico at the beginning of the outbreak, probably due to the control measures applied by the government.

  17. Temperature and humidity based projections of a rapid rise in global heat stress exposure during the 21st century

    Science.gov (United States)

    Coffel, Ethan D.; Horton, Radley M.; de Sherbinin, Alex

    2018-01-01

    As a result of global increases in both temperature and specific humidity, heat stress is projected to intensify throughout the 21st century. Some of the regions most susceptible to dangerous heat and humidity combinations are also among the most densely populated. Consequently, there is the potential for widespread exposure to wet bulb temperatures that approach and in some cases exceed postulated theoretical limits of human tolerance by mid- to late-century. We project that by 2080 the relative frequency of present-day extreme wet bulb temperature events could rise by a factor of 100–250 (approximately double the frequency change projected for temperature alone) in the tropics and parts of the mid-latitudes, areas which are projected to contain approximately half the world’s population. In addition, population exposure to wet bulb temperatures that exceed recent deadly heat waves may increase by a factor of five to ten, with 150–750 million person-days of exposure to wet bulb temperatures above those seen in today’s most severe heat waves by 2070–2080. Under RCP 8.5, exposure to wet bulb temperatures above 35 °C—the theoretical limit for human tolerance—could exceed a million person-days per year by 2080. Limiting emissions to follow RCP 4.5 entirely eliminates exposure to that extreme threshold. Some of the most affected regions, especially Northeast India and coastal West Africa, currently have scarce cooling infrastructure, relatively low adaptive capacity, and rapidly growing populations. In the coming decades heat stress may prove to be one of the most widely experienced and directly dangerous aspects of climate change, posing a severe threat to human health, energy infrastructure, and outdoor activities ranging from agricultural production to military training.

  18. Holocene fluvial geochronologies, global databases and hydrological proxies: rethinking people-river interactions and rapid climate change impacts (Invited)

    Science.gov (United States)

    Macklin, M. G.

    2009-12-01

    The assumption of the constancy of climate over time periods of around a century, which was the basis of much engineering and hydrological forward planning until recently, is now widely felt to be unsatisfactory. This re-evaluation has been prompted by a number of important empirical, interdisciplinary and technological advances in fluvial science research over the last decade that is increasingly being carried out in a global framework. Some of the more important developments have included: 1. wider application of high precision sediment-based dating techniques (e.g. OSL) to a greater range of fluvial environments; 2. worldwide database compilation and statistical analysis of 14C dated Holocene fluvial units, enabling the identification of climatic and anthropogenic environmental signals in fluvial sedimentary sequences; and 3. new earth surface observation (e.g. LIDAR) and sediment core analysis (e.g. ITRAX core scanner) techniques that are providing event-scale reconstructions of fluvial environments. Drawing on recent geoarchaeological research in the lower Nile valley, 14C database analysis and comparison of Holocene fluvial records in Europe and New Zealand, and a new 3700-year continuous flood record from the UK reconstructed from fine-grained floodplain sediments, the impact of rapid climate change on riverine societies resulting from monsoon, thermohaline circulation, ENSO and NAO variability is critically reviewed. These studies show that establishing causal relationships between river dynamics and cultural/demographic change is not a straightforward task and identifying possible natural environmental triggers of societal change is especially problematic. A solution may be to stress the inseparable nature of environmental and cultural influences, and view the physical environment as a delimiter of possible action rather than as a prescriptive agency.

  19. Reducing the Spread in Modeled Aerosol Radiative Forcing with a Global, Scattering Line-by-Line Model as Part of RFMIP

    Science.gov (United States)

    Jones, A. L.; Paynter, D.; Freidenreich, S.; Feldman, D.; Ramaswamy, V.; Collins, W. D.

    2016-12-01

    The large range in aerosol radiative forcing across CMIP5 GCMs may come from either a true range in aerosol climatology or radiative parameterization errors. One of the goals of the Radiative Forcing Model Intercomparison Project (RFMIP) is to quantify the contribution of radiative parameterization errors to the range in aerosol forcing on a global scale. This is achieved by running a benchmark-quality line-by-line code at the native resolution of each participating GCM using the atmospheric state from that GCM as input, including aerosol optical properties. Thus, the framework provides a benchmark estimate of flux for every model grid point. The resulting radiative fluxes can then be compared to those produced natively by the GCM radiative parameterization. In this way the radiative parameterization error is quantified globally and regionally while maintaining the variability in atmospheric state between models. This calculation is performed with and without aerosols to further provide an estimate of aerosol radiative forcing. This intercomparison is unique in that it performs calculations over the entire globe on each model's native grid and with each model's meteorological fields as input, thus elucidating the spatial distribution of errors and representing a wider range of atmospheric conditions in its characterizations. Previous radiative intercomparison efforts have relied on only a handful of atmospheric profiles, which are often idealized, to represent the variability of conditions in the atmosphere. For this study we present a proof of concept of the RFMIP protocol by intercomparing the results for two GCMs, GFDL's AM4 and NCAR's CESM. We demonstrate the contribution RFMIP has on reducing the range in modeled aerosol radiative forcing and the potential it can have with the participation of additional modeling centers.

  20. How Is Mono Spread?

    Science.gov (United States)

    ... Spread? Print A A A 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 ...

  1. Rapid health transition in China, 1990-2010: findings from the Global Burden of Disease Study 2010.

    Science.gov (United States)

    Yang, Gonghuan; Wang, Yu; Zeng, Yixin; Gao, George F; Liang, Xiaofeng; Zhou, Maigeng; Wan, Xia; Yu, Shicheng; Jiang, Yuhong; Naghavi, Mohsen; Vos, Theo; Wang, Haidong; Lopez, Alan D; Murray, Christopher J L

    2013-06-08

    China has undergone rapid demographic and epidemiological changes in the past few decades, including striking declines in fertility and child mortality and increases in life expectancy at birth. Popular discontent with the health system has led to major reforms. To help inform these reforms, we did a comprehensive assessment of disease burden in China, how it changed between 1990 and 2010, and how China's health burden compares with other nations. We used results of the Global Burden of Diseases, Injuries, and Risk Factors Study 2010 (GBD 2010) for 1990 and 2010 for China and 18 other countries in the G20 to assess rates and trends in mortality, causes of death, years of life lost (YLLs), years lived with disability (YLDs), disability-adjusted life-years (DALYs), and healthy life expectancy (HALE). We present results for 231 diseases and injuries and for 67 risk factors or clusters of risk factors relevant to China. We assessed relative performance of China against G20 countries (significantly better, worse, or indistinguishable from the G20 mean) with age-standardised rates and 95% uncertainty intervals. The leading causes of death in China in 2010 were stroke (1·7 million deaths, 95% UI 1·5-1·8 million), ischaemic heart disease (948,700 deaths, 774,500-1,024,600), and chronic obstructive pulmonary disease (934,000 deaths, 846,600-1,032,300). Age-standardised YLLs in China were lower in 2010 than all emerging economies in the G20, and only slightly higher than noted in the USA. China had the lowest age-standardised YLD rate in the G20 in 2010. China also ranked tenth (95% UI eighth to tenth) for HALE and 12th (11th to 13th) for life expectancy. YLLs from neonatal causes, infectious diseases, and injuries in children declined substantially between 1990 and 2010. Mental and behavioural disorders, substance use disorders, and musculoskeletal disorders were responsible for almost half of all YLDs. The fraction of DALYs from YLDs rose from 28·1% (95% UI 24·2-32·5

  2. Globalization

    DEFF Research Database (Denmark)

    Plum, Maja

    Globalization is often referred to as external to education - a state of affair facing the modern curriculum with numerous challenges. In this paper it is examined as internal to curriculum; analysed as a problematization in a Foucaultian sense. That is, as a complex of attentions, worries, ways...... of reasoning, producing curricular variables. The analysis is made through an example of early childhood curriculum in Danish Pre-school, and the way the curricular variable of the pre-school child comes into being through globalization as a problematization, carried forth by the comparative practices of PISA...

  3. Global climate change and vector-borne diseases

    Science.gov (United States)

    Ginsberg, H.S.

    2002-01-01

    Global warming will have different effects on different diseases because of the complex and idiosynchratic interactions between vectors, hosts, and pathogens that influence transmission dynamics of each pathogen. Human activities, including urbanization, rapid global travel, and vector management, have profound effects on disease transmission that can operate on more rapid time scales than does global climate change. The general concern about global warming encouraging the spread of tropical diseases is legitimate, but the effects vary among diseases, and the ecological implications are difficult to predict.

  4. Rapid characterisation of vegetation structure to predict refugia and climate change impacts across a global biodiversity hotspot

    NARCIS (Netherlands)

    Schut, A.G.T.; Wardell-Johnson, G.W.; Yates, C.J.; Keppel, G.; Baran, I.; Franklin, S.E.; Hopper, S.D.; Niel, Van K.P.; Mucina, L.; Byrne, M.

    2014-01-01

    Identification of refugia is an increasingly important adaptation strategy in conservation planning under rapid anthropogenic climate change. Granite outcrops (GOs) provide extraordinary diversity, including a wide range of taxa, vegetation types and habitats in the Southwest Australian Floristic

  5. Assessing the risk of international spread of yellow fever virus: a mathematical analysis of an urban outbreak in Asuncion, 2008.

    Science.gov (United States)

    Johansson, Michael A; Arana-Vizcarrondo, Neysarí; Biggerstaff, Brad J; Gallagher, Nancy; Marano, Nina; Staples, J Erin

    2012-02-01

    Yellow fever virus (YFV), a mosquito-borne virus endemic to tropical Africa and South America, is capable of causing large urban outbreaks of human disease. With the ease of international travel, urban outbreaks could lead to the rapid spread and subsequent transmission of YFV in distant locations. We designed a stochastic metapopulation model with spatiotemporally explicit transmissibility scenarios to simulate the global spread of YFV from a single urban outbreak by infected airline travelers. In simulations of a 2008 outbreak in Asunción, Paraguay, local outbreaks occurred in 12.8% of simulations and international spread in 2.0%. Using simple probabilistic models, we found that local incidence, travel rates, and basic transmission parameters are sufficient to assess the probability of introduction and autochthonous transmission events. These models could be used to assess the risk of YFV spread during an urban outbreak and identify locations at risk for YFV introduction and subsequent autochthonous transmission.

  6. The spreading of disorder.

    Science.gov (United States)

    Keizer, Kees; Lindenberg, Siegwart; Steg, Linda

    2008-12-12

    Imagine that the neighborhood you are living in is covered with graffiti, litter, and unreturned shopping carts. Would this reality cause you to litter more, trespass, or even steal? A thesis known as the broken windows theory suggests that signs of disorderly and petty criminal behavior trigger more disorderly and petty criminal behavior, thus causing the behavior to spread. This may cause neighborhoods to decay and the quality of life of its inhabitants to deteriorate. For a city government, this may be a vital policy issue. But does disorder really spread in neighborhoods? So far there has not been strong empirical support, and it is not clear what constitutes disorder and what may make it spread. We generated hypotheses about the spread of disorder and tested them in six field experiments. We found that, when people observe that others violated a certain social norm or legitimate rule, they are more likely to violate other norms or rules, which causes disorder to spread.

  7. Waste Crime – Waste Risks: Gaps in Meeting the Global Waste Challenge : A UNEP Rapid Response Assessment

    NARCIS (Netherlands)

    Ieva Rucevska; Christian Nelleman; Nancy Isarin; Wanhua Yang; Ning Liu; Kelly Yu; Siv Sandnaes; Katie Olley; Howard McCann; Leila Devia; L.C.J. Bisschop (Lieselot); Denise Soesilo; Tina Schoolmeester; Rune Hendriksen; Rannveig Nilsen; Claire Eamer

    2015-01-01

    markdownabstractMore than ever, our future depends upon how we manage the future of our waste. As an integrated part of sustainable development, effective waste management can reduce our global footprint. Ignoring or neglecting the challenges of waste, however, can lead to significant health,

  8. Zika Virus: Anatomy of a Global Health Crisis

    OpenAIRE

    Fellner, Chris

    2016-01-01

    Zika virus infection has emerged as the world’s newest health threat, linked to microcephaly in infants and Guillain–Barré syndrome in adults. We address the rapid global spread of this disease, and the prospects for successful prevention and treatment.

  9. Globalization of the sports economy

    OpenAIRE

    Wladimir Andreff

    2008-01-01

    Introduction – 1. Major features of a globalized sports economy – 2. International economic flows in a global sports economy – 3. Globalization as geographical spread of the sports economy – 4. Globalization of professional sports – Conclusion – References

  10. Rapid characterisation of vegetation structure to predict refugia and climate change impacts across a global biodiversity hotspot.

    Directory of Open Access Journals (Sweden)

    Antonius G T Schut

    Full Text Available Identification of refugia is an increasingly important adaptation strategy in conservation planning under rapid anthropogenic climate change. Granite outcrops (GOs provide extraordinary diversity, including a wide range of taxa, vegetation types and habitats in the Southwest Australian Floristic Region (SWAFR. However, poor characterization of GOs limits the capacity of conservation planning for refugia under climate change. A novel means for the rapid identification of potential refugia is presented, based on the assessment of local-scale environment and vegetation structure in a wider region. This approach was tested on GOs across the SWAFR. Airborne discrete return Light Detection And Ranging (LiDAR data and Red Green and Blue (RGB imagery were acquired. Vertical vegetation profiles were used to derive 54 structural classes. Structural vegetation types were described in three areas for supervised classification of a further 13 GOs across the region. Habitat descriptions based on 494 vegetation plots on and around these GOs were used to quantify relationships between environmental variables, ground cover and canopy height. The vegetation surrounding GOs is strongly related to structural vegetation types (Kappa = 0.8 and to its spatial context. Water gaining sites around GOs are characterized by taller and denser vegetation in all areas. The strong relationship between rainfall, soil-depth, and vegetation structure (R(2 of 0.8-0.9 allowed comparisons of vegetation structure between current and future climate. Significant shifts in vegetation structural types were predicted and mapped for future climates. Water gaining areas below granite outcrops were identified as important putative refugia. A reduction in rainfall may be offset by the occurrence of deeper soil elsewhere on the outcrop. However, climate change interactions with fire and water table declines may render our conclusions conservative. The LiDAR-based mapping approach presented

  11. The epidemiology and spread of drug resistant human influenza viruses.

    Science.gov (United States)

    Hurt, Aeron C

    2014-10-01

    Significant changes in the circulation of antiviral-resistant influenza viruses have occurred over the last decade. The emergence and continued circulation of adamantane-resistant A(H3N2) and A(H1N1)pdm09 viruses mean that the adamantanes are no longer recommended for use. Resistance to the newer class of drugs, the neuraminidase inhibitors, is typically associated with poorer viral replication and transmission. But 'permissive' mutations, that compensated for impairment of viral function in A(H1N1) viruses during 2007/2008, enabled them to acquire the H275Y NA resistance mutation without fitness loss, resulting in their rapid global spread. Permissive mutations now appear to be present in A(H1N1)pdm09 viruses thereby increasing the risk that oseltamivir-resistant A(H1N1)pdm09 viruses may also spread globally, a concerning scenario given that oseltamivir is the most widely used influenza antiviral. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Quasirandom Rumor Spreading

    OpenAIRE

    Doerr, Benjamin; Friedrich, Tobias; Sauerwald, Thomas

    2010-01-01

    We propose and analyze a quasirandom analogue of the classical push model for disseminating information in networks ("randomized rumor spreading"). In the classical model, in each round each informed vertex chooses a neighbor at random and informs it, if it was not informed before. It is known that this simple protocol succeeds in spreading a rumor from one vertex to all others within O(log n) rounds on complete graphs, hypercubes, random regular graphs, Erdos-Renyi random graph and Ramanujan...

  13. Pathways of lateral spreading.

    Science.gov (United States)

    Jacobi, U; Schanzer, S; Weigmann, H-J; Patzelt, A; Vergou, T; Sterry, W; Lademann, J

    2011-01-01

    In the case of topically applied substances, usually both lateral spreading and competitive penetration into the skin occur in parallel. In the present study, the pathways of lateral spreading were studied quantitatively and visually. The local distribution and lateral spreading of the UV filter substance butyl methoxydibenzoylmethane applied in an o/w emulsion was studied on the forearm and the back. The tape stripping procedure was used to determine the recovery rates inside and outside the area of application. The skin characteristics of transepidermal water loss, pH value, hydration of the stratum corneum and sebum rate were determined at both anatomic sites. Photography and laser scanning microscopy were used to visually investigate the lateral spreading of topically applied dyes. On the back, a preferred direction of lateral spreading parallel to the body axis was observed. This result was caused by differences in the network of furrows. The furrows functioned as a pathway for lateral spreading, whereas the follicles formed a reservoir for the topically applied substance. Copyright © 2011 S. Karger AG, Basel.

  14. Rapid diversification in Australia and two dispersals out of Australia in the globally distributed bee genus, Hylaeus (Colletidae: Hylaeinae).

    Science.gov (United States)

    Kayaalp, Pelin; Schwarz, Michael P; Stevens, Mark I

    2013-03-01

    Hylaeus is the only globally distributed colletid bee genus, with subgeneric and species-level diversity highest in Australia. We used one mitochondrial and two nuclear genes to reconstruct a phylogeny using Bayesian analyses of this genus based on species from Australia, Asia, Africa, Europe, Hawai'i, the New World and New Zealand. Our results concord with a ca. 30Mya Hylaeus crown age inferred by earlier studies, and we show that Hylaeus originated in Australia. Our phylogeny indicates only two dispersal events out of Australia, both shortly after the initial diversification of extant taxa. One of these dispersals was into New Zealand with only a minor subsequent radiation, but the second dispersal out of Australia resulted in a world-wide distribution. This second dispersal and radiation event, combined with very extensive early radiation of Hyleaus in Australia, poses a conundrum: what kinds of biogeographical and ecological factors could simultaneously drive global dispersal, yet strongly constrain further successful migrations out of Australia when geographical barriers appear to be weak? We argue that for hylaeine bees movement into new niches and enemy-free spaces may have favoured initial dispersal events, but that subsequent dispersals would not have entailed the original benefits of new niche space. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Forecast and control of epidemics in a globalized world.

    Science.gov (United States)

    Hufnagel, L; Brockmann, D; Geisel, T

    2004-10-19

    The rapid worldwide spread of severe acute respiratory syndrome demonstrated the potential threat an infectious disease poses in a closely interconnected and interdependent world. Here we introduce a probabilistic model that describes the worldwide spread of infectious diseases and demonstrate that a forecast of the geographical spread of epidemics is indeed possible. This model combines a stochastic local infection dynamics among individuals with stochastic transport in a worldwide network, taking into account national and international civil aviation traffic. Our simulations of the severe acute respiratory syndrome outbreak are in surprisingly good agreement with published case reports. We show that the high degree of predictability is caused by the strong heterogeneity of the network. Our model can be used to predict the worldwide spread of future infectious diseases and to identify endangered regions in advance. The performance of different control strategies is analyzed, and our simulations show that a quick and focused reaction is essential to inhibiting the global spread of epidemics.

  16. Rapid Production of E-Learning Materials with Reusable Learning Objects: Experiences from the Global Academy for Extension Practice

    Directory of Open Access Journals (Sweden)

    Mary Holz-Clause

    2012-08-01

    Full Text Available Open educational resources, institutional collaborations, and content reusability approaches have been quickly emerging to minimize the time and money spent on developing e-learning materials. Reusing content with reusable learning objects (RLOs is carving a new path for research on reusing and repurposing available high quality e-learning content. Prior research shows that this component-based approach best fits how educators prefer to access materials. In this paper, without arguing the merits and demerits of RLOs as a concept, the authors present an effective and affordable approach to creating e-learning materials with RLOs. The authors also present how they have implemented the proposed RLO approach in converting learning modules of the Global Academy for Extension Practice into multiple e-learning material formats.

  17. Rapid upslope shifts in New Guinean birds illustrate strong distributional responses of tropical montane species to global warming

    Science.gov (United States)

    Freeman, Benjamin G.; Class Freeman, Alexandra M.

    2014-01-01

    Temperate-zone species have responded to warming temperatures by shifting their distributions poleward and upslope. Thermal tolerance data suggests that tropical species may respond to warming temperatures even more strongly than temperate-zone species, but this prediction has yet to be tested. We addressed this data gap by conducting resurveys to measure distributional responses to temperature increases in the elevational limits of the avifaunas of two geographically and faunally independent New Guinean mountains, Mt. Karimui and Karkar Island, 47 and 44 y after they were originally surveyed. Although species richness is roughly five times greater on mainland Mt. Karimui than oceanic Karkar Island, distributional shifts at both sites were similar: upslope shifts averaged 113 m (Mt. Karimui) and 152 m (Karkar Island) for upper limits and 95 m (Mt. Karimui) and 123 m (Karkar Island) for lower limits. We incorporated these results into a metaanalysis to compare distributional responses of tropical species with those of temperate-zone species, finding that average upslope shifts in tropical montane species match local temperature increases significantly more closely than in temperate-zone montane species. That tropical species appear to be strong responders has global conservation implications and provides empirical support to hitherto untested models that predict widespread extinctions in upper-elevation tropical endemics with small ranges. PMID:24550460

  18. An accurate and rapid continuous wavelet dynamic time warping algorithm for unbalanced global mapping in nanopore sequencing

    KAUST Repository

    Han, Renmin

    2017-12-24

    Long-reads, point-of-care, and PCR-free are the promises brought by nanopore sequencing. Among various steps in nanopore data analysis, the global mapping between the raw electrical current signal sequence and the expected signal sequence from the pore model serves as the key building block to base calling, reads mapping, variant identification, and methylation detection. However, the ultra-long reads of nanopore sequencing and an order of magnitude difference in the sampling speeds of the two sequences make the classical dynamic time warping (DTW) and its variants infeasible to solve the problem. Here, we propose a novel multi-level DTW algorithm, cwDTW, based on continuous wavelet transforms with different scales of the two signal sequences. Our algorithm starts from low-resolution wavelet transforms of the two sequences, such that the transformed sequences are short and have similar sampling rates. Then the peaks and nadirs of the transformed sequences are extracted to form feature sequences with similar lengths, which can be easily mapped by the original DTW. Our algorithm then recursively projects the warping path from a lower-resolution level to a higher-resolution one by building a context-dependent boundary and enabling a constrained search for the warping path in the latter. Comprehensive experiments on two real nanopore datasets on human and on Pandoraea pnomenusa, as well as two benchmark datasets from previous studies, demonstrate the efficiency and effectiveness of the proposed algorithm. In particular, cwDTW can almost always generate warping paths that are very close to the original DTW, which are remarkably more accurate than the state-of-the-art methods including FastDTW and PrunedDTW. Meanwhile, on the real nanopore datasets, cwDTW is about 440 times faster than FastDTW and 3000 times faster than the original DTW. Our program is available at https://github.com/realbigws/cwDTW.

  19. Importance of vegetation processes for model spread in the fast precipitation response to CO2 forcing

    Science.gov (United States)

    DeAngelis, Anthony M.; Qu, Xin; Hall, Alex

    2016-12-01

    In the current generation of climate models, the projected increase in global precipitation over the 21st century ranges from 2% to 10% under a high-emission scenario. Some of this uncertainty can be traced to the rapid response to carbon dioxide (CO2) forcing. We analyze an ensemble of simulations to better understand model spread in this rapid response. A substantial amount is linked to how the land surface partitions a change in latent versus sensible heat flux in response to the CO2-induced radiative perturbation; a larger increase in sensible heat results in a larger decrease in global precipitation. Model differences in the land surface response appear to be strongly related to the vegetation response to increased CO2, specifically, the closure of leaf stomata. Future research should thus focus on evaluation of the vegetation physiological response, including stomatal conductance parameterizations, for the purpose of constraining the fast response of Earth's hydrologic cycle to CO2 forcing.

  20. Virus spread in networks

    NARCIS (Netherlands)

    Mieghem, P. van; Omic, J.; Kooij, R.E.

    2009-01-01

    The influence of the network characteristics on the virus spread is analyzed in a new-the N-intertwined Markov chain-model, whose only approximation lies in the application of mean field theory. The mean field approximation is quantified in detail. The N-intertwined model has been compared with the

  1. Use of ENVISAT ASAR Global Monitoring Mode to complement optical data in the mapping of rapid broad-scale flooding in Pakistan

    Directory of Open Access Journals (Sweden)

    D. O'Grady

    2011-11-01

    Full Text Available Envisat ASAR Global Monitoring Mode (GM data are used to produce maps of the extent of the flooding in Pakistan which are made available to the rapid response effort within 24 h of acquisition. The high temporal frequency and independence of the data from cloud-free skies makes GM data a viable tool for mapping flood waters during those periods where optical satellite data are unavailable, which may be crucial to rapid response disaster planning, where thousands of lives are affected. Image differencing techniques are used, with pre-flood baseline image backscatter values being deducted from target values to eliminate regions with a permanent flood-like radar response due to volume scattering and attenuation, and to highlight the low response caused by specular reflection by open flood water. The effect of local incidence angle on the received signal is mitigated by ensuring that the deducted image is acquired from the same orbit track as the target image. Poor separability of the water class with land in areas beyond the river channels is tackled using a region-growing algorithm which seeks threshold-conformance from seed pixels at the center of the river channels. The resultant mapped extents are tested against MODIS SWIR data where available, with encouraging results.

  2. Dissecting The Value-Momentum Spread: Sector Allocation Effect Versus Country Allocation Effect

    National Research Council Canada - National Science Library

    Heng-Hsing Hsieh; Kathleen Hodnett

    2012-01-01

    .... After constructing the global value and momentum style indexes from global equities, we conduct performance attribution on the global value-momentum spread over the period from 01 January 1991 to 31 December 2008...

  3. 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.

  4. 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,

  5. 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

  6. A Rapid Global Effects Capability

    Science.gov (United States)

    2016-06-01

    Types of fuel used for propulsion, horizontal vs. vertical takeoff options, launch locations, and most importantly trajectory are factors that would...a much higher, elliptical ‘flight path’ in order to re-enter the atmosphere and strike its target.107 Near-peer allies would also be able to

  7. Spatial Spillovers in Emerging Market Spreads

    OpenAIRE

    Salvatore Dell'Erba; Emanuele Baldacci; Tigran Poghosyan

    2011-01-01

    We use novel spatial econometrics techniques to explore spillovers in the sovereign bond market for 24 emerging economies during 1995-2010. The paper extends the previous literature focusing on spillover effects from advanced to emerging economies by analyzing transmission of shocks across emerging markets. After controlling for the impact of global factors, we find strong evidence of spillovers from both sovereign spreads and macroeconomic fundamentals in neighboring emerging economies. In a...

  8. 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...

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

    Science.gov (United States)

    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.

  10. 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.

  11. Innovation spread: lessons from HIV.

    Science.gov (United States)

    Talbert-Slagle, Kristina; Berg, David; Bradley, Elizabeth H

    2013-09-01

    Efficient spreading of evidence-based innovations among complex health systems remains an elusive goal despite extensive study in the social sciences. Biology provides a model of successful spread in viruses, which have evolved to spread with maximum efficiency using minimal resources. Here we explore the molecular mechanisms of human immunodeficiency virus (HIV) spread and identify five steps that are also common to a recent example of spread in complex health systems: reduction in door-to-balloon times for patients with ST-segment elevation myocardial infarction (STEMI). We then describe a new model we have developed, called AIDED, which is based on mixed-methods research but informed by the conceptual framework of HIV spread among cells. The AIDED model contains five components: Assess, Innovate, Develop, Engage and Devolve, and can describe any one of the following: the spread of HIV among cells, the spread of practices to reduce door-to-balloon time for patients with STEMI and the spread of certain family health innovations in low- and middle-income countries. We suggest that by looking to the biological sciences for a model of spread that has been honed by evolution, we may have identified fundamental steps that are necessary and sufficient for efficient, low-cost spread of health innovations among complex health systems.

  12. Global Stability of an Epidemic Model of Computer Virus

    OpenAIRE

    Yang, Xiaofan; Liu, Bei; Gan, Chenquan

    2014-01-01

    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 a...

  13. Mass Gatherings and the Spread of Respiratory Infections. Lessons from the Hajj.

    Science.gov (United States)

    Al-Tawfiq, Jaffar A; Gautret, Philippe; Benkouiten, Samir; Memish, Ziad A

    2016-06-01

    The mass gathering of people is a potential source for developing, propagating, and disseminating infectious diseases on a global scale. Of the illnesses associated with mass gatherings, respiratory tract infections are the most common, the most easily transmitted, and the most likely to be spread widely beyond the site of the meeting by attendees returning home. Many factors contribute to the spread of these infections during mass gatherings, including crowding, the health of the attendees, and the type and location of meetings. The annual Hajj in the Kingdom of Saudi Arabia is the largest recurring single mass gathering in the world. Every year more than 10 million pilgrims attend the annual Hajj and Umrah. Attendees assemble in confined areas for several days. People with a wide range of age, health, susceptibility to illness, and hygiene sophistication come in close contact, creating an enormous public health challenge. Controlling respiratory infections at the Hajj requires surveillance, rapid diagnostic testing, and containment strategies. Although the Hajj is without equal, other mass gatherings can generate similar hazards. The geographic colocalization of the Zika virus epidemic and the 2016 Summer Olympic Games in Brazil is a current example of great concern. The potential of international mass gatherings for local and global calamity calls for greater global attention and research.

  14. Why has HIV spread so rapidly in southern Africa? | Chandiwana ...

    African Journals Online (AJOL)

    The most recent published sentinel surveillance figures for Zimbabwe suggest that the national level of HIV prevalence among women attending antenatal clinics increased from 29% in 1997 to 35% in 2000. Even after adjusting for likely selection bias in sentinel sites, it was estimated that HIV prevalence amongst adults in ...

  15. Drop spreading with random viscosity

    CERN Document Server

    Xu, Feng

    2016-01-01

    We examine theoretically the spreading of a viscous liquid drop over a thin film of uniform thickness, assuming the liquid's viscosity is regulated by the concentration of a solute that is carried passively by the spreading flow. The solute is assumed to be initially heterogeneous, having a spatial distribution with prescribed statistical features. To examine how this variability influences the drop's motion, we investigate spreading in a planar geometry using lubrication theory, combining numerical simulations with asymptotic analysis. We assume diffusion is sufficient to suppress solute concentration gradients across but not along the film. The solute field beneath the bulk of the drop is stretched by the spreading flow, such that the initial solute concentration immediately behind the drop's effective contact lines has a long-lived influence on the spreading rate. Over long periods, solute swept up from the precursor film accumulates in a short region behind the contact line, allowing patches of elevated v...

  16. Global climate change and infectious diseases

    Energy Technology Data Exchange (ETDEWEB)

    Shope, R. (Yale Univ. School of Medicine, New Haven, CT (United States))

    1991-12-01

    The effects of global climate change on infectious diseases are hypothetical until more is known about the degree of change in temperature and humidity that will occur. Diseases most likely to increase in their distribution and severity have three-factor (agent, vector, and human being) and four-factor (plus vertebrate reservoir host) ecology. Aedes aegypti and Aedes albopictus mosquitoes may move northward and have more rapid metamorphosis with global warming. These mosquitoes transmit dengue virus, and Aedes aegypti transmits yellow fever virus. The faster metamorphosis and a shorter extrinsic incubation of dengue and yellow fever viruses could lead to epidemics in North America. Vibrio cholera is harbored persistently in the estuaries of the U.S. Gulf Coast. Over the past 200 years, cholera has become pandemic seven times with spread from Asia to Europe, Africa, and North America. Global warming may lead to changes in water ecology that could enhance similar spread of cholera in North America. Some other infectious diseases such as LaCrosse encephalitis and Lyme disease are caused by agents closely dependent on the integrity of their environment. These diseases may become less prominent with global warming because of anticipated modification of their habitats. Ecological studies will help as to understand more fully the possible consequences of global warming. New and more effective methods for control of vectors will be needed. 12 refs., 1 tab.

  17. 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

    channels initiates spreading depression of brain activity. In contrast, epileptic seizures show modest ion translocation and sustained depolarization below the inactivation threshold for action potential generating channels. Such modest sustained depolarization allows synchronous, highly frequent neuronal...... firing; ictal epileptic field potentials being its electrocorticographic and epileptic seizure its clinical correlate. Nevertheless, Leão in 1944 and Van Harreveld and Stamm in 1953 described in animals that silencing of brain activity induced by spreading depolarization changed during minimal electrical......, monopolar recordings here provided unequivocal evidence of spreading convulsions in patients. Hence, practically all major pathological cortical network events in animals have now been observed in people. Early spreading depolarizations may indicate a risk for late post-haemorrhagic seizures....

  18. Global civil society and its discontents

    DEFF Research Database (Denmark)

    Corry, T. Olaf

    2006-01-01

    According to enthusiasts the concept of global civil society is spreading rapidly and becoming pivotal to the reconfiguring of the statist paradigm. However, critics have recently grown more numerous and outspoken in opposition to the term claiming that it is actually perpetuating statism...... by grafting the idea of civil society onto the global by way of an unhelpful domestic analogy. This paper examines the role the concept is playing in perpetuating/reconfiguring statism. First it summarizes current criticism by identifying three basic accusations: the ambiguity of the term, the "domestic...... fallacy," and the undemocratic effects of using it. Second, these criticisms are considered in turn and it is concluded that all three points relate, ultimately, back to the failure of the critics themselves and some global civil society theorists to move beyond a state-centered framework...

  19. 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.

  20. 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.

  1. 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)

  2. Prevent the Spread of Norovirus

    Science.gov (United States)

    ... Submit Button Past Emails Prevent the Spread of Norovirus Language: English (US) Español (Spanish) Recommend on Facebook ... This leads to cramping, nausea, vomiting, and diarrhea. Norovirus Is the Most Common Cause of Gastroenteritis in ...

  3. Spread, estimators and nuisance parameters

    NARCIS (Netherlands)

    Heuvel, Edwin R. van den; Klaassen, Chris A.J.

    1997-01-01

    A general spread inequality for arbitrary estimators of a one-dimensional parameter is given. This finite-sample inequality yields bounds on the distribution of estimators in the presence of finite- or infinite-dimensional nuisance parameters.

  4. The Enemy is Still Below: The Global Diffusion of Submarines and Related Technology

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, K G

    2012-06-05

    The spread of submarines and related technology is an end product of globalization. Globalization is not a new story. By one estimate, our ancestors first crossed out of Africa roughly 80,000 years ago, and began the process that they now call globalization. With the dispersion of people around the world came the development of culture and civilization as well as the spread of ideas, goods, and technology. The process of globalization then is a long-standing one, not an innovation of the late 20th and early 21st centuries. Over the millennia, this process has been an uneven one. Globalization has often cuased great disruptions even to the societies that initiated various innovations in culture and civilization, including science and technology. Indeed, many cultures and civilizations have disappeared while some regions failed to advance as rapidly as others, so the process of globalization is not just one of continuing progress. Globalization in the current era seems to be penetrating the most remote corners of the world at a remarkable rate as a result of advances in science and technology, particularly information technology. The diffusion of science and technology is not necessarily a benign development. It could increase the potential for a global military industrial base that may have an adverse affect on world stability in the future. For example, the spread of key military capabilities, like submarines, could still have an impact, especially over the longer term, on the US capability to project power overseas.

  5. Modeling and analysis of the spread of computer virus

    Science.gov (United States)

    Zhu, Qingyi; Yang, Xiaofan; Ren, Jianguo

    2012-12-01

    Based on a set of reasonable assumptions, we propose a novel dynamical model describing the spread of computer virus. Through qualitative analysis, we give a threshold and prove that (1) the infection-free equilibrium is globally asymptotically stable if the threshold is less than one, implying that the virus would eventually die out, and (2) the infection equilibrium is globally asymptotically stable if the threshold is greater than one. Two numerical examples are presented to demonstrate the analytical results.

  6. 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.

  7. 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...

  8. A combination of improved differential and global RNA-seq reveals pervasive transcription initiation and events in all stages of the life-cycle of functional RNAs in Propionibacterium acnes, a major contributor to wide-spread human disease.

    Science.gov (United States)

    Lin, Yu-fei; A, David Romero; Guan, Shuang; Mamanova, Lira; McDowall, Kenneth J

    2013-09-14

    Sequencing of the genome of Propionibacterium acnes produced a catalogue of genes many of which enable this organism to colonise skin and survive exposure to the elements. Despite this platform, there was little understanding of the gene regulation that gives rise to an organism that has a major impact on human health and wellbeing and causes infections beyond the skin. To address this situation, we have undertaken a genome-wide study of gene regulation using a combination of improved differential and global RNA-sequencing and an analytical approach that takes into account the inherent noise within the data. We have produced nucleotide-resolution transcriptome maps that identify and differentiate sites of transcription initiation from sites of stable RNA processing and mRNA cleavage. Moreover, analysis of these maps provides strong evidence for 'pervasive' transcription and shows that contrary to initial indications it is not biased towards the production of antisense RNAs. In addition, the maps reveal an extensive array of riboswitches, leaderless mRNAs and small non-protein-coding RNAs alongside vegetative promoters and post-transcriptional events, which includes unusual tRNA processing. The identification of such features will inform models of complex gene regulation, as illustrated here for ribonucleotide reductases and a potential quorum-sensing, two-component system. The approach described here, which is transferable to any bacterial species, has produced a step increase in whole-cell knowledge of gene regulation in P. acnes. Continued expansion of our maps to include transcription associated with different growth conditions and genetic backgrounds will provide a new platform from which to computationally model the gene expression that determines the physiology of P. acnes and its role in human disease.

  9. How does spreading depression spread? Physiology and modeling

    NARCIS (Netherlands)

    Zandt, B.; ten Haken, Bernard; van Putten, Michel Johannes Antonius Maria; Dahlem, P.

    2015-01-01

    Spreading depression (SD) is a wave phenomenon in gray matter tissue. Locally, it is characterized by massive redistribution of ions across cell membranes. As a consequence, there is sustained membrane depolarization and tissue polarization that depress any normal electrical activity. Despite these

  10. Controlling droplet spreading with topography

    Science.gov (United States)

    Kant, P.; Hazel, A. L.; Dowling, M.; Thompson, A. B.; Juel, A.

    2017-09-01

    We present an experimental system that can be used to study the dynamics of a picoliter droplet (in-flight radius of 12.2 μ m ) as it spreads over substrates with topographic variations. We concentrate on the spreading of a droplet within a recessed stadium-shaped pixel, with applications to the manufacture of polymer organic light-emitting-diode displays, and find that the sloping sidewall of the pixel can either locally enhance or hinder spreading depending on whether the topography gradient ahead of the contact line is positive or negative, respectively. Locally enhanced spreading occurs via the formation of thin pointed rivulets along the sidewalls of the pixel through a mechanism similar to capillary rise in sharp corners. We demonstrate that a simplified model involving quasistatic surface-tension effects within the framework of a thin-film approximation combined with an experimentally measured dynamic spreading law, relating the speed of the contact line to the contact angle, provides excellent predictions of the evolving liquid morphologies. A key feature of the liquid-substrate interaction studied here is the presence of significant contact angle hysteresis, which enables the persistence of noncircular fluid morphologies. We also show that the spreading law for an advancing contact line can be adequately approximated by a Cox-Voinov law for the majority of the evolution. The model does not include viscous effects in the bulk of the droplet and hence the time scales for the propagation of the thin pointed rivulets are not captured. Nonetheless, this simple model can be used very effectively to predict the areas covered by the liquid and may serve as a useful design tool for systems that require precise control of liquid on substrates.

  11. Braze alloy spreading on steel

    Science.gov (United States)

    Siewert, T. A.; Heine, R. W.; Lagally, M. G.

    1978-01-01

    Scanning electron microscopy (SEM) and Auger electron microscopy (AEM) were employed to observe elemental surface decomposition resulting from the brazing of a copper-treated steel. Two types of steel were used for the study, stainless steel (treated with a eutectic silver-copper alloy), and low-carbon steel (treated with pure copper). Attention is given to oxygen partial pressure during the processes; a low enough pressure (8 x 10 to the -5th torr) was found to totally inhibit the spreading of the filler material at a fixed heating cycle. With both types of steel, copper treatment enhanced even spreading at a decreased temperature.

  12. Liquid ``Coffee Rings'' and the Spreading of Volatile Liquid Mixtures

    Science.gov (United States)

    Wood, Clay; Pye, Justin; Burton, Justin

    When a volatile liquid drop is placed on a wetting surface, it rapidly spreads and evaporates. The spreading dynamics and drop geometry are determined by a balance between thermal and interfacial forces, including Marangoni effects. However, this spreading behavior is drastically altered when drops contain a miniscule amount of a less-volatile miscible liquid (solute) in the bulk (solvent); contact line instabilities in the form of ``fingers'' develop. Characteristic finger size increases with increasing solute concentration and is apparent for concentrations as small as 0.1% by volume. Also, the spreading rate depends sensitively on the solute concentration, especially if the solute preferentially wets the substrate. At higher solute concentrations, the spreading droplet will form ``beads'' at the contact line, rather than fingers, and are deposited as the solvent recedes and evaporates, leaving behind a complex pattern of solute micro-droplets. Liquid ``coffee rings'' are often left behind after evaporation because there is a high evaporation rate of the solvent at the contact line, which increases the concentration of the solute, and the longevity of the rings depends on the solute vapor pressure. These results highlight the unusual sensitivity to contamination of volatile spreading, and the complex patterns of liquid contamination deposited following evaporation from a wetted surface. NSF 1455086.

  13. Managing Global Teams

    Directory of Open Access Journals (Sweden)

    Anca Stan

    2010-12-01

    Full Text Available Every global company’s competitive advantage depends on its ability to coordinate critical resources and information that are spread across different geographical locations. As a result of the increasingly global business environment, many companies are building teams that cross- national borders and / or include members from different countries of origin. Global teams are formed to enhance the efficiency of an organization by making effective use of the diversity or viewpoints.

  14. Global Delivery Models

    DEFF Research Database (Denmark)

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

    2015-01-01

    Global delivery models (GDMs) are transforming the global IT and business process outsourcing industry. GDMs are a new form of client-specific investment promoting service integration with clients by combining client proximity with time-zone spread for 24/7 service operations. We investigate....... Findings imply that coordination across time zones increasingly affects international operations in business-to-business and born-global industries....

  15. The clinical impact of artemisinin resistance in Southeast Asia and the potential for future spread.

    Science.gov (United States)

    Woodrow, Charles J; White, Nicholas J

    2017-01-01

    Artemisinins are the most rapidly acting of currently available antimalarial drugs. Artesunate has become the treatment of choice for severe malaria, and artemisinin-based combination therapies (ACTs) are the foundation of modern falciparum malaria treatment globally. Their safety and tolerability profile is excellent. Unfortunately, Plasmodium falciparum infections with mutations in the 'K13' gene, with reduced ring-stage susceptibility to artemisinins, and slow parasite clearance in patients treated with ACTs, are now widespread in Southeast Asia. We review clinical efficacy data from the region (2000-2015) that provides strong evidence that the loss of first-line ACTs in western Cambodia, first artesunate-mefloquine and then DHA-piperaquine, can be attributed primarily to K13 mutated parasites. The ring-stage activity of artemisinins is therefore critical for the sustained efficacy of ACTs; once it is lost, rapid selection of partner drug resistance and ACT failure are inevitable consequences. Consensus methods for monitoring artemisinin resistance are now available. Despite increased investment in regional control activities, ACTs are failing across an expanding area of the Greater Mekong subregion. Although multiple K13 mutations have arisen independently, successful multidrug-resistant parasite genotypes are taking over and threaten to spread to India and Africa. Stronger containment efforts and new approaches to sustaining long-term efficacy of antimalarial regimens are needed to prevent a global malaria emergency. © FEMS 2016.

  16. 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…

  17. Modelling the colour of strawberry spread during storage, including effects of technical variations

    NARCIS (Netherlands)

    Kadivec, Mirta; Tijskens, Pol; Kopjar, Mirela; Simčič, Marjan; Požrl, Tomaž

    2016-01-01

    The colour of freshly processed strawberry spread changes relatively rapidly from a bright red to a dull red, which then makes its appearance generally less acceptable for consumers. The colours of strawberry spreads following several processing conditions were measured under different storage

  18. Dual polarized, heat spreading rectenna

    Science.gov (United States)

    Epp, Larry W. (Inventor); Khan, Abdur R. (Inventor); Smith, R. Peter (Inventor); Smith, Hugh K. (Inventor)

    1999-01-01

    An aperture coupled patch splits energy from two different polarization components to different locations to spread heat. In addition, there is no physical electrical connection between the slot, patch and circuitry. The circuitry is located under a ground plane which shields against harmonic radiation back to the RF source.

  19. Estimation of directional wave spreading

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, S.; Bhat, S.S.; Anand, N.M.; Nayak, B.U.

    that for monsoon condition, the JONSWAP spectra is suitable as the sea state was developing and young. Directional spreading function with sech super(2) (beta theta) distribution found more suitable to the present data since the data seems to have less influence...

  20. 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.

  1. 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......, such as action potentials and synaptic transmission. Seventy years after its discovery by Leão, the mechanisms of SD and its profound metabolic and hemodynamic effects are still debated. What we did learn of consequence, however, is that SD plays a central role in the pathophysiology of a number of diseases...... breakdown in patients. The challenges of translating experimental data into human pathophysiology notwithstanding, this review provides a detailed account of bidirectional interactions between brain parenchyma and the cerebral vasculature during SD and puts this in the context of neurovascular diseases....

  2. Understanding control of network spreading from network controllability

    Science.gov (United States)

    Sun, Peng Gang; Ma, Xiaoke

    2017-09-01

    How to control the spread of an epidemic or information is a great challenge for us. A dynamic network-based system’s structural controllability provides a new way to control spreading with the minimum input of external signals, and the dynamic system is controllable if the signals can drive it from any initial state to any desired final state in finite time. Therefore, we are motivated to develop a new framework by introducing spreading networks (SNs) to describe the spreading pathways from a global view, and we try to understand the control of the spreading by the structural controllability of the SNs. The SNs are transformed from original networks, in which each node is considered as a single spreading origin. The weights of directed links pointing at its direct contacts in the SNs denote the spreading abilities, which can be determined by a new probability function. Furthermore, we also investigate the impact of the dynamics of network structures on the framework. The results show that sparse homogeneous networks with a higher transmission probability tend to trigger a larger scale of diffusion, which is easier to control. We can also see that an epidemic or information is inclined to diffuse easily on the networks with strong community strengths and heterogeneous community sizes. From the structural controllability of the SNs, we observe that driver nodes for the control of the spread tend not to be the nodes located within the core of original networks or those with high-degree. In addition, the scale of diffusion, the number of driver nodes and positions of nodes are highly associated with the degree distribution of the original networks.

  3. 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.

  4. Wetting and Spreading of Molten Volcanic Ash in Jet Engines.

    Science.gov (United States)

    Song, Wenjia; Lavallée, Yan; Wadsworth, Fabian B; Hess, Kai-Uwe; Dingwell, Donald B

    2017-04-20

    A major hazard to jet engines posed by volcanic ash is linked to the wetting and spreading of molten ash droplets on engine component surfaces. Here, using the sessile drop method, we study the evolution of the wettability and spreading of volcanic ash. We employ rapid temperature changes up to 1040-1450 °C, to replicate the heating conditions experienced by volcanic ash entering an operating jet engine. In this scenario, samples densify as particles coalesce under surface tension until they form a large system-sized droplet (containing remnant gas bubbles and crystals), which subsequently spreads on the surface. The data exhibit a transition from a heterogeneous to a homogeneous wetting regime above 1315 °C as crystals in the drops are dissolved in the melt. We infer that both viscosity and microstructural evolution are key controls on the attainment of equilibrium in the wetting of molten volcanic ash droplets.

  5. Conditions for viral influence spreading through correlated multiplex networks

    CERN Document Server

    Hu, Yanqing; Makse, Hernán A

    2014-01-01

    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 fragmenting an old network to create a new one. Typical examples include the raise of scientific ideas or abrupt changes in social media, like the raise of Facebook.com to the detriment of Myspace.com. 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...

  6. Physically Protected Spread Spectrum Communications

    Science.gov (United States)

    2016-04-14

    useful for the design of future efficient game theoretic FH satellite and mobile communications systems when a coherent FH modulation is employed under...of future efficient game theoretic FH satellite and mobile communications systems when a coherent FH modulation is employed under severe fading as...multiple-access (DS- CDMA ) spread spectrum (SS) waveform:  To investigate a novel, unique, simple, and anti-interference approach for SS systems so

  7. Drop Spreading with Random Viscosity

    Science.gov (United States)

    Xu, Feng; Jensen, Oliver

    2016-11-01

    Airway mucus acts as a barrier to protect the lung. However as a biological material, its physical properties are known imperfectly and can be spatially heterogeneous. In this study we assess the impact of these uncertainties on the rate of spreading of a drop (representing an inhaled aerosol) over a mucus film. We model the film as Newtonian, having a viscosity that depends linearly on the concentration of a passive solute (a crude proxy for mucin proteins). Given an initial random solute (and hence viscosity) distribution, described as a Gaussian random field with a given correlation structure, we seek to quantify the uncertainties in outcomes as the drop spreads. Using lubrication theory, we describe the spreading of the drop in terms of a system of coupled nonlinear PDEs governing the evolution of film height and the vertically-averaged solute concentration. We perform Monte Carlo simulations to predict the variability in the drop centre location and width (1D) or area (2D). We show how simulation results are well described (at much lower computational cost) by a low-order model using a weak disorder expansion. Our results show for example how variability in the drop location is a non-monotonic function of the solute correlation length increases. Engineering and Physical Sciences Research Council.

  8. Information Spread of Emergency Events: Path Searching on Social Networks

    Science.gov (United States)

    Hu, Hongzhi; Wu, Tunan

    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. PMID:24600323

  9. 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.

  10. Rapid, Affordable, and Point-of-Care Water Monitoring Via a Microfluidic DNA Sensor and a Mobile Interface for Global Health.

    Science.gov (United States)

    Kim, Unyoung; Ghanbari, Sarah; Ravikumar, Anusha; Seubert, John; Figueira, Silvia

    2013-01-01

    Contaminated water is a serious concern in many developing countries with severe health consequences particularly for children. Current methods for monitoring waterborne pathogens are often time consuming, expensive, and labor intensive, making them not suitable for these regions. Electrochemical detection in a microfluidic platform offers many advantages such as portability, minimal use of instrumentation, and easy integration with electronics. In many parts of the world, however, the required equipment for pathogen detection through electrochemical sensors is either not available or insufficiently portable, and operators may not be trained to use these sensors and interpret results, ultimately preventing its wide adoption. Counterintuitively, these same regions often have an extensive mobile phone infrastructure, suggesting the possibility of integrating electrochemical detection of bacterial pathogens with a mobile platform. Toward a solution to water quality interventions, we demonstrate a microfluidic electrochemical sensor combined with a mobile interface that detects the sequences from bacterial pathogens, suitable for rapid, affordable, and point-of-care water monitoring. We employ the transduction of DNA hybridization into a readily detectable electric signal by means of a conformational change of DNA stem-loop structure. Using this platform, we successfully demonstrate the detection of as low as 100 nM E. coli sequences and the automatic interpretation and mapping of the detection results via a mobile application.

  11. Examining the 'global spreading hypothesis' using graph theory ...

    African Journals Online (AJOL)

    This study examines a model pelagic foodweb from the perspective of graph theory, and calculates the changes in the positional importance of phytoplankton in the interaction network. The positional importance of algae in foodwebs is quantified and community-wide effects on how their network position can change are ...

  12. 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.

  13. 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.

  14. 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.

  15. One step closer to a global tool for rapid screening of major depression in epilepsy: validation of the French NDDI-E.

    Science.gov (United States)

    Micoulaud-Franchi, Jean-Arthur; Barkate, Gérald; Trébuchon-Da Fonseca, Agnès; Vaugier, Lisa; Gavaret, Martine; Bartolomei, Fabrice; McGonigal, Aileen

    2015-03-01

    MDE was 10.61 (SD=3.63). This study validated the French NDDI-E, with a cutoff score of 15/24 for MDE, similar to previous studies, and reinforces the NDDI-E as a global tool for detection of MDE. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Plume spread and atmospheric stability

    Energy Technology Data Exchange (ETDEWEB)

    Weber, R.O. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The horizontal spread of a plume in atmospheric dispersion can be described by the standard deviation of horizontal direction. The widely used Pasquill-Gifford classes of atmospheric stability have assigned typical values of the standard deviation of horizontal wind direction and of the lapse rate. A measured lapse rate can thus be used to estimate the standard deviation of wind direction. It is examined by means of a large dataset of fast wind measurements how good these estimates are. (author) 1 fig., 2 refs.

  17. Liquid Spreading under Nanoscale Confinement

    Science.gov (United States)

    Checco, Antonio

    2009-03-01

    Dynamic atomic force microscopy in the noncontact regime is used to study the morphology of a nonvolatile liquid (squalane) as it spreads along wettable nanostripes embedded in a nonwettable surface. Results show that the liquid profile depends on the amount of lateral confinement imposed by the nanostripes, and it is truncated at the microscopic contact line in good qualitative agreement with classical mesoscale hydrodynamics. However, the width of the contact line is found to be significantly larger than expected theoretically. This behavior may originate from small chemical inhomogeneity of the patterned stripes as well as from thermal fluctuations of the contact line.

  18. The spread of fake news by social bots

    OpenAIRE

    Shao, Chengcheng; Ciampaglia, Giovanni Luca; Varol, Onur; Flammini, Alessandro; Menczer, Filippo

    2017-01-01

    The massive spread of fake news has been identified as a major global risk and has been alleged to influence elections and threaten democracies. Communication, cognitive, social, and computer scientists are engaged in efforts to study the complex causes for the viral diffusion of digital misinformation and to develop solutions, while search and social media platforms are beginning to deploy countermeasures. However, to date, these efforts have been mainly informed by anecdotal evidence rather...

  19. The Worldwide Spread, Success, and Impact of Ragweed (Ambrosia spp.)

    OpenAIRE

    Montagnani, C.; Gentili, R.; Smith, Matt; Guarino, M. F.; Citterio, S.

    2017-01-01

    ABSTRACTThe Ambrosia species represent one of the most problematic groups of invasive weeds around the world. The ease with which they are introduced and spread in new countries, their generalist ecological requirements, and functional traits facilitate their invasion and subsequent naturalization in new areas. All of these aspects contribute to increasing their global social and economic impact, which is mostly related to pollen allergy. Here we analyze available scientific publications abou...

  20. On entanglement spreading from holography

    Science.gov (United States)

    Mezei, Márk

    2017-05-01

    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: 1. We prove holographic bounds on the entanglement velocity v E and the butterfly effect speed v B that arises in the study of chaos.

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

    Science.gov (United States)

    Nicolaides, Christos; Cueto-Felgueroso, Luis; González, Marta C; Juanes, Ruben

    2012-01-01

    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.

  2. Global Stability of an Epidemic Model of Computer Virus

    Directory of Open Access Journals (Sweden)

    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.

  3. Epidemic spread on weighted networks.

    Directory of Open Access Journals (Sweden)

    Christel Kamp

    Full Text Available The contact structure between hosts shapes disease spread. Most network-based models used in epidemiology tend to ignore heterogeneity in the weighting of contacts between two individuals. However, this assumption is known to be at odds with the data for many networks (e.g. sexual contact networks and to have a critical influence on epidemics' behavior. One of the reasons why models usually ignore heterogeneity in transmission is that we currently lack tools to analyze weighted networks, such that most studies rely on numerical simulations. Here, we present a novel framework to estimate key epidemiological variables, such as the rate of early epidemic expansion (r0 and the basic reproductive ratio (R0, from joint probability distributions of number of partners (contacts and number of interaction events through which contacts are weighted. These distributions are much easier to infer than the exact shape of the network, which makes the approach widely applicable. The framework also allows for a derivation of the full time course of epidemic prevalence and contact behaviour, which we validate with numerical simulations on networks. Overall, incorporating more realistic contact networks into epidemiological models can improve our understanding of the emergence and spread of infectious diseases.

  4. Spreading Astronomy Education Through Africa

    Science.gov (United States)

    Baki, P.

    2006-08-01

    Although Astronomy has been an important vehicle for effectively passing a wide range of scientific knowledge, teaching the basic skills of scientific reasoning, and for communicating the excitement of science to the public, its inclusion in the teaching curricula of most institutions of higher learning in Africa is rare. This is partly due to the fact that astronomy appears to be only good at fascinating people but not providing paid jobs. It is also due to the lack of trained instructors, teaching materials, and a clear vision of the role of astronomy and basic space science within the broader context of education in the physical and applied sciences. In this paper we survey some of the problems bedeviling the spread of astronomy in Africa and discuss some interdisciplinary traditional weather indicators. These indicators have been used over the years to monitor the appearance of constellations. For example, orions are closely intertwined with cultures of some ethnic African societies and could be incorporated in the standard astronomy curriculum as away of making the subject more `home grown' and to be able to reach out to the wider populace in popularizing astronomy and basic sciences. We also discuss some of the other measures that ought to be taken to effectively create an enabling environment for sustainable teaching and spread of astronomy through Africa.

  5. [Globalization and infectious diseases].

    Science.gov (United States)

    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.

  6. World Englishes and Globalization.

    Science.gov (United States)

    Bamgbose, Ayo

    2001-01-01

    Examines the theoretical concept of the world Englishes in light of globalization. Outlines phenomena in the organic spread of English around the globe and raises the issue of opportunism in English language teaching. Ethical implications and implications for research on world English are discussed. (Author/VWL)

  7. Rumor spreading in gaming social networks

    CERN Document Server

    Zhang, Yichao; Guan, Jihong; Zhou, Shuigeng

    2011-01-01

    So far, the focus on rumor spreading are mainly on some simple backgrounds, in other words, only taking consideration of the overall topological influences on its dynamical behavior. However, in the prospect of the individuality, personal strategies in the social networks play a more non-trivial role in the real social networks. To fill this gap, we will investigate the rumor spreading in gaming social networks. Our analysis is supported by the results of numerical simulations. We observe that the original rumor is still the most well known edition in case that the content is modified by the defectors. However, the portion decays with the stimulus generally. For the case that defectors keep silence in the spreading process, the scale of spreading decays with stimulus generally, suggesting the rumor can hardly spread in a community of defectors. This highlights the key role that stimulus plays in rumor spreading and the necessity to study information spreading in competitive circumstances.

  8. 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.

  9. Regulation of cerebral metabolism during cortical spreading depression.

    Science.gov (United States)

    Feuerstein, Delphine; Backes, Heiko; Gramer, Markus; Takagaki, Masatoshi; Gabel, Paula; Kumagai, Tetsuya; Graf, Rudolf

    2016-11-01

    We analyzed the metabolic response to cortical spreading depression that drastically increases local energy demand to restore ion homeostasis. During single and multiple cortical spreading depressions in the rat cortex, we simultaneously monitored extracellular levels of glucose and lactate using rapid sampling microdialysis and glucose influx using 18 F-fluorodeoxyglucose positron emission tomography while tracking cortical spreading depression using laser speckle imaging. Combining the acquired data with steady-state requirements we developed a mass-conserving compartment model including neurons and glia that was consistent with the observed data. In summary, our findings are: (1) Early breakdown of glial glycogen provides a major source of energy during increased energy demand and leaves 80% of blood-borne glucose to neurons. (2) Lactate is used solely by neurons and only if extracellular lactate levels are >80% above normal. (3) Although the ratio of oxygen and glucose consumption transiently reaches levels 90%) of the overall energy supply is from oxidative metabolism. (4) During cortical spreading depression, brain release of lactate exceeds its consumption suggesting that lactate is only a circumstantial energy substrate. Our findings provide a general scenario for the metabolic response to increased cerebral energy demand. © The Author(s) 2015.

  10. 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.

  11. Wax Spreading in Paper under Controlled Pressure and Temperature.

    Science.gov (United States)

    Hong, Wei; Zhou, Jing; Kanungo, Mandakini; Jia, Nancy; Dinsmore, Anthony D

    2018-01-09

    This work describes a novel rapid method to fabricate high-resolution paper-based microfluidic devices using wax-ink-based printing. This study demonstrates that both temperature and pressure are important knobs in controlling the device resolution. High-resolution lines and patterns were obtained by heating the paper asymmetrically from one side up to 110 °C while applying pressure up to 49 kPa. Starting with wax lines with an initial width of 130 μm, we achieve a thorough penetration through a 190 μm-thick paper with lateral spreading on the front as narrow as 90 μm. The role of temperature and pressure are systematically studied and compared with the prediction of the Lucas-Washburn equation. We found that the temperature dependence of spreading can be explained by the viscosity change of the wax, according to the Lucas-Washburn equation. The pressure dependence deviates from Lucas-Washburn behavior because of compression of the paper. An optimal condition for achieving full depth penetration of the wax yet minimizing lateral spreading is suggested after exploring various parameters including temperature, pressure, and paper type. These findings could lead to a rapid roll-to-roll fabrication of high-resolution paper-based diagnostic devices.

  12. RAPID3? Aptly named!

    Science.gov (United States)

    Berthelot, J-M

    2014-01-01

    The RAPID3 score is the sum of three 0-10 patient self-report scores: pain, functional impairment on MDHAQ, and patient global estimate. It requires 5 seconds for scoring and can be used in all rheumatologic conditions, although it has mostly been used in rheumatoid arthritis where cutoffs for low disease activity (12/30) have been set. A RAPID3 score of ≤ 3/30 with 1 or 0 swollen joints (RAPID3 ≤ 3 + ≤ SJ1) provides remission criteria comparable to Boolean, SDAI, CDAI, and DAS28 remission criteria, in far less time than a formal joint count. RAPID3 performs as well as the DAS28 in separating active drugs from placebos in clinical trials. RAPID3 also predicts subsequent structural disease progression. RAPID3 can be determined at short intervals at home, allowing the determination of the area under the curve of disease activity between two visits and flare detection. However, RAPID3 should not be seen as a substitute for DAS28 and face to face visits in routine care. Monitoring patient status with only self-report information without a rheumatologist's advice (including joints and physical examination, and consideration of imaging and laboratory tests) may indeed be as undesirable for most patients than joint examination without a patient questionnaire. Conversely, combining the RAPID3 and the DAS28 may consist in faster or more sensitive confirmation that a medication is effective. Similarly, better enquiring of most important concerns of patients (pain, functional status and overall opinion on their disorder) should reinforces patients' confidence in their rheumatologist and treatments.

  13. 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.

  14. Eco-social processes influencing infectious disease emergence and spread.

    Science.gov (United States)

    Jones, Bryony A; Betson, Martha; Pfeiffer, Dirk U

    2017-01-01

    The complexity and connectedness of eco-social processes have major influence on the emergence and spread of infectious diseases amongst humans and animals. The disciplinary nature of most research activity has made it difficult to improve our understanding of interactions and feedback loops within the relevant systems. Influenced by the One Health approach, increasing efforts have recently been made to address this knowledge gap. Disease emergence and spread is strongly influenced by host density and contact structures, pathogen characteristics and pathogen population and molecular evolutionary dynamics in different host species, and host response to infection. All these mechanisms are strongly influenced by eco-social processes, such as globalization and urbanization, which lead to changes in global ecosystem dynamics, including patterns of mobility, human population density and contact structures, and food production and consumption. An improved understanding of epidemiological and eco-social processes, including their interdependence, will be essential to be able to manage diseases in these circumstances. The interfaces between wild animals, domestic animals and humans need to be examined to identify the main risk pathways and put in place appropriate mitigation. Some recent examples of emerging infectious disease are described to illustrate eco-social processes that are influencing disease emergence and spread.

  15. The global knowledge society

    National Research Council Canada - National Science Library

    Fedoroff, Nina V

    2012-01-01

    Knowledge societies rest on a foundation of educational and research excellence. The Internet, advances in communications technology, and the rapidly expanding global fiber optic network are necessary, but not sufficient...

  16. Impacts of suppressing guide on information spreading

    CERN Document Server

    Xu, Jinghong; Ma, Baojun; Wu, Ye

    2015-01-01

    It is quite common that guides are introduced to suppress the information spreading in modern society for different purposes. In this paper, an agent-based model is established to quantitatively analyze the impacts of suppressing guides on information spreading. We find that the spreading threshold depends on the attractiveness of the information and the topology of the social network with no suppressing guides at all. Usually, one would expect that the existence of suppressing guides in the spreading procedure may result in less diffusion of information within the overall network. However, we find that sometimes the opposite is true: the manipulating nodes of suppressing guides may lead to more extensive information spreading when there are audiences with the reversal mind. These results can provide valuable theoretical references to public opinion guidance on various information, e.g., rumor or news spreading.

  17. The effects of temporally variable dispersal and landscape structure on invasive species spread.

    Science.gov (United States)

    Andrew, Margaret E; Ustin, Susan L

    2010-04-01

    Many invasive species are too widespread to realistically eradicate. For such species, a viable management strategy is to slow the rate of spread. However, to be effective, this will require detailed spread data and an understanding of the influence of environmental conditions and landscape structure on invasion rates. We used a time series of remotely sensed distribution maps and a spatial simulation model to study spread of the invasive Lepidium latifolium (perennial pepperweed) in California's Sacramento-San Joaquin River Delta. L. latifolium is a noxious weed and exhibited rapid, explosive spread. Annual infested area and empirical dispersal kernels were derived from the remotely sensed distributions in order to assess the influence of weather conditions on spread and to parameterize the simulation model. Spread rates and dispersal distances were highest for nascent infestations and in years with wet springs. Simulations revealed that spread rates were more strongly influenced by the length of long-distance dispersal than by temporal variation in its likelihood. It is thus important to capture long-distance dispersal and the conditions that facilitate spread when collecting data to parameterize spread models. Additionally, management actions performed in high-spread years, targeting long-distance recruits, can effectively contain infestations. Corridors were relatively unimportant to spread rates; their effectiveness at enhancing rate of spread was limited by the species' dispersal ability and the time needed to travel through the corridor. In contrast, habitat abundance and shape surrounding the introduction site strongly influenced invasion dynamics. Satellite patches invading large areas of invasible habitat present especially high risk.

  18. Lateral spreading of Au contacts on InP

    Science.gov (United States)

    Fatemi, Navid S.; Weizer, Victor G.

    1990-01-01

    The contact spreading phenomenon observed when small area Au contacts on InP are annealed at temperatures above about 400 C was investigated. It was found that the rapid lateral expansion of the contact metallization which consumes large quantities of InP during growth is closely related to the third stage in the series of solid state reactions that occur between InP and Au, i.e., to the Au3In-to-Au9In4 transition. Detailed descriptions are presented of both the spreading process and the Au3In-to-Au9In4 transition along with arguments that the two processes are manifestations of the same basic phenomenon.

  19. Globalization and Technology

    OpenAIRE

    Traian-Alexandru Miu

    2016-01-01

    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. W...

  20. 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

  1. Brewster angle microscopy. A new method of visualizing the spreading of Meibomian lipids.

    Science.gov (United States)

    Kaercher, T; Hönig, D; Möbius, D

    The spreading behaviour of the Meibomian lipids is important for the integrity of the whole tear film. This paper presents the application of Brewster Angle Microscopy (BAM) for the observation of the spreading process in vitro. Meibomian gland secretions were studied in a Langmuir trough. The secretion was characterized by an extremely rapid continuous spreading, suggesting that enough material would be available to recover the superficial lipid layer of the tears between the blinks of the eye. This new technique provides important information on how the normal tear film works and how tear substitutes might act.

  2. Effects of Degree of Curing on Fire Spread

    Science.gov (United States)

    Chaivaranont, W.; Evans, J. P.; Liu, Y.

    2016-12-01

    During extreme summer conditions in Australia, bushfire can become an uncontrollable natural hazard. Various factors, such as geographical and meteorological parameters greatly influence the magnitude of bushfire. In a grassland fire, there is an important factor that affects the severity of fire called the degree of curing. Degree of curing is a percentage measurement of the proportion of dead material in grassland where a 100% curing indicates a totally dead grass field. It is usually assumed constant due to the cost and difficulty in obtaining accurate field observations.To examine the importance of curing, the Phoenix RapidFire fire spread model was used to observe the magnitude and direction of grassland fire spread due to variations in the degree of curing. Idealised experiments and experiments based on 3 past fire events in Australia were conducted, where the 100 by 200 km study area is considered to be all grassland. In the idealised experiments, homogeneous curing data in various patterns were used along with extreme climate data and prescribed topography. In the past fire event experiments, satellite-derived estimated curing data, observed climate data from the nearest weather stations, and real elevation maps were used. A remotely sensed burned area map (MODIS MCD64A1 product) is also used to compare the simulated burned area of past fire events with the satellite observation.The results from both experiments showed that: 1) the rate of spread of grassland fire is significantly impeded when curing is below 75%, 2) topography has insignificant effect on fire spread direction and speed, 3) wind and curing both influence the direction and speed of spread, and 4) the model can only recreate the burned area in one out of three of the past fire events due to various causes including the fact that all past events used here were not exclusively grassland fire.

  3. Carlsberg Ridge and Mid-Atlantic Ridge: Comparison of slow spreading centre analogues

    Science.gov (United States)

    Murton, Bramley J.; Rona, Peter A.

    2015-11-01

    Eighty per cent of all mid-ocean spreading centres are slow. Using a mixture of global bathymetry data and ship-board multibeam echosounder data, we explore the morphology of global mid-ocean ridges and compare two slow spreading analogues: the Carlsberg Ridge in the north-west Indian Ocean between 57°E and 60°E, and the Kane to Atlantis super-segment of the Mid-Atlantic Ridge between 21°N and 31°N. At a global scale, mid-ocean spreading centres show an inverse correlation between segment length and spreading rate with segmentation frequency. Within this context, both the Mid-Atlantic Ridge super-segment and Carlsberg Ridge are similar: spreading at 22 and 26 mm/yr full rates respectively, being devoid of major transform faults, and being segmented by dextral, non-transform, second-order discontinuities. For these and other slow spreading ridges, we show that segmentation frequency varies inversely with flank height and ridge axis depth. Segments on both the Mid-Atlantic Ridge super-segment and Carlsberg Ridge range in aspect ratio (ridge flank height/axis width), depth and symmetry. Segments with high aspect ratios and deeper axial floors often have asymmetric rift flanks and are associated with indicators of lower degrees of melt flux. Segments with low aspect ratios have shallower axial floors, symmetric rift flanks, and evidence of robust melt supply. The relationship between segmentation, spreading rate, ridge depth and morphology, at both a global and local scale, is evidence that rates of melting of the underlying mantle and melt delivery to the crust play a significant role in determining the structure and morphology of slow spreading mid-ocean ridges.

  4. Rapid Detection of Pathogens

    Energy Technology Data Exchange (ETDEWEB)

    David Perlin

    2005-08-14

    Pathogen identification is a crucial first defense against bioterrorism. A major emphasis of our national biodefense strategy is to establish fast, accurate and sensitive assays for diagnosis of infectious diseases agents. Such assays will ensure early and appropriate treatment of infected patients. Rapid diagnostics can also support infection control measures, which monitor and limit the spread of infectious diseases agents. Many select agents are highly transmissible in the early stages of disease, and it is critical to identify infected patients and limit the risk to the remainder of the population and to stem potential panic in the general population. Nucleic acid-based molecular approaches for identification overcome many of the deficiencies associated with conventional culture methods by exploiting both large- and small-scale genomic differences between organisms. PCR-based amplification of highly conserved ribosomal RNA (rRNA) genes, intergenic sequences, and specific toxin genes is currently the most reliable approach for bacterial, fungal and many viral pathogenic agents. When combined with fluorescence-based oligonucleotide detection systems, this approach provides real-time, quantitative, high fidelity analysis capable of single nucleotide allelic discrimination (4). These probe systems offer rapid turn around time (<2 h) and are suitable for high throughput, automated multiplex operations that are critical for clinical diagnostic laboratories. In this pilot program, we have used molecular beacon technology invented at the Public health Research Institute to develop a new generation of molecular probes to rapidly detect important agents of infectious diseases. We have also developed protocols to rapidly extract nucleic acids from a variety of clinical specimen including and blood and tissue to for detection in the molecular assays. This work represented a cooperative research development program between the Kramer-Tyagi/Perlin labs on probe development

  5. Olive oil in food spreads

    Directory of Open Access Journals (Sweden)

    Blanco Muñoz, Miguel A.

    2004-03-01

    Full Text Available Chemical hydrogenation of unsaturated fatty acids is a commonly applied reaction to food industries. The process may imply the movement of double bonds in their positions on the fatty acid carbon chain, producing positional and geometrical isomers ( trans fatty acids. Through hydrogenation, unsaturated oils are converted to margarines and vegetable shortenings. The presence of trans fatty acids in foods is undesirable, as trans fatty acids raise the plasma levels of total and low-density lipoproteins (LDL, while decrease the plasma level of high-density lipoproteins (HDL, among other effects. The use of olive oil to prepare fat spread opens new insights into the commercial development of healthy novel foods with a positive image in terms of consumer appeal.La hidrogenación química de los ácidos grasos insaturados es una reacción que se utiliza con frecuencia en la industria alimentaria. El proceso implica el movimiento de los dobles enlaces en la cadena hidrocarbonada de los ácidos grasos, y la aparición de isómeros posicionales y geométricos (ácidos grasos trans . La ingesta inadecuada de alimentos que pueden contener cantidades significativas de ácidos grasos trans se asocia con el aumento en sangre de colesterol total y LDL, y la disminución de HDL, entre otros efectos. Por lo tanto, el uso de aceite de oliva en la preparación de grasas para untar constituye un importante avance en el desarrollo comercial de nuevos alimentos saludables con una imagen positiva para el consumidor.

  6. Epistemic Communities, Human Rights, and the Global Diffusion of Legislation against the Organ Trade

    Directory of Open Access Journals (Sweden)

    Fikresus Amahazion

    2016-10-01

    Full Text Available Over the past several decades, over 100 countries have passed legislation banning commercial organ transplantation. What explains this rapid, global diffusion of laws? Based on qualitative data from in-depth interviews, historical analysis, and secondary sources, this paper explores the role played by the medical epistemic community and human rights in the global spread of laws against the organ trade. In addition to shaping, guiding, and influencing norms and approaches to transplantation, the epistemic community has been instrumental in the development of various resolutions, policy initiatives, recommended practices, statements, legislation, and model laws. Moreover, the epistemic community helped position the organ trade as an issue of societal and global importance, and it persistently encouraged states to undertake actions, such as implementing legislation, to combat the organ trade. Critically, the epistemic community’s efforts against the organ trade incorporated the concepts of human rights, integrity, and dignity, which had diffused globally and become institutionalized in the period after WWII.

  7. 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...

  8. 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.

  9. 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...

  10. SPREAD: spatial phylogenetic reconstruction of evolutionary dynamics.

    Science.gov (United States)

    Bielejec, Filip; Rambaut, Andrew; Suchard, Marc A; Lemey, Philippe

    2011-10-15

    SPREAD is a user-friendly, cross-platform application to analyze and visualize Bayesian phylogeographic reconstructions incorporating spatial-temporal diffusion. The software maps phylogenies annotated with both discrete and continuous spatial information and can export high-dimensional posterior summaries to keyhole markup language (KML) for animation of the spatial diffusion through time in virtual globe software. In addition, SPREAD implements Bayes factor calculation to evaluate the support for hypotheses of historical diffusion among pairs of discrete locations based on Bayesian stochastic search variable selection estimates. SPREAD takes advantage of multicore architectures to process large joint posterior distributions of phylogenies and their spatial diffusion and produces visualizations as compelling and interpretable statistical summaries for the different spatial projections. SPREAD is licensed under the GNU Lesser GPL and its source code is freely available as a GitHub repository: https://github.com/phylogeography/SPREAD CONTACT: filip.bielejec@rega.kuleuven.be.

  11. 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.

  12. Epidemic cholera spreads like wildfire

    Science.gov (United States)

    Roy, Manojit; Zinck, Richard D.; Bouma, Menno J.; Pascual, Mercedes

    2014-01-01

    Cholera is on the rise globally, especially epidemic cholera which is characterized by intermittent and unpredictable outbreaks that punctuate periods of regional disease fade-out. These epidemic dynamics remain however poorly understood. Here we examine records for epidemic cholera over both contemporary and historical timelines, from Africa (1990-2006) and former British India (1882-1939). We find that the frequency distribution of outbreak size is fat-tailed, scaling approximately as a power-law. This pattern which shows strong parallels with wildfires is incompatible with existing cholera models developed for endemic regions, as it implies a fundamental role for stochastic transmission and local depletion of susceptible hosts. Application of a recently developed forest-fire model indicates that epidemic cholera dynamics are located above a critical phase transition and propagate in similar ways to aggressive wildfires. These findings have implications for the effectiveness of control measures and the mechanisms that ultimately limit the size of outbreaks.

  13. 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.

  14. Rapid Prototyping

    Science.gov (United States)

    1999-01-01

    Javelin, a Lone Peak Engineering Inc. Company has introduced the SteamRoller(TM) System as a commercial product. The system was designed by Javelin during a Phase II NASA funded small commercial product. The purpose of the invention was to allow automated-feed of flexible ceramic tapes to the Laminated Object Manufacturing rapid prototyping equipment. The ceramic material that Javelin was working with during the Phase II project is silicon nitride. This engineered ceramic material is of interest for space-based component.

  15. Increasing Oil Concentration Affects Consumer Perception and Physical Properties of Mayonnaise-type Spreads Containing KCl.

    Science.gov (United States)

    Torrico, Damir Dennis; Prinyawiwatkul, Witoon

    2017-08-01

    Reducing sodium intakes remains a global challenge for the food industry. KCl is a potential salt substitute but imparts bitterness when used at high concentrations. Little is known about how oil concentrations (OC) affect consumers' perception of saltiness and bitterness in emulsion products such as mayonnaise containing KCl. We evaluated consumers' perception and physical properties of mayonnaise-type spreads at various oil and tastant (NaCl or KCl) concentrations. Consumers (N = 306) evaluated saltiness, bitterness, overall taste liking (OTL) and purchase intent (PI). Viscosity, pH, water activity, and consistency/texture were also measured. Oil and tastant (NaCl or KCl) concentrations had significant effects on saltiness, viscosity, and pH. As OC increased, saltiness intensity slightly decreased for spreads. Increasing oil concentration increased viscosity. Generally, spreads containing KCl had higher bitterness and pH than spreads containing NaCl. All spreads containing KCl were penalized for being "too bitter." PI was affected by OTL for all spreads but OC was also a significant factor in the purchase decision of spreads containing NaCl. This study demonstrated that increasing OC affected consumers' taste perception (saltiness and bitterness) and spreads' physical properties including pH and viscosity. © 2017 Institute of Food Technologists®.

  16. 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 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.

  17. 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.

  18. Conditions for Viral Influence Spreading through Multiplex Correlated Social Networks

    Directory of Open Access Journals (Sweden)

    Yanqing Hu

    2014-05-01

    Full Text Available 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.

  19. 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.

  20. The velocity structure of a post-spreading volcanic seamount in the Southwest Sub-basin, South China Sea

    Science.gov (United States)

    Zhang, Jie; Li, Jiabiao; Ruan, Aiguo; Yu, Zhiteng; Niu, Xiongwei

    2017-04-01

    Post-spreading magmatism is extremely strong in the South China Sea and it is common feature for the pacific area (e.g. Castillo et al., 2010). Such seamounts formed by the post-spreading magmatism may provide key insights into a unique mechanism of strong magmatism without mantle convection as well as the crustal emplacement (e.g. Baloga et al., 1995; Kipf et al., 2013). We conducted a seismic refraction survey over an axial seamount (Longnan Seamount) in the Southwest Sub-basin, South China Sea in 2010. Results show that the post-spreading axial seamount is mainly formed by an extrusive process. Low upper-crustal velocities observed under the seamount are attributed to volcaniclastic rocks and high-porosity basalts. Velocity models reveal the lack of a large root and a relative high-velocity layer 3 underlying the seamount. The origin of axial seamounts is supposed to be buoyant decompression melting mechanism (Castillo et al., 2010; Meng and Zhang, 2014). This research was granted by the Natural Science Foundation of China (91028006, 91228205), the Scientific Research Fund of the Second Institute of Oceanography, SOA (JG1602) and the National Programme on Global Change and Air-Sea Interaction, SOA (GASI-GEOGE-01). References Castillo, P. R., Clague, D. A., Davis, A. S., et al., 2010. Petrogenesis of Davidson Seamount lavas and its implications for fossil spreading center and intraplate magmatism in the eastern Pacific. Geochemistry, Geophysics, Geosystems, 11, Q02005, doi:10.1029/2009GC002992 Baloga, S., Spudis, P. D. and Guest, J. E., 1995. The dynamics of rapidly emplaced terrestrial lava flows and implications for planetary volcanism. J. Geophys. Res., 100 (B12), 24509-24519. Kipf, A, Hauff, F., Werner, R., et al., 2014. Seamounts off the West Antarctic margin: A case for non-hotspot driven intraplate volcanism. Gondwana Res., 25 (4), 1660-1679. Meng, L., Zhang, J., 2014. The magmatic activity mechanism of the fossil spreading center in the Southwest sub

  1. Promoting information spreading by using contact memory

    Science.gov (United States)

    Gao, Lei; Wang, Wei; Shu, Panpan; Gao, Hui; Braunstein, Lidia A.

    2017-04-01

    Promoting information spreading is a booming research topic in network science community. However, the existing studies about promoting information spreading seldom took into account the human memory, which plays an important role in the spreading dynamics. In this letter we propose a non-Markovian information spreading model on complex networks, in which every informed node contacts a neighbor by using the memory of neighbor's accumulated contact numbers in the past. We systematically study the information spreading dynamics on uncorrelated configuration networks and a group of 22 real-world networks, and find an effective contact strategy of promoting information spreading, i.e., the informed nodes preferentially contact neighbors with a small number of accumulated contacts. According to the effective contact strategy, the high-degree nodes are more likely to be chosen as the contacted neighbors in the early stage of the spreading, while in the late stage of the dynamics, the nodes with small degrees are preferentially contacted. We also propose a mean-field theory to describe our model, which qualitatively agrees well with the stochastic simulations on both artificial and real-world networks.

  2. Vagus nerve stimulation inhibits cortical spreading depression.

    Science.gov (United States)

    Chen, Shih-Pin; Ay, Ilknur; de Morais, Andreia Lopes; Qin, Tao; Zheng, Yi; Sadeghian, Homa; Oka, Fumiaki; Simon, Bruce; Eikermann-Haerter, Katharina; Ayata, Cenk

    2016-04-01

    Vagus nerve stimulation has recently been reported to improve symptoms of migraine. Cortical spreading depression is the electrophysiological event underlying migraine aura and is a trigger for headache. We tested whether vagus nerve stimulation inhibits cortical spreading depression to explain its antimigraine effect. Unilateral vagus nerve stimulation was delivered either noninvasively through the skin or directly by electrodes placed around the nerve. Systemic physiology was monitored throughout the study. Both noninvasive transcutaneous and invasive direct vagus nerve stimulations significantly suppressed spreading depression susceptibility in the occipital cortex in rats. The electrical stimulation threshold to evoke a spreading depression was elevated by more than 2-fold, the frequency of spreading depressions during continuous topical 1 M KCl was reduced by ∼40%, and propagation speed of spreading depression was reduced by ∼15%. This effect developed within 30 minutes after vagus nerve stimulation and persisted for more than 3 hours. Noninvasive transcutaneous vagus nerve stimulation was as efficacious as direct invasive vagus nerve stimulation, and the efficacy did not differ between the ipsilateral and contralateral hemispheres. Our findings provide a potential mechanism by which vagus nerve stimulation may be efficacious in migraine and suggest that susceptibility to spreading depression is a suitable platform to optimize its efficacy.

  3. Spreading of correlations in the XXZ chain at finite temperatures

    Science.gov (United States)

    Bonnes, Lars; Läuchli, Andreas

    2014-03-01

    In a quantum quench, for instance by abruptly changing the interaction parameter in a spin chain, correlations can spread across the system but have to obey a speed limit set by the Lieb-Robinson bound. This results into a causal structure where the propagation front resembles a light-cone. One can ask how fast a correlation front actually propagates and how its velocity depends on the nature of the quench. This question is addressed by performing global quenches in the XXZ chain initially prepared in a finite-temperature state using minimally entangled typical thermal states (METTS). We provide numerical evidence that the spreading velocity of the spin correlation functions for the quench into the gapless phase is solely determined by the value of the final interaction and the amount of excess energy of the system. This is quite surprising as the XXZ model is integrable and its dynamics is constrained by a large amount of conserved quantities. In particular, the spreading velocity seems to interpolate linearly from a universal value at T = ∞ to the spin wave velocity of the final Hamiltonian in the limit of zero excess energy for Δfinal > 0 .

  4. Behavioral synchronization induced by epidemic spread in complex networks

    Science.gov (United States)

    Sun, Mengfeng; Lou, Yijun; Duan, Jinqiao; Fu, Xinchu

    2017-06-01

    During the spread of an epidemic, individuals in realistic networks may exhibit collective behaviors. In order to characterize this kind of phenomenon and explore the correlation between collective behaviors and epidemic spread, in this paper, we construct several mathematical models (including without delay, with a coupling delay, and with double delays) of epidemic synchronization by applying the adaptive feedback motivated by real observations. By using Lyapunov function methods, we obtain the conditions for local and global stability of these epidemic synchronization models. Then, we illustrate that quenched mean-field theory is more accurate than heterogeneous mean-field theory in the prediction of epidemic synchronization. Finally, some numerical simulations are performed to complement our theoretical results, which also reveal some unexpected phenomena, for example, the coupling delay and epidemic delay influence the speed of epidemic synchronization. This work makes further exploration on the relationship between epidemic dynamics and synchronization dynamics, in the hope of being helpful to the study of other dynamical phenomena in the process of epidemic spread.

  5. [Possible effects of climatic changes on the spread of malaria tropica--results of a strategical simulation].

    Science.gov (United States)

    Flessa, S; Müller, O

    2005-07-01

    The Earth's surface is presently undergoing a period of global warming-up, which increases the likelihood of a spread of malaria tropica. A reliable prognosis would be important for efficient prevention by initiating appropriate counter-measures well in time. The following paper presents simulations of the effects of climatic changes on the spread of malaria. We do not specifically aim at obtaining concrete data for a particular region; rather, we are concerned with gaining an insight into the complex interrelations between global environment changes and the spread of malaria.

  6. 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...

  7. Adhesion patterns in early cell spreading

    Energy Technology Data Exchange (ETDEWEB)

    Ryzhkov, Pavel; Prass, Marcus; Gummich, Meike; Kuehn, Jac-Simon; Oettmeier, Christina; Doebereiner, Hans-Guenther, E-mail: hgd@uni-bremen.d [Institut fuer Biophysik, Universitaet Bremen, D-28334 Bremen (Germany)

    2010-05-19

    Mouse embryonic fibroblasts explore the chemical suitability before spreading on a given substrate. We find this early phase of cell spreading to be characterized by transient adhesion patches with a typical mean size of (1.0 {+-} 0.4) {mu}m and a lifetime of (33 {+-} 12) s. Eventually, these patches fuse to initiate extensive spreading of the cell. We monitor cell adhesion using reflection interference contrast and total internal reflection fluorescence microscopy. Digital time lapse movies are analysed employing spatio-temporal correlation functions of adhesion patterns. Correlation length and time can be scaled to obtain a master curve at the fusion point.

  8. More efficient swimming by spreading your fingers

    Science.gov (United States)

    van de Water, Willem; van Houwelingen, Josje; Willemsen, Dennis; Breugem, Wim Paul; Westerweel, Jerry; Delfos, Rene; Grift, Ernst Jan

    2016-11-01

    A tantalizing question in free-style swimming is whether the stroke efficiency during the pull phase depends on spreading the fingers. It is a subtle effect-not more than a few percent-but it could make a big difference in a race. We measure the drag of arm models with increasing finger spreading in a wind tunnel and compare forces and moments to the results of immersed boundary simulations. Virtual arms were used in the simulations and their 3D-printed real versions in the experiment. We find an optimal finger spreading, accompanied by a marked increase of coherent vortex shedding. A simple actuator disk model explains this optimum.

  9. The Global Punk Reader

    OpenAIRE

    Gordon, Alastair; Dines, Mike; Guerra, Paula

    2015-01-01

    Edited collection of academic research articles on global punk culture Approaching its fortieth anniversary, punk culture has now spread across the planet. Indeed, most western cities and urban connotations are home to a competing range of diverse and original punk scenes. Long standing diverse punk scenes are to be found in Japan, South East Asia, China, The Middle East, Scandinavia, East and Western Europe, Russia, Australia, India and Africa. Each scene, rather than adopting traditiona...

  10. Studying Scale-Up and Spread as Social Practice: Theoretical Introduction and Empirical Case Study.

    Science.gov (United States)

    Shaw, James; Shaw, Sara; Wherton, Joseph; Hughes, Gemma; Greenhalgh, Trisha

    2017-07-07

    Health and care technologies often succeed on a small scale but fail to achieve widespread use (scale-up) or become routine practice in other settings (spread). One reason for this is under-theorization of the process of scale-up and spread, for which a potentially fruitful theoretical approach is to consider the adoption and use of technologies as social practices. This study aimed to use an in-depth case study of assisted living to explore the feasibility and usefulness of a social practice approach to explaining the scale-up of an assisted-living technology across a local system of health and social care. This was an individual case study of the implementation of a Global Positioning System (GPS) "geo-fence" for a person living with dementia, nested in a much wider program of ethnographic research and organizational case study of technology implementation across health and social care (Studies in Co-creating Assisted Living Solutions [SCALS] in the United Kingdom). A layered sociological analysis included micro-level data on the index case, meso-level data on the organization, and macro-level data on the wider social, technological, economic, and political context. Data (interviews, ethnographic notes, and documents) were analyzed and synthesized using structuration theory. A social practice lens enabled the uptake of the GPS technology to be studied in the context of what human actors found salient, meaningful, ethical, legal, materially possible, and professionally or culturally appropriate in particular social situations. Data extracts were used to illustrate three exemplar findings. First, professional practice is (and probably always will be) oriented not to "implementing technologies" but to providing excellent, ethical care to sick and vulnerable individuals. Second, in order to "work," health and care technologies rely heavily on human relationships and situated knowledge. Third, such technologies do not just need to be adopted by individuals; they need

  11. The Speed of Invasion: Rates of Spread for Thirteen Exotic Forest Insects and Diseases

    Directory of Open Access Journals (Sweden)

    Alexander M. Evans

    2016-05-01

    Full Text Available Invasive, exotic insects and diseases have a devastating effect on North American forests. The rate of spread, or range expansion, is one of the main determinants of an invasive organism’s impact, and can play a major role in structuring management response options. To better understand how exotic organisms have spread through our forests, this study employs a consistent, rigorous analytical framework to analyze a comprehensive geospatial database for the spread of seven exotic insects and six diseases. This study includes new data for six insects and two diseases in combination with five invasive species previously analyzed using the same technique. The quantile regression analysis of over 3000 records of infestation over the preceding century show that the rate of spread of invasive forest insects and diseases ranges from 4.2 km·year−1 to 57.0 km·year−1. The slowest disease spread was white pine blister rust (Cronartium ribicola at 7.4 km·year−1 while the most rapid disease spread was chestnut blight (Cryphonectria parasitica at 31.3 km·year−1. The slowest insect spread was balsam woolly adelgid (Adelges piceae (4.2 km·year−1 while the fastest was emerald ash borer (Agrilus planipennis at 57.0 km·year−1. Species that can fly long distances or are vectored by flying insects have spread faster than those that are passively dispersed. This analysis highlights the difficulty of estimating spread rates from studies of individual dispersal or flight distances, but the estimated spread rates in this study are generally in line with previous estimates.

  12. A Method to Assign Spread Codes Based on Passive RFID Communication for Energy Harvesting Wireless Sensors Using Spread Spectrum Transmission

    Directory of Open Access Journals (Sweden)

    Ken Takahashi

    2015-08-01

    Full Text Available Considerable research has been conducted on systems that collect real-world information by using numerous energy harvesting wireless sensors. The sensors need to be tiny, cheap, and consume ultra-low energy. However, such sensors have some functional limits, including being restricted to wireless communication transmission. Therefore, when more than one sensor simultaneously transmits information in these systems, the receiver may not be able to demodulate if the sensors cannot accommodate multiple access. To solve this problem, a number of proposals have been made based on spread spectrum technologies for resistance to interference. In this paper, we point out some problems regarding the application of such sensors, and explain the assumption of spread codes assignment based on passive radio frequency identification (RFID communication. During the spread codes assignment, the system cannot work. Hence, efficient assignment method is more appropriate. We consider two assignment methods and assessed them in terms of total assignment time through an experiment. The results show the total assignment time in case of Electronic Product Code (EPC Global Class-1 Generation-2 which is an international standard for wireless protocols and the relationship between the ratio of the time taken by the read/write command and the ratio of total assignment time by the two methods. This implies that more efficient methods are obtained by considering the time ratio of read/write command.

  13. Can Suicide Tries Spread Among Soldiers?

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_167432.html Can Suicide Tries Spread Among Soldiers? Increased risk seen within ... if another member of their unit has attempted suicide in the previous year. In fact, the researchers ...

  14. Epidemic spreading with information-driven vaccination

    Science.gov (United States)

    Ruan, Zhongyuan; Tang, Ming; Liu, Zonghua

    2012-09-01

    Epidemic spreading has been well studied in the past decade, where the main concentration is focused on the influence of network topology but little attention is paid to the individual's crisis awareness. We here study how the crisis awareness, i.e., personal self-protection, influences the epidemic spreading by presenting a susceptible-infected-recovered model with information-driven vaccination. We introduce two parameters to quantitatively characterize the crisis awareness. One is the information creation rate λ and the other is the information sensitivity η. We find that the epidemic spreading can be significantly suppressed in both the homogeneous and heterogeneous networks when both λ and η are relatively large. More interesting is that the needed vaccine will be significantly reduced when the information is well spread, which is a good news for the poor countries and regions with limited resources.

  15. Emergence of Blind Areas in Information Spreading

    CERN Document Server

    Zhang, Zi-Ke; Han, Xiao-Pu; Liu, Chuang

    2013-01-01

    Recently, contagion-based (disease, information, etc.) spreading on social networks has been extensively studied. In this paper, other than traditional full interaction, we propose a partial interaction based spreading model, considering that the informed individuals would transmit information to only a certain fraction of their neighbors due to the transmission ability in real-world social networks. Simulation results on three representative networks (BA, ER, WS) indicate that the spreading efficiency is highly correlated with the network heterogeneity. In addition, a special phenomenon, namely \\emph{Information Blind Areas} where the network is separated by several information-unreachable clusters, will emerge from the spreading process. Furthermore, we also find that the size distribution of such information blind areas obeys power-law-like distribution, which has very similar exponent with that of site percolation. Detailed analyses show that the critical value is decreasing along with the network heterog...

  16. Zika Probably Not Spread Through Saliva: Study

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_167531.html Zika Probably Not Spread Through Saliva: Study Research with ... HealthDay News) -- Scientists have some interesting news about Zika: You're unlikely to get the virus from ...

  17. Spreading of charged micro-droplets

    Directory of Open Access Journals (Sweden)

    Joseph Iaia

    2013-09-01

    Full Text Available We consider the spreading of a charged microdroplet on a flat dielectric surface whose spreading is driven by surface tension and electrostatic repulsion. This leads to a third order nonlinear partial differential equation that gives the evolution of the height profile. Assuming the droplets are circular we are able to prove existence of solutions with infinite contact angle and in many cases we are able to prove nonexistence of solutions with finite contact angle.

  18. Irregularities and Forecast Studies of Equatorial Spread

    Science.gov (United States)

    2016-07-13

    document in the published literature . The result implies that the aeronomy of the postsunset equatorial ionosphere is sufficiently well understood for...of equatorial spread F in the Peruvian sector, J. Geophys. Res. Space Physics, 119, 38153827, doi:10.1002/2014JA019889. ◦ Hysell, D. L., M. A. Milla...L. Condori, and J. W. Meriwether (2014), Data-driven numer- ical simulations of equatorial spread F in the Peruvian sector: 2. Autumnal equinox, J

  19. VAGUS NERVE STIMULATION INHIBITS CORTICAL SPREADING DEPRESSION

    OpenAIRE

    Chen, Shih-Pin; Ay, Ilknur; de Morais, Andreia Lopes; Qin, Tao; Zheng,Yi; Sadhegian, Homa; Oka, Fumiaki; Simon, Bruce; Eikermann-Haerter, Katharina; Ayata, Cenk

    2016-01-01

    Vagus nerve stimulation has recently been reported to improve symptoms of migraine. Cortical spreading depression is the electrophysiological event underlying migraine aura, and a trigger for headache. We tested whether vagus nerve stimulation inhibits cortical spreading depression to explain its anti-migraine effect. Vagus nerve stimulation was delivered either non-invasively through the skin or directly by electrodes placed around the vagus nerve unilaterally. Systemic physiology was monito...

  20. Simultaneous boiling and spreading of liquefied petroleum gas on water. Final report, December 12, 1978-March 31, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Chang, H.R.; Reid, R.C.

    1981-04-01

    An experimental and theoretical investigation was carried out to study the boiling and spreading of liquid nitrogen, liquid methane and liquefied petroleum gas (LPG) on water in a one-dimensional configuration. Primary emphasis was placed on the LPG studies. Experimental work involved the design and construction of a spill/spread/boil apparatus which permitted the measurement of spreading and local boil-off rates. With the equations of continuity and momentum transfer, a mathematical model was developed to describe the boiling-spreading phenomena of cryogens spilled on water. The model accounted for a decrease in the density of the cryogenic liquid due to bubble formation. The boiling and spreading rates of LPG were found to be the same as those of pure propane. An LPG spill was characterized by the very rapid and violent boiling initially and highly irregular ice formation on the water surface. The measured local boil-off rates of LPG agreed reasonably well with theoretical predictions from a moving boundary heat transfer model. The spreading velocity of an LPG spill was found to be constant and determined by the size of the distributor opening. The maximum spreading distance was found to be unaffected by the spilling rate. These observations can be explained by assuming that the ice formation on the water surface controls the spreading of LPG spills. While the mathematical model did not predict the spreading front adequately, it predicted the maximum spreading distance reasonably well.

  1. 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.

  2. 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.

  3. Emergence of blind areas in information spreading.

    Science.gov (United States)

    Zhang, Zi-Ke; Zhang, Chu-Xu; Han, Xiao-Pu; Liu, Chuang

    2014-01-01

    Recently, contagion-based (disease, information, etc.) spreading on social networks has been extensively studied. In this paper, other than traditional full interaction, we propose a partial interaction based spreading model, considering that the informed individuals would transmit information to only a certain fraction of their neighbors due to the transmission ability in real-world social networks. Simulation results on three representative networks (BA, ER, WS) indicate that the spreading efficiency is highly correlated with the network heterogeneity. In addition, a special phenomenon, namely Information Blind Areas where the network is separated by several information-unreachable clusters, will emerge from the spreading process. Furthermore, we also find that the size distribution of such information blind areas obeys power-law-like distribution, which has very similar exponent with that of site percolation. Detailed analyses show that the critical value is decreasing along with the network heterogeneity for the spreading process, which is complete the contrary to that of random selection. Moreover, the critical value in the latter process is also larger than that of the former for the same network. Those findings might shed some lights in in-depth understanding the effect of network properties on information spreading.

  4. Emergence of blind areas in information spreading.

    Directory of Open Access Journals (Sweden)

    Zi-Ke Zhang

    Full Text Available Recently, contagion-based (disease, information, etc. spreading on social networks has been extensively studied. In this paper, other than traditional full interaction, we propose a partial interaction based spreading model, considering that the informed individuals would transmit information to only a certain fraction of their neighbors due to the transmission ability in real-world social networks. Simulation results on three representative networks (BA, ER, WS indicate that the spreading efficiency is highly correlated with the network heterogeneity. In addition, a special phenomenon, namely Information Blind Areas where the network is separated by several information-unreachable clusters, will emerge from the spreading process. Furthermore, we also find that the size distribution of such information blind areas obeys power-law-like distribution, which has very similar exponent with that of site percolation. Detailed analyses show that the critical value is decreasing along with the network heterogeneity for the spreading process, which is complete the contrary to that of random selection. Moreover, the critical value in the latter process is also larger than that of the former for the same network. Those findings might shed some lights in in-depth understanding the effect of network properties on information spreading.

  5. Twenty years of invasion: a review of round goby Neogobius melanostomus biology, spread and ecological implications.

    Science.gov (United States)

    Kornis, M S; Mercado-Silva, N; Vander Zanden, M J

    2012-02-01

    The round goby Neogobius melanostomus is one of the most wide-ranging invasive fish on earth, with substantial introduced populations within the Laurentian Great Lakes watershed, the Baltic Sea and several major European rivers. Rapid expansion and deleterious ecosystem effects have motivated extensive research on this species; here this research is synthesized. Maps of the global distribution are provided and the invasion history of N. melanostomus, which spread more rapidly at first in North America, but has undergone substantial expansion over the past decade in the Baltic Sea, is summarized. Meta-analyses comparing their size at age, diet, competitors and predators in North American and European ecosystems are provided. Size at age is region specific, with saline habitats typically supporting larger and faster growing individuals than fresh water. Neogobius melanostomus prey differs substantially between regions, demonstrating a capacity to adapt to locally abundant food sources. Neogobius melanostomus comprise at least 50% of the diet of eight taxa in at least one site or life stage; in total, 16 predator taxa are documented from the Laurentian Great Lakes v. five from Eurasia. Invasive N. melanostomus are the only common forage fish to heavily exploit mussels in the Laurentian Great Lakes and the Baltic Sea, facilitating the transfer of energy from mussels to higher trophic levels in both systems. Neogobius melanostomus morphology, life history, reproduction, habitat preferences, environmental tolerances, parasites, environmental effects, sampling strategies and management are also discussed. Neogobius melanostomus inhabit a wide range of temperate freshwater and brackish-water ecosystems and will probably continue to spread via ballast water, accidental bait release and natural dispersal worldwide. Climate change will probably enhance N. melanostomus expansion by elevating water temperatures closer to its energetic optimum of 26° C. Future research needs

  6. Evolutionary trajectory of white spot syndrome virus (WSSV) genome shrinkage during spread in Asia

    NARCIS (Netherlands)

    Zwart, M.P.; Bui Thi Minh Dieu,; Hemerik, L.; Vlak, J.M.

    2010-01-01

    Background - White spot syndrome virus (WSSV) is the sole member of the novel Nimaviridae family, and the source of major economic problems in shrimp aquaculture. WSSV appears to have rapidly spread worldwide after the first reported outbreak in the early 1990s. Genomic deletions of various sizes

  7. Collective behavior and critical fluctuations in the spatial spreading of obesity, diabetes and cancer

    CERN Document Server

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

    2012-01-01

    Non-communicable diseases like diabetes, obesity and certain forms of cancer have been 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 global epidemics. Here, we implement a spatial spreading analysis to investigate whether diabetes, obesity and cancer show spatial correlations revealing the effect of collective and global factors acting above individual choices. We adapt a theoretical framework for critical physical systems displaying collective behavior to decipher the laws of spatial spreading of diseases. 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. This collective behavior indicates that the spreading dynamics of obesity, diabetes and some forms of cancer like lung can...

  8. 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.)

  9. Genome sequencing - the ultimate answer to global real time genotyping and surveillance?

    DEFF Research Database (Denmark)

    Hendriksen, Rene S.

    2013-01-01

    the technology with “plug and play” bioinformatic toolboxes and using an established global genomic database for microorganisms, facilitate a global surveillance in real time with the potential to predict and prevent future public health threats. Conclusion: Recently, several international meetings have been...... of the complete human genome sequence in 2003, whole genome sequencing (WGS) has greatly increased our ability to in a rapid and more reliable way distinguish between epidemiologically unrelated isolates from the same bacterial species and thereby enhance our capacity to detect outbreaks, conduct surveillance...... organised to discuss the possibility of using WGS as diagnostic tool on a global scale. These meetings were attended by scientists and policy makers from around the world. The general conclusion of these meetings was that the technology exists and that the spread in the application should be linked...

  10. Cytoskeletal filament assembly and the control of cell spreading and function by extracellular matrix

    Science.gov (United States)

    Mooney, D. J.; Langer, R.; Ingber, D. E.

    1995-01-01

    This study was undertaken to analyze how cell binding to extracellular matrix produces changes in cell shape. We focused on the initial process of cell spreading that follows cell attachment to matrix and, thus, cell 'shape' changes are defined here in terms of alterations in projected cell areas, as determined by computerized image analysis. Cell spreading kinetics and changes in microtubule and actin microfilament mass were simultaneously quantitated in hepatocytes plated on different extracellular matrix substrata. The initial rate of cell spreading was highly dependent on the matrix coating density and decreased from 740 microns 2/h to 50 microns 2/h as the coating density was lowered from 1000 to 1 ng/cm2. At approximately 4 to 6 hours after plating, this initial rapid spreading rate slowed and became independent of the matrix density regardless of whether laminin, fibronectin, type I collagen or type IV collagen was used for cell attachment. Analysis of F-actin mass revealed that cell adhesion to extracellular matrix resulted in a 20-fold increase in polymerized actin within 30 minutes after plating, before any significant change in cell shape was observed. This was followed by a phase of actin microfilament disassembly which correlated with the most rapid phase of cell extension and ended at about 6 hours; F-actin mass remained relatively constant during the slow matrix-independent spreading phase. Microtubule mass increased more slowly in spreading cells, peaking at 4 hours, the time at which the transition between rapid and slow spreading rates was observed. However, inhibition of this early rise in microtubule mass using either nocodazole or cycloheximide did not prevent this transition. Use of cytochalasin D revealed that microfilament integrity was absolutely required for hepatocyte spreading whereas interference with microtubule assembly (using nocodazole or taxol) or protein synthesis (using cycloheximide) only partially suppressed cell extension. In

  11. Spreading of Cholera through Surface Water

    Science.gov (United States)

    Bertuzzo, E.; Casagrandi, R.; Gatto, M.; Rodriguez-Iturbe, I.; Rinaldo, A.

    2009-12-01

    Cholera epidemics are still a major public health concern to date in many areas of the world. In order to understand and forecast cholera outbreaks, one of the most important factors is the role played by the environmental matrix in which the disease spreads. We study how river networks, acting as environmental corridors for pathogens, affect the spreading of cholera epidemics. The environmental matrix in which the disease spreads is constituted by different human communities and their hydrologic interconnections. Each community is characterized by its spatial position, population size, water resources availability and hygiene conditions. By implementing a spatially explicit cholera model we seek the effects on epidemic dynamics of: i) the topology and metrics of the pathogens pathways that connect different communities; ii) the spatial distribution of the population size; and iii) the spatial distributions and quality of surface water resources and public health conditions, and how they vary with population size. The model has been applied to study the space-time evolution of a well documented cholera epidemic occurred in the KwaZulu-Natal province of South Africa. The epidemic lasted for two years and involved about 140,000 confirmed cholera cases. The model does well in reproducing the distribution of the cholera cases during the two outbreaks as well as their spatial spreading. We further extend the model by deriving the speed of propagation of traveling fronts in the case of uniformly distributed systems for different topologies: one and two dimensional lattices and river networks. The derivation of the spreading celerity proves instrumental in establishing the overall conditions for the relevance of spatially explicit models. The conditions are sought by comparison between spreading and disease timescales. Consider a cholera epidemic that starts from a point and spreads throughout a finite size system, it is possible to identify two different timescales: i

  12. Post-Tanner spreading of nematic droplets

    Energy Technology Data Exchange (ETDEWEB)

    Mechkov, S; Oshanin, G [Laboratoire de Physique Theorique de la Matiere Condensee, Universite Pierre et Marie Curie, 4 place Jussieu, 75252 Paris Cedex 5 (France); Cazabat, A M, E-mail: mechkov@lptmc.jussieu.f, E-mail: anne-marie.cazabat@lps.ens.f, E-mail: oshanin@lptmc.jussieu.f [Laboratoire de Physique Statistique, Ecole Normale Superieure, 75252 Paris Cedex 5 (France)

    2009-11-18

    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 Rapproxt{sup 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 Rapproxt{sup a}lpha with alpha 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.

  13. Turbulent wedge spreading dynamics and control strategies

    Science.gov (United States)

    Suryanarayanan, Saikishan; Goldstein, David; Brown, Garry

    2017-11-01

    Turbulent wedges are encountered in some routes to transition in wall bounded flows, particularly those involving surface roughness. They are characterized by strongly turbulent regions that are formed downstream of large disturbances, and spread into the non-turbulent flow. Altering the wedge spreading mechanism is a possible drag reduction strategy. Following recent studies of Goldstein, Chu and Brown (Flow Turbul. Combust. 98(1), 2017) and Kuester and White (Exp. Fluids 57(4), 2016), we explore the relation between the base flow vorticity field and turbulent wedge spreading using immersed boundary direct numerical simulations. The lateral spreading rate of the wedges are similar for high Reynolds number boundary layers and Couette flow, but differences emerge in wall normal propagation of turbulence. We also attempt to utilize the surface texture based strategy suggested by Strand and Goldstein (J. Fluid Mech. 668, 2011) to reduce the spreading of isolated turbulent spots, for turbulent wedge control. The effects of height, spacing and orientation of fins on the dynamics of wedge evolution are studied. The results are interpreted from a vorticity dynamics point of view. Supported by AFOSR # FA9550-15-1-0345.

  14. Extended oil spill spreading with Langmuir circulation.

    Science.gov (United States)

    Simecek-Beatty, Debra; Lehr, William J

    2017-09-15

    When spilled in the ocean, most crude oils quickly spread into a thin film that ruptures into smaller slicks distributed over a larger area. Observers have also reported the film tearing apart into streaks that eventually merge forming fewer but longer bands of floating oil. Understanding this process is important to model oil spill transport. First, slick area is calculated using a spreading model. Next, Langmuir circulation models are used to approximate the merging of oiled bands. Calculations are performed on Troll blended and Alaska North Slope crude oils and results compared with measurements from the 1990s North Sea field experiments. Langmuir circulation increases the oil area but decreases the surface coverage of oil. This work modifies existing oil spreading formulas by providing a surface area correction due to the effects of Langmuir circulation. The model's simplicity is advantageous in situations with limited data, such as emergency oil spill response. Published by Elsevier Ltd.

  15. Diffusive spreading in nature, technology and society

    CERN Document Server

    Caro, Jürgen; Kärger, Jörg; Vogl, Gero

    2018-01-01

    This book deals with randomly moving objects and their spreading. The objects considered are particles like atoms and molecules, just as living beings like humans, animals, plants, bacteria and even abstract entities like ideas, rumors, information, innovations and linguistic features. The book explores and communicates the laws behind these movements and reports about astonishing similarities and very specific features typical of the given object under considerations. Leading scientists in disciplines as different as archeology, epidemics, linguistics and sociology, in contact with their colleagues from engineering, natural sciences and mathematics, introduce into the phenomena of spreading as relevant for their fields. An introductory chapter on “Spreading Fundamentals” provides a common basis for all these considerations, with a minimum of mathematics, selected and presented for enjoying rather than frustrating the reader.

  16. 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.

  17. 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.

  18. Epidemic spreading on evolving signed networks

    CERN Document Server

    Saeedian, M; Jafari, G R; Kertesz, J

    2016-01-01

    Most studies of disease spreading consider the underlying social network as obtained without the contagion, though epidemic influences peoples willingness to contact others: A friendly contact may be turned to unfriendly to avoid infection. We study the susceptible-infected (SI) disease spreading model on signed networks, in which each edge is associated with a positive or negative sign representing the friendly or unfriendly relation between its end nodes. In a signed network, according to Heiders theory, edge signs evolve such that finally a state of structural balance is achieved, corresponding to no frustration in physics terms. However, the danger of infection affects the evolution of its edge signs. To describe the coupled problem of the sign evolution and disease spreading, we generalize the notion of structural balance by taking into account the state of the nodes. We introduce an energy function and carry out Monte-Carlo simulations on complete networks to test the energy landscape, where we find loc...

  19. 9 CFR 319.762 - Ham spread, tongue spread, and similar products.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Ham spread, tongue spread, and similar products. 319.762 Section 319.762 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... AND VOLUNTARY INSPECTION AND CERTIFICATION DEFINITIONS AND STANDARDS OF IDENTITY OR COMPOSITION Meat...

  20. The spread of gossip in American schools

    Science.gov (United States)

    Lind, P. G.; da Silva, L. R.; Andrade, J. S., Jr.; Herrmann, H. J.

    2007-06-01

    Gossip is defined as a rumor which specifically targets one individual and essentially only propagates within its friendship connections. How fast and how far a gossip can spread is for the first time assessed quantitatively in this study. For that purpose we introduce the "spread factor" and study it on empirical networks of school friendships as well as on various models for social connections. We discover that there exists an ideal number of friendship connections an individual should have to minimize the danger of gossip propagation.

  1. Harry Hess and sea-floor spreading

    OpenAIRE

    Allwardt, Alan O.

    1999-01-01

    Harry Hess's hypothesis of sea-floor spreading brought together his long-standing interests in island arcs, oceanic topography, and the oceanic crust. The one unique feature of Hess's hypothesis was the origin of the oceanic crust as a hydration rind on the top of the mantle -- an idea that was not well received, even by the early converts to sea-floor spreading. Hess never changed his mind on this issue, and his stubbornness illuminates the logic of his discovery. Published and archival reco...

  2. Compressive Sensing for Spread Spectrum Receivers

    DEFF Research Database (Denmark)

    Fyhn, Karsten; Jensen, Tobias Lindstrøm; Larsen, Torben

    2013-01-01

    to a decrease in the two design parameters. This paper investigates the use of Compressive Sensing (CS) in a general Code Division Multiple Access (CDMA) receiver. We show that when using spread spectrum codes in the signal domain, the CS measurement matrix may be simplified. This measurement scheme, named...... Compressive Spread Spectrum (CSS), allows for a simple, effective receiver design. Furthermore, we numerically evaluate the proposed receiver in terms of bit error rate under different signal to noise ratio conditions and compare it with other receiver structures. These numerical experiments show that though...

  3. 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.

  4. What Lies Beneath? An Evaluation of Rapid Assessment Tools for Management of Hull Fouling

    Science.gov (United States)

    Clarke Murray, Cathryn; Therriault, Thomas W.; Pakhomov, Evgeny

    2013-08-01

    Despite an increased understanding of marine invasions, non-indigenous species (NIS) continue to be redistributed at both global and regional scales. Since prevention is an important element of NIS programs, monitoring vectors responsible for NIS introductions and spread, such as hull fouling, has become a priority and methods should be selected carefully to balance accuracy, time, and cost. Two common fouling assessment tools for the marine recreational boating vector were evaluated for accuracy using a traditional underwater SCUBA survey in coastal British Columbia: a dockside level of fouling assessment and a behavioral questionnaire model. Results showed that although rapid, dockside assessments did not provide an accurate assessment of fouling present below the surface, at least not in this region. In contrast, a questionnaire-based model using four easily obtained variables (boat type, age of antifouling paint, storage type, and occurrence of long distance trips) reliably identified boats carrying macrofouling species, a proxy for risk of NIS transport. Once validated, this fouling model tool could be applied in border inspection or quarantine situations where decisions must be made quickly. Further development and refinement of rapid assessment tools would improve our ability to prevent new introductions and manage spread of existing invasive species.

  5. Modelling the evolution and spread of HIV immune escape mutants.

    Science.gov (United States)

    Fryer, Helen R; Frater, John; Duda, Anna; Roberts, Mick G; Phillips, Rodney E; McLean, Angela R

    2010-11-18

    During infection with human immunodeficiency virus (HIV), immune pressure from cytotoxic T-lymphocytes (CTLs) selects for viral mutants that confer escape from CTL recognition. These escape variants can be transmitted between individuals where, depending upon their cost to viral fitness and the CTL responses made by the recipient, they may revert. The rates of within-host evolution and their concordant impact upon the rate of spread of escape mutants at the population level are uncertain. Here we present a mathematical model of within-host evolution of escape mutants, transmission of these variants between hosts and subsequent reversion in new hosts. The model is an extension of the well-known SI model of disease transmission and includes three further parameters that describe host immunogenetic heterogeneity and rates of within host viral evolution. We use the model to explain why some escape mutants appear to have stable prevalence whilst others are spreading through the population. Further, we use it to compare diverse datasets on CTL escape, highlighting where different sources agree or disagree on within-host evolutionary rates. The several dozen CTL epitopes we survey from HIV-1 gag, RT and nef reveal a relatively sedate rate of evolution with average rates of escape measured in years and reversion in decades. For many epitopes in HIV, occasional rapid within-host evolution is not reflected in fast evolution at the population level.

  6. 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…

  7. Globalization and Multicultural Communication: Unity in Diversity

    Science.gov (United States)

    Nihalani, Paroo

    2008-01-01

    Communication is one of the keywords of the global age. The ever-increasing use of English as a World language has clearly meant that British RP and American Standard English (GA) are no longer seen as the models that learners aspire to. With the global spread of English, three major related questions come to our mind: (a) diversity and…

  8. Reducing the spread of antimicrobial-resistant microorganisms. Control of vancomycin-resistant enterococci.

    Science.gov (United States)

    Shay, D K; Goldmann, D A; Jarvis, W R

    1995-06-01

    Strategies to reduce the spread of hospital-acquired microorganisms resistant to multiple antimicrobial agents are discussed. Because hospitals have experienced a rapid increase in the incidence of infection and colonization with vancomycin-resistant enterococci (VRE) in the past 5 years, the Hospital Infection Control Practices Advisory Committee of the Centers for Disease Control and Prevention has issued recommendations for preventing the spread of vancomycin resistance. Controlling VRE dissemination in pediatric patients requires prompt detection of VRE by microbiology laboratories, education of staff and families about VRE, use of infection control measures to prevent person-to-person VRE transmission, and prudent vancomycin use.

  9. 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.

  10. Subarachnoid Hemorrhage, Spreading Depolarizations and Impaired Neurovascular Coupling

    Directory of Open Access Journals (Sweden)

    Masayo Koide

    2013-01-01

    Full Text Available Aneurysmal subarachnoid hemorrhage (SAH has devastating consequences on brain function including profound effects on communication between neurons and the vasculature leading to cerebral ischemia. Physiologically, neurovascular coupling represents a focal increase in cerebral blood flow to meet increased metabolic demand of neurons within active regions of the brain. Neurovascular coupling is an ongoing process involving coordinated activity of the neurovascular unit—neurons, astrocytes, and parenchymal arterioles. Neuronal activity can also influence cerebral blood flow on a larger scale. Spreading depolarizations (SD are self-propagating waves of neuronal depolarization and are observed during migraine, traumatic brain injury, and stroke. Typically, SD is associated with increased cerebral blood flow. Emerging evidence indicates that SAH causes inversion of neurovascular communication on both the local and global level. In contrast to other events causing SD, SAH-induced SD decreases rather than increases cerebral blood flow. Further, at the level of the neurovascular unit, SAH causes an inversion of neurovascular coupling from vasodilation to vasoconstriction. Global ischemia can also adversely affect the neurovascular response. Here, we summarize current knowledge regarding the impact of SAH and global ischemia on neurovascular communication. A mechanistic understanding of these events should provide novel strategies to treat these neurovascular disorders.

  11. Invasion and spreading of Cabomba caroliniana revealed by RAPD markers

    Science.gov (United States)

    Jin, Xiaofeng; Ding, Bingyang; Gao, Shuqin; Jiang, Weimei

    2005-12-01

    Applying randomly amplified polymorphic DNA (RAPD), the genetic variation of Cabomba caroliniana Gray (cabomba or fanwort), a new alien plant in China, was analyzed in this paper. Total 143 bands, including 47 polymorphic bands, were amplified from 23 primers in 20 samples. The sampling distance was large, but its genetic diversity was low. The main results were that: (1) Cabomba, which grew and dispersed mainly in fragment, was an abundant and dominant species in freshwater, and its main dispersal mechanism was vegetative reproduction (2) Cabomba was originally introduced into China as an aquarium submerged plant. Somehow, those discarded cabomba became invasive species in the areas of Hangzhou, Shanghai, and Meicheng, and other places. (3) Although the level of genetic diversity in cabomba was low, their rapid dispersion and propagation could seriously harm to local aquatic community. Therefore, specific measure should be used to control cabomba from uncontrolled spreading and damage to local vegetation communities.

  12. Lognormal infection times of online information spread

    NARCIS (Netherlands)

    Doerr, C.; Blenn, N.; Van Mieghem, P.

    2013-01-01

    The infection times of individuals in online information spread such as the inter-arrival time of Twitter messages or the propagation time of news stories on a social media site can be explained through a convolution of lognormally distributed observation and reaction times of the individual

  13. A model to forecast peak spreading.

    Science.gov (United States)

    2012-04-01

    As traffic congestion increases, the K-factor, defined as the proportion of the 24-hour traffic volume that occurs during the peak hour, may decrease. This behavioral response is known as peak spreading: as congestion grows during the peak travel tim...

  14. Restricted spread of tomato spotted wilt virus

    NARCIS (Netherlands)

    Maris, P.C.; Joosten, N.N.; Goldbach, R.W.; Peters, D.

    2003-01-01

    Spread of Tomato spotted wilt virus (TSWV) and population development of its vector Frankliniella occidentalis were studied on the pepper accessions CPRO-1 and Pikante Reuzen, which are resistant and susceptible to thrips, respectively. Viruliferous thrips were released on plants of each accession

  15. Model of Opinion Spreading in Social Networks

    CERN Document Server

    Kanovsky, Igor

    2011-01-01

    We proposed a new model, which capture the main difference between information and opinion spreading. In information spreading additional exposure to certain information has a small effect. Contrary, when an actor is exposed to 2 opinioned actors the probability to adopt the opinion is significant higher than in the case of contact with one such actor (called by J. Kleinberg "the 0-1-2 effect"). In each time step if an actor does not have an opinion, we randomly choose 2 his network neighbors. If one of them has an opinion, the actor adopts opinion with some low probability, if two - with a higher probability. Opinion spreading was simulated on different real world social networks and similar random scale-free networks. The results show that small world structure has a crucial impact on tipping point time. The "0-1-2" effect causes a significant difference between ability of the actors to start opinion spreading. Actor is an influencer according to his topological position in the network.

  16. Natural Spread of Plant Viruses by Birds

    NARCIS (Netherlands)

    Peters, D.; Engels, C.; Sarra, S.

    2012-01-01

    Observations made in Mali strongly suggest that Rice yellow mottle virus (RYMV) is spread by weaverbirds (Quelea quelea) below and around baobab trees (Adansonia digitata) in which they nest. Rice leaves in bird nests appeared to be infected. In Spain, an infection of Southern bean mosaic virus

  17. Spread of Rare Fungus from Vancouver Island

    Centers for Disease Control (CDC) Podcasts

    2006-12-20

    Cryptococcus gattii, a rare fungus normally found in the tropics, has infected people and animals on Vancouver Island, Canada. Dr. David Warnock, Director, Division of Foodborne, Bacterial, and Mycotic Diseases, CDC, discusses public health concerns about further spread of this organism.  Created: 12/20/2006 by Emerging Infectious Diseases.   Date Released: 12/29/2006.

  18. Spread of Tylodelphys mashonense (digenea: diplostomidae) by ...

    African Journals Online (AJOL)

    Despite the fact that Tylodelphys mashonense, parasites of the cranial cavity of the catfish Clarias gariepinus, are ubiquitous in freshwater systems, little is known on their spread. As such, we examined a total of 152 piscivorous birds, belonging to 6 species; 43 great cormorant Phalacrocorax carbo, 33 grey heron Ardea ...

  19. Introduction, establishment and spread of the Southern ...

    African Journals Online (AJOL)

    ... native fishes and predation on fish larvae. Pseudocrenilabrus philander in the Baakens River therefore satisfies all criteria for an invasive species in this river and was categorised as invasive using a unified framework for biological invasions. Keywords: abundance, cichlid, electrofishing, establishment, invasion, spread ...

  20. Damage spreading on networks: Clustering effects

    Indian Academy of Sciences (India)

    The damage spreading of the Ising model on three kinds of networks is studied with Glauber dynamics. One of the networks is generated by evolving the hexagonal lattice with the star-triangle transformation. Another kind of network is constructed by connecting the midpoints of the edges of the topological hexagonal lattice.

  1. 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.

  2. Rapid response manufacturing (RRM)

    Energy Technology Data Exchange (ETDEWEB)

    Cain, W.D. [Lockheed Martin Energy Systems, Inc., Oak Ridge, TN (United States); Waddell, W.L. [National Centers for Manufacturing Sciences, Ann Arbor, MI (United States)

    1997-02-18

    US industry is fighting to maintain its competitive edge in the global market place. Today markets fluctuate rapidly. Companies, to survive, have to be able to respond with quick-to-market, improved, high quality, cost efficient products. The way products are developed and brought to market can be improved and made more efficient through the proper incorporation of emerging technologies. The RRM project was established to leverage the expertise and resources of US private industries and federal agencies to develop, integrate, and deploy new technologies that meet critical needs for effective product realization. The RRM program addressed a needed change in the US Manufacturing infrastructure that will ensure US competitiveness in world market typified by mass customization. This project provided the effort needed to define, develop and establish a customizable infrastructure for rapid response product development design and manufacturing. A major project achievement was the development of a broad-based framework for automating and integrating the product and process design and manufacturing activities involved with machined parts. This was accomplished by coordinating and extending the application of feature-based product modeling, knowledge-based systems, integrated data management, and direct manufacturing technologies in a cooperative integrated computing environment. Key technological advancements include a product model that integrates product and process data in a consistent, minimally redundant manner, an advanced computer-aided engineering environment, knowledge-based software aids for design and process planning, and new production technologies to make products directly from design application software.

  3. A measurement instrument for spread of quality improvement in healthcare

    NARCIS (Netherlands)

    S.S. Slaghuis (Sarah); M.M.H. Strating (Mathilde); R.A. Bal (Roland); A.P. Nieboer (Anna)

    2013-01-01

    textabstractAbstract Objective. The aim of this study was to develop and test a measurement instrument for spread of quality improvement in healthcare. The instrument distinguishes: (i) spread of work practices and their results and (ii) spread practices and effectiveness. Relations between spread

  4. 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.

  5. Rapidly moving contact lines and damping contributions

    Science.gov (United States)

    Xia, Yi; Daniel, Susan; Steen, Paul

    2017-11-01

    Contact angle varies dynamically with contact line (CL) speed when a liquid moves across a solid support, as when a liquid spreads rapidly. For sufficiently rapid spreading, inertia competes with capillarity to influence the interface shape near the support. We use resonant-mode plane-normal support oscillations of droplets to drive lateral contact-line motion. Reynolds numbers based on CL speeds are high and capillary numbers are low. These are inertial-capillary motions. By scanning the driving frequency, we locate the frequency at peak amplification (resonance), obtain the scaled peak height (amplification factor) and a measure of band-width (damping ratio). We report how a parameter for CL mobility depends on these scanning metrics, with the goal of distinguishing contributions from the bulk- and CL-dissipation to overall damping.

  6. 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.

  7. Teaching for Global Understanding.

    Science.gov (United States)

    Schaeffler, Walter S.

    1979-01-01

    Explains why global education programs are needed at all educational levels. Reasons include international interdependence, rapid communication, and the likelihood that students will one day travel to a foreign country. Methods should involve mass media, community resources, language study, stress on intercultural sensitivity, and the case study…

  8. Implementation of rapid diagnostics with antimicrobial stewardship.

    Science.gov (United States)

    Minejima, Emi; Wong-Beringer, Annie

    2016-11-01

    Antimicrobial stewardship (ASP) is an intervention-based program to improve patient outcomes to infection while limiting spread of resistance and unintended consequences. Many rapid diagnostic tools are now FDA cleared for clinical use, with three evaluated across multiple settings: Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry, Verigene, and FilmArray. Areas covered: This review will focus on studies published that evaluated ASP intervention with rapid diagnostic implementation on outcomes of infection. A description of the key ASP personnel, rapid diagnostic notification methods, hours of notification, and scope of ASP intervention is summarized. Expert commentary: It is critical that ASPs continually re-evaluate and evolve with technological advances. Rapid diagnostic tools are powerful in their ability to identify organisms quickly. A trained clinician is needed to evaluate the results and interact with the providers to educate them on result interpretation and optimal antimicrobial selection to maximize treatment success.

  9. Spread prediction model of continuous steel tube based on BP neural network

    Science.gov (United States)

    Zhai, Jian-wei; Yu, Hui; Zou, Hai-bei; Wang, San-zhong; Liu, Li-gang

    2017-07-01

    According to the geometric pass of roll and technological parameters of three-roller continuous mandrel rolling mill in a factory, a finite element model is established to simulate the continuous rolling process of seamless steel tube, and the reliability of finite element model is verified by comparing with the simulation results and actual results of rolling force, wall thickness and outer diameter of the tube. The effect of roller reduction, roller rotation speed and blooming temperature on the spread rule is studied. Based on BP(Back Propagation) neural network technology, a spread prediction model of continuous rolling tube is established for training wall thickness coefficient and spread coefficient of the continuous rolling tube, and the rapid and accurate prediction of continuous rolling tube size is realized.

  10. On the Spreading of Partially Miscible Liquids.

    Science.gov (United States)

    Santiago-Rosanne, Maria; Vignes-Adler, Michèle; Velarde, Manuel G.

    2001-02-15

    As time proceeds, partially miscible liquids spread as a cap surrounded by a primary film according to power laws, t(n), for both the leading edge (front) and the central cap. The corresponding exponents depend on the thickness, H, of the liquid aqueous substrate and the deviation of concentration from its saturation value, DeltaC=C-C(sat). As long as H is thick enough, here H>/=5 mm, the exponents are n=1/2 and n=1/3 for the front and the central cap, respectively. For thinner layers, H approximately 2 mm, and moderate DeltaC, the spreading is drastically hindered and the measured values can go down to n=0.1, due to the additional friction imposed by the confinement of the convective cells generated by dissolution below the primary film which anchor on the solid surface beneath the liquid substrate. Copyright 2001 Academic Press.

  11. Epidemic spreading on weighted complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Ye [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China); Liu, Chuang, E-mail: liuchuang@hznu.edu.cn [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China); Zhang, Chu-Xu [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China); Zhang, Zi-Ke, E-mail: zhangzike@gmail.com [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China)

    2014-01-31

    Nowadays, the emergence of online services provides various multi-relation information to support the comprehensive understanding of the epidemic spreading process. In this Letter, we consider the edge weights to represent such multi-role relations. In addition, we perform detailed analysis of two representative metrics, outbreak threshold and epidemic prevalence, on SIS and SIR models. Both theoretical and simulation results find good agreements with each other. Furthermore, experiments show that, on fully mixed networks, the weight distribution on edges would not affect the epidemic results once the average weight of whole network is fixed. This work may shed some light on the in-depth understanding of epidemic spreading on multi-relation and weighted networks.

  12. Connectivity disruption sparks explosive epidemic spreading

    CERN Document Server

    Böttcher, L; Goles, E; Helbing, D; Herrmann, H J

    2016-01-01

    We investigate the spread of an infection or other malfunction of cascading nature when a system component can recover only if it remains reachable from a functioning central component. We consider the susceptible-infected-susceptible model, typical of mathematical epidemiology, on a network. Infection spreads from infected to healthy nodes, with the addition that infected nodes can only recover when they remain connected to a predefined central node, through a path that contains only healthy nodes. In this system, clusters of infected nodes will absorb their noninfected interior because no path exists between the central node and encapsulated nodes. This gives rise to the simultaneous infection of multiple nodes. Interestingly, the system converges to only one of two stationary states: either the whole population is healthy or it becomes completely infected. This simultaneous cluster infection can give rise to discontinuous jumps of different sizes in the number of failed nodes. Larger jumps emerge at lower ...

  13. 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.

  14. Quasirandom Rumor Spreading: An Experimental Analysis

    OpenAIRE

    Doerr, Benjamin; Friedrich, Tobias; Künnemann, Marvin; Sauerwald, Thomas

    2010-01-01

    We empirically analyze two versions of the well-known "randomized rumor spreading" protocol to disseminate a piece of information in networks. In the classical model, in each round each informed node informs a random neighbor. In the recently proposed quasirandom variant, each node has a (cyclic) list of its neighbors. Once informed, it starts at a random position of the list, but from then on informs its neighbors in the order of the list. While for sparse random graphs a better performance ...

  15. Lognormal infection times of online information spread.

    Directory of Open Access Journals (Sweden)

    Christian Doerr

    Full Text Available The infection times of individuals in online information spread such as the inter-arrival time of Twitter messages or the propagation time of news stories on a social media site can be explained through a convolution of lognormally distributed observation and reaction times of the individual participants. Experimental measurements support the lognormal shape of the individual contributing processes, and have resemblance to previously reported lognormal distributions of human behavior and contagious processes.

  16. Lognormal infection times of online information spread.

    Science.gov (United States)

    Doerr, Christian; Blenn, Norbert; Van Mieghem, Piet

    2013-01-01

    The infection times of individuals in online information spread such as the inter-arrival time of Twitter messages or the propagation time of news stories on a social media site can be explained through a convolution of lognormally distributed observation and reaction times of the individual participants. Experimental measurements support the lognormal shape of the individual contributing processes, and have resemblance to previously reported lognormal distributions of human behavior and contagious processes.

  17. Lognormal Infection Times of Online Information Spread

    OpenAIRE

    Christian Doerr; Norbert Blenn; Piet Van Mieghem

    2013-01-01

    The infection times of individuals in online information spread such as the inter-arrival time of Twitter messages or the propagation time of news stories on a social media site can be explained through a convolution of lognormally distributed observation and reaction times of the individual participants. Experimental measurements support the lognormal shape of the individual contributing processes, and have resemblance to previously reported lognormal distributions of human behavior and cont...

  18. Prediction of fire spread following nuclear explosions

    Science.gov (United States)

    Craig C. Chandler; Theodore G. Storey; Charles D. Tangren

    1963-01-01

    Mass fires are likely to follow a nuclear attack. Since it is important to the civil defense program to be able to predict rate, duration, and extent of spread of such fires, the Office of Civil Defense, U.S. Department of Defense, issued a joint contract to the Forest Service and to United Research Services, Inc., to study this field. We surveyed the literature,...

  19. Ethnicity and the spread of civil war

    OpenAIRE

    Bosker, Maarten; de Ree, Joppe

    2010-01-01

    Civil wars critically hinder a country's development process. This paper shows that civil wars can also have severe international consequences. Anecdotal evidence highlights that civil wars sometimes spill over international boundaries. Using a more rigorous econometric approach we provide evidence that conflict spillovers are indeed quantitatively very important. Also, they are context dependent. Ethnicity in particular plays a key role in the spread of civil war. Only ethnic civil wars spil...

  20. Predictive power of air travel and socio-economic data for early pandemic spread.

    Directory of Open Access Journals (Sweden)

    Parviez Hosseini

    Full Text Available BACKGROUND: Controlling the pandemic spread of newly emerging diseases requires rapid, targeted allocation of limited resources among nations. Critical, early control steps would be greatly enhanced if the key risk factors can be identified that accurately predict early disease spread immediately after emergence. METHODOLOGY/PRINCIPAL FINDINGS: Here, we examine the role of travel, trade, and national healthcare resources in predicting the emergence and initial spread of 2009 A/H1N1 influenza. We find that incorporating national healthcare resource data into our analyses allowed a much greater capacity to predict the international spread of this virus. In countries with lower healthcare resources, the reporting of 2009 A/H1N1 cases was significantly delayed, likely reflecting a lower capacity for testing and reporting, as well as other socio-political issues. We also report substantial international trade in live swine and poultry in the decade preceding the pandemic which may have contributed to the emergence and mixed genotype of this pandemic strain. However, the lack of knowledge of recent evolution of each H1N1 viral gene segment precludes the use of this approach to determine viral origins. CONCLUSIONS/SIGNIFICANCE: We conclude that strategies to prevent pandemic influenza virus emergence and spread in the future should include: 1 enhanced surveillance for strains resulting from reassortment in traded livestock; 2 rapid deployment of control measures in the initial spreading phase to countries where travel data predict the pathogen will reach and to countries where lower healthcare resources will likely cause delays in reporting. Our results highlight the benefits, for all parties, when higher income countries provide additional healthcare resources for lower income countries, particularly those that have high air traffic volumes. In particular, international authorities should prioritize aid to those poorest countries where both the risk

  1. Branching dynamics of viral information spreading

    Science.gov (United States)

    Iribarren, José Luis; Moro, Esteban

    2011-10-01

    Despite its importance for rumors or innovations propagation, peer-to-peer collaboration, social networking, or marketing, the dynamics of information spreading is not well understood. Since the diffusion depends on the heterogeneous patterns of human behavior and is driven by the participants’ decisions, its propagation dynamics shows surprising properties not explained by traditional epidemic or contagion models. Here we present a detailed analysis of our study of real viral marketing campaigns where tracking the propagation of a controlled message allowed us to analyze the structure and dynamics of a diffusion graph involving over 31 000 individuals. We found that information spreading displays a non-Markovian branching dynamics that can be modeled by a two-step Bellman-Harris branching process that generalizes the static models known in the literature and incorporates the high variability of human behavior. It explains accurately all the features of information propagation under the “tipping point” and can be used for prediction and management of viral information spreading processes.

  2. Did ice-age bovids spread tuberculosis?

    Science.gov (United States)

    Rothschild, Bruce M.; Martin, Larry D.

    2006-11-01

    Pathognomonic metacarpal undermining is a skeletal pathology that has been associated with Mycobacterium tuberculosis in bovids. Postcranial artiodactyl, perissodactyl, and carnivore skeletons were examined in major university and museum collections of North America and Europe for evidence of this and other pathology potentially attributable to tuberculosis. Among nonproboscidean mammals from pre-Holocene North America, bone lesions indicative of tuberculosis were restricted to immigrant bovids from Eurasia. No bone lesions compatible with diagnosis of tuberculosis were found in large samples of other pre-Holocene (164 Oligocene, 397 Miocene, and 1,041 Plio Pleistocene) North American mammals, including 114 antilocaprids. Given the unchanged frequency of bovid tubercular disease during the Pleistocene, it appears that most did not die from the disease but actually reached an accommodation with it (as did the mastodon) (Rothschild and Laub 2006). Thus, they were sufficiently long-lived to assure greater spread of the disease. The relationships of the proboscidean examples need further study, but present evidence suggests a Holarctic spread of tuberculosis during the Pleistocene, with bovids acting as vectors. While the role of other animals in the transmission of tuberculosis could be considered, the unique accommodation achieved by bovids and mastodons makes them the likely “culprits” in its spread.

  3. Epidemic spreading on evolving signed networks

    Science.gov (United States)

    Saeedian, M.; Azimi-Tafreshi, N.; Jafari, G. R.; Kertesz, J.

    2017-02-01

    Most studies of disease spreading consider the underlying social network as obtained without the contagion, though epidemic influences people's willingness to contact others: A "friendly" contact may be turned to "unfriendly" to avoid infection. We study the susceptible-infected disease-spreading model on signed networks, in which each edge is associated with a positive or negative sign representing the friendly or unfriendly relation between its end nodes. In a signed network, according to Heider's theory, edge signs evolve such that finally a state of structural balance is achieved, corresponding to no frustration in physics terms. However, the danger of infection affects the evolution of its edge signs. To describe the coupled problem of the sign evolution and disease spreading, we generalize the notion of structural balance by taking into account the state of the nodes. We introduce an energy function and carry out Monte Carlo simulations on complete networks to test the energy landscape, where we find local minima corresponding to the so-called jammed states. We study the effect of the ratio of initial friendly to unfriendly connections on the propagation of disease. The steady state can be balanced or a jammed state such that a coexistence occurs between susceptible and infected nodes in the system.

  4. The effect of infected external computers on the spread of viruses: A compartment modeling study

    Science.gov (United States)

    Yang, Lu-Xing; Yang, Xiaofan

    2013-12-01

    Inevitably, there exist infected computers outside of the Internet. This paper aims to understand how infected external computers affect the spread of computer viruses. For that purpose, a new virus-antivirus spreading model, which takes into account the effect of infected/immune external computers, is established. A systematic study shows that, unlike most previous models, the proposed model admits no virus-free equilibrium and admits a globally asymptotically stable viral equilibrium. This result implies that it would be practically impossible to eradicate viruses on the Internet. As a result, inhibiting the virus prevalence to below an acceptable level would be the next best thing. A theoretical study reveals the effect of different parameters on the steady virus prevalence. On this basis, a number of suggestions are made so as to contain virus spreading.

  5. 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.

  6. Axonal and Transynaptic Spread of Prions

    Science.gov (United States)

    Shearin, Harold

    2014-01-01

    ABSTRACT Natural transmission of prion diseases depends upon the spread of prions from the nervous system to excretory or secretory tissues, but the mechanism of prion transport in axons and into peripheral tissue is unresolved. Here, we examined the temporal and spatial movement of prions from the brain stem along cranial nerves into skeletal muscle as a model of axonal transport and transynaptic spread. The disease-specific isoform of the prion protein, PrPSc, was observed in nerve fibers of the tongue approximately 2 weeks prior to PrPSc deposition in skeletal muscle. Initially, PrPSc deposits had a small punctate pattern on the edge of muscle cells that colocalized with synaptophysin, a marker for the neuromuscular junction (NMJ), in >50% of the cells. At later time points PrPSc was widely distributed in muscle cells, but PrPSc deposition at the NMJ, suggesting additional prion replication and dissemination within muscle cells. In contrast to the NMJ, PrPSc was not associated with synaptophysin in nerve fibers but was found to colocalize with LAMP-1 and cathepsin D during early stages of axonal spread. We propose that PrPSc-bound endosomes can lead to membrane recycling in which PrPSc is directed to the synapse, where it either moves across the NMJ into the postsynaptic muscle cell or induces PrPSc formation on muscle cells across the NMJ. IMPORTANCE Prion diseases are transmissible and fatal neurodegenerative diseases in which prion dissemination to excretory or secretory tissues is necessary for natural disease transmission. Despite the importance of this pathway, the cellular mechanism of prion transport in axons and into peripheral tissue is unresolved. This study demonstrates anterograde spread of prions within nerve fibers prior to infection of peripheral synapses (i.e., neuromuscular junction) and infection of peripheral tissues (i.e., muscle cells). Within nerve fibers prions were associated with the endosomal-lysosomal pathway prior to entry into

  7. Against Globalization

    DEFF Research Database (Denmark)

    Philipsen, Lotte; Baggesgaard, Mads Anders

    2013-01-01

    In order to understand globalization, we need to consider what globalization is not. That is, in order to understand the mechanisms and elements that work toward globalization, we must, in a sense, read against globalization, highlighting the limitations of the concept and its inherent conflicts...

  8. Amalgamating Oncolytic Viruses to Enhance Their Safety, Consolidate Their Killing Mechanisms, and Accelerate Their Spread

    Science.gov (United States)

    Ayala-Breton, Camilo; Suksanpaisan, Lukkana; Mader, Emily K; Russell, Stephen J; Peng, Kah-Whye

    2013-01-01

    Oncolytic viruses are structurally and biologically diverse, spreading through tumors and killing them by various mechanisms and with different kinetics. Here, we created a hybrid vesicular stomatitis/measles virus (VSV/MV) that harnesses the safety of oncolytic MV, the speed of VSV, and the tumor killing mechanisms of both viruses. Oncolytic MV targets CD46 and kills by forcing infected cells to fuse with uninfected neighbors, but propagates slowly. VSV spreads rapidly, directly lysing tumor cells, but is neurotoxic and loses oncolytic potency when neuroattenuated by conventional approaches. The hybrid VSV/MV lacks neurotoxicity, replicates rapidly with VSV kinetics, and selectively targets CD46 on tumor cells. Its in vivo performance in a myeloma xenograft model was substantially superior to either MV or widely used recombinant oncolytic VSV-M51. PMID:23842448

  9. Amalgamating oncolytic viruses to enhance their safety, consolidate their killing mechanisms, and accelerate their spread.

    Science.gov (United States)

    Ayala-Breton, Camilo; Suksanpaisan, Lukkana; Mader, Emily K; Russell, Stephen J; Peng, Kah-Whye

    2013-10-01

    Oncolytic viruses are structurally and biologically diverse, spreading through tumors and killing them by various mechanisms and with different kinetics. Here, we created a hybrid vesicular stomatitis/measles virus (VSV/MV) that harnesses the safety of oncolytic MV, the speed of VSV, and the tumor killing mechanisms of both viruses. Oncolytic MV targets CD46 and kills by forcing infected cells to fuse with uninfected neighbors, but propagates slowly. VSV spreads rapidly, directly lysing tumor cells, but is neurotoxic and loses oncolytic potency when neuroattenuated by conventional approaches. The hybrid VSV/MV lacks neurotoxicity, replicates rapidly with VSV kinetics, and selectively targets CD46 on tumor cells. Its in vivo performance in a myeloma xenograft model was substantially superior to either MV or widely used recombinant oncolytic VSV-M51.

  10. 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.

  11. 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…

  12. Shelf Life Extension of Maple pea (Pisum sativum var. arvense L. Spread Using Sous Vide

    Directory of Open Access Journals (Sweden)

    Ķirse Asnate

    2016-12-01

    Full Text Available The aim of this study was to determine the effect of sous vide packaging on the shelf life of maple pea (Pisum sativum var. arvense L. spread. Pea spreads were made of ground re-hydrated cooked maple peas ‘Bruno’ (Pisum sativum var. arvense L., to which salt, citric acid, oil, and spices were added. Pea spread was stored in polyamide/polyethylene (PA/PE film pouches, packaged in vacuum and hermetically sealed. Pea spread pouches were heat treated in a water bath, then rapidly cooled in ice-water and stored at 4.0 ± 0.5 °C. Sous vide was applied in three different heat regimens +(65.0; 80.0 and 100.0 ± 0.5 °C with cooking times 5, 10, 15, 20, 25, and 30 min at a constant temperature. Total plate count was determined according to ISO 4833-1:2014 on Plate Count Agar and Enterobacteriaceae determination was performed in accordance with ISO 21528-2:2004 on Violet Red Bile Glucose Agar. Total plate count in pea spread without thermal treatment was 3.41 log10 CFU g−1, in all sous vide packaged pea spread samples microbial contamination was significantly lower (p < 0.05. Enterobacteriaceae were not detected in any samples. It is possible to extend the shelf life of sous vide maple pea spread up to 14 weeks when stored at 4.0 ± 0.5 °C.

  13. Neurotoxicity of the Cyanotoxin BMAA Through Axonal Degeneration and Intercellular Spreading.

    Science.gov (United States)

    Tan, Vanessa X; Lassus, Benjamin; Lim, Chai K; Tixador, Philippe; Courte, Josquin; Bessede, Alban; Guillemin, Gilles J; Peyrin, Jean-Michel

    2018-01-01

    β-Methylamino-L-alanine (BMAA) is implicated in neurodegeneration and neurotoxicity, particularly in ALS-Parkinson Dementia Complex. Neurotoxic properties of BMAA have been partly elucidated, while its transcellular spreading capacity has not been examined. Using reconstructed neuronal networks in microfluidic chips, separating neuronal cells into two subcompartments-(1) the proximal, containing first-order neuronal soma and dendrites, and (2) a distal compartment, containing either only axons originating from first-order neurons or second-order striatal neurons-creates a cortico-striatal network. Using this system, we investigated the toxicity and spreading of BMAA in murine primary neurons. We used a newly developed antibody to detect BMAA in cells. After treatment with 10 μM BMAA, the cyanotoxin was incorporated in first-degree neurons. We also observed a rapid trans-neuronal spread of BMAA to unexposed second-degree neurons in 48 h, followed by axonal degeneration, with limited somatic death. This in vitro study demonstrates BMAA axonal toxicity at sublethal concentrations and, for the first time, the transcellular spreading abilities of BMAA. This neuronal dying forward spread that could possibly be associated with progression of some neurodegenerative diseases especially amyotrophic lateral sclerosis.

  14. Diffusion of global sustainability standards

    OpenAIRE

    Schouten, Greetje; Vellema, Sietze; Wijk, van, C.A.P.

    2016-01-01

    The past two decades saw a rapid proliferation of sustainability standards created by multi-stakeholder partnerships of multinationals and international NGOs. This paper argues that the transformative capacity of these global partnerships to bring about sustainable change largely depends on how well the institutional features of global sustainability standards fit local organizational fields. This paper therefore aims to unravel the dynamics of global-local interactions. To this end, the conc...

  15. 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.

  16. Consequences of Rift Propagation for Spreading in Thick Oceanic Crust in Iceland

    Science.gov (United States)

    Karson, J. A.

    2015-12-01

    Iceland has long been considered a natural laboratory for processes related to seafloor spreading, including propagating rifts, migrating transforms and rotating microplates. The thick, hot, weak crust and subaerial processes of Iceland result in variations on the themes developed along more typical parts of the global MOR system. Compared to most other parts of the MOR, Icelandic rift zones and transform faults are wider and more complex. Rift zones are defined by overlapping arrays of volcanic/tectonic spreading segments as much as 50 km wide. The most active rift zones propagate N and S away from the Iceland hot spot causing migration of transform faults. A trail of crust deformed by bookshelf faulting forms in their wakes. Dead or dying transform strands are truncated along pseudofaults that define propagation rates close to the full spreading rate of ~20 mm/yr. Pseudofaults are blurred by spreading across wide rift zones and laterally extensive subaerial lava flows. Propagation, with decreasing spreading toward the propagator tips causes rotation of crustal blocks on both sides of the active rift zones. The blocks deform internally by the widespread reactivation of spreading-related faults and zones of weakness along dike margins. The sense of slip on these rift-parallel strike-slip faults is inconsistent with transform-fault deformation. These various deformation features as well as subaxial subsidence that accommodate the thickening of the volcanic upper crustal units are probably confined to the brittle, seismogenic, upper 10 km of the crust. At least beneath the active rift zones, the upper crust is probably decoupled from hot, mechanically weak middle and lower gabbroic crust resulting in a broad plate boundary zone between the diverging lithosphere plates. Similar processes may occur at other types of propagating spreading centers and magmatic rifts.

  17. Bridging the health security divide: department of defense support for the global health security agenda.

    Science.gov (United States)

    Moudy, Robin M; Ingerson-Mahar, Michael; Kanter, Jordan; Grant, Ashley M; Fisher, Dara R; Jones, Franca R

    2014-01-01

    In 2011, President Obama addressed the United Nations General Assembly and urged the global community to come together to prevent, detect, and fight every kind of biological danger, whether a pandemic, terrorist threat, or treatable disease. Over the past decade, the United States and key international partners have addressed these dangers through a variety of programs and strategies aimed at developing and enhancing countries' capacity to rapidly detect, assess, report, and respond to acute biological threats. Despite our collective efforts, however, an increasingly interconnected world presents heightened opportunities for human, animal, and zoonotic diseases to emerge and spread globally. Further, the technical capabilities required to develop biological agents into a weapon are relatively low. The launch of the Global Health Security Agenda (GHSA) provides an opportunity for the international community to enhance the linkages between the health and security sectors, accelerating global efforts to prevent avoidable epidemics and bioterrorism, detect threats early, and respond rapidly and effectively to biological threats. The US Department of Defense (DoD) plays a key role in achieving GHSA objectives through its force health protection, threat reduction, and biodefense efforts at home and abroad. This article focuses on GHSA activities conducted in the DoD Office of the Assistant Secretary of Defense for Nuclear, Chemical, and Biological Defense.

  18. Collaboration in Pennsylvania: Rapidly Spreading Improved Chronic Care for Patients to Practices

    Science.gov (United States)

    Bricker, Patricia L.; Baron, Richard J.; Scheirer, Jorge J.; DeWalt, Darren A.; Derrickson, John; Yunghans, Suzanne; Gabbay, Robert A.

    2010-01-01

    Introduction: Pennsylvania's Improving Performance in Practice (IPIP) program is administered by the Pennsylvania (PA) chapters of the American Academy of Family Physicians, American College of Physicians, and American Academy of Pediatrics. The project has provided coaching, monthly measurement, and patient registry support for 155 primary-care…

  19. Spreading and Deposit Characteristics of a Rapid Dry Granular Avalanche Across 3D Topography: Experimental Study

    Science.gov (United States)

    Wang, Yu-Feng; Xu, Qiang; Cheng, Qian-Gong; Li, Yan; Luo, Zhong-Xu

    2016-11-01

    Aiming to understand the propagation and deposit behaviours of a granular avalanche along a 3D complex basal terrain, a new 3D experimental platform in 1/400 scale was developed according to the natural terrain of the Xiejiadianzi rock avalanche, with a series of laboratory experiments being conducted. Through the conduction of these tests, parameters, including the morphological evolution of sliding mass, run-outs and velocities of surficial particles, thickness contour and centre of final deposit, equivalent frictional coefficient, and energy dissipation, are documented and analysed, with the geomorphic control effect, material grain size effect, drop angle effect, and drop distance effect on rock avalanche mobility being discussed primarily. From the study, some interesting conclusions for a better understanding of rock avalanche along a 3D complex basal topography are reached. (1) For the granular avalanche tested in this study, great differences between the evolutions of the debris along the right and left branch valleys were observed, with an obvious geomorphic control effect on avalanche mobility presented. In addition, some other interesting features, including groove-like trough and superelevation, were also observed under the control of the topographic interferences. (2) The equivalent frictional coefficients of the granular avalanches tested here range from 0.48 to 0.57, which is lower than that reached with a set-up composed of an inclined chute and horizontal plate and higher than that reached using a set-up composed of only an inclined chute. And the higher the drop angle and fine particle content, the higher the equivalent frictional coefficient. The effect of drop distance on avalanche mobility is minor. (3) For a granular avalanche, momentum transfer plays an important role in the motion of mass, which can accelerate the mobility of the front part greatly through delivering the kinetic energy of the rear part to the front.

  20. 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.

  1. 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.

  2. A novel quantitative volumetric spreading index definition and assessment of astrocyte spreading in vitro.

    Science.gov (United States)

    Tiryaki, Volkan Müjdat; Ayres, Virginia M; Ahmed, Ijaz; Shreiber, David I

    2017-08-01

    A novel quantitative volumetric spreading index (VSI) is defined that depends on the total distance between object voxels and the contact surface plane in three-dimensional (3D) space. The VSI, which ranges from 0 to 1, is rotationally invariant around the z-axis. VSI can be used to quantify the degree of individual cell spreading, which is important for analysis of cell interactions with their environment. The VSIs of astrocytes cultured on a nanofibrillar surface and three different comparative planar surfaces have been calculated from confocal laser scanning microscope z-series images, and the effects of both culture surface and immunoreactivity on the degree of cell spreading were investigated. VSI calculations indicated a statistical correlation between increased reactivity, based on immunolabeling for glial fibrillary acidic protein, and decreased cell spreading. Further results provided a quantitative measure for the increased spreading of quiescent-like and reactive-like astrocytes on planar substrates functionalized with poly-l-lysine. © 2017 International Society for Advancement of Cytometry. © 2017 International Society for Advancement of Cytometry.

  3. 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.

  4. Predictive Validation of an Influenza Spread Model

    Science.gov (United States)

    Hyder, Ayaz; Buckeridge, David L.; Leung, Brian

    2013-01-01

    Background Modeling plays a critical role in mitigating impacts of seasonal influenza epidemics. Complex simulation models are currently at the forefront of evaluating optimal mitigation strategies at multiple scales and levels of organization. Given their evaluative role, these models remain limited in their ability to predict and forecast future epidemics leading some researchers and public-health practitioners to question their usefulness. The objective of this study is to evaluate the predictive ability of an existing complex simulation model of influenza spread. Methods and Findings We used extensive data on past epidemics to demonstrate the process of predictive validation. This involved generalizing an individual-based model for influenza spread and fitting it to laboratory-confirmed influenza infection data from a single observed epidemic (1998–1999). Next, we used the fitted model and modified two of its parameters based on data on real-world perturbations (vaccination coverage by age group and strain type). Simulating epidemics under these changes allowed us to estimate the deviation/error between the expected epidemic curve under perturbation and observed epidemics taking place from 1999 to 2006. Our model was able to forecast absolute intensity and epidemic peak week several weeks earlier with reasonable reliability and depended on the method of forecasting-static or dynamic. Conclusions Good predictive ability of influenza epidemics is critical for implementing mitigation strategies in an effective and timely manner. Through the process of predictive validation applied to a current complex simulation model of influenza spread, we provided users of the model (e.g. public-health officials and policy-makers) with quantitative metrics and practical recommendations on mitigating impacts of seasonal influenza epidemics. This methodology may be applied to other models of communicable infectious diseases to test and potentially improve their predictive

  5. Vectorised Spreading Activation algorithm for centrality measurement

    Directory of Open Access Journals (Sweden)

    Alexander Troussov

    2011-01-01

    Full Text Available Spreading Activation is a family of graph-based algorithms widely used in areas such as information retrieval, epidemic models, and recommender systems. In this paper we introduce a novel Spreading Activation (SA method that we call Vectorised Spreading Activation (VSA. VSA algorithms, like “traditional” SA algorithms, iteratively propagate the activation from the initially activated set of nodes to the other nodes in a network through outward links. The level of the node’s activation could be used as a centrality measurement in accordance with dynamic model-based view of centrality that focuses on the outcomes for nodes in a network where something is flowing from node to node across the edges. Representing the activation by vectors allows the use of the information about various dimensionalities of the flow and the dynamic of the flow. In this capacity, VSA algorithms can model multitude of complex multidimensional network flows. We present the results of numerical simulations on small synthetic social networks and multi­dimensional network models of folksonomies which show that the results of VSA propagation are more sensitive to the positions of the initial seed and to the community structure of the network than the results produced by traditional SA algorithms. We tentatively conclude that the VSA methods could be instrumental to develop scalable and computationally efficient algorithms which could achieve synergy between computation of centrality indexes with detection of community structures in networks. Based on our preliminary results and on improvements made over previous studies, we foresee advances and applications in the current state of the art of this family of algorithms and their applications to centrality measurement.

  6. Reduce proton energy spread by target ablation

    CERN Document Server

    Zhao, Shuan; Chen, Jiaer; Yan, Xueqing

    2015-01-01

    It's shown that, with strong target ablation monoenergetic protons along the laser direction is available during the laser aluminum foil interaction, which is different from the classic TNSA theory. When the laser pre-pulse is too strong that the whole target is vaporized, the energetic electrons generated in the gas preplasma will play an important role for the ion acceleration because the sheath field will not be available. These electrons beam, which is highly directional, will setup triangle envelope acceleration field along the laser direction at the target rear, reducing the ion energy spread.

  7. Epidemic spreading with immunization on bipartite networks

    CERN Document Server

    Tanimoto, Shinji

    2011-01-01

    Bipartite networks are composed of two types of nodes and there are no links between nodes of the same type. Thus the study of epidemic spread and control on such networks is relevant to sexually transmitted diseases (STDs). When entire populations of two types cannot be immunized and the effect of immunization is not perfect, we have to consider the targeted immunization with immunization rates. We derive the epidemic thresholds of SIR and SIS models with immunization and illustrate the results with STDs on heterosexual contact networks.

  8. Preventing the spread of HIV infection.

    Science.gov (United States)

    Perry, Nicky

    Approximately 96,000 people are living with HIV in the UK, a quarter of whom are unaware they are infected. While in some parts of the world the number of people newly infected with HIV has fallen, in the UK in 2011 there was a rise in the number of men who have sex with men being diagnosed. HIV prevention strategies are a public health priority, while ongoing research into HIV testing in all clinical settings remains a priority. This article explores preventive measures that can be used to reduce the spread of HIV and offers advice on how nurses can contribute to these.

  9. Experiments on non-isothermal spreading

    Energy Technology Data Exchange (ETDEWEB)

    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.). [Deutsch] Es werden Experimente zur Ausbreitung achsensymmetrischer, viskoser Fluessigkeitstropfen auf Glas vorgestellt. Zwei Fluessigkeiten werden betrachtet: Fuer Silikonoeltropfen (M-100) beobachten wir eine unbeschraenkte Ausbreitung, waehrend sich Paraffinoeltropfen gegen eine stationaere Endkontur entwickeln. Die Silikonoelexperimente bestaetigen teilweise die Ergebnisse frueherer Experimentatoren, die Paraffinoelexperimente liefern gaenzlich neue Daten. Wir finden, dass die Schwerkraft fuer lange Zeiten den Ausbreitungsprozess kontrolliert. Fuer kurze Zeiten spielen dagegen Kapillaritaetskraefte eine wichtigere Rolle. Wird die Glasplatte gegenueber der Umgebung zusaetzlich erwaermt oder gekuehlt, so treiben thermokapillare Kraefte eine Stroemung innerhalb des Tropfens. Die Dynamik der Ausbreitung wird dadurch massgeblich geaendert. Eine Erwaermung (Kuehlung) fuehrt zu einer

  10. The global transmission and control of influenza.

    Directory of Open Access Journals (Sweden)

    Eben Kenah

    2011-05-01

    Full Text Available New strains of influenza spread around the globe via the movement of infected individuals. The global dynamics of influenza are complicated by different patterns of influenza seasonality in different regions of the world. We have released an open-source stochastic mathematical model of the spread of influenza across 321 major, strategically located cities of the world. Influenza is transmitted between cities via infected airline passengers. Seasonality is simulated by increasing the transmissibility in each city at the times of the year when influenza has been observed to be most prevalent. The spatiotemporal spread of pandemic influenza can be understood through clusters of global transmission and links between them, which we identify using the epidemic percolation network (EPN of the model. We use the model to explain the observed global pattern of spread for pandemic influenza A(H1N1 2009-2010 (pandemic H1N1 2009 and to examine possible global patterns of spread for future pandemics depending on the origin of pandemic spread, time of year of emergence, and basic reproductive number (. We also use the model to investigate the effectiveness of a plausible global distribution of vaccine for various pandemic scenarios. For pandemic H1N1 2009, we show that the biggest impact of vaccination was in the temperate northern hemisphere. For pandemics starting in the temperate northern hemisphere in May or April, vaccination would have little effect in the temperate southern hemisphere and a small effect in the tropics. With the increasing interconnectedness of the world's population, we must take a global view of infectious disease transmission. Our open-source, computationally simple model can help public health officials plan for the next pandemic as well as deal with interpandemic influenza.

  11. Recording, analysis, and interpretation of spreading depolarizations in neurointensive care

    DEFF Research Database (Denmark)

    Dreier, Jens P; Fabricius, Martin; Ayata, Cenk

    2017-01-01

    Spreading depolarizations (SD) are waves of abrupt, near-complete breakdown of neuronal transmembrane ion gradients, are the largest possible pathophysiologic disruption of viable cerebral gray matter, and are a crucial mechanism of lesion development. Spreading depolarizations are increasingly r...

  12. Help Control Mosquitoes that Spread Dengue, Chikungunya, and Zika Viruses

    Science.gov (United States)

    Help Control Mosquitoes that Spread Dengue, Chikungunya, and Zika Viruses B Z Z Z Z . Aside from being ... or Aedes albopictus ) can spread dengue, chikungunya, or Zika viruses. People become infected with dengue, chikungunya, or Zika ...

  13. 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...

  14. Global Strategy

    DEFF Research Database (Denmark)

    Li, Peter Ping

    2013-01-01

    Global strategy differs from domestic strategy in terms of content and process as well as context and structure. The content of global strategy can contain five key elements, while the process of global strategy can have six major stages. These are expounded below. Global strategy is influenced...... by rich and complementary local contexts with diverse resource pools and game rules at the national level to form a broad ecosystem at the global level. Further, global strategy dictates the interaction or balance between different entry strategies at the levels of internal and external networks....

  15. 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; Dortet, Laurent; Bernabeu, Sandrine; Simon, Stéphanie; Volland, Hervé

    2017-07-01

    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 . Copyright © 2017 Boutal et al.

  16. 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

  17. 21 CFR 133.175 - Pasteurized cheese spread.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Pasteurized cheese spread. 133.175 Section 133.175... FOR HUMAN CONSUMPTION CHEESES AND RELATED CHEESE PRODUCTS Requirements for Specific Standardized Cheese and Related Products § 133.175 Pasteurized cheese spread. Pasteurized cheese spread is the food...

  18. 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...

  19. Experiences Spreading Organic Solid Wastes on Forest Land

    Science.gov (United States)

    J.H. Wilhoit; L.J. Samuelson

    1998-01-01

    This paper reviews experiences spreading organic solid wastes on forest land over the past six years. Presented are some of the first-ever reported results on tree growth responses from fertilizing pine trees with poultry litter, spreader distribution pattern results for spreading in a pine plantation stand, and a discussion of equipment-related experiences spreading...

  20. Cumulative effects in Xitsonga: High-tone spreading and depressor ...

    African Journals Online (AJOL)

    Depressor consonants in Xitsonga block high-tone spreading. These voiced obstruents and breathy voice consonants do phonetically lower pitch, but phonological blocking of H-tone spreading is not common. This paper reports new findings in which depressors allow H tone to spread into toneless words in Xitsonga, ...

  1. A lattice model for influenza spreading.

    Directory of Open Access Journals (Sweden)

    Antonella Liccardo

    Full Text Available We construct a stochastic SIR model for influenza spreading on a D-dimensional lattice, which represents the dynamic contact network of individuals. An age distributed population is placed on the lattice and moves on it. The displacement from a site to a nearest neighbor empty site, allows individuals to change the number and identities of their contacts. The dynamics on the lattice is governed by an attractive interaction between individuals belonging to the same age-class. The parameters, which regulate the pattern dynamics, are fixed fitting the data on the age-dependent daily contact numbers, furnished by the Polymod survey. A simple SIR transmission model with a nearest neighbors interaction and some very basic adaptive mobility restrictions complete the model. The model is validated against the age-distributed Italian epidemiological data for the influenza A(H1N1 during the [Formula: see text] season, with sensible predictions for the epidemiological parameters. For an appropriate topology of the lattice, we find that, whenever the accordance between the contact patterns of the model and the Polymod data is satisfactory, there is a good agreement between the numerical and the experimental epidemiological data. This result shows how rich is the information encoded in the average contact patterns of individuals, with respect to the analysis of the epidemic spreading of an infectious disease.

  2. SIS Epidemic Spreading with Heterogeneous Infection Rates

    CERN Document Server

    Qu, Bo

    2015-01-01

    In this work, we aim to understand the influence of the heterogeneity of infection rates on the Susceptible-Infected-Susceptible (SIS) epidemic spreading. Specifically, we keep the recovery rates the same for all nodes and study the influence of the moments of the independently identically distributed (i.i.d.) infection rates on the average fraction $y_\\infty$ of infected nodes in the meta-stable state, which indicates the severity of the overall infection. Motivated by real-world datasets, we consider the log-normal and gamma distributions for the infection rates and we design as well a symmetric distribution so that we have a systematic view of the influence of various distributions. By continuous-time simulations on several types of networks, theoretical proofs and physical interpretations, we conclude that: 1) the heterogeneity of infection rates on average retards the virus spread, and 2) a larger even-order moment of the infection rates leads to a smaller average fraction of infected nodes, but the odd-...

  3. Principles of spread-spectrum communication systems

    CERN Document Server

    Torrieri, Don

    2015-01-01

    This book provides a concise but lucid explanation of the fundamentals of spread-spectrum systems with an emphasis on theoretical principles. The choice of specific topics is tempered by the author’s judgment of their practical significance and interest to both researchers and system designers. The book contains many improved derivations of the classical theory and presents the latest research results that bring the reader to the frontier of the field. This third edition includes new coverage of topics such as CDMA networks, acquisition and synchronization in DS-CDMA cellular networks, hopsets for FH-CDMA ad hoc networks, implications of information theory, the central limit theorem, the power spectral density of FH/CPM complex envelopes, adaptive filters, and adaptive arrays.   ·         Focuses on the fundamentals of spread-spectrum communication systems and provides current examples of their applications ·         Includes problem sets at the end of each chapter to assist readers in co...

  4. Spread F – an old equatorial aeronomy problem finally resolved?

    Directory of Open Access Journals (Sweden)

    R. F. Woodman

    2009-05-01

    Full Text Available One of the oldest scientific topics in Equatorial Aeronomy is related to Spread-F. It includes all our efforts to understand the physical mechanisms responsible for the existence of ionospheric F-region irregularities, the spread of the traces in a night-time equatorial ionogram – hence its name – and all other manifestations of the same. It was observed for the first time as an abnormal ionogram in Huancayo, about 70 years ago. But only recently are we coming to understand the physical mechanisms responsible for its occurrence and its capricious day to day variability. Several additional techniques have been used to reveal the spatial and temporal characteristics of the F-region irregularities responsible for the phenomenon. Among them we have, in chronological order, radio star scintillations, trans-equatorial radio propagation, satellite scintillations, radar backscatter, satellite and rocket in situ measurements, airglow, total electron content techniques using the propagation of satellite radio signals and, recently, radar imaging techniques. Theoretical efforts are as old as the observations. Nevertheless, 32 years after their discovery, Jicamarca radar observations showed that none of the theories that had been put forward could explain them completely. The observations showed that irregularities were detected at altitudes that were stable according to the mechanisms proposed. A breakthrough came a few years later, again from Jicamarca, by showing that some of the "stable" regions had become unstable by the non-linear propagation of the irregularities from the unstable to the stable region of the ionosphere in the form of bubbles of low density plasma. A problem remained, however; the primary instability mechanism proposed, an extended (generalized Rayleigh-Taylor instability, was too slow to explain the rapid development seen by the observations. Gravity waves in the neutral background have been proposed as a seeding mechanism to

  5. Globalization & technology

    DEFF Research Database (Denmark)

    Narula, Rajneesh

    Technology and globalization are interdependent processes. Globalization has a fundamental influence on the creation and diffusion of technology, which, in turn, affects the interdependence of firms and locations. This volume examines the international aspect of this interdependence at two levels...

  6. PEMANASAN GLOBAL

    Directory of Open Access Journals (Sweden)

    Vivi Triana

    2008-03-01

    Full Text Available Pemanasan global (global warming pada dasarnya merupakan fenomena peningkatan temperature global dari tahun ke tahun karena terjadinya efek rumah kaca (greenhouse effect yang disebabkan oleh meningkatnya emisi gas-gas seperti karbondioksida (CO2, metana (CH4, dinitrooksida (N2O dan CFC sehingga energy matahari terperangkap dalam atmosfer bumi. Berbagai literatur menunjukkan kenaikan temperatur global termasuk Indonesia yang terjadi pada kisaran 1,5 – 40 °C pada akhir abad 21.

  7. Effects of awareness diffusion and self-initiated awareness behavior on epidemic spreading - an approach based on multiplex networks

    CERN Document Server

    Kan, Jia-Qian

    2015-01-01

    In this paper, we study the interplay between the epidemic spreading and the diffusion of awareness in multiplex networks. In the model, an infectious disease can spread in one network representing the paths of epidemic spreading (contact network), leading to the diffusion of awareness in the other network (information network), and then the diffusion of awareness will cause individuals to take social distances, which in turn affects the epidemic spreading. As for the diffusion of awareness, we assume that, on the one hand, individuals can be informed by other aware neighbors in information network, on the other hand, the susceptible individuals can be self-awareness induced by the infected neighbors in the contact networks (local information) or mass media (global information). Through Markov chain approach and numerical computations, we find that the density of infected individuals and the epidemic threshold can be affected by the structures of the two networks and the effective transmission rate of the awa...

  8. Health promotion in globalization

    Directory of Open Access Journals (Sweden)

    Álvaro Franco-Giraldo

    2012-10-01

    Full Text Available Objective: to unravel some theoretical and factual elements required to implement more effective health promotion strategies and practices in the field of health services whilst following the great challenges that globalization has imposed on the health systems, which are inevitably expressed in the local context (glocalization. Methodology: a narrative review taking into account the concepts of globalization and health promotion in relation to health determinants. The authors approach some courses of action and strategies for health promotion based on the social principles and universal values that guide health promotion, health service reorientation and primary healthcare, empowerment, social participation, and inter-sectoral and social mobilization. Discussion: the discussion focuses on the redirection of health promotion services in relation to the wave of health reforms that has spread throughout the world under the neoliberal rule. The author also discusses health promotion, its ineffectiveness, and the quest for renewal. Likewise, the author sets priorities for health promotion in relation to social determinants. Conclusion: the current global order, in terms of international relations, is not consistent with the ethical principles of health promotion. In this paper, the author advocates for the implementation of actions to change the social and physical life conditions of people based on changes in the use of power in society and the appropriate practice of politics in the context of globalization in order to achieve the effectiveness of the actions of health promotion.

  9. Impact Of Coral Structures On Wave Directional Spreading Across A Shallow Reef Flat - Lizard Island, Northern Great Barrier Reef

    Science.gov (United States)

    Leon, J. X.; Baldock, T.; Callaghan, D. P.; Hoegh-guldberg, O.; Mumby, P.; Phinn, S. R.; Roelfsema, C. M.; Saunders, M. I.

    2013-12-01

    Coral reef hydrodynamics operate at several and overlapping spatial-temporal scales. Waves have the most important forcing function on shallow (stress, directly mixing water (temperature and nutrients) and transporting sediments, nutrients and plankton. Reef flats are very effective at dissipating wave energy and providing an important ecosystem service by protecting highly valued shorelines. The effectiveness of reef flats to dissipate wave energy is related to the extreme hydraulic roughness of the benthos and substrate composition. Hydraulic roughness is usually obtained empirically from frictional-dissipation calculations, as detailed field measurements of bottom roughness (e.g. chain-method or profile gauges) is a very labour and time-consuming task. In this study we measured the impact of coral structures on wave directional spreading. Field data was collected during October 2012 across a reef flat on Lizard Island, northern Great Barrier Reef. Wave surface levels were measured using an array of self-logging pressure sensors. A rapid in situ close-range photogrammetric method was used to create a high-resolution (0.5 cm) image mosaic and digital elevation model. Individual coral heads were extracted from these datasets using geo-morphometric and object-based image analysis techniques. Wave propagation was modelled using a modified version of the SWAN model which includes the measured coral structures in 2m by 1m cells across the reef. The approach followed a cylinder drag approach, neglecting skin friction and inertial components. Testing against field data included bed skin friction. Our results show, for the first time, how the variability of the reef benthos structures affects wave dissipation across a shallow reef flat. This has important implications globally for coral reefs, due to the large extent of their area occupied by reef flats, particularly, as global-scale degradation in coral reef health is causing a lowering of reef carbonate production that

  10. 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.

  11. Spread of endosepsis in calimyrna fig orchards.

    Science.gov (United States)

    Michailides, T J; Morgan, D P

    1998-07-01

    ABSTRACT Pollination of the edible fig (Ficus carica cv. Calimyrna) is mediated by a small symbiotic wasp, Blastophaga psenes, that inhabits the syconium cavity of the spring crop of fig pollinator trees (caprifigs). These fig wasps also carry propagules, mainly of Fusarium verticillioides (formerly F. moniliforme) and other Fusarium spp., which cause endosepsis, from pollinator figs to the edible Calimyrna figs in California. Spread of endosepsis was studied in one experimental and up to four commercial Calimyrna fig orchards from 1989 through 1995. The incidence of endosepsis in fruit collected from the tree canopy at either 2.0 m (high) height, from the north and south of the tree canopy, and from the outer (direct sunlight) and inner (shaded) canopy were similar. More wasps were captured in fig trees located 3.5 to 10 m east or west of the source than in trees 48 to 63 m from the source. In addition, significantly more wasps entered the syconia of trees closest (9 to 12.7 m) to the source than the syconia of the second or third trees (18 to 38.2 m) from the source. Endosepsis decreased with distance from the source, decreasing faster to the south than in other directions from the source. In addition, the disease-vectoring wasps decreased with increased distance from the source, which also described the disease spread from the contamination source for most directions, with a sharper decline south of the source. A 3-year study in three commercial Calimyrna orchards showed there is no secondary spread of fig endosepsis in the field. Although endosepsis can complete as many cycles (three to four) as its vector in fig pollinator trees, in Calimyrna figs it is considered a monocyclic disease. Because fig wasp pollinators prefer to stay close to the contamination source when receptive Calimyrna figs are available in close proximity, only disease sources (caprifigs trees) found among Calimyrna trees or at a distance less than 50 m from the borders of Calimyrna orchards

  12. Hydroclimatological And Anthropogenic Drivers For Cholera Spreading

    Science.gov (United States)

    Righetto, Lorenzo; Bertuzzo, Enrico; Mari, Lorenzo; Casagrandi, Renato; Gatto, Marino; Rinaldo, Andrea

    2010-05-01

    The nature of waterborne diseases, among which cholera has a prominent importance, calls for a better understanding of the link between epidemic spreading, water and climate. To this end, we have developed a framework which involves a network-based description of a river system, connected with local communities which act as nodes of the network. This has allowed us to produce consistent simulations of real case studies. More recent investigations comprise the evaluation of the spreading velocity of an epidemic wave by means of a reaction-diffusion modeling approach. In particular, we have found that both transport processes and epidemiological quantities, such as the basic reproduction number, have a crucial effect in controlling the spreading of the epidemics. We first developed a description of bacterial movement along the network driven by advection and diffusion; afterward, we have included the movement of human populations. This latter model allowed us to establish the conditions that can trigger epidemic waves that start from the coastal region, where bacteria are autochthonous, and travel inland. In particular, our findings suggest that even relatively low values of human diffusion can have the epidemic propagate upstream. The interaction between climate, hydrology and epidemic events is still much debated, since no clear correlation between climatologic and epidemiological phenomena has emerged so far. However, a spatial assessment of hydrological and epidemiological mechanisms could be crucial to understand the evolution of cholera outbreaks. In particular, a hotly debated topic is the understanding of the mechanisms that can generate patterns of cholera incidence that exhibit an intra-annual double peak, as frequently observed in endemic region such as Bangladesh. One of the possible explanations proposed in the literature is that spring droughts cause bacteria concentration in water to rise dramatically, triggering the first peak. On the other hand

  13. Receiver design for spread-spectrum communications with a small spread in underwater clustered multipath channels.

    Science.gov (United States)

    Kuai, Xiaoyan; Zhou, Shengli; Wang, Zhaohui; Cheng, En

    2017-03-01

    This paper studies a direct-sequence spread-spectrum communication system with a small spreading factor (e.g., a single digit) in underwater acoustic multipath channels. Exploiting the channel characteristics that the propagation paths can be grouped into distinct clusters, a receiver with a set of parallel branches is proposed, where per-survivor processing (PSP) is applied on each branch to deal with the signal from one cluster while explicitly treating the signals from other clusters as structured interference. As such, it overcomes a major limitation of an existing PSP based receiver [Zhou, Morozov, and Preisig, J. Acoust. Soc. Am. 133, 2746-2754 (2013)], avoiding exponential complexity increase when the spreading factor decreases. On the first branch, joint channel estimation and interference cancellation are performed based solely on the survivor paths. On the other branches, joint channel estimation and interference cancellation are carried out based on the survivor paths and the tentatively decoded data. The bit log-likelihood ratios from different branches are combined for channel decoding. Performance results based on simulations and collected data sets validate the superior performance of the proposed receiver over the conventional RAKE receiver, which is effective only when the spreading factor is large.

  14. 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.

  15. Small RNAs and the competing endogenous RNA network in high grade serous ovarian cancer tumor spread.

    Science.gov (United States)

    Bachmayr-Heyda, Anna; Auer, Katharina; Sukhbaatar, Nyamdelger; Aust, Stefanie; Deycmar, Simon; Reiner, Agnes T; Polterauer, Stephan; Dekan, Sabine; Pils, Dietmar

    2016-06-28

    High grade serous ovarian cancer (HGSOC) is among the most deadly malignancies in women, frequently involving peritoneal tumor spread. Understanding molecular mechanisms of peritoneal metastasis is essential to develop urgently needed targeted therapies. We described two peritoneal tumor spread types in HGSOC apparent during surgery: miliary (numerous millet-sized implants) and non-miliary (few big, bulky implants). The former one is defined by a more epithelial-like tumor cell characteristic with less immune cell reactivity and with significant worse prognosis, even if corrected for typical clinicopathologic factors.23 HGSOC patients were enrolled in this study. Isolated tumor cells from fresh tumor tissues of ovarian and peritoneal origin and from ascites were used for ribosomal RNA depleted RNA and small RNA sequencing. RT-qPCR was used to validate results and an independent cohort of 32 patients to validate the impact on survival. Large and small RNA sequencing data were integrated and a new gene-miRNA set analysis method was developed.Thousands of new small RNAs (miRNAs and piwi-interacting RNAs) were predicted and a 13 small RNA signature was developed to predict spread type from formalin-fixed paraffin-embedded tissues. Furthermore, integrative analyses of RNA sequencing and small RNA sequencing data revealed a global upregulation of the competing endogenous RNA network in tumor tissues of non-miliary compared to miliary spread, i.e. higher expression of circular RNAs and long non-coding RNAs compared to coding RNAs but unchanged abundance of small RNAs. This global deregulated expression pattern could be co-responsible for the spread characteristic, miliary or non-miliary, in ovarian cancer.

  16. 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.

  17. Global usability

    CERN Document Server

    Douglas, Ian

    2011-01-01

    The concept of usability has become an increasingly important consideration in the design of all kinds of technology. As more products are aimed at global markets and developed through internationally distributed teams, usability design needs to be addressed in global terms. Interest in usability as a design issue and specialist area of research and education has developed steadily in North America and Europe since the 1980's. However, it is only over the last ten years that it has emerged as a global concern. Global Usability provides an introduction to the important issues in globalizing des

  18. Ligand-Mediated Friction Determines Morphodynamics of Spreading T Cells

    Science.gov (United States)

    Dillard, Pierre; Varma, Rajat; Sengupta, Kheya; Limozin, Laurent

    2014-01-01

    Spreading of T cells on antigen presenting cells is a crucial initial step in immune response. Spreading occurs through rapid morphological changes concomitant with the reorganization of surface receptors and of the cytoskeleton. Ligand mobility and frictional coupling of receptors to the cytoskeleton were separately recognized as important factors but a systematic study to explore their biophysical role in spreading was hitherto missing. To explore the impact of ligand mobility, we prepared chemically identical substrates on which molecules of anti-CD3 (capable of binding and activating the T cell receptor complex), were either immobilized or able to diffuse. We quantified the T cell spreading area and cell edge dynamics using quantitative reflection interference contrast microscopy, and imaged the actin distribution. On mobile ligands, as compared to fixed ligands, the cells spread much less, the actin is centrally, rather than peripherally distributed and the edge dynamics is largely altered. Blocking myosin-II or adding molecules of ICAM1 on the substrate largely abrogates these differences. We explain these observations by building a model based on the balance of forces between activation-dependent actin polymerization and actomyosin-generated tension on one hand, and on the frictional coupling of the ligand-receptor complexes with the actin cytoskeleton, the membrane and the substrate, on the other hand. Introducing the measured edge velocities in the model, we estimate the coefficient of frictional coupling between T Cell receptors or LFA-1 and the actin cytoskeleton. Our results provide for the first time, to our knowledge, a quantitative framework bridging T cell-specific biology with concepts developed for integrin-based mechanisms of spreading. PMID:25468342

  19. Overview and summary of the Spread F Experiment (SpreadFEx

    Directory of Open Access Journals (Sweden)

    D. C. Fritts

    2009-05-01

    Full Text Available We provide here an overview of, and a summary of results arising from, an extensive experimental campaign (the Spread F Experiment, or SpreadFEx performed from September to November 2005, with primary measurements in Brazil. The motivation was to define the potential role of neutral atmosphere dynamics, specifically gravity wave motions propagating upward from the lower atmosphere, in seeding Rayleigh-Taylor instability (RTI and plasma bubbles extending to higher altitudes. Campaign measurements focused on the Brazilian sector and included ground-based optical, radar, digisonde, and GPS measurements at a number of fixed and temporary sites. Related data on convection and plasma bubble structures were also collected by GOES 12, and the GUVI instrument aboard the TIMED satellite.

    Initial results of our SpreadFEx analyses are described separately by Fritts et al. (2009. Further analyses of these data provide additional evidence of 1 gravity wave (GW activity near the mesopause apparently linked to deep convection predominantly to the west of our measurement sites, 2 small-scale GWs largely confined to lower altitudes, 3 larger-scale GWs apparently penetrating to much higher altitudes, 4 substantial GW amplitudes implied by digisonde electron densities, and 5 apparent influences of these perturbations in the lower F-region on the formation of equatorial spread F, RTI, and plasma bubbles extending to much higher altitudes. Other efforts with SpreadFEx data have also yielded 6 the occurrence, locations, and scales of deep convection, 7 the spatial and temporal evolutions of plasma bubbles, 8 2-D (height-resolved structures in electron density fluctuations and equatorial spread F at lower altitudes and plasma bubbles above, and 9 the occurrence of substantial tidal perturbations to the large-scale wind and temperature fields extending to bottomside F-layer and higher altitudes. Collectively, our various SpreadFEx analyses suggest direct links

  20. Overview and summary of the Spread F Experiment (SpreadFEx

    Directory of Open Access Journals (Sweden)

    D. C. Fritts

    2009-05-01

    Full Text Available We provide here an overview of, and a summary of results arising from, an extensive experimental campaign (the Spread F Experiment, or SpreadFEx performed from September to November 2005, with primary measurements in Brazil. The motivation was to define the potential role of neutral atmosphere dynamics, specifically gravity wave motions propagating upward from the lower atmosphere, in seeding Rayleigh-Taylor instability (RTI and plasma bubbles extending to higher altitudes. Campaign measurements focused on the Brazilian sector and included ground-based optical, radar, digisonde, and GPS measurements at a number of fixed and temporary sites. Related data on convection and plasma bubble structures were also collected by GOES 12, and the GUVI instrument aboard the TIMED satellite. Initial results of our SpreadFEx analyses are described separately by Fritts et al. (2009. Further analyses of these data provide additional evidence of 1 gravity wave (GW activity near the mesopause apparently linked to deep convection predominantly to the west of our measurement sites, 2 small-scale GWs largely confined to lower altitudes, 3 larger-scale GWs apparently penetrating to much higher altitudes, 4 substantial GW amplitudes implied by digisonde electron densities, and 5 apparent influences of these perturbations in the lower F-region on the formation of equatorial spread F, RTI, and plasma bubbles extending to much higher altitudes. Other efforts with SpreadFEx data have also yielded 6 the occurrence, locations, and scales of deep convection, 7 the spatial and temporal evolutions of plasma bubbles, 8 2-D (height-resolved structures in electron density fluctuations and equatorial spread F at lower altitudes and plasma bubbles above, and 9 the occurrence of substantial tidal perturbations to the large-scale wind and temperature fields extending to bottomside F-layer and higher altitudes. Collectively, our various SpreadFEx analyses suggest direct links between

  1. The spread of tomato yellow leaf curl virus from the Middle East to the world.

    Directory of Open Access Journals (Sweden)

    Pierre Lefeuvre

    2010-10-01

    Full Text Available The ongoing global spread of Tomato yellow leaf curl virus (TYLCV; Genus Begomovirus, Family Geminiviridae represents a serious looming threat to tomato production in all temperate parts of the world. Whereas determining where and when TYLCV movements have occurred could help curtail its spread and prevent future movements of related viruses, determining the consequences of past TYLCV movements could reveal the ecological and economic risks associated with similar viral invasions. Towards this end we applied Bayesian phylogeographic inference and recombination analyses to available TYLCV sequences (including those of 15 new Iranian full TYLCV genomes and reconstructed a plausible history of TYLCV's diversification and movements throughout the world. In agreement with historical accounts, our results suggest that the first TYLCVs most probably arose somewhere in the Middle East between the 1930s and 1950s (with 95% highest probability density intervals 1905-1972 and that the global spread of TYLCV only began in the 1980s after the evolution of the TYLCV-Mld and -IL strains. Despite the global distribution of TYLCV we found no convincing evidence anywhere other than the Middle East and the Western Mediterranean of epidemiologically relevant TYLCV variants arising through recombination. Although the region around Iran is both the center of present day TYLCV diversity and the site of the most intensive ongoing TYLCV evolution, the evidence indicates that the region is epidemiologically isolated, which suggests that novel TYLCV variants found there are probably not direct global threats. We instead identify the Mediterranean basin as the main launch-pad of global TYLCV movements.

  2. 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...

  3. Mutual Feedback Between Epidemic Spreading and Information Diffusion

    CERN Document Server

    Zhan, Xiu-Xiu; Zhou, Ge; Zhang, Zi-Ke; Sun, Gui-Quan; Zhu, Jonathan J H

    2015-01-01

    The impact that information diffusion has on epidemic spreading has recently attracted much attention. As a disease begins to spread in the population, information about the disease is transmitted to others, which in turn has an effect on the spread of disease. In this paper, using empirical results of the propagation of H7N9 and information about the disease, we clearly show that the spreading dynamics of the two-types of processes influence each other. We build a mathematical model in which both types of spreading dynamics are described using the SIS process in order to illustrate the influence of information diffusion on epidemic spreading. Both the simulation results and the pairwise analysis reveal that information diffusion can increase the threshold of an epidemic outbreak, decrease the final fraction of infected individuals and significantly decrease the rate at which the epidemic propagates. Additionally, we find that the multi-outbreak phenomena of epidemic spreading, along with the impact of inform...

  4. Trigeminal perineural spread of renal cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Hornik, Alejandro; Rosenblum, Jordan; Biller, Jose [Stritch School of Medicine, Loyola University Medical Center, Chicago (United States)

    2012-07-01

    A 55-year-old man had a five-day history of 'pins and needles' sensation on the left chin. Examination showed decreased pinprick sensation on the territory of the left mandibular branch of the trigeminal nerve. Brain magnetic resonance imaging (MRI) with gadolinium showed enhancement involving the left mandibular branch. Computed tomography (CT) of the chest, abdomen, and pelvis showed a left kidney mass diagnosed as renal carcinoma following nephrectomy. The 'numb-chin' syndrome heralds or accompanies systemic malignancies. Trigeminal perineural spread has been well-documented in head and neck neoplasms, however, to our knowledge, it has not been reported in renal neoplasms. (author)

  5. Spread of epidemic disease on networks

    Science.gov (United States)

    Newman, M. E.

    2002-07-01

    The study of social networks, and in particular the spread of disease on networks, has attracted considerable recent attention in the physics community. In this paper, we show that a large class of standard epidemiological models, the so-called susceptible/infective/removed (SIR) models can be solved exactly on a wide variety of networks. In addition to the standard but unrealistic case of fixed infectiveness time and fixed and uncorrelated probability of transmission between all pairs of individuals, we solve cases in which times and probabilities are nonuniform and correlated. We also consider one simple case of an epidemic in a structured population, that of a sexually transmitted disease in a population divided into men and women. We confirm the correctness of our exact solutions with numerical simulations of SIR epidemics on networks.

  6. Modeling Epidemics Spreading on Social Contact Networks.

    Science.gov (United States)

    Zhang, Zhaoyang; Wang, Honggang; Wang, Chonggang; Fang, Hua

    2015-09-01

    Social contact networks and the way people interact with each other are the key factors that impact on epidemics spreading. However, it is challenging to model the behavior of epidemics based on social contact networks due to their high dynamics. Traditional models such as susceptible-infected-recovered (SIR) model ignore the crowding or protection effect and thus has some unrealistic assumption. In this paper, we consider the crowding or protection effect and develop a novel model called improved SIR model. Then, we use both deterministic and stochastic models to characterize the dynamics of epidemics on social contact networks. The results from both simulations and real data set conclude that the epidemics are more likely to outbreak on social contact networks with higher average degree. We also present some potential immunization strategies, such as random set immunization, dominating set immunization, and high degree set immunization to further prove the conclusion.

  7. Quantifier spreading: children misled by ostensive cues

    Directory of Open Access Journals (Sweden)

    Katalin É. Kiss

    2017-04-01

    Full Text Available This paper calls attention to a methodological problem of acquisition experiments. It shows that the economy of the stimulus employed in child language experiments may lend an increased ostensive effect to the message communicated to the child. Thus, when the visual stimulus in a sentence-picture matching task is a minimal model abstracting away from the details of the situation, children often regard all the elements of the stimulus as ostensive clues to be represented in the corresponding sentence. The use of such minimal stimuli is mistaken when the experiment aims to test whether or not a certain element of the stimulus is relevant for the linguistic representation or interpretation. The paper illustrates this point by an experiment involving quantifier spreading. It is claimed that children find a universally quantified sentence like 'Every girl is riding a bicycle 'to be a false description of a picture showing three girls riding bicycles and a solo bicycle because they are misled to believe that all the elements in the visual stimulus are relevant, hence all of them are to be represented by the corresponding linguistic description. When the iconic drawings were replaced by photos taken in a natural environment rich in accidental details, the occurrence of quantifier spreading was radically reduced. It is shown that an extra object in the visual stimulus can lead to the rejection of the sentence also in the case of sentences involving no quantification, which gives further support to the claim that the source of the problem is not (or not only the grammatical or cognitive difficulty of quantification but the unintended ostensive effect of the extra object.  This article is part of the special collection: Acquisition of Quantification

  8. From Rifting of a volcanic province to Oceanic Spreading in the Andaman Sea, South-East Asia.

    Science.gov (United States)

    Jourdain, A.; Singh, S. C.; Klinger, Y.

    2015-12-01

    The Andaman Sea is an enigmatic feature in the Indian Ocean region. It contains the volcanic provinces of Alcock and Sewell Rises and an active spreading center. The recent rifting in the Andaman Sea initiated 4.5 Ma ago, rifting the Alcock and Seawell Rises that were formed by extensive volcanism between 23-16 Ma. The spreading started with a full spreading rate of 1.6 cm/yr and increased to 3.8 cm/yr in the last 2.5 Ma. We have access to high-resolution deep seismic reflection data crossing the whole spreading center from the rifted volcanic provinces to the spreading center. The data show the whole oceanic crust up to the Moho. The Andaman Sea is covered with a thick pile of sediments that record the tectonic history of the rift system up to the spreading axis, allowing to decipher the whole process from rifting to spreading for the first time. We see a very rapid phase of transition from the rifting of the rises to the spreading in less than 20 km. Then a succession of at least 7 half-grabens is well recorded by the sediments on both sides of the spreading center. These half grabens are separated by outward tilted low angle detachment faults, which form the base of steeply dipping normal faults due to stretching. These low angle faults seem to connect with axial magma chambers that control evolution of the rift valley. We find that new detachment faults develop every 350,000 years, forming a new rift valley. The images of active normal faults within the central rift valley allow us to quantify the formation of oceanic crust by tectonic versus magmatic processes.

  9. Digital Watermarks Using Discrete Wavelet Transformation and Spectrum Spreading

    Directory of Open Access Journals (Sweden)

    Ryousuke Takai

    2003-12-01

    Full Text Available In recent tears, digital media makes rapid progress through the development of digital technology. Digital media normally assures fairly high quality, nevertheless can be easily reproduced in a perfect form. This perfect reproducibility takes and advantage from a certain point of view, while it produces an essential disadvantage, since digital media is frequently copied illegally. Thus the problem of the copyright protection becomes a very important issue. A solution of this problem is to embed digital watermarks that is not perceived clearly by usual people, but represents the proper right of original product. In our method, the images data in the frequency domain are transformed by the Discrete Wavelet Transform and analyzed by the multi resolution approximation, [1]. Further, the spectrum spreading is executed by using PN-sequences. Choi and Aizawa [7] embed watermarks by using block correlation of DCT coefficients. Thus, we apply Discrete Cosine Transformation, abbreviated to DCT, instead of the Fourier transformation in order to embed watermarks.If the value of this variance is high then we decide that the block has bigger magnitude for visual fluctuations. Henceforth, we may embed stronger watermarks, which gives resistance for images processing, such as attacks and/or compressions.

  10. 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.

  11. Responding to global infectious disease outbreaks: lessons from SARS on the role of risk perception, communication and management.

    Science.gov (United States)

    Smith, Richard D

    2006-12-01

    With increased globalisation comes the likelihood that infectious disease appearing in one country will spread rapidly to another, severe acute respiratory syndrome (SARS) being a recent example. However, although SARS infected some 10,000 individuals, killing around 1000, it did not lead to the devastating health impact that many feared, but a rather disproportionate economic impact. The disproportionate scale and nature of this impact has caused concern that outbreaks of more serious disease could cause catastrophic impacts on the global economy. Understanding factors that led to the impact of SARS might help to deal with the possible impact and management of such other infectious disease outbreaks. In this respect, the role of risk--its perception, communication and management--is critical. This paper looks at the role that risk, and especially the perception of risk, its communication and management, played in driving the economic impact of SARS. It considers the public and public health response to SARS, the role of the media and official organisations, and proposes policy and research priorities for establishing a system to better deal with the next global infectious disease outbreak. It is concluded that the potential for the rapid spread of infectious disease is not necessarily a greater threat than it has always been, but the effect that an outbreak can have on the economy is, which requires further research and policy development.

  12. Host immune responses that promote initial HIV spread.

    Science.gov (United States)

    Wendelsdorf, K; Dean, G; Hu, Shuhua; Nordone, S; Banks, H T

    2011-11-21

    The host inflammatory response to HIV invasion is a necessary component of the innate antiviral activity that vaccines and early interventions seek to exploit/enhance. However, the response is dependent on CD4+ T-helper cell 1 (Th1) recruitment and activation. It is this very recruitment of HIV-susceptible target cells that is associated with the initial viral proliferation. Hence, global enhancement of the inflammatory response by T-cells and dendritic cells will likely feed viral propagation. Mucosal entry sites contain inherent pathways, in the form of natural regulatory T-cells (nTreg), that globally dampen the inflammatory response. We created a model of this inflammatory response to virus as well as inherent nTreg-mediated regulation of Th1 recruitment and activation. With simulations using this model we sought to address the net effect of nTreg activation and its specific functions as well as identify mechanisms of the natural inflammatory response that are best targeted to inhibit viral spread without compromising initial antiviral activity. Simulation results provide multiple insights that are relevant to developing intervention strategies that seek to exploit natural immune processes: (i) induction of the regulatory response through nTreg activation expedites viral proliferation due to viral production by nTreg itself and not to reduced Natural Killer (NK) cell activity; (ii) at the same time, induction of the inflammation response through either DC activation or Th1 activation expedites viral proliferation; (iii) within the inflammatory pathway, the NK response is an effective controller of viral proliferation while DC-mediated stimulation of T-cells is a significant driver of viral proliferation; and (iv) nTreg-mediated DC deactivation plays a significant role in slowing viral proliferation by inhibiting T-cell stimulation, making this function an aide to the antiviral immune response. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. 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 larg...

  14. Evolution of dispersal and life history interact to drive accelerating spread of an invasive species.

    Science.gov (United States)

    Perkins, T Alex; Phillips, Benjamin L; Baskett, Marissa L; Hastings, Alan

    2013-08-01

    Populations on the edge of an expanding range are subject to unique evolutionary pressures acting on their life-history and dispersal traits. Empirical evidence and theory suggest that traits there can evolve rapidly enough to interact with ecological dynamics, potentially giving rise to accelerating spread. Nevertheless, which of several evolutionary mechanisms drive this interaction between evolution and spread remains an open question. We propose an integrated theoretical framework for partitioning the contributions of different evolutionary mechanisms to accelerating spread, and we apply this model to invasive cane toads in northern Australia. In doing so, we identify a previously unrecognised evolutionary process that involves an interaction between life-history and dispersal evolution during range shift. In roughly equal parts, life-history evolution, dispersal evolution and their interaction led to a doubling of distance spread by cane toads in our model, highlighting the potential importance of multiple evolutionary processes in the dynamics of range expansion. © 2013 John Wiley & Sons Ltd/CNRS.

  15. The Phylogeographic and Spatiotemporal Spread of HCV in Pakistani Population.

    Directory of Open Access Journals (Sweden)

    Noor-Ul-Huda Ghori

    Full Text Available Hepatitis C Virus (HCV is the most prevalent human pathogen in Pakistan and is the major cause of liver cirrhosis and hepatocellular carcinoma in infected patients. It has shifted from being hypo-endemic to being hyper-endemic. There was no information about the origin and evolution of the local variants. Here we use newly developed phyloinformatic methods of sequence analysis to conduct the first comprehensive investigation of the evolutionary and biogeographic history in unprecedented detail and breadth. Considering evolutionary rate and molecular-clock hypothesis in context, we reconstructed the spatiotemporal spread of HCV in the whole territory of its circulation using a combination of Bayesian MCMC methods utilizing all sequences available in GenBank. Comparative analysis were performed and were addressed. Whole genome and individual gene analysis have shown that sub-types 1a, 1b and 3a are recognized as epidemic strains and are distributed globally. Here we confirm that the origin of HCV 3a genotypes is in South Asia and HCV has evolved in the region to become stably adapted to the host environment.

  16. 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

  17. Hydrothermal vent fields and chemosynthetic biota on the world's deepest seafloor spreading centre

    Science.gov (United States)

    Connelly, Douglas P.; Copley, Jonathan T.; Murton, Bramley J.; Stansfield, Kate; Tyler, Paul A.; German, Christopher R.; Van Dover, Cindy L.; Amon, Diva; Furlong, Maaten; Grindlay, Nancy; Hayman, Nicholas; Hühnerbach, Veit; Judge, Maria; Le Bas, Tim; McPhail, Stephen; Meier, Alexandra; Nakamura, Ko-ichi; Nye, Verity; Pebody, Miles; Pedersen, Rolf B.; Plouviez, Sophie; Sands, Carla; Searle, Roger C.; Stevenson, Peter; Taws, Sarah; Wilcox, Sally

    2012-01-01

    The Mid-Cayman spreading centre is an ultraslow-spreading ridge in the Caribbean Sea. Its extreme depth and geographic isolation from other mid-ocean ridges offer insights into the effects of pressure on hydrothermal venting, and the biogeography of vent fauna. Here we report the discovery of two hydrothermal vent fields on the Mid-Cayman spreading centre. The Von Damm Vent Field is located on the upper slopes of an oceanic core complex at a depth of 2,300 m. High-temperature venting in this off-axis setting suggests that the global incidence of vent fields may be underestimated. At a depth of 4,960 m on the Mid-Cayman spreading centre axis, the Beebe Vent Field emits copper-enriched fluids and a buoyant plume that rises 1,100 m, consistent with >400 °C venting from the world's deepest known hydrothermal system. At both sites, a new morphospecies of alvinocaridid shrimp dominates faunal assemblages, which exhibit similarities to those of Mid-Atlantic vents. PMID:22233630

  18. 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.

  19. Spatial accessibility and the spread of HIV-1 subtypes and recombinants.

    Science.gov (United States)

    Tatem, Andrew J; Hemelaar, Joris; Gray, Rebecca R; Salemi, Marco

    2012-11-28

    The global spread of HIV-1 main group (group M) has resulted in differential distributions of subtypes and recombinants, with the greatest diversity being found in sub-Saharan Africa. The explanations for the current subtype distribution patterns are likely multifactorial, but the promotion of human migrations and movements through transportation link availability and quality, summarized through 'accessibility', have been consistently cited as strong drivers. We sought to address the question of whether accessibility has been a significant factor in HIV-1 spread across mainland Africa through spatial analyses of molecular epidemiology, transport network and land cover data. The distribution of HIV-1 subtypes and recombinants in sub-Saharan Africa for the period 1998-2008 was mapped using molecular epidemiology data at a finer level of detail than ever before. Moreover, hypotheses on the role of distance, road network structure and accessibility in explaining the patterns seen were tested using spatial datasets representing African transport infrastructure, land cover and an accessibility model of landscape travel speed. Coherent spatial patterns in HIV-1 subtype distributions across the continent exist, and a substantial proportion of the variance in the distribution and diversity pattern seen can be explained by variations in regional spatial accessibility. The study confirms quantitatively the influence of transport infrastructure on HIV-1 spread within Africa, presents an approach for examining potential future impacts of road development projects and, more generally, highlights the importance of accessibility in the spread of communicable diseases.

  20. 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

  1. Global Mindset

    DEFF Research Database (Denmark)

    Sørensen, Olav Jull

    2016-01-01

    way of thinking about the global business reality. The other extreme is a GM as an organizational capability and process with a GM in a continuous state of becoming – and thus in a continuously alignment with a dynamic context. In addition, we argue for what we call “situational capabilities”, i......The concept of Global Mindset (GM) – the way to think about the global reality – is on the agenda of multinational companies concomitant with the increase in global complexity, uncertainty and diversity. In spite of a number of studies, the concept is still fluid and far from a managerial...

  2. Utilizing Information Technology to Facilitate Rapid Acquisition

    Science.gov (United States)

    2006-06-01

    ordering systems to facilitate streamlined commercial item acquisitions that reap the benefits of improved efficiency, reduced overall costs, and...PAGES 109 14. SUBJECT TERMS Rapid Acquisition, eCommerce , eProcurement, Information Technology, Contracting, Global Information Network...streamlined commercial item acquisitions that reap the benefits of improved efficiency, reduced overall costs, and timeliness. This thesis

  3. Dynamical analysis of rumor spreading model with impulse vaccination and time delay

    Science.gov (United States)

    Huo, Liang'an; Ma, Chenyang

    2017-04-01

    Rumor cause unnecessary conflicts and confusion by misleading the cognition of the public, its spreading has largely influence on human affairs. All kinds of rumors and people's suspicion are often caused by the lack of official information. Hence, the official should take a variety of channels to deny the rumors. The promotion of scientific knowledge is implemented to improve the quality of the whole nation, reduce the harm caused by rumor spreading. In this paper, regarding the process of the science education that official deny the rumor many times as periodic impulse, we propose a XWYZ rumor spreading model with impulse vaccination and time delay, and analyze the global dynamics behaviors of the model. By using the discrete dynamical system determined by the comparison theory and Floquet theorem, we show that there exists a rumor-free periodic solution. Further, we show that the rumor-free periodic solution is globally attractive under appropriate conditions. We also obtain a sufficient condition for the permanence of model. Finally, with the numerical simulation, our results indicate that large vaccination rate, short impulse period or long latent period is sufficient condition for the extinction of the rumors.

  4. Emerging and re-emerging Infectious diseases: a global health threat.

    Science.gov (United States)

    Tukei, P M

    1996-05-01

    The HIV/AIDS pandemic can truly be described as an infectious disease that has recently emerged and judging from its rapid global spread, it leaves no doubt that it is one of the greatest health threats mankind has to contend with. This pandemic has alerted and stimulated the international scientific community to seriously reflect oa other recent episodes of emerging and re-emerging infections. The examples that have recently been observed and addressed include new emerging infectious diseases, unusual manifestations of previously known diseases and unusual eruption of known diseases in unusual geographic foci or unusual altitudes. The scientific community has considered the following as plausible explanations for the epidemics: 1. It is known that micro-organisms mutate and selection pressures for appearance of resistant strains are encouraged by the widespread misuse of drugs; 2. Human population pressures, particularly ih the developing world, is leading migration to urban slums. Other populations are venturing into virgin jungles to open up new agricultural land. In the same category are economic pursuits in the forest or alteration of the environment by economic activities such as new dams and roads. All these activities put new susceptible populations at risk of interacting with new disease ecological systems. It is also tempting to include in this category civil disruptions which have led to acute displacement of large populations within a country or across international borders as refugees; 3. The re-emergence of some of the old familiar diseases, hitherto considered well controlled, can be attributed directly to the deterioration of health services as a result of global economic depression which has affected some countries more severely than others; 4. There is sound and growing scientific evidence implicating global warming as contributing to some of the new disease manifestations. The threat to health by emerging and re-emerging infectious diseases is a

  5. Globalization, Corporatism, and Critical Language Education

    Science.gov (United States)

    Luke, Allan; Luke, Carmen; Graham, Phil

    2007-01-01

    This article explores the impacts of economic and cultural globalization on language and language education. It acknowledges the spread of English and the negative impacts of this upon other languages and language communities. The case is made that new conditions of economic dominance by multinational corporations raise the stakes for schooling…

  6. Robustness of double random phase encoding spread-space spread-spectrum image watermarking technique

    Science.gov (United States)

    Liu, Shi; Hennelly, Bryan M.; Sheridan, John T.

    2013-09-01

    In this paper the robustness of a recently proposed image watermarking scheme is investigated, namely the Double Random Phase Encoding spread-space spread-spectrum watermarking (DRPE SS-SS) technique. In the DRPE SS-SS method, the watermark is in the form of a digital barcode image which is numerically encrypted using a simulation of the optical DRPE process. This produces a random complex image, which is then processed to form a real valued random image with a low number of quantization levels. This signal is added to the host image. Extraction of the barcode, involves applying an inverse DRPE process to the watermarked image followed by a low pass filter. This algorithm is designed to utilize the capability of the DRPE to reversibly spread the energy of the watermarking information in both the space and spatial frequency domains, and the energy of the watermark in any spatial or spatial frequency bin is very small. The common geometric transformations and signal processing operations are performed using both the informed and the blind detections for different barcode widths and different quantization levels. The results presented indicate that the DRPE SS-SS method is robust to scaling, JPEG compression distortion, cropping, low pass and high pass filtering. It is also demonstrated that the bigger the barcode width is, the lower the false positive rate will be.

  7. Global survey of malaria rapid diagnostic test (RDT) sales, procurement and lot verification practices: assessing the use of the WHO-FIND Malaria RDT Evaluation Programme (2011-2014).

    Science.gov (United States)

    Incardona, Sandra; Serra-Casas, Elisa; Champouillon, Nora; Nsanzabana, Christian; Cunningham, Jane; González, Iveth J

    2017-05-15

    Malaria rapid diagnostic tests (RDTs) play a critical role in malaria case management, and assurance of quality is a key factor to promote good adherence to test results. Since 2007, the World Health Organization (WHO) and the Foundation for Innovative New Diagnostics (FIND) have coordinated a Malaria RDT Evaluation Programme, comprising a pre-purchase performance evaluation (product testing, PT) and a pre-distribution quality control of lots (lot testing, LT), the former being the basis of WHO recommendations for RDT procurement. Comprehensive information on malaria RDTs sold worldwide based on manufacturers' data and linked to independent performance data is currently not available, and detailed knowledge of procurement practices remains limited. The use of the PT/LT Programme results as well as procurement and lot verification practices were assessed through a large-scale survey, gathering product-specific RDT sales and procurement data (2011-14 period) from a total of 32 manufacturers, 12 procurers and 68 National Malaria Control Programmes (NMCPs). Manufacturers' reports showed that RDT sales had more than doubled over the four years, and confirmed a trend towards increased compliance with the WHO procurement criteria (from 83% in 2011 to 93% in 2014). Country-level reports indicated that 74% of NMCPs procured only 'WHO-compliant' RDT products, although procurers' transactions datasets revealed a surprisingly frequent overlap of different products and even product types (e.g., Plasmodium falciparum-only and Plasmodium-pan) in the same year and country (60 and 46% of countries, respectively). Importantly, the proportion of 'non-complying' (i.e., PT low scored or not evaluated) products was found to be higher in the private health care sector than in the public sector (32% vs 5%), and increasing over time (from 22% of private sector sales in 2011 to 39% in 2014). An estimated 70% of the RDT market was covered by the LT programme. The opinion about the PT

  8. IMPACT OF GLOBALIZATION ON MACROECONOMIC POLICY

    OpenAIRE

    Clementina IVAN-UNGUREANU

    2008-01-01

    Globalization – the growing integration of economies and societies around the world – has been one of the most hotly-debated topics in international economics over the past few years. Rapid growth and poverty reduction in some countries that were poor 20 years ago have been positive aspects of globalization. But globalization has also generated significant international opposition to concerns about increased inequality and environmental degradation. There are many definitions of globalization...

  9. Unification of theoretical approaches for epidemic spreading on complex networks.

    Science.gov (United States)

    Wang, Wei; Tang, Ming; Eugene Stanley, H; Braunstein, Lidia A

    2017-03-01

    Models of epidemic spreading on complex networks have attracted great attention among researchers in physics, mathematics, and epidemiology due to their success in predicting and controlling scenarios of epidemic spreading in real-world scenarios. To understand the interplay between epidemic spreading and the topology of a contact network, several outstanding theoretical approaches have been developed. An accurate theoretical approach describing the spreading dynamics must take both the network topology and dynamical correlations into consideration at the expense of increasing the complexity of the equations. In this short survey we unify the most widely used theoretical approaches for epidemic spreading on complex networks in terms of increasing complexity, including the mean-field, the heterogeneous mean-field, the quench mean-field, dynamical message-passing, link percolation, and pairwise approximation. We build connections among these approaches to provide new insights into developing an accurate theoretical approach to spreading dynamics on complex networks.

  10. 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.

  11. Suppressing disease spreading by using information diffusion on multiplex networks

    CERN Document Server

    Wang, Wei; Cai, Shi-Min; Tang, Ming; Braunstein, Lidia A; Stanley, H Eugene

    2016-01-01

    Although there is always an interplay between the dynamics of information diffusion and disease spreading, the empirical research on the systemic coevolution mechanisms connecting these two spreading dynamics is still lacking. Here we investigate the coevolution mechanisms and dynamics between information and disease spreading by utilizing real data and a proposed model on multiplex network. Our empirical analysis finds asymmetrical interactions between the information and disease spreading dynamics. Our results obtained from both the theoretical framework and intensive stochastic numerical simulations suggest that an information outbreak can be triggered on a communication network by its own spreading dynamics or the disease outbreak on a contact network, but that the disease threshold is not affected by information spreading. Our key finding is that there is an optimal information transmission rate that markedly suppresses the disease speading. We find that the time evolution of the dynamics in the proposed...

  12. Spreading Optics in the primary school

    Science.gov (United States)

    Gargallo, Ana; Gómez-Varela, Ana I.; Gónzalez-Nuñez, Héctor; Delgado, Tamara; Almaguer, Citlalli; Cambronero, Ferran; García-Sánchez, Ángel; Pallarés, David; Aymerich, María; Aragón, Ángel L.; Flores-Arias, Maria T.

    2015-04-01

    The USC-OSA is a student chapter located at the University of Santiago de Compostela (Spain) whose objective is to bring optics and photonics knowledge closer to general public. In order to arouse kids' interest in Optics we developed an activity called Funny Light. This activity consisted on a visit of some USC-OSA members to a several local primary schools where we organized several optics experiments. In this work we present the optics demonstrations and the reaction of the 6 years-old students. The activities with greater acceptance include an explanation of light properties as polarization, refraction or reflection, and the workshop where they learnt how to build their own kaleidoscope and made a chromatic disk. Besides, they also participated in a demonstration and explanation of color properties and some optical illusions. We think that this activity has several benefits including spreading Optics through children meanwhile they have fun and experiment science in real life, as well as helping teachers to explain some complex properties and Physics phenomena of light. Given the broad acceptance of this activity, we are intending to make it a routine event of our student chapter repeating it every year.

  13. Spreading continents kick-started plate tectonics.

    Science.gov (United States)

    Rey, Patrice F; Coltice, Nicolas; Flament, Nicolas

    2014-09-18

    Stresses acting on cold, thick and negatively buoyant oceanic lithosphere are thought to be crucial to the initiation of subduction and the operation of plate tectonics, which characterizes the present-day geodynamics of the Earth. Because the Earth's interior was hotter in the Archaean eon, the oceanic crust may have been thicker, thereby making the oceanic lithosphere more buoyant than at present, and whether subduction and plate tectonics occurred during this time is ambiguous, both in the geological record and in geodynamic models. Here we show that because the oceanic crust was thick and buoyant, early continents may have produced intra-lithospheric gravitational stresses large enough to drive their gravitational spreading, to initiate subduction at their margins and to trigger episodes of subduction. Our model predicts the co-occurrence of deep to progressively shallower mafic volcanics and arc magmatism within continents in a self-consistent geodynamic framework, explaining the enigmatic multimodal volcanism and tectonic record of Archaean cratons. Moreover, our model predicts a petrological stratification and tectonic structure of the sub-continental lithospheric mantle, two predictions that are consistent with xenolith and seismic studies, respectively, and consistent with the existence of a mid-lithospheric seismic discontinuity. The slow gravitational collapse of early continents could have kick-started transient episodes of plate tectonics until, as the Earth's interior cooled and oceanic lithosphere became heavier, plate tectonics became self-sustaining.

  14. On the spreading of impacting drops

    CERN Document Server

    Wildeman, Sander; Sun, Chao; Lohse, Detlef

    2016-01-01

    The energy budget and dissipation mechanisms during droplet impact on solid surfaces are studied numerically and theoretically. We find that for high impact velocities and negligible surface friction, about one half of the initial kinetic energy is transformed into surface energy, independent of the impact parameters and the detailed energy loss mechanism(s). We argue that this seemingly universal rule is related to the deformation mode of the droplet and is reminiscent of pipe flow undergoing a sudden expansion, for which the head loss can be calculated by multiplying the kinetic energy of the incoming flow by a geometrical factor. For impacts on a no-slip surface also dissipation in the shear boundary layer at the solid surface is important. In this case the head loss acts as a lower bound on the total dissipation for small viscosities. This new view on the impact problem allows for simple analytical estimates of the maximum spreading diameter of impacting drops as a function of the impact parameters and th...

  15. Estimating spread of violent behaviour with children

    Directory of Open Access Journals (Sweden)

    Volkova E.N.

    2016-06-01

    Full Text Available The article is to problems of violence (physical, psychological, sexual to children in the region of Nyzhniy Novgorod in the Russian Federation. It was used international tool for questionnaire ICAST-C. В исследовании приняли участие 227 children par- ticipated in this study (131 girls, 96 boys in the age of 11 to 18 years old. The results show that 78,4% of children have some experience of violence and abuse. 3/4 — in family, and 2/3 — at school. High level of psychological abuse at home was shown (more than 2/3 , at home it is more often than at school (54% versus 30%. Children suffer from physical abuse at home (49% versus 33% at school. Though they suffer from sexual abuse at school (27%. All kinds of abuse take place among girls as well as among boys. Except physical abuse at school where it is more usual among boys (45%, versus (33% girls. Girls suffer more at home. Teenagers suffer less, than youngsters. Emotional abuse is not spread widely (40% versus 60—75% in other groups. In general they suffer from sexual abuse not often, though it is usually at home (8,5% cases.

  16. Forecasting scintillation activity and equatorial spread F

    Science.gov (United States)

    Anderson, David N.; Redmon, Robert J.

    2017-03-01

    When transionospheric radio waves propagate through an irregular ionosphere with plasma depletions or "bubbles," they are subject to sporadic enhancement and fading, which is referred to as scintillation. Communication and navigation systems may be subject to these detrimental effects if the scintillation is strong enough. It is critical to have knowledge of the current ionospheric conditions so that system operators can distinguish between the natural radio environment and system-induced failures. In this paper we briefly describe the Forecasting Ionospheric Real-time Scintillation Tool UHF scintillation forecasting technique, which utilizes the observed characteristic parameter h'F from a ground-based, ionospheric sounder near the magnetic equator. The prereversal enhancement in vertical E × B drift velocity after sunset is the prime driver for creating plasma depletions and bubbles. In addition, there exists a "threshold" in the h'F value at 1930 LT, h'Fthr, such that, on any given evening, if h'F is significantly above h'Fthr, then scintillation activity is likely to occur, and if it is below h'Fthr, scintillation activity is unlikely to occur. We use this technique to explain the lack of scintillation activity prior to the Halloween storm in October 2003 in the Peruvian longitude sector. In addition, we have carried out a study which forecasts the occurrence or nonoccurrence of equatorial spread F (ESF), on a night-to-night basis, in five longitude sectors. The overall forecasting success is greater than 80% for each of the five longitude sectors.

  17. Insights into intercontinental spread of Zika virus.

    Science.gov (United States)

    Liang, Dachao; Leung, Ross Ka Kit; Lee, Shui Shan; Kam, Kai Man

    2017-01-01

    The epidemic of Zika virus (ZIKV) infection in South America has led to World Health Organization's declaration of a Public Health Emergency of International Concern. To further inform effective public health policy, an understanding of ZIKV's transmission mechanisms is crucial. To characterize the intercontinental transmission of ZIKV, we compiled and analyzed more than 250 gene sequences together with their sequence-related geographic and temporal information, sampled across 27 countries spanning from 1947 to 2016. After filtering and selecting appropriate sequences, extensive phylogenetic analyses were performed. Although phylogeographic reconstruction supported the transmission route of the virus in Africa, South-eastern Asia, Oceania and Latin America, we discovered that the Eastern Africa origin of ZIKV was disputable. On a molecular level, purifying selection was found to be largely responsible for the evolution of non-structural protein 5 and envelope protein E. Our dataset and ancestral sequences reconstruction analysis captured previously unidentified amino acid changes during evolution. Finally, based on the estimation of the time to the most recent common ancestors for the non-structural protein 5 gene, we hypothesized potential specific historic events that occurred in the 1940s and might have facilitated the spread of Zika virus from Africa to South-eastern Asia. Our findings provide new insights into the transmission characteristics of ZIKV, while further genetic and serologic studies are warranted to support the design of tailored prevention strategies.

  18. Insights into intercontinental spread of Zika virus.

    Directory of Open Access Journals (Sweden)

    Dachao Liang

    Full Text Available The epidemic of Zika virus (ZIKV infection in South America has led to World Health Organization's declaration of a Public Health Emergency of International Concern. To further inform effective public health policy, an understanding of ZIKV's transmission mechanisms is crucial. To characterize the intercontinental transmission of ZIKV, we compiled and analyzed more than 250 gene sequences together with their sequence-related geographic and temporal information, sampled across 27 countries spanning from 1947 to 2016. After filtering and selecting appropriate sequences, extensive phylogenetic analyses were performed. Although phylogeographic reconstruction supported the transmission route of the virus in Africa, South-eastern Asia, Oceania and Latin America, we discovered that the Eastern Africa origin of ZIKV was disputable. On a molecular level, purifying selection was found to be largely responsible for the evolution of non-structural protein 5 and envelope protein E. Our dataset and ancestral sequences reconstruction analysis captured previously unidentified amino acid changes during evolution. Finally, based on the estimation of the time to the most recent common ancestors for the non-structural protein 5 gene, we hypothesized potential specific historic events that occurred in the 1940s and might have facilitated the spread of Zika virus from Africa to South-eastern Asia. Our findings provide new insights into the transmission characteristics of ZIKV, while further genetic and serologic studies are warranted to support the design of tailored prevention strategies.

  19. Spreading of persistent infections in heterogeneous populations

    Science.gov (United States)

    Sanz, J.; Floría, L. M.; Moreno, Y.

    2010-05-01

    Up to now, the effects of having heterogeneous networks of contacts have been studied mostly for diseases which are not persistent in time, i.e., for diseases where the infectious period can be considered very small compared to the lifetime of an individual. Moreover, all these previous results have been obtained for closed populations, where the number of individuals does not change during the whole duration of the epidemics. Here, we go one step further and analyze, both analytically and numerically, a radically different kind of diseases: those that are persistent and can last for an individual’s lifetime. To be more specific, we particularize to the case of tuberculosis’ (TB) infection dynamics, where the infection remains latent for a period of time before showing up and spreading to other individuals. We introduce an epidemiological model for TB-like persistent infections taking into account the heterogeneity inherent to the population structure. This sort of dynamics introduces new analytical and numerical challenges that we are able to sort out. Our results show that also for persistent diseases the epidemic threshold depends on the ratio of the first two moments of the degree distribution so that it goes to zero in a class of scale-free networks when the system approaches the thermodynamic limit.

  20. Antimicrobial resistance: a global view from the 2013 World Healthcare-Associated Infections Forum

    Science.gov (United States)

    2013-01-01

    Antimicrobial resistance (AMR) is now a global threat. Its emergence rests on antimicrobial overuse in humans and food-producing animals; globalization and suboptimal infection control facilitate its spread. While aggressive measures in some countries have led to the containment of some resistant gram-positive organisms, extensively resistant gram-negative organisms such as carbapenem-resistant enterobacteriaceae and pan-resistant Acinetobacter spp. continue their rapid spread. Antimicrobial conservation/stewardship programs have seen some measure of success in reducing antimicrobial overuse in humans, but their reach is limited to acute-care settings in high-income countries. Outside the European Union, there is scant or no oversight of antimicrobial administration to food-producing animals, while evidence mounts that this administration leads directly to resistant human infections. Both horizontal and vertical infection control measures can interrupt transmission among humans, but many of these are costly and essentially limited to high-income countries as well. Novel antimicrobials are urgently needed; in recent decades pharmaceutical companies have largely abandoned antimicrobial discovery and development given their high costs and low yield. Against this backdrop, international and cross-disciplinary collaboration appears to be taking root in earnest, although specific strategies still need defining. Educational programs targeting both antimicrobial prescribers and consumers must be further developed and supported. The general public must continue to be made aware of the current scale of AMR’s threat, and must perceive antimicrobials as they are: a non-renewable and endangered resource. PMID:24237856

  1. EBOLA VACCINE. VSV-EBOV rapidly protects macaques against infection with the 2014/15 Ebola virus outbreak strain.

    Science.gov (United States)

    Marzi, Andrea; Robertson, Shelly J; Haddock, Elaine; Feldmann, Friederike; Hanley, Patrick W; Scott, Dana P; Strong, James E; Kobinger, Gary; Best, Sonja M; Feldmann, Heinz

    2015-08-14

    The latest Ebola virus (EBOV) epidemic spread rapidly through Guinea, Sierra Leone, and Liberia, creating a global public health crisis and accelerating the assessment of experimental therapeutics and vaccines in clinical trials. One of those vaccines is based on recombinant vesicular stomatitis virus expressing the EBOV glycoprotein (VSV-EBOV), a live-attenuated vector with marked preclinical efficacy. Here, we provide the preclinical proof that VSV-EBOV completely protects macaques against lethal challenge with the West African EBOV-Makona strain. Complete and partial protection was achieved with a single dose given as late as 7 and 3 days before challenge, respectively. This indicates that VSV-EBOV may protect humans against EBOV infections in West Africa with relatively short time to immunity, promoting its use for immediate public health responses. Copyright © 2015, American Association for the Advancement of Science.

  2. Global Uddannelse

    DEFF Research Database (Denmark)

    Jensen, Niels Rosendal

    Antologien handler om "demokratiproblemer i den globale sammenhæng" (del I) og "demokratiproblemer i uddannelse og for de offentligt ansatte" (del II), bundet sammen af et mellemstykke, der rækker ud mod begge poler både det globale og det lokale ved at knytte det til forholdet mellem marked...

  3. Developing Globalization

    DEFF Research Database (Denmark)

    Hansen, Annette Skovsted

    2017-01-01

    This chapter is the first qualitative micro case study of one aspect of globalization: personal networks as a concrete outcome of development assistance spending. The empirical findings related in this paper present circumstantial evidence that Japanese foreign aid has contributed to globalization...

  4. Gendering Globalization

    DEFF Research Database (Denmark)

    Siim, Birte

    2009-01-01

    The current global financial situation bluntly and brutally brings home the fact that the global and local are closely connected in times of opportunity as well as crises. The articles in this issue of Asia Insights are about ontra-action between Asia, particularly China, and the Nordic countries...

  5. Global Mindsets

    DEFF Research Database (Denmark)

    Global Mindsets: Exploration and Perspectives seeks to tackle a topic that is relatively new in research and practice, and is considered by many to be critical for firms seeking to conduct global business. It argues that multiple mindsets exist (across and within organizations), that they operate...... in a global context, and that they are dynamic and undergo change and action. Part of the mindset(s) may depend upon place, situation and context where individuals and organizations operate. The book will examine the notion of "mindset" is situational and dynamic, especially in a global setting, why...... it is important for future scholars and managers and how it could be conceptualized. Global Mindsets: Exploration and Perspectives is split into two major sections; the first examines where the literature currently is with respect to the knowledge in the field and what conceptual frameworks guide the thinking...

  6. Identifying node spreading influence for tunable clustering coefficient networks

    Science.gov (United States)

    Wang, Zi-Yi; Han, Jing-Ti; Zhao, Jun

    2017-11-01

    Identifying the node spreading influence is of significant for information and innovation diffusion. In this paper, we argue that the spreading process should be taken into account for identifying the node spreading influence and investigate the effect of the network structure, measured by the clustering coefficient, on the performance of spreading dynamics. Firstly, we generate a series of networks with tunable clustering coefficients. Then, taking into account the spreading process, we explore the performances among the Dynamics-sensitive (DS) index and the degree, between, closeness, eigenvector indices. Comparing with the Susceptible-Infective-Removed (SIR) model, the extensive results show that, for different spreading time steps and clustering coefficients, the DS centrality outperforms the performance, τ > 0 . 97, of degree, betweenness, closeness and eigenvector measures. Moreover, the accuracy of closeness and eigenvector centrality is similar and conducts better in networks with larger spreading rate β = 0 . 20 , τ > 0 . 93. As the clustering coefficient increases, all the performances decrease but DS centrality with least percent of 1.16 at most under β = 0 . 10, and Closeness with the largest percent of 9.75 under β = 0 . 05. This work suggests that the spreading influence not only depends on the network structure, more importantly, the spreading dynamic process also affect the performance greatly, which should be taken into account simultaneously.

  7. Spread of the spiraling white fly Aleurodicus dispersus (Homoptera ...

    African Journals Online (AJOL)

    Spread of the spiraling white fly Aleurodicus dispersus (Homoptera: Aleyrodidae) and its parasitoids Encarcia species (Hymenoptera: Aphelinidae) on horticultural plants in Northwest and Central Nigeria.

  8. Ice Control with Brine Spread with Nozzles on Highways

    DEFF Research Database (Denmark)

    Bolet, Lars; Fonnesbech, Jens Kristian

    2010-01-01

    that the salt will run from the high level of the road to the lower level”. In the test the salt moved 1 meter in 3 hours. The knowledge gained from the measurements in the county of Funen - brine spread with nozzles, spreading salt to high level of the road and using GPS controlled spreading – was implemented......During the years 1996-2006, the former county of Funen, Denmark, gradually replaced pre-wetted salt with brine spread with nozzles as anti-icing agent in all her ice control activities. The replacement related to 1000 kilometres of highways. Jeopardizing neither road safety nor traffic flow...

  9. Scaling of energy spreading in strongly nonlinear disordered lattices

    Science.gov (United States)

    Mulansky, Mario; Ahnert, Karsten; Pikovsky, Arkady

    2011-02-01

    To characterize a destruction of Anderson localization by nonlinearity, we study the spreading behavior of initially localized states in disordered, strongly nonlinear lattices. Due to chaotic nonlinear interaction of localized linear or nonlinear modes, energy spreads nearly subdiffusively. Based on a phenomenological description by virtue of a nonlinear diffusion equation, we establish a one-parameter scaling relation between the velocity of spreading and the density, which is confirmed numerically. From this scaling it follows that for very low densities the spreading slows down compared to the pure power law.

  10. 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.

  11. Role of Human Action in the Spread of Honey Bee (Hymenoptera: Apidae) Pathogens.

    Science.gov (United States)

    Owen, Robert

    2017-06-01

    The increased annual losses in European honey bee (Apis mellifera) colonies in North America and some other countries is usually attributed to a range of factors including pathogens, poor nutrition, and insecticides. In this essay, I will argue that the global trade in honey bees and migratory beekeeping practices within countries has enabled pathogens to spread quickly. Beekeepers' management strategies have also contributed to the spread of pathogens as well as the development of resistance to miticides and antibiotics, and exacerbated by hobby beekeepers. The opportunities for arresting honey bee declines rest as strongly with individual beekeepers as they do with the dynamics of disease. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. ONR seafloor natural laboratories on slow- and fast-spreading mid-ocean ridges

    Science.gov (United States)

    Tucholke, Brian E.; Macdonald, Ken C.; Fox, Paul J.

    Long-term Natural Laboratories for in-depth studies of the seafloor at both a slowspreading (60 mm/yr) mid-ocean ridge are being established by the Office of Naval Research. The two Natural Laboratories were selected for their representativeness of global mid-ocean ridge environments, and for their logistic accessibility. The Natural Laboratory region for the slow-spreading regime is on the Mid-Atlantic Ridge from Kane Fracture Zone north to about 27°30″N (Figure 1), and the fast-spreading counterpart is on the East Pacific Rise at about 8°-10°30″N, from Siqueiros to Clipperton Fracture Zone (Figure 2). Together, the two Natural Laboratories include most significant geologic variables that are thought to control both the shape and structure of the igneous crust and the scatter of acoustic wavefields from the bottom/subbottom (BSB) at low angles of incidence.

  13. Spread dynamics of perennial pepperweed (Lepidium latifolium) in two seasonal wetland areas

    Science.gov (United States)

    Renz, Mark J.; Steinmaus, Scott J.; Gilmer, David S.; DiTomaso, Joseph M.

    2012-01-01

    Perennial pepperweed is an invasive plant that is expanding rapidly in several plant communities in the western United States. In California, perennial pepperweed has aggressively invaded seasonal wetlands, resulting in degradation of habitat quality. We evaluated the rate and dynamics of population spread, assessed the effect of disturbance on spread, and determined the biotic and abiotic factors influencing the likelihood of invasion. The study was conducted at eight sites within two wetland regions of California. Results indicate that in undisturbed sites, spread was almost exclusively through vegetative expansion, and the average rate of spread was 0.85 m yr−1 from the leading edge. Spread in sites that were disked was more than three times greater than in undisturbed sites. While smaller infestations increased at a faster rate compared with larger populations, larger infestations accumulated more newly infested areas than smaller infestations from year to year. Stem density was consistently higher in the center of the infestations, with about 2.4 times more stems per square meter compared with the leading edge at the perimeter of the population. The invasion by perennial pepperweed was positively correlated with increased water availability but was negatively correlated with the cover of perennial and annual species. Thus, high cover of resident vegetation can have a suppressive effect on the rate of invasion, even in wetland ecosystems. On the basis of these results, we recommend that resident plant cover not be disturbed, especially in wet areas adjacent to areas currently infested with perennial pepperweed. For infested areas, management efforts should be prioritized to focus on controlling satellite populations as well as the leading edge of larger infestations first. This strategy could reduce the need for costly active restoration efforts by maximizing the probability of successful re-establishment of resident vegetation from the adjacent seedbank.

  14. 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.

  15. Seasonal phenology of Amphorophora agathonica (Hemiptera: Aphididae) and spread of viruses in red raspberry in Washington.

    Science.gov (United States)

    Lightle, D M; Quito-Avila, D; Martin, R R; Lee, J C

    2014-04-01

    Amphorophora agathonica (Hottes) is the primary vector of aphid-transmitted viruses in red raspberry in the Pacific Northwest region of the United States. To better understand the biology of the aphid, we estimated the lower developmental threshold and studied the seasonal activity of A. agathonica in commercial fields in northern Washington state. In addition, we monitored the spread of raspberry viruses (raspberry latent virus and raspberry leaf mottle virus, RLMV) to determine how rapidly fields became infected and whether there was a relationship between aphid presence and infection. The lower developmental threshold of A. agathonica was estimated to be 2.7°C. In the field, apterous and alate aphid populations began rapidly increasing at ≍800 growing degree-days and peaked at 1,050 growing degree-days. RLMV spread rapidly, with 30-60% of plants in four different commercial fields testing positive after three growing seasons. There was no discernible relationship between the presence or abundance of aphids based on 10 leaves sampled per plant location, and the odds of that plant becoming infected with RLMV.

  16. Global Warming and Energy Transition: A Public Policy Imperative

    Science.gov (United States)

    Stone, G. T.

    2006-12-01

    The historic transition from fossil fuels to alternative energy resources has begun. This development is commonly attributed to increasing energy costs and the need for energy security. Looming ever larger, however, is the issue that will soon drive the third energy revolution: global warming. A preponderance of evidence documents accelerating warming, enlarging impacts, and human causes -- principally combustion of fossil fuels. The carbon dioxide (C02) content of Earth's atmosphere has increased more than 35 percent since the beginning of the industrial revolution and is the highest in 650,000 years. This dramatic rise of C02 and attendant positive feedbacks are already forcing significant impacts worldwide. These include atmospheric warming with shifting climatic and habitat zones, spreading tropical disease, and more extreme weather events; rapid ice loss at high latitude and high altitude; ocean warming and acidification with coral reef bleaching and intensifying tropical storms; rising sea level; and accelerating extinction rates. The 2007 draft report of the Intergovernmental Panel on Climate Change (IPCC) predicts greater warming than in previous models. A tipping point to abrupt climate change may be imminent. It is incumbent upon geoscientists and geoscience educators to assume leadership in addressing this challenge through public outreach and general education. The following topics should be integrated into all appropriate courses: the evidence of global warming and its causes; observed present and predicted future impacts of global warming; mitigation and adaptation strategies; and implications for energy policies and economic opportunities. New entry-level science and general education courses -- such as Climate Change Fundamentals and Energy in Nature, Technology, and Society -- are proving to be effective should be widely developed In addition, by workshops and presentations to civic and business organizations and by demonstrated examples of

  17. Rapid Prototyping Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The ARDEC Rapid Prototyping (RP) Laboratory was established in December 1992 to provide low cost RP capabilities to the ARDEC engineering community. The Stratasys,...

  18. Global migration of influenza A viruses in swine

    Science.gov (United States)

    The emergence of the 2009 A/H1N1 pandemic virus underscores the importance of understanding how influenza A viruses evolve in swine on a global scale. To reveal the frequency, patterns and drivers of the spread of swine influenza virus globally, we conducted the largest phylogenetic analysis of swin...

  19. 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.

  20. 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...

  1. 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 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®

  2. Global Content in Global Coursebooks

    Directory of Open Access Journals (Sweden)

    Mimoun Melliti

    2013-10-01

    Full Text Available This study aims at exploring the issue of “globality” in global coursebooks as manifested in investing features of connectedness, avoiding inappropriacy, and preserving inclusivity. To do this exploration, two research methods, content analysis and the questionnaire, were adopted. The content of an example of global coursebooks, Headway Intermediate (H/I, in addition to the perception of 251 of its users at Institute Bourguiba for Living Languages (IBLV were investigated. The results obtained revealed that “globality,” in terms of connectedness, inappropriacy, and inclusivity is partial in H/I as learners’ perceptions of it do not map with the content in the coursebook. This study raises questions about the suitability of global coursebooks to globally diverse learners and reveals the necessity of taking measures in the direction of localizing the content of English as a foreign language (EFL coursebooks.

  3. Going Global

    DEFF Research Database (Denmark)

    Harrington, Brooke

    2015-01-01

    This study links theories of relationality and institutional change to deepen understanding of professionals’ role in globalization. In previous institutional research, it has been conventional to treat professionals as agents of firms or transnational organizations, and institutional change...... environment. It also broadens the model of agency to include invention and improvisation by individual professionals, as a counterpart to collective strategic action. The argument is based on data from a 16-nation study exploring the emergence of a particular ‘globalized localism’: the transformation...... to specify a new, more detailed model of the ways local practices and ideas develop into global institutions....

  4. 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

  5. Globalization and management

    Directory of Open Access Journals (Sweden)

    Danimir Štros

    2014-12-01

    Full Text Available Globalization as an ongoing process allows and promotes the development of economy of big countries as well as developing countries that are seeking their place in the global market. Interactive communication has been enabled between people, companies, civil society organizations and other institutions, whose needs can be met over the internet anywhere in the world and at any time. Also, professional and competent human resources are needed and therefore it is necessary to invest in new knowledge, innovation, new technologies and lifelong learning. In this environment, management sets its strategic goals through which it will be able to carry out the plans for the sale of products or services. Nowadays, a manager has to have interdisciplinary skills and lifelong education because only in this way it is possible to respond to the constant and rapid changes in the world. We are witnesses that Europe has reunited in order to compete with the less developed countries with their products and services. Europe has long refused to accept the managerial style of governance, particularly in public administration and is therefore far behind the U.S., but also the Third World countries. Until recently, European public administration was more focused on the implementation of laws and regulations and less on managerial governance of the U.S. type. Global environment requires the continuous research, monitoring competition, innovation and the ability to change rapidly.

  6. The global distribution of the arbovirus vectors Aedes aegypti and Ae. albopictus

    Science.gov (United States)

    Kraemer, Moritz UG; Sinka, Marianne E; Duda, Kirsten A; Mylne, Adrian QN; Shearer, Freya M; Barker, Christopher M; Moore, Chester G; Carvalho, Roberta G; Coelho, Giovanini E; Van Bortel, Wim; Hendrickx, Guy; Schaffner, Francis; Elyazar, Iqbal RF; Teng, Hwa-Jen; Brady, Oliver J; Messina, Jane P; Pigott, David M; Scott, Thomas W; Smith, David L; Wint, GR William; Golding, Nick; Hay, Simon I

    2015-01-01

    Dengue and chikungunya are increasing global public health concerns due to their rapid geographical spread and increasing disease burden. Knowledge of the contemporary distribution of their shared vectors, Aedes aegypti and Aedes albopictus remains incomplete and is complicated by an ongoing range expansion fuelled by increased global trade and travel. Mapping the global distribution of these vectors and the geographical determinants of their ranges is essential for public health planning. Here we compile the largest contemporary database for both species and pair it with relevant environmental variables predicting their global distribution. We show Aedes distributions to be the widest ever recorded; now extensive in all continents, including North America and Europe. These maps will help define the spatial limits of current autochthonous transmission of dengue and chikungunya viruses. It is only with this kind of rigorous entomological baseline that we can hope to project future health impacts of these viruses. DOI: http://dx.doi.org/10.7554/eLife.08347.001 PMID:26126267

  7. OCCURRENCE AND SPREAD OF OKRA LEAF CURL VIRUS ...

    African Journals Online (AJOL)

    ABSTRACT. Thé spread of okra leaf curl virus disease (OLCD) in two different ecological areas of Côte d'lvoire and the response of okra varieties and landrace cultivars to the disease were examined in 1986 and. 1991. Much disease spread occurred at Boueké in August, september and october. No linear relationship.

  8. Dynamics of a spreading thin film with gravitational counterflow ...

    Indian Academy of Sciences (India)

    PhD thesis, Princeton University. Davis J M and Troian S M 2003 Influence of attractive van der waals interactions on the optimal excitations in thermocapillary driven spreading. Phys. Rev. E 67: 016,308. Davis J M and Troian S M 2004 Influence of boundary slip on the optimal excitations in thermocapillary driven spreading ...

  9. 12 CFR 619.9180 - Fixed interest spread.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Fixed interest spread. 619.9180 Section 619.9180 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM DEFINITIONS § 619.9180 Fixed interest spread. A percentage to be added to the cost of money to the bank or association as the means of...

  10. Human activity and the spread of Phytophthora ramorum

    Science.gov (United States)

    Hall J. Cushman; Michelle Cooper; Ross K. Meentemeyer; Shelly Benson

    2008-01-01

    Increasing numbers of studies are finding that humans can facilitate the spread of exotic plant species in protected wildlands. Hiking trails commonly serve as conduits for invaders and the number of exotic plant species occurring in protected areas is often correlated positively with visitation rates. Despite such evidence linking human activity to the spread of...

  11. An examination of fire spread thresholds in discontinuous fuel beds

    Science.gov (United States)

    Mark A. Finney; Jack D. Cohen; Isaac C. Grenfell; Kara M. Yedinak

    2010-01-01

    Many fuel beds, especially live vegetation canopies (conifer forests, shrub fields, bunch-grasses) contain gaps between vegetation clumps. Fires burning in these fuel types often display thresholds for spread that are observed to depend on environmental factors like wind, slope, and fuel moisture content. To investigate threshold spread behaviours, we conducted a set...

  12. A Deadly Path: Bacterial Spread During Bubonic Plague.

    Science.gov (United States)

    Gonzalez, Rodrigo J; Miller, Virginia L

    2016-04-01

    Yersinia pestis causes bubonic plague, a fulminant disease where host immune responses are abrogated. Recently developed in vivo models of plague have resulted in new ideas regarding bacterial spread in the body. Deciphering bacterial spread is key to understanding Y. pestis and the immune responses it encounters during infection. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Predicting the rate of spread of introduced animals and plants

    NARCIS (Netherlands)

    Hengeveld, R.; Bosch, van den F.

    1996-01-01

    This paper includes an estimate of what needs to be known for predicting the spreading rates of introduced animal and plant species. Existing models, although capturing the principal aspects of the spreading process, still prove to be too simple. Even in their initial state of development, they

  14. Determinants of Commercial Banks' Interest Rate Spread in Namibia ...

    African Journals Online (AJOL)

    This paper investigates the determinants of commercial banks interest rate spread in Namibia, using a panel data analysis of bank level dada. It applied the OLS technique to identify the bank-specific variables that have been influencing interest rate spread in Namibia over the period 2004 – 2011. The results of the study ...

  15. Spreading history of the Arabian Sea: Some new constraints

    Digital Repository Service at National Institute of Oceanography (India)

    Chaubey, A; Bhattacharya, G.C; Murty, G.P.S.; Desa, M.

    before the formation of All. The hiatus between these spreading spisodes, characterizEd. by a magnetic quiet zone., was much shorter (18 x 10 sup(6) yr) than previously believed. After spreading restarted, the younger phase continued at a very slow rate...

  16. Theory of flame spread above solids. [fuel exothermic surface reactions

    Science.gov (United States)

    Sirignano, W. A.

    1974-01-01

    A theory for flame spread above a solid fuel is presented. The special case is considered whereby the oxidation is an exothermic surface reaction. The spreading rate is predicted as a function of the thermochemical properties, fuel-bed thickness, and convective velocity. Also, the theory predicts temperature, mass fraction, and heat flux as a function of position.

  17. Explosive spread F caused by lightning-induced electromagnetic effects

    Science.gov (United States)

    Liao, C. P.; Freidberg, J. P.; Lee, M. C.

    1989-01-01

    Lightning-produced electromagnetic effects may produce significant modifications in the ionospheric plasmas. An outstanding phenomenon investigated in this paper is the so-called explosive spread F, whose close link with lightning has been identified (Woodman and Kudeki, 1984). Parametric instability excited by the lightning-induced whistler waves is proposed as a potential source mechanism causing the explosive spread F.

  18. Global Managers

    DEFF Research Database (Denmark)

    Barakat, Livia L.; Lorenz, Melanie P.; Ramsey, Jase R.

    2016-01-01

    . Practical implications: – Results imply that global managers should increase their CQ in order to improve their job satisfaction and ultimately perform better in an international context. Originality/value: – The authors make three primary contributions to the international business literature. First......Purpose: – The purpose of this paper is to examine the effect of cultural intelligence (CQ) on the job performance of global managers. Design/methodology/approach: – In total, 332 global managers were surveyed from multinational companies operating in Brazil. The mediating effect of job...... satisfaction was tested on the CQ-job performance relationship. Findings: – The findings suggest that job satisfaction transmits the effect of CQ to job performance, such that global managers high in CQ exhibit more job satisfaction in an international setting, and therefore perform better at their jobs...

  19. Gendered globalization

    DEFF Research Database (Denmark)

    Milwertz, Cecilia Nathansen; Cai, Yiping

    2017-01-01

    Both the People’s Republic of China (PRC) and Nordic countries (Sweden, Iceland, Denmark, Norway and Finland) view gender equality as a social justice issue and are politically committed towards achieving gender equality nationally and internationally. Since China has taken a proactive position o...... on globalization and global governance, gender equality is possibly an area that China may wish to explore in collaboration with the Nordic countries....

  20. Global Social Media Directory: A Resource Guide

    Energy Technology Data Exchange (ETDEWEB)

    Noonan, Christine F.; Piatt, Andrew W.

    2014-10-23

    The Global Social Media Directory is a resource guide providing information on social networking services around the globe. This information changes rapidly, therefore, this document will be updated on a regular basis and as funding permits.