166 research outputs found

    Antikaon production in nucleon-nucleon reactions near threshold

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    The antikaon production cross section from nucleon-nucleon reactions near threshold is studied in a meson exchange model. We include both pion and kaon exchange, but neglect the interference between the amplitudes. In case of pion exchange the antikaon production cross section can be expressed in terms of the antikaon production cross section from a pion-nucleon interaction, which we take from the experimental data if available. Otherwise, a K∗K^*-resonance exchange model is introduced to relate the different reaction cross sections. In case of kaon exchange the antikaon production cross section is related to the elastic KNKN and KˉN\bar KN cross sections, which are again taken from experimental measurements. We find that the one-meson exchange model gives a satisfactory fit to the available data for the NN→NNKKˉNN\to NNK\bar K cross section at high energies. We compare our predictions for the cross section near threshold with an earlier empirical parameterization and that from phase space models.Comment: 16 pages, LaTeX, 5 postscript figures included, submitted to Z. Phys.

    Patterns and drivers of tree Mortality in Iberian Forests: climatic effects are modified by competition

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    Tree mortality is a key process underlying forest dynamics and community assembly. Understanding how tree mortality is driven by simultaneous drivers is needed to evaluate potential effects of climate change on forest composition. Using repeat-measure information fromc.400,000 trees from the Spanish Forest Inventory, we quantified the relative importance of tree size, competition, climate and edaphic conditions on tree mortality of 11 species, and explored the combined effect of climate and competition. Tree mortality was affected by all of these multiple drivers, especially tree size and asymmetric competition, and strong interactions between climate and competition were found. All species showed L-shaped mortality patterns (i.e. showed decreasing mortality with tree size), but pines were more sensitive to asymmetric competition than broadleaved species. Among climatic variables, the negative effect of temperature on tree mortality was much larger than the effect of precipitation. Moreover, the effect of climate (mean annual temperature and annual precipitation) on tree mortality was aggravated at high competition levels for all species, but especially for broadleaved species. The significant interaction between climate and competition on tree mortality indicated that global change in Mediterranean regions, causing hotter and drier conditions and denser stands, could lead to profound effects on forest structure and composition. Therefore, to evaluate the potential effects of climatic change on tree mortality, forest structure must be considered, since two systems of similar composition but different structure could radically differ in their response to climatic conditions

    Future exoplanet research: XUV (EUV and X-ray) detection and characterization

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    This chapter gives an overview of the current status of XUV research in exoplanets and highlights the prospects of future observations. Fundamental questions about the formation and the physical and chemical evolution of exoplanets, particularly hot Jupiters, are addressed through the different lines of XUV research: these comprise XUV irradiation of planetary atmospheres by the host stars, and consequent mass loss and atmospheric evaporation; X-ray and UV transits in exoplanet systems; and Star-Planet Interactions, most often determined by magnetic and tidal forces. While no other UV instrumentation as powerful as that carried by the Hubble Space Telescope will be available for detailed studies in the foreseeable future, the discovery potential of future revolutionary X-ray observatories, such as ATHENA and Lynx, will provide accurate atmosphere characterization and will make strides towards establishing the physics of the interactions between exoplanets and their host stars

    Winning Fights Induces Hyperaggression via the Action of the Biogenic Amine Octopamine in Crickets

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    Winning an agonistic interaction against a conspecific is known to heighten aggressiveness, but the underlying events and mechanism are poorly understood. We quantified the effect of experiencing successive wins on aggression in adult male crickets (Gryllus bimaculatus) by staging knockout tournaments and investigated its dependence on biogenic amines by treatment with amine receptor antagonists. For an inter-fight interval of 5 min, fights between winners escalated to higher levels of aggression and lasted significantly longer than the preceding round. This winner effect is transient, and no longer evident for an inter-fight interval of 20 min, indicating that it does not result from selecting individuals that were hyper-aggressive from the outset. A winner effect was also evident in crickets that experienced wins without physical exertion, or that engaged in fights that were interrupted before a win was experienced. Finally, the winner effect was abolished by prior treatment with epinastine, a highly selective octopamine receptor blocker, but not by propranolol, a ß-adrenergic receptor antagonist, nor by yohimbine, an insect tyramine receptor blocker nor by fluphenazine an insect dopamine-receptor blocker. Taken together our study in the cricket indicates that the physical exertion of fighting, together with some rewarding aspect of the actual winning experience, leads to a transient increase in aggressive motivation via activation of the octopaminergic system, the invertebrate equivalent to the adrenergic system of vertebrates

    Combining qualitative and quantitative understanding for exploring cross-sectoral climate change impacts, adaptation and vulnerability in Europe

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    Climate change will affect all sectors of society and the environment at all scales, ranging from the continental to the national and local. Decision-makers and other interested citizens need to be able to access reliable science-based information to help them respond to the risks of climate change impacts and assess opportunities for adaptation. Participatory integrated assessment (IA) tools combine knowledge from diverse scientific disciplines, take account of the value and importance of stakeholder ‘lay insight’ and facilitate a two-way iterative process of exploration of ‘what if’s’ to enable decision-makers to test ideas and improve their understanding of the complex issues surrounding adaptation to climate change. This paper describes the conceptual design of a participatory IA tool, the CLIMSAVE IA Platform, based on a professionally facilitated stakeholder engagement process. The CLIMSAVE (climate change integrated methodology for cross-sectoral adaptation and vulnerability in Europe) Platform is a user-friendly, interactive web-based tool that allows stakeholders to assess climate change impacts and vulnerabilities for a range of sectors, including agriculture, forests, biodiversity, coasts, water resources and urban development. The linking of models for the different sectors enables stakeholders to see how their interactions could affect European landscape change. The relationship between choice, uncertainty and constraints is a key cross-cutting theme in the conduct of past participatory IA. Integrating scenario development processes with an interactive modelling platform is shown to allow the exploration of future uncertainty as a structural feature of such complex problems, encouraging stakeholders to explore adaptation choices within real-world constraints of future resource availability and environmental and institutional capacities, rather than seeking the ‘right’ answers

    Adaptation in integrated assessment modeling: where do we stand?

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    Adaptation is an important element on the climate change policy agenda. Integrated assessment models, which are key tools to assess climate change policies, have begun to address adaptation, either by including it implicitly in damage cost estimates, or by making it an explicit control variable. We analyze how modelers have chosen to describe adaptation within an integrated framework, and suggest many ways they could improve the treatment of adaptation by considering more of its bottom-up characteristics. Until this happens, we suggest, models may be too optimistic about the net benefits adaptation can provide, and therefore may underestimate the amount of mitigation they judge to be socially optimal. Under some conditions, better modeling of adaptation costs and benefits could have important implications for defining mitigation targets. © Springer Science+Business Media B.V. 2009

    Forest biodiversity, ecosystem functioning and the provision of ecosystem services

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    Forests are critical habitats for biodiversity and they are also essential for the provision of a wide range of ecosystem services that are important to human well-being. There is increasing evidence that biodiversity contributes to forest ecosystem functioning and the provision of ecosystem services. Here we provide a review of forest ecosystem services including biomass production, habitat provisioning services, pollination, seed dispersal, resistance to wind storms, fire regulation and mitigation, pest regulation of native and invading insects, carbon sequestration, and cultural ecosystem services, in relation to forest type, structure and diversity. We also consider relationships between forest biodiversity and multifunctionality, and trade-offs among ecosystem services. We compare the concepts of ecosystem processes, functions and services to clarify their definitions. Our review of published studies indicates a lack of empirical studies that establish quantitative and causal relationships between forest biodiversity and many important ecosystem services. The literature is highly skewed; studies on provisioning of nutrition and energy, and on cultural services, delivered by mixed-species forests are under-represented. Planted forests offer ample opportunity for optimising their composition and diversity because replanting after harvesting is a recurring process. Planting mixed-species forests should be given more consideration as they are likely to provide a wider range of ecosystem services within the forest and for adjacent land uses. This review also serves as the introduction to this special issue of Biodiversity and Conservation on various aspects of forest biodiversity and ecosystem services

    Free-Living Turtles Are a Reservoir for Salmonella but Not for Campylobacter

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    Different studies have reported the prevalence of Salmonella in turtles and its role in reptile-associated salmonellosis in humans, but there is a lack of scientific literature related with the epidemiology of Campylobacter in turtles. The aim of this study was to evaluate the prevalence of Campylobacter and Salmonella in free-living native (Emys orbicularis, n=83) and exotic (Trachemys scripta elegans, n=117) turtles from 11 natural ponds in Eastern Spain. In addition, different types of samples (cloacal swabs, intestinal content and water from Turtle containers) were compared. Regardless of the turtle species, natural ponds where individuals were captured and the type of sample taken, Campylobacter was not detected. Salmonella was isolated in similar proportions in native (8.0±3.1%) and exotic (15.0±3.3%) turtles (p=0.189). The prevalence of Salmonella positive turtles was associated with the natural ponds where animals were captured. Captured turtles from 8 of the 11 natural ponds were positive, ranged between 3.0±3.1% and 60.0±11.0%. Serotyping revealed 8 different serovars among four Salmonella enterica subspecies: S. enterica subsp. enterica (n = 21), S. enterica subsp. salamae (n = 2), S. enterica subsp. diarizonae (n = 3), and S. enterica subsp. houtenae (n = 1). Two serovars were predominant: S. Thompson (n=16) and S. typhimurium (n=3). In addition, there was an effect of sample type on Salmonella detection. The highest isolation of Salmonella was obtained from intestinal content samples (12.0±3.0%), while lower percentages were found for water from the containers and cloacal swabs (8.0±2.5% and 3.0±1.5%, respectively). Our results imply that free-living turtles are a risk factor for Salmonella transmission, but do not seem to be a reservoir for Campylobacter. We therefore rule out turtles as a risk factor for human campylobacteriosis. Nevertheless, further studies should be undertaken in other countries to confirm these results.This work was supported by the Conselleria de Infraestructura, Territorio y Medio Ambiente for their assistance and financial support (Life09-Trachemys, Resolution 28/02/12 CITMA). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.MarĂ­n, C.; Ingresa-Capaccioni, S.; GonzĂĄlez BodĂ­, S.; Marco JimĂ©nez, F.; Vega Garcia, S. (2013). Free-Living Turtles Are a Reservoir for Salmonella but Not for Campylobacter. PLoS ONE. 8(8):1-6. https://doi.org/10.1371/journal.pone.0072350S1688(2012). The European Union Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents and Food‐borne Outbreaks in 2010. EFSA Journal, 10(3). doi:10.2903/j.efsa.2012.2597Kapperud, G. (2003). Factors Associated with Increased and Decreased Risk of Campylobacter Infection: A Prospective Case-Control Study in Norway. American Journal of Epidemiology, 158(3), 234-242. doi:10.1093/aje/kwg139Mermin, J., Hutwagner, L., Vugia, D., Shallow, S., Daily, P., 
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 Shiferaw, B. (2004). Risk Factors for SporadicCampylobacterInfection in the United States: A Case‐Control Study in FoodNet Sites. Clinical Infectious Diseases, 38(s3), S285-S296. doi:10.1086/381598STUDAHL, A., & ANDERSSON, Y. (2000). Risk factors for indigenous campylobacter infection: a Swedish case-control study. Epidemiology and Infection, 125(2), 269-275. doi:10.1017/s0950268899004562NEIMANN, J., ENGBERG, J., MØLBAK, K., & WEGENER, H. C. (2003). A case–control study of risk factors for sporadic campylobacter infections in Denmark. Epidemiology and Infection, 130(3), 353-366. doi:10.1017/s0950268803008355DOORDUYN, Y., VAN DEN BRANDHOF, W. E., VAN DUYNHOVEN, Y. T. H. P., BREUKINK, B. J., WAGENAAR, J. A., & VAN PELT, W. (2010). Risk factors for indigenous Campylobacter jejuni and Campylobacter coli infections in The Netherlands: a case-control study. Epidemiology and Infection, 138(10), 1391-1404. doi:10.1017/s095026881000052xSchroter, M., Roggentin, P., Hofmann, J., Speicher, A., Laufs, R., & Mack, D. (2004). Pet Snakes as a Reservoir for Salmonella enterica subsp. diarizonae (Serogroup IIIb): a Prospective Study. Applied and Environmental Microbiology, 70(1), 613-615. doi:10.1128/aem.70.1.613-615.2004Van Meervenne, E., Botteldoorn, N., Lokietek, S., Vatlet, M., Cupa, A., Naranjo, M., 
 Bertrand, S. (2009). Turtle-associated Salmonella septicaemia and meningitis in a 2-month-old baby. Journal of Medical Microbiology, 58(10), 1379-1381. doi:10.1099/jmm.0.012146-0Williams, L. P. (1965). Pet Turtles as a Cause of Human Salmonellosis. JAMA: The Journal of the American Medical Association, 192(5), 347. doi:10.1001/jama.1965.03080180005001Feeley, J. C., & Treger, M. D. (1969). Penetration of Turtle Eggs by Salmonella braenderup. Public Health Reports (1896-1970), 84(2), 156. doi:10.2307/4593527Mermin, J., Hoar, B., & Angulo, F. J. (1997). Iguanas and Salmonella Marina Infection in Children: A Reflection of the Increasing Incidence of Reptile-associated Salmonellosis in the United States. PEDIATRICS, 99(3), 399-402. doi:10.1542/peds.99.3.399Rodgers, G. L., Long, S. S., Smergel, E., & Dampier, C. (2002). Salmonella Infection Associated With a Pet Lizard in Siblings With Sickle Cell Anemia: An Avoidable Risk. Journal of Pediatric Hematology/Oncology, 24(1), 75-76. doi:10.1097/00043426-200201000-00020Tu, Z.-C., Zeitlin, G., Gagner, J.-P., Keo, T., Hanna, B. A., & Blaser, M. J. (2004). Campylobacter fetus of Reptile Origin as a Human Pathogen. Journal of Clinical Microbiology, 42(9), 4405-4407. doi:10.1128/jcm.42.9.4405-4407.2004Hidalgo-Vila, J., DĂ­az-Paniagua, C., PĂ©rez-Santigosa, N., de Frutos-Escobar, C., & Herrero-Herrero, A. (2008). Salmonella in free-living exotic and native turtles and in pet exotic turtles from SW Spain. Research in Veterinary Science, 85(3), 449-452. doi:10.1016/j.rvsc.2008.01.011Harris, J. R., Neil, K. P., Behravesh, C. B., Sotir, M. J., & Angulo, F. J. (2010). Recent Multistate Outbreaks of HumanSalmonellaInfections Acquired from Turtles: A Continuing Public Health Challenge. Clinical Infectious Diseases, 50(4), 554-559. doi:10.1086/649932Geue, L., & Löschner, U. (2002). Salmonella enterica in reptiles of German and Austrian origin. Veterinary Microbiology, 84(1-2), 79-91. doi:10.1016/s0378-1135(01)00437-0SĂĄnchez-JimĂ©nez, M. M., RincĂłn-Ruiz, P. A., Duque, S., Giraldo, M. A., RamĂ­rez-Monroy, D. M., Jaramillo, G., & Cardona-Castro, N. (2011). Salmonella enterica in semi-aquatic turtles in Colombia. The Journal of Infection in Developing Countries, 5(05), 361-364. doi:10.3855/jidc.1126HEALTH SURVEY OF WILD AND CAPTIVE BOG TURTLES (CLEMMYS MUHLENBERGII) IN NORTH CAROLINA AND VIRGINIA. (2002). Journal of Zoo and Wildlife Medicine, 33(4), 311-316. doi:10.1638/1042-7260(2002)033[0311:hsowac]2.0.co;2Richards, J. M., Brown, J. D., Kelly, T. R., Fountain, A. L., & Sleeman, J. M. (2004). ABSENCE OF DETECTABLE SALMONELLA CLOACAL SHEDDING IN FREE-LIVING REPTILES ON ADMISSION TO THE WILDLIFE CENTER OF VIRGINIA. Journal of Zoo and Wildlife Medicine, 35(4), 562-563. doi:10.1638/03-070Hidalgo-Vila, J., DĂ­az-Paniagua, C., de Frutos-Escobar, C., JimĂ©nez-MartĂ­nez, C., & PĂ©rez-Santigosa, N. (2007). Salmonella in free living terrestrial and aquatic turtles. Veterinary Microbiology, 119(2-4), 311-315. doi:10.1016/j.vetmic.2006.08.012Acheson, D., & Allos, B. M. (2001). Campylobacter jejuni Infections: Update on Emerging Issues and Trends. Clinical Infectious Diseases, 32(8), 1201-1206. doi:10.1086/319760Briones, V., Tellez, S., Goyache, J., Ballesteros, C., del Pilar Lanzarot, M., Dominguez, L., & Fernandez-Garayzabal, J. F. (2004). Salmonella diversity associated with wild reptiles and amphibians in Spain. Environmental Microbiology, 6(8), 868-871. doi:10.1111/j.1462-2920.2004.00631.xMan, S. M. (2011). The clinical importance of emerging Campylobacter species. Nature Reviews Gastroenterology & Hepatology, 8(12), 669-685. doi:10.1038/nrgastro.2011.191Ugarte-Ruiz, M., GĂłmez-Barrero, S., Porrero, M. C., Álvarez, J., GarcĂ­a, M., ComerĂłn, M. C., 
 DomĂ­nguez, L. (2012). Evaluation of four protocols for the detection and isolation of thermophilic Campylobacter from different matrices. Journal of Applied Microbiology, 113(1), 200-208. doi:10.1111/j.1365-2672.2012.05323.xJeffrey, J. S., Tonooka, K. H., & Lozanot, J. (2001). Prevalence of Campylobacter spp. from Skin, Crop, and Intestine of Commercial Broiler Chicken Carcasses at Processing. Poultry Science, 80(9), 1390-1392. doi:10.1093/ps/80.9.1390Perko-MĂ€kelĂ€, P., Isohanni, P., Katzav, M., Lund, M., HĂ€nninen, M.-L., & Lyhs, U. (2009). A longitudinal study of Campylobacter distribution in a turkey production chain. Acta Veterinaria Scandinavica, 51(1). doi:10.1186/1751-0147-51-18Saelinger, C. A., Lewbart, G. A., Christian, L. S., & Lemons, C. L. (2006). Prevalence ofSalmonellaspp in cloacal, fecal, and gastrointestinal mucosal samples from wild North American turtles. Journal of the American Veterinary Medical Association, 229(2), 266-268. doi:10.2460/javma.229.2.266Chambers, D. L., & Hulse, A. C. (2006). Salmonella Serovars in the Herpetofauna of Indiana County, Pennsylvania. Applied and Environmental Microbiology, 72(5), 3771-3773. doi:10.1128/aem.72.5.3771-3773.2006Gaertner, J. P., Hahn, D., Jackson, J., Forstner, M. R. J., & Rose, F. L. (2008). Detection of Salmonellae in Captive and Free-Ranging Turtles Using Enrichment Culture and Polymerase Chain Reaction. Journal of Herpetology, 42(2), 223-231. doi:10.1670/07-1731.1Magnino, S., Colin, P., Dei-Cas, E., Madsen, M., McLauchlin, J., Nöckler, K., 
 Van Peteghem, C. (2009). Biological risks associated with consumption of reptile products. International Journal of Food Microbiology, 134(3), 163-175. doi:10.1016/j.ijfoodmicro.2009.07.001XIA, X., ZHAO, S., SMITH, A., MCEVOY, J., MENG, J., & BHAGWAT, A. (2009). Characterization of Salmonella isolates from retail foods based on serotyping, pulse field gel electrophoresis, antibiotic resistance and other phenotypic properties. International Journal of Food Microbiology, 129(1), 93-98. doi:10.1016/j.ijfoodmicro.2008.11.007Franco, A., Hendriksen, R. S., Lorenzetti, S., Onorati, R., Gentile, G., Dell’Omo, G., 
 Battisti, A. (2011). Characterization of Salmonella Occurring at High Prevalence in a Population of the Land Iguana Conolophus subcristatus in GalĂĄpagos Islands, Ecuador. PLoS ONE, 6(8), e23147. doi:10.1371/journal.pone.0023147Scheelings, T. F., Lightfoot, D., & Holz, P. (2011). PREVALENCE OF SALMONELLA IN AUSTRALIAN REPTILES. Journal of Wildlife Diseases, 47(1), 1-11. doi:10.7589/0090-3558-47.1.1Pasmans, F., Blahak, S., Martel, A., & Pantchev, N. (2008). Introducing reptiles into a captive collection: The role of the veterinarian. The Veterinary Journal, 175(1), 53-68. doi:10.1016/j.tvjl.2006.12.009Strohl, P., Tilly, B., Fremy, S., Brisabois, A., & Guerin-Faublee, V. (2004). Prevalence of Salmonella shedding in faeces by captive chelonians. Veterinary Record, 154(2), 56-58. doi:10.1136/vr.154.2.5
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