CoSyR: a novel beam dynamics code for the modeling of synchrotron radiation effects

The self-consistent nonlinear dynamics of a relativistic charged particle beam interacting with its complete self-fields is a fundamental problem underpinning many of the accelerator design issues in high brightness beam applications, as well as the development of advanced accelerators. Particularly, synchrotron radiation induced effects in a magnetic dispersive beamline element can lead to collective beam instabilities and emittance growth. A novel beam dynamic code is developed based on a Lagrangian method for the calculation of the particles' radiation near-fields using wavefront/wavelet meshes via the Green's function of the Maxwell equations. These fields are then interpolated onto a moving mesh for dynamic update of the beam. This method allows radiation co-propagation and self-consistent interaction with the beam in the simulation at greatly reduced numerical errors. Multiple levels of parallelisms are inherent in this method and implemented in our code CoSyR to enable at-scale simulations of nonlinear beam dynamics on modern computing platforms using MPI, multi-threading, and GPUs. CoSyR has been used to evaluate the transverse and longitudinal coherent radiation effects on the beam and to investigate beam optics designs proposed for mitigation of beam brightness degradation in a magnetic bunch compressor. In this paper, the design of CoSyR, as well as the benchmark with other coherent synchrotron radiation models, are described and discussed.Comment: 17 pages, 14 figure

Creating a Worldwide Network For the Global Environment for Network Innovations (GENI) and Related Experimental Environments

Many important societal activities are global in scope, and as these activities continually expand world-wide, they are increasingly based on a foundation of advanced communication services and underlying innovative network architecture, technology, and core infrastructure. To continue progress in these areas, research activities cannot be limited to campus labs and small local testbeds or even to national testbeds. Researchers must be able to explore concepts at scale—to conduct experiments on world-wide testbeds that approximate the attributes of the real world. Today, it is possible to take advantage of several macro information technology trends, especially virtualization and capabilities for programming technology resources at a highly granulated level, to design, implement and operate network research environments at a global scale. GENI is developing such an environment, as are research communities in a number of other countries. Recently, these communities have not only been investigating techniques for federating these research environments across multiple domains, but they have also been demonstration prototypes of such federations. This chapter provides an overview of key topics and experimental activities related to GENI international networking and to related projects throughout the world

Diversity, host specialization, and geographic structure of filarial nematodes infecting Malagasy bats

We investigated filarial infection in Malagasy bats to gain insights into the diversity of these parasites and explore the factors shaping their distribution. Samples were obtained from 947 individual bats collected from 52 sites on Madagascar and representing 31 of the 44 species currently recognized on the island. Samples were screened for the presence of micro-and macro-parasites through both molecular and morphological approaches. Phylogenetic analyses showed that filarial diversity in Malagasy bats formed three main groups, the most common represented by Litomosa spp. infecting Miniopterus spp. (Miniopteridae); a second group infecting Pipistrellus cf. hesperidus (Vespertilionidae) embedded within the Litomosoides cluster, which is recognized herein for the first time from Madagascar; and a third group composed of lineages with no clear genetic relationship to both previously described filarial nematodes and found in M. griveaudi, Myotis goudoti, Neoromicia matroka (Vespertilionidae), Otomops madagascariensis (Molossidae), and Paratriaenops furculus (Hipposideridae). We further analyzed the infection rates and distribution pattern of Litomosa spp., which was the most diverse and prevalent filarial taxon in our sample. Filarial infection was disproportionally more common in males than females in Miniopterus spp., which might be explained by some aspect of roosting behavior of these cave-dwelling bats. We also found marked geographic structure in the three Litomosa clades, mainly linked to bioclimatic conditions rather than host-parasite associations. While this study demonstrates distinct patterns of filarial nematode infection in Malagasy bats and highlights potential drivers of associated geographic distributions, future work should focus on their alpha taxonomy and characterize arthropod vectors

Interaction between antimalarial 2-Aryl-3H-indol-3-one derivatives and human serum albumin

Binding of drugs to plasma proteins, such as albumin, is a major factor which determines their pharmacokinetics and pharmacological effects. Therefore, the interactions between human serum albumin (HSA) and four antimalarial compounds selected in the 2-aryl-3H-indol-3-one series have been investigated using UV-visible, fluorescence and circular dichroism (CD) spectroscopies. Compounds produced a static quenching of the intrinsic fluorescence of HSA. The thermodynamic parameters have shown that the binding reaction is endothermic for three compounds while exothermic for the 2-phenyl-3H-indol-3-one, 3. The interaction is entropically driven with predominant hydrophobic forces with binding affinities of the order of 104 M-1. The highest binding constant is observed for 3 (K-lambda=280nm = 4.53 x 10(4) M-1) which is also the less active compound against Plasmodium falciparum. Synchronous fluorescence gave qualitative information on the conformational changes of HSA while quantitative data were obtained with CD. Displacement experiments with site markers indicated that drugs bind to HSA at site I (subdomain IIA). In addition, the apparent binding constant and the binding site number were calculated in the presence of different ions

Structural health monitoring in the Sydney harbour bridge using spectral moments

© 2017 International Society for Structural Health Monitoring of Intelligent Infrastrucure. All rights reserved. The motivation behind this paper is to develop a spectral-based damage identification scheme using output only acceleration responses. The presented method is in the context of non-model-based damage identification methods and does not require any representative numerical/analytical model of the structure. The method utilizes spectral moments of the response as damage sensitive feature. Spectral moments directly retrieve information from the power spectral density of the response. Unlike the modal data that only provide information at a limited number of eigen-frequencies, spectral moments capture information from the entire spectra, hence they can distinguish any subtle differences between a normal and distorted signal. The feasibility of the approach in damage identification was validated using real data from the Sydney Harbour Bridge. There are approximately 800 jack arches over a total distance of 1.2 km need to be continuously monitored. For this study, two instrumented jack arches were considered. These joints are located on the eastern side of the bridge underneath the bus lane near the north pylon. One of these two joints had a known crack in 2012, along the front face propagating toward the surface of the deck, while the other joint was intact. This damage was repaired in 2013. Acceleration data were collected from tri-axial accelerometers mounted on the base of each joint before and after repair. The presented spectral-based method along with the hypothesis testing involving the KS-test were applied to obtain a decision on whether or not the structure is damaged. Spectral moments with different orders were also investigated. It was demonstrated that the proposed spectrum-driven feature can reliably distinguish between the healthy and damaged joints which is of great importance for the asset owner. The presented results illustrated high potential of this approach to identify damage in real-life structures

Cross-testbed experimentation using the Planetlab-NITOS federation

Federation of network testbeds has been identified as a key goal in the experimental testbeds community, leading to a recent activity burst in this research field. In this demo, we describe a federated experiment between the NITOS wireless testbed and the Planetlab Europe (PLE) testbed. The federation scheme supporting this experiment was initially established during the Onelab2 EU project and was enhanced during the OpenLab EU project. The experiment constitutes in testing the implementation of an end-to-end delay aware Wi-Fi association scheme, in an environment where a wireless station situated at NITOS is sending traffic towards a remote PLE server. © 2012 ICST Institute for Computer Science, Social Informatics and Telecommunications Engineering

Short Note: Preliminary fish survey of Lac Tseny in north- western Madagascar

We surveyed the fish fauna of Lac Tseny, in the Sofia Region of northwestern Madagascar, during October 2010 by observing commercial catches and targeted netting of areas used by endemic species. We recorded seven native fish species at the lake, including three endemic cichlids, a herring and a catfish. We confirmed the continued survival of the Critically Endangered Paretroplus menarambo, as well as the presence of a Paretroplus taxon that may be new to science. The commercial fishery in the lake is sustained by introduced tilapiines and the native Sauvagella robusta. The three endemic cichlids (Paretroplus spp.) were not targeted by commercial fishermen, but when caught in small numbers were retained for domestic consumption. Submerged trees in the west of the lake restrict fishing with nets and probably provide important habitat for P. menarambo. Priority next steps at the lake include (i) additional surveys and biological studies of the endemic fish species and the Critically Endangered Madagascar big - headed turtle, Erymnochelys madagascariensis, (ii) clarification of the taxonomic status of Paretroplus cf. kieneri and, should it prove a new taxon, its formal scientific description, and (iii) continued engagement with fishing communities and authorities to promote practices that benefit livelihoods and the survival of threatened fish species.RÉSUMÉLa composition spécifique de l’ichtyofaune du lac Tseny, dans l’ouest de Madagascar (région de Sofia) a été inventoriée au cours du mois d’octobre 2010, en observant les prises des pêcheurs et des pêches ciblées sur les espèces endémiques. Sept espèces de poissons indigènes ont été observées, dont trois cichlidés endémiques (Paretroplus menarambo, Paretroplus lamenabe et Paretroplus cf. kieneri), un hareng indigène (Sauvagella robusta) et un poisson-chat (Arius madagascariensis). Deux de ces espèces sont classées comme Menacées dans la Liste Rouge de l’UICN : P. menarambo est une espèce en Danger Critique d’Extinction qui n’est connue que du lac Tseny et A. madagascariensis est une espèce en Danger d’Extinction et endémique de la région de Sofia. Un des poissons que nous avons inventorié dans le genre Paretroplus semble être une forme non décrite. Les pêcheurs ont indiqué que P. menarambo est associé à des arbres immergés le long de la rive occidentale du lac qui offrent un habitat propice à la reproduction et à l’alimentation. Ces arbres immergés empêchent l’utilisation des filets pour la pêche et limitent ainsi la pression de pêche qui s’exerce sur cette espèce. Les trois espèces endémiques de Paretroplus sont prisées par les pêcheurs qui les gardent pour leur consommation personnelle plutôt que de les vendre. La pêche commerciale pratiquée dans le lac semble pérenne grâce à la présence de tilapias allogènes et du hareng indigène (Sauvagella robusta) qui approvisionnent les marchés de poisson local (Tsaratanana), régionaux (Boriziny et Mandritsara) et national (Antananarivo). Les populations locales ont rapporté que la surpêche, l’immigration, l’utilisation illégale de filets à petit maillage et le non respect de la saison de fermeture de la pêche étaient les principales menaces pesant sur l’ichtyofaune du lac Tseny. Une baisse de la pêche commerciale pourrait entraîner une ruée vers les espèces endémiques et l’ouverture des zones d’arbres immergés pour la pêche. Le lac Tseny abrite un assemblage unique de poissons qui doivent être protégés dans leur habitat qui est essentiel aux cichlidés endémiques par le maintien d’une pêche commerciale pérenne. Les prochaines étapes à mener en priorité pour le lac incluent : (i) des études supplémentaires sur la biologie des poissons endémiques et de la Podocnémide de Madagascar (Erymnochelys madagascariensis), une tortue en Danger Critique d’Extinction, (ii) la clarification du statut taxinomique de Paretroplus cf. kieneri qui pourrait être une nouvelle espèce et sa description, le cas échéant, et (iii) l’engagement continu avec les communautés de pêcheurs et les autorités locales pour promouvoir des pratiques équitables en faveur des populations riveraines et pour la survie des espèces de poissons menacées