WorldWideScience

Sample records for mac robertson land

  1. The structure and origin of Prydz Bay and MacRobertson Shelf, East Antarctica

    Science.gov (United States)

    Stagg, H. M. J.

    1985-04-01

    A marine geophysical survey in early 1982, conducted by the Australian Bureau of Mineral Resources, indicated that much of Prydz Bay is underlain by a sedimentary basin. Severe seismic multiples preclude an accurate estimate of total sediment thickness, but interpretation of the seismic and magnetic data suggest that it is probably at least 5 km. The trends of the southeast basin margin and of mild faulting and folding in the southwest indicate an overall NNE trend, roughly orthogonal to the continental margin. In the south of Prydz Bay, two series of seismic sequences are evident, separated by a mildly erosional unconformity. The lower series ranges from poorly- to well-stratified, has minor folding and faulting, and probably derives from continental and perhaps shallow marine pre-breakup sediments. The upper series is generally well-stratified, and prograded near the shelf edge; it probably represents shallow marine post-breakup sediments. The seabed is distinctly unconformable with the underlying sediments, implying both that much of the upper series sediments and some of the lower series sediments have been bulldozed off by advances of the Amery Ice Shelf, and that present sedimentation rates are very low. Possible thin moraines or tillites in the northeast part of the Prydz Bay are also attributed to these glacial advances. The continental slope and rise sedimentary section ranges from at least 3 km thick off Prydz Bay, to thin off the MacRobertson Shelf to the west, reflecting the more prolific sediment source in Prydz Bay. The deep water section includes several seismic sequences, the most distinctive being interpreted as sheet volcanics and turbidite fans. The deepest visible unconformity is locally strongly faulted and may separate the pre-breakup and post-breakup sediments. Indo-Antarctic breakup has been tentatively dated as Early Neocomian (130 Ma) and the E-W orientation of the resultant Antarctic coast invites interpretation of the Lambert Glacier

  2. Celebrating Stephen Robertson's retirement

    NARCIS (Netherlands)

    Hiemstra, Djoerd; Tait, J.; MacFarlane, A; Belkin, N.

    2013-01-01

    Stephen Robertson retired from the Microsoft Research Lab in Cambridge during the summer of 2013 after a long career as one of the most influential, well-liked and eminent researchers in Information Retrieval throughout the world.

  3. The remarkable Dr Robertson

    OpenAIRE

    Hammarton, Tansy C.

    2016-01-01

    Muriel Robertson (1883–1973) was a pioneering protozoologist who made a staggering number of important contributions to the fields of parasitology, bacteriology and immunology during her career, which spanned nearly 60 years. These contributions were all the more remarkable given the scientific and social times in which she worked. While Muriel is perhaps best known for her work on the life cycle and transmission of the African trypanosome, Trypanosoma brucei, which she carried out in Uganda ...

  4. Mac Bible

    CERN Document Server

    Spivey, Dwight

    2009-01-01

    This essential guide answers all your questions on using a Macintosh computer, whether you?re unpacking your very first Mac after switching from a PC or upgrading from an older Mac. You?ll walk through all pre-installed Mac applications, including using Mac OS X, browsing the Web using Safari, downloading music from the iTunes store, troubleshooting Mac-specific problems, organizing photos in iPhoto, organizing calendars in iCal, editing digital video in iMovie, and more.

  5. Les Robertson, CERN's LCG project manager

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    "The LCG will provide a vital test-bed for the new Grid computing technologies that are set to revolutionise the way scientists use the world's computing resources in areas ranging from fundamental research to medical diagnosis," said Les Robertson, CERN's LCG project manager. The Grid is a new method of sharing processing power between computers in centres around the world.

  6. Macs for dummies

    CERN Document Server

    Baig, Edward C

    2014-01-01

    Get the most out of your Mac with this comprehensive guide Macs For Dummies, 13th Edition is the ultimate guide to your Mac, fully updated to include information about the latest updates. The book walks you through troubleshooting, syncing mobile devices, integrating Windows, and more, so you can take advantage of everything Macs have to offer. Whether you're a new user, a recent convert, or you just want to get the most out of your Mac, this book puts all the information you need in one place. Discover what makes Macs superior computing machines. Learn the basics, from mastering the Dock and

  7. Windows for Intel Macs

    CERN Document Server

    Ogasawara, Todd

    2008-01-01

    Even the most devoted Mac OS X user may need to use Windows XP, or may just be curious about XP and its applications. This Short Cut is a concise guide for OS X users who need to quickly get comfortable and become productive with Windows XP basics on their Macs. It covers: Security Networking ApplicationsMac users can easily install and use Windows thanks to Boot Camp and Parallels Desktop for Mac. Boot Camp lets an Intel-based Mac install and boot Windows XP on its own hard drive partition. Parallels Desktop for Mac uses virtualization technology to run Windows XP (or other operating systems

  8. Ellen MacArthur

    Institute of Scientific and Technical Information of China (English)

    Teodora; Lazarova

    2006-01-01

    Just over a year since breaking the round theworld solo record on board her 75 foot trimaranB&O,Ellen MacArthur embarked on a newventure:the Asian Record Circuit 2006,incorpo-rating the ‘Tour Of China’,and bringing a differ-ent set of challenges into new territories.Wespoke to Ellen and her team during their recent(April)stopover in Oingdao.When did you start sailing and what inspiredyou(you grew up in Derbyshire,in the UK,quite far away from the water)?I was introduced to sailing by my Aunt Thea ona small sailing boat called Cabaret.We wentsailing along the east coast of EngLand andbefore I knew it,I was hooked on sailing.I wasso inspired that when I was at school,I saved

  9. Chaotic Friedmann-Robertson-Walker Cosmology

    CERN Document Server

    Calzetta, E A

    1993-01-01

    We show that the dynamics of a spatially closed Friedmann - Robertson - Walker Universe conformally coupled to a real, free, massive scalar field, is chaotic, for large enough field amplitudes. We do so by proving that this system is integrable under the adiabatic approximation, but that the corresponding KAM tori break up when non adiabatic terms are considered. This finding is confirmed by numerical evaluation of the Lyapunov exponents associated with the system, among other criteria. Chaos sets strong limitations to our ability to predict the value of the field at the Big Crunch, from its given value at the Big Bang. (Figures available on request)

  10. Enterprise Mac administrators guide

    CERN Document Server

    Smith, William

    2015-01-01

    IT departments everywhere will be integrating Macs and Mac OS X into their IT infrastructure and this book will tell them how to do it. It will serve as an authoritative, useful and frequently referenced book on Mac OS X administration.

  11. La lutte pour la terre macédonienne : un projet grec de 1909 The fight for Macedonian land: a greek plan of 1909

    Directory of Open Access Journals (Sweden)

    Spyros Karavas

    2012-05-01

    Full Text Available Comment « sauver » la Macédoine des Bulgares ? Le consul de Grèce à Serrès, Sachtouris, voit là, en 1909, un problème autant agraire que national. À cette question qui obsède les politiques grecs de son temps, il croit trouver une solution : acheter des tchifliks qui seraient ensuite partagés entre des paysans que les propriétaires hellènes se chargeraient « d’helléniser ». Conjoncture difficile, hausse des prix, manque de volonté des financiers, son plan reste inappliqué, en revanche les Jeunes-Turcs achèteront des terres pour « turquifier »... la Macédoine.How to « save » Macedonia from Bulgarians? The Greek consul at Serres, Sachtouris, sees in that question, in 1909, a problem that is national as much as it is agrarian. To this particular question, that obsesses Greek politician of his time, he believes that he has found a solution: buy tchifliks which would be then shared among farmers that the Greek owners would then try to turn into Hellenes. Due to the difficult economic situation, the rising prices, the lack of willingness on behalf of the financial contributors, his plans was never implemented, quite the contrary, it was the Young Turks who bought land in order to turn Macedonia...into a Turkish territory.Πώς να « σωθεί » η Μακεδονία από τους Βουλγάρους ; Ο πρόξενος της Ελλάδας στις Σέρρες, Σαχτούρης, το 1909 εντοπίζει ένα πρόβλημα τόσο αγροτικό όσο και εθνικό. Σ’αυτό το ερώτημα που βασανίζει τους έλληνες πολιτικούς της εποχής, πιστεύει ότι βρήκε τη λύση : την αγορά τσιφλικιών που κατόπιν θα μοιράζονταν σε αγρότες που οι έλληνες ιδιοκτήτες τους θα « εξελλήνιζαν ». Οι δύσκολες πε

  12. Mac at Work

    CERN Document Server

    Sparks, David

    2011-01-01

    Bridge the gap between using a Mac at home and at the office. Now that you love your Mac at home, you want to use one at the office without missing a beat of productivity or professionalism. This unique guide shows you how.  You'll find best Mac business practices for handling word processing, spreadsheet and presentation creation, task and project management, and graphics. The book also explores topics such as hardware maintenance, how to synchronize with multiple computers, data backup, and communication with Windows networks.: Covers the nuts and bolts of using a Mac at work, including sync

  13. Enterprise Mac Security Mac OS X Snow Leopard Security

    CERN Document Server

    Edge, Stephen Charles; Hunter, Beau; Sullivan, Gene; LeBlanc, Dee-Ann

    2010-01-01

    A common misconception in the Mac community is that Mac's operating system is more secure than others. While this might be true in certain cases, security on the Mac is still a crucial issue. When sharing is enabled or remote control applications are installed, Mac OS X faces a variety of security threats. Enterprise Mac Security: Mac OS X Snow Leopard is a definitive, expert-driven update of the popular, slash-dotted first edition and was written in part as a companion to the SANS Institute course for Mac OS X. It contains detailed Mac OS X security information, and walkthroughs on securing s

  14. Mass neutrino oscillations in Robertson-Walker space-time

    Institute of Scientific and Technical Information of China (English)

    Huang Xiu-Ju; Li Ze-Jun; Wang Yong-Jiu

    2006-01-01

    Along the geodesic we calculate the interference phase of the mass neutrinos propagating in the radial direction in Robertson-Walker space-time. Since our universe is expanding, the phase factor Φ is increasing under the condition of the same proper physical distance l. Different values of curvature parameter k in Robertson-Walker metric represent different cosmological models, correspondingly, we obtain the different interference phases.

  15. Casimir densities for a boundary in Robertson-Walker spacetime

    Energy Technology Data Exchange (ETDEWEB)

    Saharian, A.A., E-mail: saharian@ictp.i [Department of Physics, Yerevan State University, 1 Alex Manoogian Street, 0025 Yerevan (Armenia); Setare, M.R., E-mail: rezakord@ipm.i [Department of Science of Bijar, University of Kurdistan, Bijar (Iran, Islamic Republic of)

    2010-04-12

    For scalar and electromagnetic fields we evaluate the vacuum expectation value of the energy-momentum tensor induced by a curved boundary in the Robertson-Walker spacetime with negative spatial curvature. In order to generate the vacuum densities we use the conformal relation between the Robertson-Walker and Rindler spacetimes and the corresponding results for a plate moving by uniform proper acceleration through the Fulling-Rindler vacuum. For the general case of the scale factor the vacuum energy-momentum tensor is presented as the sum of the boundary free and boundary induced parts.

  16. The MAC framework: redefining MAC protocols for wireless sensor networks

    NARCIS (Netherlands)

    Parker, T.; Halkes, G.; Bezemer, M.; Langendoen, K.

    2010-01-01

    Most current WSN MAC protocol implementations have multiple tasks to perform—deciding on correct timing, sending of packets, sending of acknowledgements, etc. However, as much of this is common to all MAC protocols, there is duplication of functionality, which leads to larger MAC protocol code size

  17. The MAC framework: redefining MAC protocols for wireless sensor networks

    NARCIS (Netherlands)

    Parker, T.; Halkes, G.; Bezemer, M.; Langendoen, K.

    2010-01-01

    Most current WSN MAC protocol implementations have multiple tasks to perform—deciding on correct timing, sending of packets, sending of acknowledgements, etc. However, as much of this is common to all MAC protocols, there is duplication of functionality, which leads to larger MAC protocol code size

  18. Recent results from MAC

    Energy Technology Data Exchange (ETDEWEB)

    MAC Collaboration

    1982-05-01

    Some preliminary results from the MAC detector at PEP are presented. These include measurements of the angular distribution of ..gamma gamma.., ..mu mu.. and tau tau final states, a determination of the tau lifetime, a measurement of R, and a presentation of the inclusive muon p/sub perpendicular/ distribution for hadronic events.

  19. Macs For Seniors For Dummies

    CERN Document Server

    Chambers, Mark L

    2012-01-01

    You're never too old to fall in love—with your Mac! You took a while, but you are now the proud owner of your first Mac computer. Macs For Seniors For Dummies is just for you. This friendly, accessible guide walks you through choosing a Mac and learning how to use it. You'll find yourself falling head over heels for your Mac in no time. Macs For Seniors For Dummies introduces you to all the basics that you need to know: turning the Mac on and getting connected; using the keyboard and mouse; working with files and folders; navigate around the Mac desktop and OS X Lion; setting up an Inter

  20. Optimal entanglement witnesses from generalized reduction and Robertson maps

    Energy Technology Data Exchange (ETDEWEB)

    Chruscinski, Dariusz; Pytel, Justyna, E-mail: darch@fizyka.umk.pl [Institute of Physics, Nicolaus Copernicus University, Grudziadzka 5/7, 87-100 Torun (Poland)

    2011-04-22

    We provide a generalization of the reduction and Robertson positive maps in matrix algebras. They give rise to a new class of optimal entanglement witnesses. Their structural physical approximation is analyzed. As a byproduct we provide new examples of PPT (positive partial transpose) entangled states.

  1. Optimal entanglement witnesses from generalized reduction and Robertson maps

    CERN Document Server

    Chruściński, Dariusz

    2010-01-01

    We provide a generalization of the reduction and Robertson positive maps in matrix algebras. They give rise to a new class of optimal entanglement witnesses. Their structural physical approximations is analyzed. As a byproduct we provide a new examples of PPT (Positive Partial Transpose) entangled states.

  2. Optimal entanglement witnesses from generalized reduction and Robertson maps

    Science.gov (United States)

    Chruściński, Dariusz; Pytel, Justyna

    2011-04-01

    We provide a generalization of the reduction and Robertson positive maps in matrix algebras. They give rise to a new class of optimal entanglement witnesses. Their structural physical approximation is analyzed. As a byproduct we provide new examples of PPT (positive partial transpose) entangled states.

  3. Robertson-Schrödinger formulation of Ozawa's uncertainty principle

    Science.gov (United States)

    Bastos, Catarina; Bernardini, Alex E.; Bertolami, Orfeu; Costa Dias, Nuno; Nuno Prata, João

    2015-07-01

    A more general measurement disturbance uncertainty principle is presented in a Robertson-Schrödinger formulation. It is shown that it is stronger and having nicer properties than Ozawa's uncertainty relations. In particular it is invariant under symplectic transformations. One shows also that there are states of the probe (measuring device) that saturate the matrix formulation of measurement disturbance uncertainty principle.

  4. Robertson-Schr\\"odinger formulation of Ozawa's Uncertainty Principle

    CERN Document Server

    Bastos, Catarina; Bertolami, O; Dias, N C; Prata, J N

    2014-01-01

    A more general measurement disturbance uncertainty principle is presented in a Robertson-Schr\\"odinger formulation. It is shown that it is stronger and having nicer properties than Ozawa's uncertainty relations. In particular is invariant under symplectic transformations. One shows also that there are states of the probe (measuring device) that saturate the matrix formulation of measurement disturbance uncertainty principle.

  5. f-symbols in Robertson-Walker space-times

    CERN Document Server

    Popa, F C; Popa, Florian Catalin; Tintareanu-Mircea, Ovidiu

    2004-01-01

    In a Robertson-Walker space-time a spinning particle model is investigated and we show that in a stationary case, there exists a class of new structures called f-symbols which can generate reducible Killing tensors and supersymmetry algebras.

  6. Behavior of Friedmann-Lemaître-Robertson-Walker Singularities

    Science.gov (United States)

    Fernández-Jambrina, L.

    2016-08-01

    In Stoica (Int. J. Theor. Phys. 55, 71-80, 2016) a regularization procedure is suggested for regularizing Big Bang singularities in Friedmann-Lemaître-Robertson-Walker (FLRW) spacetimes. We argue that this procedure is only appliable to one case of Big Bang singularities and does not affect other types of singularities.

  7. On physics of the Poynting-Robertson effect

    CERN Document Server

    Klacka, J

    2001-01-01

    Detailed discussion of university textbook statements (Harwit 1988) concerning the Poynting-Robertson effect (P-R effect) is presented. Discussion is concentrated on better physical understanding of the P-R effect. References to complete correct equation of motion for real dust particle are also presented.

  8. iMac pocket genius

    CERN Document Server

    Hart-Davis, Guy

    2010-01-01

    If you want to get the very most out of your iMac, put this savvy Portable Genius guide to work. Want to make the most of the new Magic Mouse and the latest iLife apps? Set up a wireless network using your iMac's AirPort card? Watch television on your iMac, or show iMac videos and movies on your television? You'll find cool and useful Genius tips, full-color screenshots, and pages of easy-to-access shortcuts and tools that will save you time and let you enjoy your iMac to the max.

  9. Monolithic MACS micro resonators

    Science.gov (United States)

    Lehmann-Horn, J. A.; Jacquinot, J.-F.; Ginefri, J. C.; Bonhomme, C.; Sakellariou, D.

    2016-10-01

    Magic Angle Coil Spinning (MACS) aids improving the intrinsically low NMR sensitivity of heterogeneous microscopic samples. We report on the design and testing of a new type of monolithic 2D MACS resonators to overcome known limitations of conventional micro coils. The resonators' conductors were printed on dielectric substrate and tuned without utilizing lumped element capacitors. Self-resonance conditions have been computed by a hybrid FEM-MoM technique. Preliminary results reported here indicate robust mechanical stability, reduced eddy currents heating and negligible susceptibility effects. The gain in B1 /√{ P } is in agreement with the NMR sensitivity enhancement according to the principle of reciprocity. A sensitivity enhancement larger than 3 has been achieved in a monolithic micro resonator inside a standard 4 mm rotor at 500 MHz. These 2D resonators could offer higher performance micro-detection and ease of use of heterogeneous microscopic substances such as biomedical samples, microscopic specimens and thin film materials.

  10. Blind Cognitive MAC Protocols

    CERN Document Server

    Mehanna, Omar; Gamal, Hesham El

    2008-01-01

    We consider the design of cognitive Medium Access Control (MAC) protocols enabling an unlicensed (secondary) transmitter-receiver pair to communicate over the idle periods of a set of licensed channels, i.e., the primary network. The objective is to maximize data throughput while maintaining the synchronization between secondary users and avoiding interference with licensed (primary) users. No statistical information about the primary traffic is assumed to be available a-priori to the secondary user. We investigate two distinct sensing scenarios. In the first, the secondary transmitter is capable of sensing all the primary channels, whereas it senses one channel only in the second scenario. In both cases, we propose MAC protocols that efficiently learn the statistics of the primary traffic online. Our simulation results demonstrate that the proposed blind protocols asymptotically achieve the throughput obtained when prior knowledge of primary traffic statistics is available.

  11. MacBook for dummies

    CERN Document Server

    Chambers , Mark L

    2014-01-01

    Make friends with your MacBook the fun and easy way! Ultra-light, ultra-fast, and ultra-powerful, the MacBook is the coolest laptop in town, and longtime Mac guru Mark L. Chambers is just the guy to help you get to know your MacBook in no time. Take a closer look at the latest features, get the lowdown on OS X, unleash your creative forces with iLife, take care of business with the iWork applications, and sync it all with iCloud with the expert advice in this bestselling MacBook guide. Whether this is your first MacBook or your first laptop, period, you''ll learn to navigate the Mac desktop, c

  12. Macs For Dummies, Pocket Edition

    CERN Document Server

    Baig, Edward C

    2011-01-01

    The fun and easy way to make the most of your wonderful Mac. Simply Mac-nificent — all the cool things your Mac can do! This handy guide helps you figure out the nuts and bolts of your Mac. Navigate the Mac desktop, use the Safari Web browser to surf the Internet, e-mail photos to friends and family, create and print documents, rip audio CDs, and more. The fun begins right here!. Open the book and find: How to set up and configure your Mac; Tips for getting around on the Mac desktop; Steps for setting up an e-mail account and browsing the Internet; Details about the free programs that come wit

  13. iMac portable genius

    CERN Document Server

    Hart-Davis, Guy

    2010-01-01

    The most up-to-date coverage on the latest iMac advice, tools, and shortcuts Cool and useful tips, full-color screenshots, and savvy advice show you how to get the most out of your iMac. Fully updated to cover the iMac's latest features and capabilities, this guide is packed with indispensible information on iLife '09 and Mac OS X Snow Leopard, and shows you how to customize your iMac in a way that it will work best for you.Explores all the bells and whistles of the iMac, including the new Magic Mouse, iLife apps such as iPhoto and iMovie, and Mac OS X Snow LeopardShows yo

  14. Friedman-Robertson-Walker Models with Late-Time Acceleration

    Institute of Scientific and Technical Information of China (English)

    Abdussattar; S. R. Prajapati2

    2011-01-01

    @@ In order to account for the observed cosmic acceleration, a modiGcation of the ansatz for the variation of density in Friedman-Robertson-Walker (FRW) FRW models given by Islam is proposed.The modified ansatz leads to an equation of state which corresponds to that of a variable Chaplygin gas, which in the course of evolution reduces to that of a modified generalized Chaplygin gas (MGCG) and a Chaplygin gas (CG), exhibiting late-time acceleration.%In order to account for the observed cosmic acceleration, a modification of the ansatz for the variation of density in Friedman-Robertson-Walker (FRW) FRW models given by Islam is proposed. The modified ansatz leads to an equation of state which corresponds to that of a variable Chaplygin gas, which in the course of evolution reduces to that ora modified generalized Chaplygin gas (MGCG) and a Chaplygin gas (CG), exhibiting late-time acceleration.

  15. The Poynting-Robertson Effect and Advancement of Perihelion

    CERN Document Server

    Klacka, J

    2002-01-01

    The Poynting-Robertson (P-R) effect has been applied to meteoroids -- interplanetary dust particles -- for several decades. It is well known that the P-R effect produces only changes in the orbital plane of the particle. Provided the initial orbits are not near circular, the differential equations governing the secular changes in both eccentricity and semimajor axis have been known since the time of Robertson. In fact, the P-R effect also causes an advancement of perihelion. The correct expression is i) a decreasing function of beta (the ratio of radiation pressure force to gravity force) for all beta less than 1, ii) the perihelion circulates in a negative direction for particles with beta > {sqrt(73) - 5} / 4, iii) the rate of the advancement of perihelion is not bounded for beta --> 1. Thus, the correct expression differs both quantitatively and qualitatively from those given in the literature.

  16. Friedmann-Robertson-Walker Models with Late-Time Acceleration

    CERN Document Server

    Abdussattar,

    2016-01-01

    In order to account for the observed cosmic acceleration, a modification of the ansatz for the variation of density in Friedman-Robertson-Walker (FRW) models given by Islam is proposed. The modified ansatz leads to an equation of state which corresponds to that of a variable Chaplygin gas, which in the course of evolution reduces to that of a modified generalized Chaplygin gas (MGCG) and a Chaplygin gas (CG), exhibiting late-time acceleration.

  17. On the existence of perturbed Robertson-Walker universes

    Energy Technology Data Exchange (ETDEWEB)

    D' Eath, P.D.

    1976-05-01

    Solutions of the full nonlinear field equations of general relativity near the Robertson-Walker universes are examined, together with their relation to linearized perturbations. A method due to Choquet-Bruhat and Deser is used to prove existence theorems for solutions near Robertson-Walker constraint data of the constraint equations on a spacelike hypersurface. These theorems allow one to regard the matter fluctuations as independent quantities, ranging over certain function spaces. In the k=-1 case the existence theory describes perturbations which may vary within uniform bounds throughout space. When k=+1 a modification of the method leads to a theorem which clarifies some unusual features of these constraint perturbations. The k=0 existence theorem refers only to perturbations which die away at large distances. The connection between linearized constraint solutions and solutions of the full constraints is discussed. For k= +- 1 backgrounds, solutions of the linearized constraints are analyzed using transverse-traceless decompositions of symmetric tensors. Finally the time-evolution of perturbed constraint data and the validity of linearized perturbation theory for Robertson-Walker universes are considered. (AIP)

  18. iMac for dummies

    CERN Document Server

    Chambers, Mark L

    2014-01-01

    Do it all with your iMac and this bestselling For Dummies guide! You're still a little giddy from finally scoring your new iMac, and you can't wait to get started. Even if you're already in love with your iMac, it helps to have a little guidance to really get the most out of this ultimate all-in-one computer. This updated edition of iMac For Dummies is the ideal way to learn the iMac fundamentals from setting up and personalizing your machine to importing files, making FaceTime video calls, surfing the web, using your favorite programs and apps, and everything in between. Trusted Mac guru Mark

  19. Learn Excel 2011 for Mac

    CERN Document Server

    Hart-Davis, Guy

    2011-01-01

    Microsoft Excel 2011 for Mac OS X is a powerful application, but many of its most impressive features can be difficult to find. Learn Excel 2011 for Mac by Guy Hart-Davis is a practical, hands-on approach to learning all of the details of Excel 2011 in order to get work done efficiently on Mac OS X. From using formulas and functions to creating databases, from analyzing data to automating tasks, you'll learn everything you need to know to put this powerful application to use for a variety of tasks. What you'll learn * The secrets of the Excel for Mac interface! * How to create effective workbo

  20. Macs for seniors for dummies

    CERN Document Server

    Chambers, Mark L

    2009-01-01

    Over 50 and thinking about getting your first computer? A user-friendly Mac is a great choice, and Macs For Seniors For Dummies walks you through choosing one and learning to use it. You won't even need your grandchildren to help! Macs For Seniors For Dummies introduces you to all the basic things you may not have encountered before-how to use the keyboard and mouse, work with files and folders, navigate around the Mac OS X desktop, set up an Internet connection, and much more. You'll learn to:Choose the Mac that's right for you, set it up, run programs and manage files, and hook up a printerU

  1. iMac for dummies

    CERN Document Server

    Chambers, Mark L

    2012-01-01

    The bestselling guide to the ultimate all-in-one computer—now updated and revised throughout! If you're looking for speed, performance, and power, the iMac is the ultimate all-in-one computer. From its superior performance, powerful operating system, and amazing applications, the iMac is one awesome machine, and the fun, friendly, and approachable style of iMac For Dummies is an ideal way to get started with the basics. You'll learn the fundamentals of the iMac including setting up and customizing your iMac and the software that comes with it, importing files from your old computer, send

  2. Beyond the Friedmann-Lemaatre-Robertson-Walker Big Bang Singularity

    Institute of Scientific and Technical Information of China (English)

    Cristi Stoica

    2012-01-01

    Einstein's equation,in its standard form,breaks down at the Big Bang singularity.A new version,equivalent to Einstein's whenever the latter is defined,but applicable in wider situations,is proposed.The new equation remains smooth at the Big Bang singularity of the Friedmann-Lemaatre-Robertson-Walker model.It is a tensor equation defined in terms of the Ricci part of the Riemann curvature.It is obtained by taking the Kulkarni-Nomizu product between Einstein's equation and the metric tensor.

  3. On signature transition in Robertson-Walker cosmologies

    CERN Document Server

    Ghafoori-Tabrizi, K; Sepangi, H R

    2000-01-01

    We analyse a classical model of gravitation coupled to a self interacting scalar field. We show that, within the context of this model for Robertson-Walker cosmologies, there exist solutions in the spatially non-flat cases exhibiting transitions from a Euclidean to a Lorentzian spacetime. We then discuss the conditions under which these signature changing solutions to Einstein's field equations exist. In particular, we find that an upper bound for the cosmological constant exists and that close to the signature changing hypersurface, both the scale factor and the scalar field have to be constant. Moreover we find that the signature changing solutions do not exist when the scalar field is massless.

  4. Gravitational birefringence of light in Robertson-Walker cosmologies

    CERN Document Server

    Duval, C

    2016-01-01

    The spacetime evolution of massless spinning particles in a Robertson-Walker background is derived using the deterministic system of equations of motion due to Papapetrou, Souriau and Saturnini. A numerical integration of this system of differential equations in the case of the standard model is performed. The deviation of the photon worldlines from the null geodesics is of the order of the wavelength. Perturbative solutions are also worked out in a more general case. An experimental measurement of this deviation would test the acceleration of our expanding universe.

  5. On the Poynting-Robertson Effect and Analytical Solutions

    CERN Document Server

    Klacka, J

    2000-01-01

    Solutions of the two-body problem with the simultaneous action of the solar electromagnetic radiation in the form of the Poynting-Robertson effect are discussed. Special attention is devoted to pseudo-circular orbits and terminal values of osculating elements. The obtained results complete those of Klacka and Kaufmannova (1992) and Breiter and Jackson (1998). Terminal values of osculating elements presented in Breiter and Jackson (1998) are of no physical sense due to the fact that relativistic equation of motion containing only first order of $\\vec{v}/c$ was used in the paper.

  6. On Physical Interpretation of the Poynting-Robertson Effect

    CERN Document Server

    Klacka, J

    2000-01-01

    Comments to the statements of Srikanth (1999) are presented. As for the standard definition of the Poynting-Robertson drag, the results of Srikanth (1999) are incorrect. Srikanth's statements about the isothermality condition and ``red-shift'' are also discussed. Srikanth's results are generalized for the most general case of the equation of motion when momentum loss per unit time is proportional to -v/c (higher orders are neglected), where v is (heliocentric) velocity of the particle, c is the speed of light.

  7. Real Dust Particles and Unimportance of the Poynting-Robertson Effect

    CERN Document Server

    Kocifaj, M

    1999-01-01

    The importance of the Poynting-Robertson effect on the motion of interplanetary dust particles is discussed. Precise numerical calculations for real dust particle show that condition for the validity of the Poynting-Robertson effect is not fulfilled. The interaction of the (solar) electromagnetic radiation with really shaped dust particle is different from that which yields the Poynting-Robertson effect. The magnitude of the Poynting-Robertson effect's deceleration term is in one to two orders in magnitude (it depends on particle's size) less important than terms corresponding to nonforward (or, nonbackward) scattering.

  8. Gotcha! Macs lose their innocence

    CERN Multimedia

    Computer Security Team

    2012-01-01

    Still believe your Mac is secure because Microsoft PCs fall prey to viruses and worms but Macs don’t? Time to wake up! This year has seen the first major compromise of Macs worldwide*. How is yours doing?   The “Flashback” Trojan is affecting Apple’s own variant of Java and compromises Macs via so-called drive-by infections, i.e. when you visit an appropriately prepared (infected!) website - and this might not necessarily be a site with questionable contents, but could well be a popular, reputable one. Security Companies worldwide have been monitoring this particular Trojan for a while and have estimated that more than half a million Macs were compromised. Connected to a few central command and control servers, the compromised Macs were then supporting the malicious activity of the bad guys! Fortunately, the security companies have now been able to take over those command and control servers and stop their destructive drive. So, Mac users, face the f...

  9. Java and Mac OS X

    CERN Document Server

    Davis, T Gene

    2010-01-01

    Learn the guidelines of integrating Java with native Mac OS X applications with this Devloper Reference book. Java is used to create nearly every type of application that exists and is one of the most required skills of employers seeking computer programmers. Java code and its libraries can be integrated with Mac OS X features, and this book shows you how to do just that. You'll learn to write Java programs on OS X and you'll even discover how to integrate them with the Cocoa APIs.: Shows how Java programs can be integrated with any Mac OS X feature, such as NSView widgets or screen savers; Re

  10. Mac Programming for Absolute Beginners

    CERN Document Server

    Wang, Wallace

    2011-01-01

    Want to learn how to program on your Mac? Not sure where to begin? Best-selling author Wallace Wang will explain how to get started with Cocoa, Objective-C, and Xcode. Whether you are an experienced Windows coder moving to the Mac, or you are completely new to programming, you'll see how the basic design of a Mac OS X program works, how Objective-C differs from other languages you may have used, and how to use the Xcode development environment. Most importantly, you'll learn how to use elements of the Cocoa framework to create windows, store data, and respond to users in your own Mac programs.

  11. MacBook portable genius

    CERN Document Server

    Miser, Brad

    2008-01-01

    The Genius is in. You don't have to be a genius to use a MacBook. But if you want to get the very most out of yours, put this savvy Portable Genius guide to work. Want to connect your MacBook to other Macs? Use Expose to its fullest potential? Troubleshoot? You'll find cool and useful Genius tips, insider secrets, full-color screenshots, and pages of easy-to-access shortcuts and tools that will save you loads of time and make your MacBook IQ soar. Portable GENIUS Fun, hip, and straightforward, the new Portable Genius series gives forward-thinking Apple users useful informat

  12. Mac mini真体验

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    2005年,Mac mini首次登场,众所周知,苹果的模具更换的并不频繁,在外貌没有大幅改变的情况下,迄今为止,Mac mini实际上已经更新了7代。最新的Mac mini的工业设计实际上延续了2008年开始的Unibody一体成型铝合金机身设计与其他Mac在外观上保持了一致的元素。更小的Mac mini看起来更加性感诱人,那么,你需要它么?

  13. The Political Use of Mythic Discourse: Prophetic Interpretation in Pat Robertson's Presidential Campaign.

    Science.gov (United States)

    O'Leary, Stephen; McFarland, Michael

    1989-01-01

    Studies the development of a political ideology that draws on the resources of myth. Analyzes how Pat Robertson's concepts of apocalyptic fulfillment provided an ideological basis for his 1988 presidential campaign, but resulted in significant rhetorical problems. Finds that the transformation in Robertson's apocalyptic vision stemmed from his…

  14. Fiverr MacGyver

    Science.gov (United States)

    Hut, Rolf; van de Giesen, Nick; Larson, Martha

    2014-05-01

    Crowdsourcing has become popular over the past years, also for scientific endeavors. There are many Citizen Science projects and crowdfunding platforms, such as Kickstarter, that are make helpful contributions to moving environmental science forward. An interesting underused source of useful crowd-derived contributions to research is the website Fiverr.com. On this platform, thousands of people, acting as small-scale freelance contractors, offer their skills in the form of services. The platform offers a chance for people to take a hobby, skill, or pastime and make it something more by reaching out to a wider audience and by receiving a payment in return for services. As is typical of other crowdsourcing platforms, the tasks are small and usually self contained. As the name Fiverr suggests, offers start at US5 to provide a particular service. Services offered range from graphic design, to messages sung or spoken with various styles or accents, to complete apps for Android or iPhone. Skill providers on the platform can accept a range of variation of definition in the tasks, some can be described in general terms, for others it is more appropriate to provide examples. Fiverr provides a central location for those offering skills and those needing services to find each other, it makes it possible to communicate and exchange files, to make payments, and it provides support for resolving disputes. In all cases, it is important to keep expectations aligned with the nature of the platform: quality can and will vary. Ultimately, the critical contribution of Fiverr is not to replace professional services or otherwise save money, but rather to provide access to a large group of people with specialized skills who are able to make a contribution on short notice. In the context of this session, it can be considered a pool of people with MacGyver skills lying in wait of a MacGyyer task to attack. There are many ways in which Fiverr tasks, which are called 'gigs', can be useful in

  15. MacBook Teach Yourself VISUALLY

    CERN Document Server

    Miser, Brad

    2010-01-01

    Like the MacBook itself, Teach Yourself VISUALLY MacBook, Second Edition is designed to be visually appealing, while providing excellent functionality at the same time. By using this book, MacBook users will be empowered to do everyday tasks quickly and easily. From such basic steps as powering on or shutting down the MacBook, working on the Mac desktop with the Dashboard and its widgets to running Windows applications, Teach Yourself VISUALLY MacBook, Second Edition covers all the vital information and provides the help and support a reader needs—in many ways it's like having a Mac Genius at

  16. Switching to a Mac portable genius

    CERN Document Server

    McFedries, Paul

    2011-01-01

    Switching from a PC to a Mac is a breeze with this book Anyone considering making the move to Mac from the Windows world will find this book smoothes the way. While Macs are famous for ease of use, there are fundamental differences in Mac and PC ways of thinking, plus there?s the hassle of moving files, calendars, and other essential data from one platform to another. This guide lays out all the information, explains basic Mac procedures for the newcomer, offers great tips on data-sharing (including running Windows applications on a Mac), and provides everything the new Mac user needs to move

  17. Switching to a Mac For Dummies

    CERN Document Server

    Reinhold, Arnold

    2011-01-01

    Learn how to make the switch from PC to Mac a completely smooth transition The number of Mac users continues to increase significantly each year. If you are one of those people and are eager but also anxious about making the switch, then fear not! This friendly guide skips the jargon to deliver you an easy-to-read, understandable introduction to the Macintosh computer. Computer guru Arnold Reinhold walks you through the Mac OS, user interface, and icons. You'll learn how to set up your Mac, move your files from your PC to your Mac, switch applications, get your Mac online, network your Mac, se

  18. Electromagnetic Radiation in Multiply Connected Robertson-Walker Cosmologies

    CERN Document Server

    Tomaschitz, R

    1993-01-01

    Maxwell's equations on a topologically nontrivial cosmological background are studied. The cosmology is locally determined by a Robertson-Walker line element, but the spacelike slices are open hyperbolic manifolds, whose topology and geometry may vary in time. In this context the spectral resolution of Maxwell's equations in terms of horospherical elementary waves generated at infinity of hyperbolic space is given. The wave fronts are orthogonal to bundles of unstable geodesic rays, and the eikonal of geometric optics appears just as the phase of the horospherical waves. This fact is used to attach to the unstable geodesic rays a quantum mechanical momentum. In doing so the quantized energy-momentum tensor of the radiation field is constructed in a geometrically and dynamically transparent way, without appealing to the intricacies of the second quantization. In particular Planck's radiation formula, and the bearing of the multiply connected topology on the fluctuations in the temperature of the background rad...

  19. Classical and Quantum Dispersion in Robertson-Walker Cosmologies

    CERN Document Server

    Tomaschitz, R

    1993-01-01

    The instability of world lines in Robertson-Walker universes of negative spatial curvature is investigated. A probabilistic description of this instability, similar to the Liouville equation, is developed, but in a manifestly covariant, non-Hamiltonian form. To achieve this the concept of a horospherical geodesic flow of expanding bundles of parallel world lines is introduced. An invariant measure and a covariant evolution equation for the probability density on which this flow acts is constructed. The orthogonal surfaces to these bundles of trajectories are horospheres, closed surfaces in three-space, touching the boundary at infinity of hyperbolic space, where the flow lines emerge. These horospheres are just the wave fronts of spherical waves, which constitute a complete set of eigenfunctions of the Klein-Gordon equation. This fact suggests that the evolution of the quantum mechanical density with the classical one be compared, and asymptotic identity in the asymptotically flat region is found. This leads,...

  20. Higgs effective potential in a perturbed Robertson-Walker background

    CERN Document Server

    Maroto, Antonio L

    2014-01-01

    We calculate the one-loop effective potential of a scalar field in a Robertson-Walker background with scalar metric perturbations. A complete set of orthonormal solutions of the perturbed equations is obtained by using the adiabatic approximation for comoving observers. After analyzing the problem of renormalization in inhomogeneous backgrounds, we get the explicit contribution of metric perturbations to the effective potential. We apply these results to the Standard Model Higgs effective potential and evaluate the effects of metric perturbations on the Higgs vacuum expectation value. Space-time variations are found, which are proportional to the gravitational slip parameter, with a typical amplitude of the order of $\\Delta\\phi/\\phi\\simeq 10^{-11}$ on cosmological scales. We also discuss possible astrophysical signatures in the Solar System and in the Milky Way that could open new possibilities to explore the symmetry breaking sector of the electroweak interactions.

  1. Null hypersurfaces in generalized Robertson-Walker spacetimes

    Science.gov (United States)

    Navarro, Matias; Palmas, Oscar; Solis, Didier A.

    2016-08-01

    We study the geometry of null hypersurfaces M in generalized Robertson-Walker spacetimes. First we characterize such null hypersurfaces as graphs of generalized eikonal functions over the fiber and use this characterization to show that such hypersurfaces are parallel if and only if their fibers are also parallel. We further use this technique to construct several examples of null hypersurfaces in both de Sitter and anti de Sitter spaces. Then we characterize all the totally umbilical null hypersurfaces M in a Lorentzian space form (viewed as a quadric in a semi-Euclidean ambient space) as intersections of the space form with a hyperplane. Finally we study the totally umbilical spacelike hypersurfaces of null hypersurfaces in space forms and characterize them as planar sections of M.

  2. On Friedmann-Robertson-Walker model in conformal teleparallel gravity

    Energy Technology Data Exchange (ETDEWEB)

    Silva, J.G.; Ulhoa, S.C. [International Center of Condensed Matter Physics Universidade de Brasilia, Instituto de Fisica, Brasilia, DF (Brazil); Santos, A.F. [Universidade Federal de Mato Grosso, Instituto de Fisica, Mato Grosso (Brazil); University of Victoria, Department of Physics and Astronomy, Victoria, BC (Canada)

    2016-03-15

    In this paper we use the conformal teleparallel gravity to study an isotropic and homogeneous Universe which is settled by the Friedmann-Robertson-Walker metric. The conformal symmetry demands the existence of a scalar field which works as a dark field for this model. We solve numerically the field equations then we obtain the behavior of some cosmological parameters such as the scale factor, the deceleration parameter and the energy density of the perfect fluid which is the matter field of our model. The field equations, which we called modified Friedmann equations, allow us to define a dark fluid, with dark energy density and pressure, responsible for the acceleration in the Universe, once we defined an equation of state for the dark fluid. (orig.)

  3. Mac OS X Lion在Mac App Store上线

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    2011年7月20日,Apple宣布具有超过250种新功能的世界最先进操作系统的第八个重要版本Mac OS X Lion今天在Mac App StoreTM推出并可进行下载,价格为29.99美元。Lion的诸多超强功能包括:全新Multi-Touch手势;全系统支持全屏应用程序;

  4. As-Built documentation of programs to implement the Robertson and Doraiswamy/Thompson models

    Science.gov (United States)

    Valenziano, D. J. (Principal Investigator)

    1981-01-01

    The software which implements two spring wheat phenology models is described. The main program routines for the Doraiswamy/Thompson crop phenology model and the basic Robertson crop phenology model are DTMAIN and BRMAIN. These routines read meteorological data files and coefficient files, accept the planting date information and other information from the user, and initiate processing. Daily processing for the basic Robertson program consists only of calculation of the basic Robertson increment of crop development. Additional processing in the Doraiswamy/Thompson program includes the calculation of a moisture stress index and correction of the basic increment of development. Output for both consists of listings of the daily results.

  5. Violation of the Robertson-Schr\\"odinger uncertainty principle and non-commutative quantum mechanics

    CERN Document Server

    Bastos, Catarina; Dias, Nuno Costa; Prata, João Nuno

    2012-01-01

    We show that a possible violation of the Robertson-Schr\\"odinger uncertainty principle may signal the existence of a deformation of the Heisenberg-Weyl algebra. More precisely, we prove that any Gaussian in phase-space (even if it violates the Robertson-Schr\\"odinger uncertainty principle) is always a quantum state of an appropriate non-commutative extension of quantum mechanics. Conversely, all canonical non-commutative extensions of quantum mechanics display states that violate the Robertson-Schr\\"odinger uncertainty principle.

  6. Office 2011 for Mac For Dummies

    CERN Document Server

    LeVitus, Bob

    2011-01-01

    Get started with Office 2011 for Mac and discover the creative possibilitiesThe leading suite of productivity software for the Mac, Microsoft Office helps users complete common business tasks, including word processing, e-mail, presentations, financial analysis, and much more. Office 2011 for Mac For Dummies is the perfect companion for Microsoft Office for Mac users upgrading to the newest version, new computer users, and those who may have switched from the Windows version of Office. Written by one of the most popular gurus in the Mac community, Bob "Dr. Mac" LeVitus, the book explains every

  7. Separation and divergence: the untold story of James Robertson's and John Bowlby's theoretical dispute on mother-child separation.

    Science.gov (United States)

    van der Horst, Frank C P; van der Veer, René

    2009-01-01

    The work of Robertson and Bowlby is generally seen as complementary, Robertson being the practically oriented observer and Bowlby focusing on theoretical explanations for Robertson's observations. The authors add to this picture an "untold story" of the collaboration between Robertson and Bowlby: the dispute between the two men that arose in the 1960s about the corollaries of separation and the ensuing personal animosity. On the basis of unique archival materials, this until now little known aspect of the history of attachment theory is extensively documented. The deteriorating relationship between Robertson and Bowlby is described against the background of different currents in psychoanalysis in Britain in the interbellum.

  8. Poynting-Robertson-like Drag at the Sun's Surface

    Science.gov (United States)

    Cunnyngham, Ian; Emilio, Marcelo; Kuhn, Jeff; Scholl, Isabelle; Bush, Rock

    2017-02-01

    The Sun's internal rotation Ω (r ,Θ ) has previously been measured using helioseismology techniques and found to be a complex function of colatitude θ and radius r . From helioseismology and observations of apparently "rooted" solar magnetic tracers, we know that the surface rotates more slowly than much of the interior. The cause of this slow-down is not understood, but it is important for understanding stellar rotation generally and any plausible theory of the solar interior. A new analysis using 5-min solar p -mode limb oscillations as a rotation "tracer" finds an even larger velocity gradient in a thin region at the top of the photosphere. This shear occurs where the solar atmosphere radiates energy and angular momentum. We suggest that the net effect of the photospheric angular momentum loss is similar to Poynting-Robertson "photon braking" on, for example, Sun-orbiting dust. The resultant photospheric torque is readily computed and, over the Sun's lifetime, is found to be comparable to the apparent angular momentum deficit in the near-surface shear layer.

  9. Are explanations of the Poynting-Robertson effect correct?

    CERN Document Server

    Klacka, J; Pastor, P; Komar, L

    2009-01-01

    Physics of the Poynting-Robertson (P-R) effect is discussed and compared with the statements published in the past thirty years. Relativistically covariant formulation reveals the essence of the P-R effect and points out to nonphysical explanations in scientific papers and monographs. Although the final equation of motion $m$ $d\\vec{v} / dt$ $=$ ($S A'\\bar{Q'}_{pr}$ $ / $ $c$) ${(1 - \\vec{v} \\cdot \\vec{e} / c) \\vec{e} - \\vec{v} / c}$ has been usually correctly presented and used, its derivation and explanation of its essence is frequently incorrect. The relativistically covariant form of the equation of motion yields the P-R effect as an action of the radiation pressure force on a moving spherical body. No "P-R drag", as a particular relativistically covariant equation of motion, exists. Omission of the nonphysical term "P-R drag" excludes any confusion in the published definitions. The difference between the effects of solar electromagnetic and corpuscular (solar wind) radiation is stressed. The force acting...

  10. Poynting-Robertson Effects in Saturn's F Ring

    Science.gov (United States)

    Giuliatti Winter, S. M.

    2000-10-01

    Observations from the Voyager spacecraft have shown that the narrow F ring of Saturn is composed of micrometer-sized particles that extend inward from the core (Showalter et al., Icarus, 1992; Graps et al., Icarus, 1984). These small particles can be disturbed by the effects of the Poynting-Robertson drag (PR drag), which cause their orbital decay. The F ring particles are also perturbed by the nearby satellite Prometheus. The effects of the satellite are intensified during the closest approach with the ring particles. At this special configuration gaps are formed in the ring as result of scattering of particles in the direction of the planet (Giuliatti Winter et al.,PSS, 2000). In this work we analyze the effects of the PR drag combined with the perturbations of the satellite Prometheus. Our results show that depending on the initial conditions of the ring particles the satellite can avoid the orbital decay caused by the PR drag (Giuliatti Winter & Guimar\\ aes, 2000). There are some resonance locations in the region between Prometheus and the F ring, some of them with the satellite Atlas (Giuliatti Winter, 1994). We also analyze the orbital evolution of a dust ring particle subjected to PR drag and Atlas perturbations. Acknowledgement: SMGW (Proc. 99/11965) thanks FAPESP for the financial support.

  11. E. Graeme Robertson--dynamics in fluid and light.

    Science.gov (United States)

    Kempster, P A; Gerraty, R P; Bower, S P C

    2013-02-01

    An eponymous lecture at the Australian and New Zealand Association of Neurologists Annual Scientific Meeting commemorates E. Graeme Robertson (1903-75), and some neurologists will know that particular Australian practices in clinical neurology, so far as they exist, have origins in his career. This is a historical article on the literary record of a man who had his own sense of history--an affinity with the past as well as an awareness of future generations of readers. He wrote authoritative texts on pneumoencephalography before new technology made it obsolete, and he produced a series of books on decorative architectural cast iron in Australian cities. A talent for visual interpretation seems to have drawn him to both of these topics; a common theme is contrast between light and dark, which is expatiated in images and in clear, well-written prose in his publications. We review his medical writings, including some largely forgotten principles of cerebrospinal fluid physics that he discovered when researching pneumoencephalography. We also explore his obsession with cast iron--its architectural historical significance, his techniques for photographing it, and some of the ways that it related to his life's work as a clinical neurologist.

  12. Land

    CSIR Research Space (South Africa)

    Audouin, M

    2007-01-01

    Full Text Available Unsustainable agricultural practices have had a role to play in the degradation of land on which agriculture depends. South Africa has an international obligation to develop a National Action Programme (NAP), the purpose of which is to identify...

  13. Spacetime emergence of the robertson-walker universe from a matrix model.

    Science.gov (United States)

    Erdmenger, Johanna; Meyer, René; Park, Jeong-Hyuck

    2007-06-29

    Using a novel, string theory-inspired formalism based on a Hamiltonian constraint, we obtain a conformal mechanical system for the spatially flat four-dimensional Robertson-Walker Universe. Depending on parameter choices, this system describes either a relativistic particle in the Robertson-Walker background or metric fluctuations of the Robertson-Walker geometry. Moreover, we derive a tree-level M theory matrix model in this time-dependent background. Imposing the Hamiltonian constraint forces the spacetime geometry to be fuzzy near the big bang, while the classical Robertson-Walker geometry emerges as the Universe expands. From our approach, we also derive the temperature of the Universe interpolating between the radiation and matter dominated eras.

  14. (Genetics and molecular biology of Robertson's Mutator: A workshop series): Final report

    Energy Technology Data Exchange (ETDEWEB)

    Buckner, B.

    1988-01-01

    The objectives of the Workshop Series on the Genetics and Molecular Biology of Robertson's Mutator were to assess and consolidate interpretations of current Mutator research and to recognize and honor the outstanding contributions of Donald S. Robertson. To this end, a program of lectures, workshops, posters and opportunities for informal interaction was planned and carried out as indicated in the enclosed registration booklet. Within the context of the workshops, several topics were discussed. These discussions are summarized in abstract form.

  15. Mac OS X Lion Server For Dummies

    CERN Document Server

    Rizzo, John

    2011-01-01

    The perfect guide to help administrators set up Apple's Mac OS X Lion Server With the overwhelming popularity of the iPhone and iPad, more Macs are appearing in corporate settings. The newest version of Mac Server is the ideal way to administer a Mac network. This friendly guide explains to both Windows and Mac administrators how to set up and configure the server, including services such as iCal Server, Podcast Producer, Wiki Server, Spotlight Server, iChat Server, File Sharing, Mail Services, and support for iPhone and iPad. It explains how to secure, administer, and troubleshoot the networ

  16. Take Control of Maintaining Your Mac

    CERN Document Server

    Kissell, Joe

    2009-01-01

    Keep your Mac running smoothly with our easy maintenance program! Regular maintenance is necessary to avoid problems and to ensure your Mac runs at peak performance, but it's hard to know what to do and when to do it. Best-selling author Joe Kissell has now applied his commonsense approach to the task of maintaining your Mac, whether you use Tiger or Leopard! Learn how to start on the right foot; what you should do daily, weekly, monthly, and yearly; and how to prepare for Mac OS X updates. Joe even explains how to monitor your Mac's health and debunks common panaceas. Read this book to lea

  17. Switching to a Mac For Dummies

    CERN Document Server

    Reinhold, Arnold

    2007-01-01

    Thinking of making the switch from your PC to a Mac? Congratulations! You're in for a great, virus-free ride. And Switching to Mac For Dummies makes it smoother than you ever imagined. From buying the Mac that's right for you to transferring your files to breaking your old Windows habits and learning to do things the (much easier) Mac way, it makes the whole process practically effortless. Whether you've been using Windows XP, Vista, or even Linux, you'll find simple, straightforward ways to make your transition go smoothly. That will leave you plenty of time to get familiar with Mac'

  18. Switching to the Mac The Missing Manual

    CERN Document Server

    Pogue, David

    2010-01-01

    Is Windows giving you pause? Ready to make the leap to the Mac instead? There has never been a better time to switch from Windows to Mac, and this incomparable guide will help you make a smooth transition. New York Times columnist and Missing Manuals creator David Pogue gets you past three challenges: transferring your stuff, assembling Mac programs so you can do what you did with Windows, and learning your way around Mac OS X. Learning to use a Mac is not a piece of cake, but once you do, the rewards are oh-so-much better. No viruses, worms, or spyware. No questionable firewalls, inefficien

  19. Cognitive MAC designs for OSA networks

    CERN Document Server

    Derakhshani, Mahsa

    2014-01-01

    This SpringerBrief presents recent advances in the cognitive MAC designs for opportunistic spectrum access (OSA) networks. It covers the basic MAC functionalities and MAC enhancements of IEEE 802.11. Later chapters discuss the existing MAC protocols for OSA and classify them based on characteristic features. The authors provide new research in adaptive carrier sensing-based MAC designs tailored for OSA, which optimize spectrum utilization and ensure a peaceful coexistence of licensed and unlicensed systems. Analytically devised via optimization and game-theoretic approaches, these adaptive M

  20. Relativistic models of thin disks immersed in a Robertson-Walker type spacetime Modelos relativistas de discos delgados inmersos en un espacio-tiempo tipo Robertson-Walker

    Directory of Open Access Journals (Sweden)

    Gonzalo García Reyes

    2013-11-01

    Full Text Available Using the well known “displace, cut and reflect” method used to generate disks from given solutions of Einstein field equations, we construct some relativistic models of time dependent thin disks of infinite extension made of a perfect fluid based on the Robertson-Walker metric. Two simple families of models of disks based on Robertson-Walker solutions admitting Matter and Ricci collineations are presented. We obtain disks that are in agreement with all the energy conditions.Usando el método de “desplazamiento, corte y reflexión” se construyen algunos modelos relativistas exactas de soluciones que representan discos delgados de extensión infinita, dependientes del tiempo y hechos de un fluido perfecto, basados en la métrica de Robertson-Walker. Se presentan dos familias simples de modelos de discos basados sobre el espacio tiempo de Robertson-Walker que admiten colineaciones de Ricci y de materia. Se obtienen modelos de discos que satisfacen todas las condiciones de energía.

  1. Assessment of voice and speech symptoms in early Parkinson's disease by the Robertson dysarthria profile.

    Science.gov (United States)

    Defazio, Giovanni; Guerrieri, Marta; Liuzzi, Daniele; Gigante, Angelo Fabio; di Nicola, Vincenzo

    2016-03-01

    Changes in voice and speech are thought to involve 75-90% of people with PD, but the impact of PD progression on voice/speech parameters is not well defined. In this study, we assessed voice/speech symptoms in 48 parkinsonian patients staging dysarthria profile (a clinical-perceptual method exploring all components potentially involved in speech difficulties), the Voice handicap index (a validated measure of the impact of voice symptoms on quality of life) and the speech evaluation parameter contained in the Unified Parkinson's Disease Rating Scale part III (UPDRS-III). Accuracy and metric properties of the Robertson dysarthria profile were also measured. On Robertson dysarthria profile, all parkinsonian patients yielded lower scores than healthy control subjects. Differently, the Voice Handicap Index and the speech evaluation parameter contained in the UPDRS-III could detect speech/voice disturbances in 10 and 75% of PD patients, respectively. Validation procedure in Parkinson's disease patients showed that the Robertson dysarthria profile has acceptable reliability, satisfactory internal consistency and scaling assumptions, lack of floor and ceiling effects, and partial correlations with UPDRS-III and Voice Handicap Index. We concluded that speech/voice disturbances are widely identified by the Robertson dysarthria profile in early parkinsonian patients, even when the disturbances do not carry a significant level of disability. Robertson dysarthria profile may be a valuable tool to detect speech/voice disturbances in Parkinson's disease.

  2. Mac OS X Tiger for Unix Geeks

    CERN Document Server

    Jepson, Brian

    2005-01-01

    If you're one of the many Unix developers drawn to Mac OS X for its Unix core, you'll find yourself in surprisingly unfamiliar territory. Unix and Mac OS X are kissing cousins, but there are enough pitfalls and minefields in going from one to another that even a Unix guru can stumble, and most guides to Mac OS X are written for Mac aficionados. For a Unix developer, approaching Tiger from the Mac side is a bit like learning Russian by reading the Russian side of a Russian-English dictionary. Fortunately, O'Reilly has been the Unix authority for over 25 years, and in Mac OS X Tiger for Unix Gee

  3. Teach yourself visually Mac Mini

    CERN Document Server

    Hart-Davis, Guy

    2012-01-01

    The perfect how-to guide for visual learners Apple?s Mac Mini packs a powerful punch is in a small package, including both HDMI and Thunderbolt ports plus the acclaimed OS X. But if you want to get the very most from all this power and versatility, be sure to get this practical visual guide. With full-color, step-by-step instructions as well as screenshots and illustrations on every page, it clearly shows you how to accomplish tasks rather than burying you in pages of text. Discover helpful visuals and how-tos on the OS, hardware specs, Launchpad, the App Store, multimedia capabilities (such

  4. Web Development with the Mac

    CERN Document Server

    Vegh, Aaron

    2010-01-01

    Learn Web development the Apple way and build a business. With a focus on both coding and creative development, this in-depth guide thoroughly covers what you need to know to build winning websites for clients — from what it takes to bring a business online to how to make your site interactive to how to run a freelance web business. In between, you'll master the technical tools of the trade — such as HTML, CSS, JavaScript, PHP, and Ruby on Rails — and learn how to create beautiful interfaces using Photoshop . This book covers everything a fledgling web developer working on a Mac needs to launc

  5. A mammometric comparison of modiifed Robertson versus Wise pattern inferior pedicle reduction mammoplasty

    Institute of Scientific and Technical Information of China (English)

    Victor Z Zhu; Ajul Shah; Rachel Lentz; Tracy Sturrock; Alexander F Au; Stephanie L Kwei

    2016-01-01

    Aim: The advent of 3D photoimaging and mammometrics has allowed for quantitative, volumetric breast analyses. This study uses 3D photoimaging and mammometrics to compare the postoperative morphometric outcomes of the modiifed Robertson technique to the more traditional Wise pattern inferior pedicle technique. Methods: Inferior pedicle reduction mammoplasty was performed using either a Wise pattern or modiifed Robertson skin incision. 3D photography and analysis were done at 1-3 months and 6-12 months postoperatively. Results: There were 14 breasts in the modiifed Robertson group (ROB) and 24 breasts in the Wise pattern group (WISE). There were no signiifcant differences in demographic data or amount of tissue resected. At 6-12 months, the modiifed Robertson cohort demonstrated increased superior pole fullness (62.9%ROB vs. 58.3%WISE, P=0.05). The Wise cohort, however, maintained greater maximum breast projection (5.52 cm ROB vs. 6.54 cm WISE, P=0.01) and increased medial pole fullness (29.6%ROB vs. 46.9%WISE, P<0.01). There was no difference in tissue shifting from the superior pole to the inferior pole over time (+3.36 superior pole%ROB vs.+1.42 superior pole%WISE, P=0.28). Areola surface area increased equally in both cohorts (+3.08 cm2 ROB vs.+2.59 cm2 WISE, P=0.77);however, the ifnal size of the areola was greater in the modiifed Robertson cohort (26.9 cm2 ROB vs. 21.6 cm2 WISE, P<0.01). Conclusion:Using 3D mammometrics, we found increased superior pole fullness in the modiifed Robertson group while the Wise pattern group demonstrated greater medial pole fullness and maximum breast projection.

  6. Analysis of 3gpp-MAC and two-key 3gpp-MAC

    DEFF Research Database (Denmark)

    Knudsen, Lars Ramkilde; Mitchell, C.J.

    2003-01-01

    Forgery and key-recovery attacks are described on the 3gpp-MAC scheme, proposed for inclusion in the 3gpp specification. Three main classes of attack are given, all of which operate whether or not truncation is applied to the MAC value. Attacks in the first class use a large number of 'chosen MACs......', those in the second class use a large number of 'known MACs', and those in the third class require a large number of MAC verifications, but very few known MACS and no chosen MACS. The first class yields both forgery and key-recovery attacks, whereas the second and third classes are key-recovery attacks...... only. Both single-key and two-key variants of 3gpp-MAC are considered; the forgery attacks are relevant to both variants, whereas the key-recovery attacks are only relevant to the two-key variant....

  7. Analysis of 3gpp-MAC and two-key 3gpp-MAC

    DEFF Research Database (Denmark)

    Knudsen, Lars Ramkilde; Mitchell, C.J.

    2003-01-01

    Forgery and key-recovery attacks are described on the 3gpp-MAC scheme, proposed for inclusion in the 3gpp specification. Three main classes of attack are given, all of which operate whether or not truncation is applied to the MAC value. Attacks in the first class use a large number of 'chosen MACs......', those in the second class use a large number of 'known MACs', and those in the third class require a large number of MAC verifications, but very few known MACS and no chosen MACS. The first class yields both forgery and key-recovery attacks, whereas the second and third classes are key-recovery attacks...... only. Both single-key and two-key variants of 3gpp-MAC are considered; the forgery attacks are relevant to both variants, whereas the key-recovery attacks are only relevant to the two-key variant....

  8. Mac protocols for cyber-physical systems

    CERN Document Server

    Xia, Feng

    2015-01-01

    This book provides a literature review of various wireless MAC protocols and techniques for achieving real-time and reliable communications in the context of cyber-physical systems (CPS). The evaluation analysis of IEEE 802.15.4 for CPS therein will give insights into configuration and optimization of critical design parameters of MAC protocols. In addition, this book also presents the design and evaluation of an adaptive MAC protocol for medical CPS, which exemplifies how to facilitate real-time and reliable communications in CPS by exploiting IEEE 802.15.4 based MAC protocols. This book wil

  9. Take control of troubleshooting your Mac

    CERN Document Server

    Kissell, Joe

    2009-01-01

    Learn how to solve any Mac problem with Joe Kissell's expert advice! We may love our Macs, but they can still suffer significant problems. In this essential guide from best-selling author Joe Kissell, you'll learn 17 basic troubleshooting procedures and how to solve 9 common problems, along with an easy-to-follow way to troubleshoot novel problems. Whether your Mac won't turn on, experiences kernel panics repeatedly, or is glacially slow, this book has the calm, friendly advice you need to find a solution. Following in the footsteps of his critically acclaimed books Take Control of Mac OS X

  10. Teach yourself visually MacBook Pro

    CERN Document Server

    Hart-Davis, Guy

    2014-01-01

    Clear instructions to help visual learners get started with their MacBook Pro Covering all the essential information you need to get up to speed with your MacBook Pro, this new edition provides you with the most up-to-date information on performing everyday tasks quickly and easily. From basics such as powering on or shutting down the MacBook Pro to more advanced tasks such as running Windows applications, this visual guide provides the help and support you need to confidently use your MacBook Pro to its full potential.Empowers you to perform everyday tasks quickly and easilyCovers new hardwa

  11. Take control the Mac OS X lexicon

    CERN Document Server

    Zardetto, Sharon

    2009-01-01

    This ebook explains a little bit of everything; in fact, it's The Mac OS X (and then some) Lexicon because it's never just you and your Mac. It's you and your Mac and the Web, and your email, and that article you just read that threw 17 new acronyms at you or assumed that you knew all sorts of networking terms. Or it's you and your Mac and Finder features you've never touched, such as burn folders, smart folders, or proxy icons, and that mysterious Services submenu. This book is a great guide for Macintosh users everywhere who have trouble keeping up with the latest jargon, fo

  12. Macs all-in-one for dummies

    CERN Document Server

    Hutsko, Joe

    2014-01-01

    Your all-in-one guide to unleashing your Mac's full potential It's a Mac world out there. But if you haven't read the instruction manual, you may be neglecting some of your computer's coolest features. Turn to Macs All-in-One For Dummies' jam-packed guide to access the incredible tools within your computer. With this fully updated reference, you will learn how to use Launchpad and Mission Control; protect your Mac; back up and restore data with Time Machine; sync across devices in iCloud; import, organize, and share photos; direct in iMovie; compose in GarageBand; and so much more. The possi

  13. Viscous Cosmology and Thermodynamics of Apparent Horizon in Modified Friedman-Robertson-Walkers Universe

    Science.gov (United States)

    Sadeghi, J.; Naji, J.; Vaez, H.; Khanpour, B.

    2014-09-01

    In this paper, we write modified Friedman-Robertson-Walkers (FRW) equation in the form of first law of thermodynamics at the apparent horizon. We consider the universe filled with the viscous fluid. Here we employ the general expression of temperature gravity and entropy at the apparent horizon of FRW universe and obtain the generalized first law of thermodynamics at the special condition for the modified FRW equation. The generalized first law of thermodynamics help us to arrange the α 1, α 2, β 1 and β 2 in modified Friedman-Robertson-Walkers equation.

  14. Quicksilver Power Mac G4

    CERN Multimedia

    2001-01-01

    A new generation with a reworked motherboard is launched on 2001 with however the same Graphite box. It also included a processor speed-bump, and brought the DVD-R "SuperDrive" to the mid-level model. The Quicksilver PowerMac was available in three configurations: The 733 MHz model, with 128 MB of RAM, a 40 GB hard drive, and a CD-RW drive, was 1,699 dollars, the 867 MHz configuration, with 128 MB of RAM, a 60 GB hard drive and a DVD-R drive, was 2,499 dollars, and the high-end dual-800 MHz model, with 256 MB of RAM, an 80 GB hard drive and a DVD-R drive, was 3,499 dollars. The 733 MHz model is the first personal computer to have a DVD burner, named SuperDrive at Apple. The design was updated on 2002 with 800 MHz, 933 MHz and dual 1 GHz configurations, becoming the first Mac to reach 1 GHz.

  15. Wound healing in Mac-1 deficient mice.

    Science.gov (United States)

    Chen, Lin; Nagaraja, Sridevi; Zhou, Jian; Zhao, Yan; Fine, David; Mitrophanov, Alexander Y; Reifman, Jaques; DiPietro, Luisa A

    2017-05-01

    Mac-1 (CD11b/CD18) is a macrophage receptor that plays several critical roles in macrophage recruitment and activation. Because macrophages are essential for proper wound healing, the impact of Mac-1 deficiency on wound healing is of significant interest. Prior studies have shown that Mac-1(-/-) mice exhibit deficits in healing, including delayed wound closure in scalp and ear wounds. This study examined whether Mac-1 deficiency influences wound healing in small excisional and incisional skin wounds. Three millimeter diameter full thickness excisional wounds and incisional wounds were prepared on the dorsal skin of Mac-1 deficient (Mac-1(-/-) ) and wild type (WT) mice, and wound healing outcomes were examined. Mac-1 deficient mice exhibited a normal rate of wound closure, generally normal levels of total collagen, and nearly normal synthesis and distribution of collagens I and III. In incisional wounds, wound breaking strength was similar for Mac-1(-/-) and WT mice. Wounds of Mac-1 deficient mice displayed normal total macrophage content, although macrophage phenotype markers were skewed as compared to WT. Interestingly, amounts of TGF-β1 and its downstream signaling molecules, SMAD2 and SMAD3, were significantly decreased in the wounds of Mac-1 deficient mice compared to WT. The results suggest that Mac-1 deficiency has little impact on the healing of small excisional and incisional wounds. Moreover, the findings demonstrate that the effect of single genetic deficiencies on wound healing may markedly differ among wound models. These conclusions have implications for the interpretation of the many prior studies that utilize a single model system to examine wound healing outcomes in genetically deficient mice. © 2017 by the Wound Healing Society.

  16. A MAC Mode for Lightweight Block Ciphers

    DEFF Research Database (Denmark)

    Luykx, Atul; Preneel, Bart; Tischhauser, Elmar Wolfgang;

    2016-01-01

    , but also allows high-performance parallel implementations. We highlight this in a comprehensive implementation study, instantiating LightMAC with PRESENT and the AES. Moreover, LightMAC allows flexible trade-offs between rate and maximum message length. Unlike PMAC and its many derivatives, Light...

  17. MAC-awake of sevoflurane in children.

    Science.gov (United States)

    Davidson, Andrew J; Wong, Aaron; Knottenbelt, Graham; Sheppard, Suzette; Donath, Susan; Frawley, Geoff

    2008-08-01

    Age influences the potency of anesthetic agents, but there is little information on how age influences MAC-awake. MAC-awake may be an important aspect of anesthesia potency for the prevention of awareness during anesthesia. The aim of this study was to measure MAC-awake in a range of ages in children. After institutional ethics approval and informed parental consent 60 children were enrolled; 20 in each of three age groups (2 to awake. The Dixon up-down method was used to determine progression of subsequent concentrations and MAC-awake (ED50) for the three age groups were obtained using the probit model. This study found evidence for a difference in ED50 between age groups (P = 0.008). The MAC-awake was highest in the youngest group (0.66%) and similar in the older groups (0.45% and 0.43%). Although MAC-awake changes with age, in the ages where awareness has been reported, MAC-awake was found to be relatively low, and therefore it seems unlikely that age-specific changes to MAC-awake are a cause for awareness in children aged 5-12 years.

  18. Nomogram to estimate age-related MAC.

    NARCIS (Netherlands)

    Lerou, J.G.C.

    2004-01-01

    BACKGROUND: In clinical practice it is difficult to estimate rapidly two important values: (i) the total age-corrected MAC multiple from measured end-expired concentrations of volatile agent and nitrous oxide; (ii) the end-expired concentration of volatile agent needed to obtain a given total MAC

  19. VLA-MAC: A Variable Load Adaptive MAC Protocol for Wireless Sensor Networks

    Science.gov (United States)

    Yao, Guoliang; Liu, Hao; Chen, Hao; Shi, Longxin

    This letter presents VLA-MAC, a novel adaptive MAC protocol for wireless sensor networks that can achieve high energy efficiency and low latency in variable load conditions. In VLA-MAC, traffic load is measured online and utilized for adaptive adjustment. VLA-MAC transmits packets via a burst style to alleviate packets accumulation problem and achieve low latency in high load condition. Furthermore, it also saves obvious energy by removing unnecessary listen period in low load condition. Unlike current approach, VLA-MAC does not need to adjust duty-cycle according to load online. Simulation results based on ns-2 show the performance improvements of our protocol.

  20. Comments on the article "Changing attitudes towards the care of children in hospital: a new assessment of the influence of the work of Bowlby and Robertson in the UK, 1940-1970" by Frank C.P. van der Horst and Rene van der Veer (Attachment and Human Development Vol 11, No 2, March 2009, 119-142).

    Science.gov (United States)

    Lindsay, Mary

    2009-11-01

    The authors give an impressive list of references, but these do not reflect the situation in the UK; most of those looking after children in hospital did not write about what they did or read about what others did. Children in hospital saw little or nothing of their parents, and once they had 'settled' the doctors and nurses were unaware of their distress. John Bowlby's interest in maternal deprivation led him to appoint James Robertson as his research assistant, to observe responses of young children to loss of maternal care on admission to hospital. They formulated the theoretical framework of the three stages through which the children went; protest, despair, and detachment constituting a developmental interference. Robertson was so concerned when nobody would listen that in 1952 he made the film 'A Two Year Old Goes to Hospital', which upset children's doctors and nurses. It also probably contributed to the government setting up in 1957 a Committee chaired by Sir Harry Platt to consider the Welfare of Children in Hospital. 'Going to Hospital with Mother' was made by Robertson in 1958. With Dermod MacCarthy he showed the films to the Committee, who accepted the suggestions in Robertson's Memorandum which included unrestricted visiting and mothers being admitted with their young children. The Report, known as the Platt Report, was published in 1959. Robertson could then show his films publicly, campaign in the media and encourage the pressure group NAWCH (the National Association for the Welfare of Children in Hospital) who were successful in getting many of the Committee's recommendations implemented, to the benefit of all children in hospital.

  1. Mac OS X Snow Leopard for dummies

    CERN Document Server

    LeVitus, Bob

    2010-01-01

    Get to know Snow Leopard and make the most of your Mac Snow Leopard has a few new tricks up its sleeve, so whether you're new to Mac or a longtime Mac-thusiast, Mac expert Bob LeVitus has tips you'll appreciate. Learn how to start up your Mac, get to know the Dock and Finder, work your way through windows and dialogs, and organize and manage files and folders. Open the book and find: How to navigate around the Finder, Dock, and desktop Tips for opening, closing, resizing, and moving windows Steps for keeping Snow Leopard organized How to back up your system with Time Machine® Troubleshooting a

  2. Robertson-Walker cosmological models with perfect fluid in general relativity

    Institute of Scientific and Technical Information of China (English)

    Rishi Kumar Tiwari

    2011-01-01

    Einstein's field equations with variable gravitational and cosmological constants are considered in the presence of perfect fluid for a Robertson-Walker universe by assuming the cosmological term to be proportional to R-m (R is a scale factor and m is a constant). A variety of solutions is presented. The physical significance of the cosmological models has also been discussed.

  3. On Maximal Surfaces in Certain Non-Flat 3-Dimensional Robertson-Walker Spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Romero, Alfonso, E-mail: aromero@ugr.es [Universidad de Granada, Departamento de Geometria y Topologia (Spain); Rubio, Rafael M., E-mail: rmrubio@uco.es [Universidad de Cordoba, Departamento de Matematicas, Campus de Rabanales (Spain)

    2012-09-15

    An upper bound for the integral, on a geodesic disc, of the squared length of the gradient of a distinguished function on any maximal surface in certain non-flat 3-dimensional Robertson-Walker spacetimes is obtained. As an application, a new proof of a known Calabi-Bernstein's theorem is given.

  4. Comparison of CSMA based MAC protocols of wireless sensor networks

    CERN Document Server

    singh, Himanshu

    2012-01-01

    Energy conservation has been an important area of interest in Wireless Sensor networks (WSNs). Medium Access Control (MAC) protocols play an important role in energy conservation. In this paper, we describe CSMA based MAC protocols for WSN and analyze the simulation results of these protocols. We implemented S-MAC, T-MAC, B-MAC, B-MAC+, X-MAC, DMAC and Wise-MAC in TOSSIM, a simulator which unlike other simulators simulates the same code running on real hardware. Previous surveys mainly focused on the classification of MAC protocols according to the techniques being used or problem dealt with and presented a theoretical evaluation of protocols. This paper presents the comparative study of CSMA based protocols for WSNs, showing which MAC protocol is suitable in a particular environment and supports the arguments with the simulation results. The comparative study can be used to find the best suited MAC protocol for wireless sensor networks in different environments.

  5. Mac OS X for Unix Geeks (Leopard)

    CERN Document Server

    Rothman, Ernest E; Rosen, Rich

    2009-01-01

    If you've been lured to Mac OS X because of its Unix roots, this invaluable book serves as a bridge between Apple's Darwin OS and the more traditional Unix systems. The new edition offers a complete tour of Mac OS X's Unix shell for Leopard and Tiger, and helps you find the facilities that replace or correspond to standard Unix utilities. Learn how to compile code, link to libraries, and port Unix software to Mac OS X and much more with this concise guide.

  6. Mac OS X Lion portable genius

    CERN Document Server

    Spivey, Dwight

    2012-01-01

    Two e-books, Mac OS X Lion Portable Genius and MacBook Pro Portable Genius, Third Edition, bundled in one package Books in the Portable Genius series provide readers with the most accessible, useful information possible, including plenty of tips and techniques for the most-used features in a product or software. These e-books will show you what you may not find out by just working with your MacBook Pro and OS X Lion. Genius icons present smart or innovative ways to do something, saving time and hassle. Easy-to-find information gives you the essentials plus insightful tips on how to navigate

  7. Office 2008 for Mac for dummies

    CERN Document Server

    LeVitus, Bob

    2013-01-01

    Office 2008 for Mac is here, with great new enhancements to all your favorite office productivity tools. Who better than "Dr. Mac, "Bob LeVitus, to show you how to load and use them all? From choosing the best version for your needs to managing your life with your online calendar, Office 2008 For Mac For Dummies covers what you need to know. It compares the Student/Teacher Edition, Standard Edition, and Professional Edition, then walks you through installing your preferred version and keeping it up to date. You'll find out all the things you can do with Word, Excel, PowerPoint, and Entourage,

  8. Wireless sensors networks MAC protocols analysis

    CERN Document Server

    Chaari, Lamia

    2010-01-01

    Wireless sensors networks performance are strictly related to the medium access mechanism. An effective one, require non-conventional paradigms for protocol design due to several constraints. An adequate equilibrium between communication improvement and data processing capabilities must be accomplished. To achieve low power operation, several MAC protocols already proposed for WSN. The aim of this paper is to survey and to analyze the most energy efficient MAC protocol in order to categorize them and to compare their performances. Furthermore we have implemented some of WSN MAC protocol under OMNET++ with the purpose to evaluate their performances.

  9. Beginning Mac OS X Snow Leopard programming

    CERN Document Server

    Trent, Michael

    2010-01-01

    Michael Trent is a technical reviewer for numerous books and magazine articles and the coauthor of Beginning Mac OS X Programming with Drew McCormack. Drew McCormack is an experienced computational scientist, founder of the ""The Mental Faculty""-an independent company developing software for the Mac and iPhone-and the coauthor of Beginning Mac OS X Programming with Michael Trent. Wrox Beginning guides are crafted to make learning programming languages and technologies easier than you think, providing a structured, tutorial format that will guide you through all the techniques involved.

  10. Learn Office 2011 for Mac OS X

    CERN Document Server

    Hart-Davis, Guy

    2011-01-01

    Office for Mac remains the leading productivity suite for Mac, with Apple's iWork and the free OpenOffice.org trailing far behind. And now it's being updated with a cleaner interface and more compatibility with Exchange and SharePoint. Learn Office 2011 for Mac OS X offers a practical, hands-on approach to using Office 2011 applications to create and edit documents and get work done efficiently. You'll learn how to customize Office, design, create, and share documents, manipulate data in a spreadsheet, and create lively presentations. You'll also discover how to organize your email, contacts,

  11. MAC Layer Hurdles in BSNs

    CERN Document Server

    Ullah, Sana; Choi, Young-Woo; Lee, Hyung-Soo; Kwak, Kyung Sup

    2009-01-01

    The last few decades have seen considerable research progress in microelectronics and integrated circuits, system-on-chip design, wireless communication, and sensor technology. This progress has enabled the seamless integration of autonomous wireless sensor nodes around a human body to create a Body Sensor Network (BSN). The development of a proactive and ambulatory BSN induces a number of enormous issues and challenges. This paper presents the technical hurdles during the design and implementation of a low-power Medium Access Control (MAC) protocol for in-body and on-body sensor networks. We analyze the performance of IEEE 802.15.4 protocol for the on-body sensor network. We also provide a comprehensive insight into the heterogeneous characteristics of the in-body sensor network. A low-power technique called Pattern-Based Wake-up Table is proposed to handle the normal traffic in a BSN. The proposed technique provides a reliable solution towards low-power communication in the in-body sensor network.

  12. CR-MAC: A multichannel MAC protocol for cognitive radio ad hoc networks

    CERN Document Server

    Kamruzzaman, S M

    2010-01-01

    This paper proposes a cross-layer based cognitive radio multichannel medium access control (MAC) protocol with TDMA, which integrate the spectrum sensing at physical (PHY) layer and the packet scheduling at MAC layer, for the ad hoc wireless networks. The IEEE 802.11 standard allows for the use of multiple channels available at the PHY layer, but its MAC protocol is designed only for a single channel. A single channel MAC protocol does not work well in a multichannel environment, because of the multichannel hidden terminal problem. Our proposed protocol enables secondary users (SUs) to utilize multiple channels by switching channels dynamically, thus increasing network throughput. In our proposed protocol, each SU is equipped with only one spectrum agile transceiver, but solves the multichannel hidden terminal problem using temporal synchronization. The proposed cognitive radio MAC (CR-MAC) protocol allows SUs to identify and use the unused frequency spectrum in a way that constrains the level of interference...

  13. H-MAC: A Hybrid MAC Protocol for Wireless Sensor Networks

    CERN Document Server

    Mehta, S; 10.5121/ijcnc.2010.2208

    2010-01-01

    In this paper, we propose a hybrid medium access control protocol (H-MAC) for wireless sensor networks. It is based on the IEEE 802.11's power saving mechanism (PSM) and slotted aloha, and utilizes multiple slots dynamically to improve performance. Existing MAC protocols for sensor networks reduce energy consumptions by introducing variation in an active/sleep mechanism. But they may not provide energy efficiency in varying traffic conditions as well as they did not address Quality of Service (QoS) issues. H-MAC, the propose MAC protocol maintains energy efficiency as well as QoS issues like latency, throughput, and channel utilization. Our numerical results show that H-MAC has significant improvements in QoS parameters than the existing MAC protocols for sensor networks while consuming comparable amount of energy.

  14. Learn Mac OS X Snow Leopard

    CERN Document Server

    Meyers, Scott

    2009-01-01

    You're smart and savvy, but also busy. This comprehensive guide to Apple's Mac OS X 10.6, Snow Leopard, gives you everything you need to know to live a happy, productive Mac life. Learn Mac OS X Snow Leopard will have you up and connected lickity split. With a minimum of overhead and a maximum of useful information, you'll cover a lot of ground in the time it takes other books to get you plugged in. If this isn't your first experience with Mac OS X, skip right to the "What's New in Snow Leopard" sections. You may also find yourself using this book as a quick refresher course or a way

  15. Macintosh Troubleshooting Pocket Guide for Mac OS

    CERN Document Server

    Lerner, David; Corporation, Tekserve

    2009-01-01

    The Macintosh Troubleshooting Pocket Guide covers the most common user hardware and software trouble. It's not just a book for Mac OS X (although it includes tips for OS X and Jaguar), it's for anyone who owns a Mac of any type-- there are software tips going back as far as OS 6. This slim guide distills the answers to the urgent questions that Tekserve's employee's answer every week into a handy guide that fits in your back pocket or alongside your keyboard.

  16. Enhanced Sleep Mode MAC Control for EPON

    DEFF Research Database (Denmark)

    Yan, Ying; Dittmann, Lars

    2011-01-01

    This paper introduces sleep mode operations for EPON. New MAC control functions are proposed to schedule sleep periods. Traffic profiles are considered to optimize energy efficiency and network performances. Simulation results are analyzed in OPNET modeler.......This paper introduces sleep mode operations for EPON. New MAC control functions are proposed to schedule sleep periods. Traffic profiles are considered to optimize energy efficiency and network performances. Simulation results are analyzed in OPNET modeler....

  17. 42 CFR 405.1120 - Filing briefs with the MAC.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Filing briefs with the MAC. 405.1120 Section 405....1120 Filing briefs with the MAC. Upon request, the MAC will give the party requesting review, as well... ending with the date the brief is received by the MAC will not be counted toward the adjudication...

  18. 42 CFR 423.1974 - Medicare Appeals Council (MAC) review.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Medicare Appeals Council (MAC) review. 423.1974..., MAC review, and Judicial Review § 423.1974 Medicare Appeals Council (MAC) review. An enrollee who is dissatisfied with an ALJ hearing decision may request that the MAC review the ALJ's decision or dismissal as...

  19. 42 CFR 423.2130 - Effect of the MAC's decision.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Effect of the MAC's decision. 423.2130 Section 423... (CONTINUED) MEDICARE PROGRAM VOLUNTARY MEDICARE PRESCRIPTION DRUG BENEFIT Reopening, ALJ Hearings, MAC review, and Judicial Review § 423.2130 Effect of the MAC's decision. The MAC's decision is final and binding...

  20. 42 CFR 405.1130 - Effect of the MAC's decision.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Effect of the MAC's decision. 405.1130 Section 405....1130 Effect of the MAC's decision. The MAC's decision is final and binding on all parties unless a Federal district court issues a decision modifying the MAC's decision or the decision is revised as the...

  1. 42 CFR 423.2118 - Obtaining evidence from the MAC.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Obtaining evidence from the MAC. 423.2118 Section..., MAC review, and Judicial Review § 423.2118 Obtaining evidence from the MAC. An enrollee may request... the costs of providing these items. If an enrollee requests evidence from the MAC and an opportunity...

  2. 42 CFR 423.2126 - Case remanded by the MAC.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Case remanded by the MAC. 423.2126 Section 423.2126... (CONTINUED) MEDICARE PROGRAM VOLUNTARY MEDICARE PRESCRIPTION DRUG BENEFIT Reopening, ALJ Hearings, MAC review, and Judicial Review § 423.2126 Case remanded by the MAC. (a) When the MAC may remand a case to the ALJ...

  3. 42 CFR 423.2120 - Filing briefs with the MAC.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Filing briefs with the MAC. 423.2120 Section 423... (CONTINUED) MEDICARE PROGRAM VOLUNTARY MEDICARE PRESCRIPTION DRUG BENEFIT Reopening, ALJ Hearings, MAC review, and Judicial Review § 423.2120 Filing briefs with the MAC. Upon request, the MAC will give the...

  4. The Poynting-Robertson Effect and Secular Changes of Orbital Elements

    CERN Document Server

    Klacka, J

    2002-01-01

    The Poynting-Robertson (P-R) effect has been applied to meteoroids for several decades. It is well known that the P-R effect produces only changes in the orbital plane of the particle. The differential equations governing the secular changes in both eccentricity and semi-major axis are known since the time of Robertson, provided the initial orbits are not near circular. A disadvantage of this type of osculating orbital elements is that it cannot be applied to motion of arbitrarily shaped particles. Relevant type of osculating orbital elements is discussed. It's application to the P-R effect is presented and simple analytical formulae for secular changes in both eccentricity and semi-major axis are derived.

  5. Inhomogeneous relativistic Boltzmann equation near vacuum in the Robertson-Walker space-time

    CERN Document Server

    Takou, Etienne

    2016-01-01

    In this paper, we consider the Cauchy problem for the relativistic Boltzmann equation with near vacuum initial data where the distribution function depends on the time, the position and the impulsion. The collision kernel considered here is for the hard potentials case and the background space-time in which the study is done is the Robertson-Walker space-time. Unique global (in time) mild solution is obtained in a suitable weighted space.

  6. Reciprocal classes of p-valently spirallike and p-valently Robertson functions

    Directory of Open Access Journals (Sweden)

    Shiraishi Hitoshi

    2011-01-01

    Full Text Available Abstract For p-valently spirallike and p-valently Robertson functions in the open unit disk U , reciprocal classes S p ( α , β , and C p ( α , β are introduced. The object of the present paper is to discuss some interesting properties for functions f(z belonging to the classes Sp(α,β and Cp(α,β . 2010 Mathematics Subject Classification Primary 30C45

  7. On uniqueness of the foliation by comoving observers restspaces of a Generalized Robertson-Walker spacetime

    Science.gov (United States)

    Pelegrín, José A. S.; Romero, Alfonso; Rubio, Rafael M.

    2017-02-01

    A characterization of the foliation by spacelike slices of an (n+1)-dimensional spatially closed Generalized Robertson-Walker spacetime is given by means of studying a natural mean curvature type equation on spacelike graphs. Under some natural assumptions, of physical or geometric nature, all the entire solutions of such an equation are obtained. In particular, the case of entire spacelike graphs in de Sitter spacetime is faced and completely solved by means of a new application of a known integral formula.

  8. Quantum evolution of scalar fields in Robertson-Walker space-time

    CERN Document Server

    Éboli, Oscar J P

    1995-01-01

    We study the \\lambda \\phi^4 field theory in a flat Robertson-Walker space-time using the functional Sch\\"odinger picture. We introduce a simple Gaussian approximation to analyze the time evolution of pure states and we establish the renormalizability of the approximation. We also show that the energy-momentum tensor in this approximation is finite once we consider the usual mass and coupling constant renormalizations.

  9. Robertson-Schrödinger-type formulation of Ozawa's noise-disturbance uncertainty principle

    Science.gov (United States)

    Bastos, Catarina; Bernardini, Alex E.; Bertolami, Orfeu; Costa Dias, Nuno; Prata, João Nuno

    2014-04-01

    In this work we derive a matrix formulation of a noise-disturbance uncertainty relation, which is akin to the Robertson-Schrödinger uncertainty principle. Our inequality is stronger than Ozawa's uncertainty principle and takes noise-disturbance correlations into account. Moreover, we show that for certain types of measurement interactions it is covariant with respect to linear symplectic transformations of the noise and disturbance operators. Finally, we also study the tightness of our matrix inequality.

  10. Robertson-Schroedinger type formulation of Ozawa's noise-disturbance uncertainty principle

    CERN Document Server

    Bastos, Catarina; Bertolami, Orfeu; Dias, Nuno Costa; Prata, Joao Nuno

    2013-01-01

    In this work we derive a matrix formulation of a noise-disturbance uncertainty relation, which is akin to the Robertson-Schr\\"odinger uncertainty principle. Our inequality is stronger than Ozawa's uncertainty principle and takes noise-disturbance correlations into account. Moreover, we show that, for certain types of measurement interactions, it is covariant with respect to linear symplectic transformations of the noise and disturbance operators.

  11. Hadronic Matter in the Robertson-Walker Metric and the Early Universe

    CERN Document Server

    Cunha, Ivan E

    2015-01-01

    In this work, the Friedman equations for hadronic matter in the Robertson-Walker metric in the early Universe are obtained. We consider the hadronic phase, formed after the hadronization of the quark-gluon plasma, that means times from 10^{-6}s to 1s. The set of equations is derived and the behavior of the system is studied considering one approximate analytical solution.

  12. On Parallel Transport in Quantum Bundles over Robertson-Walker Spacetimes

    OpenAIRE

    1996-01-01

    A recently-developed theory of quantum general relativity provides a propagator for free-falling particles in curved spacetimes. These propagators are constructed by parallel-transporting quantum states within a quantum bundle associated to the Poincare frame bundle. We consider such parallel transport in the case that the spacetime is a classical Robertson-Walker universe. An explicit integral formula is developed which expresses the propagators for parallel transport between any two points ...

  13. Covariant and quasi-covariant quantum dynamics in Robertson-Walker space-times

    CERN Document Server

    Buchholz, D; Summers, S J; Buchholz, Detlev; Mund, Jens; Summers, Stephen J.

    2002-01-01

    We propose a canonical description of the dynamics of quantum systems on a class of Robertson-Walker space-times. We show that the worldline of an observer in such space-times determines a unique orbit in the local conformal group SO(4,1) of the space-time and that this orbit determines a unique transport on the space-time. For a quantum system on the space-time modeled by a net of local algebras, the associated dynamics is expressed via a suitable family of ``propagators''. In the best of situations, this dynamics is covariant, but more typically the dynamics will be ``quasi-covariant'' in a sense we make precise. We then show by using our technique of ``transplanting'' states and nets of local algebras from de Sitter space to Robertson-Walker space that there exist quantum systems on Robertson-Walker spaces with quasi-covariant dynamics. The transplanted state is locally passive, in an appropriate sense, with respect to this dynamics.

  14. Poynting-Robertson drag and solar wind in the space debris problem

    CERN Document Server

    Lhotka, Christoph; Gales, Catalin

    2016-01-01

    We analyze the combined effect of Poynting-Robertson and solar wind drag on space debris. We derive a model within Cartesian, Gaussian and Hamiltonian frameworks. We focus on the geosynchronous resonance, although the results can be easily generalized to any resonance. By numerical and analytical techniques, we compute the drift in semi-major axis due to Poynting-Robertson and solar wind drag. After a linear stability analysis of the equilibria, we combine a careful investigation of the regular, resonant, chaotic behavior of the phase space with a long-term propagation of a sample of initial conditions. The results strongly depend on the value of the area-to-mass ratio of the debris, which might show different dynamical behaviors: temporary capture or escape from the geosynchronous resonance, as well as temporary capture or escape from secondary resonances involving the rate of variation of the longitude of the Sun. Such analysis shows that Poynting-Robertson and solar wind drag must be taken into account, wh...

  15. Relativistic Chaos in Robertson-Walker Cosmologies The Topological Structure of Space-Time and the Microscopic Dynamics

    CERN Document Server

    Tomaschitz, R

    1991-01-01

    Keywords: Robertson-Walker cosmology, relativistic chaos, mixing, Bernoulli property, time evolution, quantum fields, quantum chaos, bound states, energy functional, hyperbolic manifold, deformation space, Kleinian group, limit set, Hausdorff dimension, convex hull.

  16. SA-MAC:Self-Stabilizing Adaptive MAC Protocol for Wireless Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    波澄; 韩君泽; 李向阳; 王昱; 肖波

    2014-01-01

    A common method of prolonging the lifetime of wireless sensor networks is to use low power duty cycling protocol. Existing protocols consist of two categories: sender-initiated and receiver-initiated. In this paper, we present SA-MAC, a self-stabilizing adaptive MAC protocol for wireless sensor networks. SA-MAC dynamically adjusts the transmission time-slot, waking up time-slot, and packet detection pattern according to current network working condition, such as packet length and wake-up patterns of neighboring nodes. In the long run, every sensor node will find its own transmission phase so that the network will enter a stable stage when the network load and qualities are static. We conduct extensive experiments to evaluate the energy consumption, packet reception rate of SA-MAC in real sensor networking systems. Our results indicate that SA-MAC outperforms other existing protocols.

  17. Mac OS X Snow Leopard试用

    Institute of Scientific and Technical Information of China (English)

    大大

    2009-01-01

    苹果新一代操作系统Mac OS X 10.6 Snow Leopard(雪豹)于8月底上市。根据NPD集团的统计数据,该系统在美国市场前两周的销售非常喜人,是2007年Mac OS X 10.5 Leopard上市销量的2倍以上,是2005年的Mac OS X 10.4 Tiger操作系统的售量的4倍。假如你也对升级价格仅需88元雪豹系统感兴趣,就让我们从一起升级安装开始,体验它独特的魅力。

  18. MacBook Pro Portable Genius

    CERN Document Server

    Miser, Brad

    2011-01-01

    Tips and techniques for forward-thinking MacBook Pro users Now that you have a MacBook Pro, you need just one more accessory, your very own copy of MacBook Pro Portable Genius, Third Edition. This handy, compact book lets you in on a wealth of tips and tricks, so you get the very most out of Apple's very popular notebook. Discover the latest on the most recent release of iLife, get the skinny on the new Intel Core i7 and i5 processors in the Pro, see how to go wireless in a smart way, and much more. The book is easy to navigate, doesn't skimp on the essentials, and helps you save time and avoi

  19. MacSelfService online tutorial

    CERN Document Server

    CERN. Geneva

    2016-01-01

    Mac Self-Service is a functionality within the Mac Desktop Service built and maintained to empower CERN users by giving them easy access to applications and configurations through the Self-Service application. This tutorial (text attached to the event page) explains how to install Mac Self-Service and how to use it to install applications and printers. Content owner: Vincent Nicolas Bippus Presenter: Pedro Augusto de Freitas Batista Tell us what you think via e-learning.support at cern.ch More tutorials in the e-learning collection of the CERN Document Server (CDS) https://cds.cern.ch/collection/E-learning%20modules?ln=en All info about the CERN rapid e-learning project is linked from http://twiki.cern.ch/ELearning  

  20. John Bowlby and James Robertson: theorists, scientists and crusaders for improvements in the care of children in hospital.

    Science.gov (United States)

    Alsop-Shields, L; Mohay, H

    2001-07-01

    John Bowlby and James Robertson, two men who were extremely influential in the latter part of the 20th Century, combined scientific theory with evangelism to bring about changes in the way in which children were cared for in hospitals and other institutions. This paper discusses their work together, their theories and their influence on the care of children and paediatric nursing. Bowlby and Robertson collaborated early in their working relationship on research about separation of mother and child. Bowlby was the scientist who developed classic theories about maternal separation. Robertson focused his research on separation of mother and child due to hospital admission. Between the two of them, they derived a classic theory about the phases of 'protest', 'despair' and 'denial' (Bowlby called this last stage 'detachment') through which small children pass when isolated from their mothers for a length of time. Bowlby became an internationally recognized theorist, widely acclaimed and considered an expert in the field of maternal care and child development. Robertson, with his wife, Joyce, not only continued Bowlby's work investigating children separated from their mothers, but also took on the role of campaigner for the welfare of children in hospital. James Robertson, with his impressive speaking powers, established an international reputation proselytizing the need to admit parents to hospital with their children. The work of Bowlby and Robertson coincided with new knowledge about cross-infection, which had been one of the reasons for excluding parents from hospital wards. At the same time, and influenced by their work, community groups, which championed the idea of admitting parents with their children, developed. The combination of these factors provided a catalyst for changes within the health systems of many developed countries. Because of the theoretical work of Bowlby and Robertson's missionary zeal, government policies, staff attitudes and parents

  1. Mac OS X Snow Leopard pocket guide

    CERN Document Server

    Seiblod, Chris

    2009-01-01

    Whether you're new to the Mac or a longtime user, this handy book is the quickest way to get up to speed on Snow Leopard. Packed with concise information in an easy-to-read format, Mac OS X Snow Leopard Pocket Guide covers what you need to know and is an ideal resource for problem-solving on the fly. This book goes right to the heart of Snow Leopard, with details on system preferences, built-in applications, and utilities. You'll also find configuration tips, keyboard shortcuts, guides for troubleshooting, lots of step-by-step instructions, and more. Learn about new features and changes s

  2. MacBook Pro Portable Genius

    CERN Document Server

    Miser, Brad

    2012-01-01

    Discover loads of tips and techniques for the newest MacBook Pro You're already ahead of the game with a MacBook Pro. Now you can get even more out the popular Apple notebook with the new edition of this handy, compact book. Crammed with savvy insights and tips on key tools and shortcuts, this book will help you increase your productivity and keep your Apple digital lifestyle on track. From desktop sharing and wireless networking to running Windows applications, this book avoids fluff, doesn't skimp on the essentials, saves you time and hassle, and shows you what you most want to know. Include

  3. MAC2: A Multi-Hop Adaptive MAC Protocol with Packet Concatenation for Wireless Sensor Networks

    Science.gov (United States)

    Nguyen, Kien; Meis, Ulrich; Ji, Yusheng

    Wireless sensor network MAC protocols switch radios off periodically, employing the so-called duty cycle mechanism, in order to conserve battery power that would otherwise be wasted by energy-costly idle listening. In order to minimize the various negative side-effects of the original scheme, especially on latency and throughput, various improvements have been proposed. In this paper, we introduce a new MAC protocol called MAC2(Multi-hop Adaptive with packet Concatenation-MAC) which combines three promising techniques into one protocol. Firstly, the idea to forward packets over multiple hops within one operational cycle as initially introduced in RMAC. Secondly, an adaptive method that adjusts the listening period according to traffic load minimizing idle listening. Thirdly, a packet concatenation scheme that not only increases throughput but also reduces power consumption that would otherwise be incurred by additional control packets. Furthermore, MAC2 incorporates the idea of scheduling data transmissions with minimum latency, thereby performing packet concatenation together with the multi-hop transmission mechanism in a most efficient way. We evaluated MAC2 using the prominent network simulator ns-2 and the results show that our protocol can outperform DW-MAC — a state of the art protocol both in terms of energy efficiency and throughput.

  4. Spontaneous Compactification to Robertson-Walker Universe Due To Dynamical Torsion

    CERN Document Server

    Malyshenko, V O; Malyshenko, Viktoria; Ricoy, Domingo Marin

    1997-01-01

    We investigate multidimensional gravity with the Gauss-Bonnet term and with torsion on the space of extra dimensions chosen to be the group manifold of a simple Lie group. We take the Robertson-Walker ansatz for the 4-dimensional space-time and study the potential of a dilaton and torsion fields. It is shown that for certain values of the parameters of the initial theory the potential has classically stable minima, corresponding to the spontaneous compactification of the extra dimensions. However, these minima have zero torsion.

  5. Transplantation of Local Nets and Geometric Modular Action on Robertson-Walker Space-Times

    CERN Document Server

    Buchholz, D; Summers, S J; Buchholz, Detlev; Mund, Jens; Summers, Stephen J.

    2001-01-01

    A novel method of transplanting algebras of observables from de Sitter space to a large class of Robertson-Walker space-times is exhibited. It allows one to establish the existence of an abundance of local nets on these spaces which comply with a recently proposed condition of geometric modular action. The corresponding modular symmetry groups appearing in these examples also satisfy a condition of modular stability, which has been suggested as a substitute for the requirement of positivity of the energy in Minkowski space. Moreover, they exemplify the conjecture that the modular symmetry groups are generically larger than the isometry and conformal groups of the underlying space-times.

  6. Inhomogeneous Viscous Fluids in a Friedmann-Robertson-Walker (FRW Universe

    Directory of Open Access Journals (Sweden)

    Ratbay Myrzakulov

    2013-07-01

    Full Text Available We give a brief review of some aspects of inhomogeneous viscous fluids in a flat Friedmann-Robertson-Walker Universe. In general, it is pointed out that several fluid models may bring the future Universe evolution to become singular, with the appearance of the so-called Big Rip scenario. We investigate the effects of fluids coupled with dark matter in a de Sitter Universe, by considering several cases. Due to this coupling, the coincidence problem may be solved, and if the de Sitter solution is stable, the model is also protected against the Big Rip singularity.

  7. Gravitational waves in Friedman-Lemaitre-Robertson-Walker cosmology, material perturbations and the Huygens principle

    CERN Document Server

    Kulczycki, Wojciech

    2016-01-01

    We analyze propagation equations for the polar modes of gravitational waves in cosmological space-times. We prove that polar gravitational waves must perturb --- unlike axial modes --- the material content of the Friedman-Lemaitre-Robertson-Walker spacetimes. The whole gravitational dynamics reduces to the single "master equation" that has the same form as for axial modes. That allows us to conclude that the status of the Huygens principle is the same for axial and gravitational waves. In particular, this principle is valid exactly in radiation spacetimes with the vanishing cosmological constant, and it is broken otherwise.

  8. The Solar Poynting-Robertson Effect On Particles Orbiting Solar System Bodies: Circular Orbits

    Science.gov (United States)

    Rubincam, David P.

    2013-01-01

    The Poynting-Robertson effect from sunlight impinging directly on a particle which orbits a Solar System body (planet, asteroid, comet) is considered from the Sun's rest frame. There appear to be no significant first-order terms in V(sub b)/c for circular orbits, where V(sub b) is the body's speed in its orbit about the Sun and c is the speed of light, when the particle's orbital semimajor axis is much smaller than the body's orbital semimajor axis about the Sun as is mainly the case in the Solar System.

  9. A KMS-like state of Hadamard type on Robertson-Walker spacetimes and its time evolution

    CERN Document Server

    Trucks, M

    1998-01-01

    In this work we define a new state on the Weyl algebra of the free massive scalar Klein-Gordon field on a Robertson-Walker spacetime and prove that it is a Hadamard state. The state is supposed to approximate a thermal equilibrium state on a Robertson-Walker spacetime and we call it an adiabatic KMS state. This opens the possibility to do quantum statistical mechanics on Robertson-Walker spacetimes in the algebraic framework and the analysis of the free Bose gas on Robertson-Walker spacetimes. The state reduces to an adiabatic vacuum state if the temperature is zero and it reduces to the usual KMS state if the scaling factor in the metric of the Robertson-Walker spacetime is constant. In the second part of our work we discuss the time evolution of adiabatic KMS states. The time evolution is described in terms of semigroups. We prove the existence of a propagator on the classical phase space. This defines a time evolution on the one-particle Hilbert space. We use this time evolution to analyze the evolution of...

  10. Results from the MAC Vertex chamber

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, H.N.

    1987-05-01

    The design, construction, and performance characteristics of a high precision gaseous drift chamber made of thin walled proportional tubes are described. The device achieved an average spatial resolution of 45 ..mu..m in use for physics analysis with the MAC detector. The B-lifetime result obtained with this chamber is discussed.

  11. MacIntyre, Managerialism and Universities

    Science.gov (United States)

    Stolz, Steven A.

    2017-01-01

    MacIntyre's earlier work and concern with social science enquiry not only exposes its limits, but also provides an insight into how its knowledge claims have been put to ideological use. He maintains that the institutional embodiment of these ideological ideas is the bureaucratic manager who has had a negative role to play in social structures…

  12. AH-MAC: Adaptive Hierarchical MAC Protocol for Low-Rate Wireless Sensor Network Applications

    Directory of Open Access Journals (Sweden)

    Adnan Ismail Al-Sulaifanie

    2017-01-01

    Full Text Available This paper proposes an adaptive hierarchical MAC protocol (AH-MAC with cross-layer optimization for low-rate and large-scale wireless sensor networks. The main goal of the proposed protocol is to combine the strengths of LEACH and IEEE 802.15.4 while offsetting their weaknesses. The predetermined cluster heads are supported with an energy harvesting circuit, while the normal nodes are battery-operated. To prolong the network’s operational lifetime, the proposed protocol transfers most of the network’s activities to the cluster heads while minimizing the node’s activity. Some of the main features of this protocol include energy efficiency, self-configurability, scalability, and self-healing. The simulation results showed great improvement of the AH-MAC over LEACH protocol in terms of energy consumption and throughput. AH-MAC consumes eight times less energy while improving throughput via acknowledgment support.

  13. CA-MAC: A Novel MAC Protocol to Alleviate Congestion in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    WU, J.

    2013-11-01

    Full Text Available Even if the traffic pattern is known and the network topology is simple, a strong congestion can take place in wireless sensor networks (WSNs due to the data gathering effect and the duty-cycle operation. In this paper, we propose a novel medium access control (MAC protocol to alleviate the congestion, which is referred to as the congestion alleviation-MAC (CA-MAC. It adopts an adaptive contention window (ACW, which allows the nodes with more buffered packets to transmit with a higher probability, as well as an intelligent burst packet transmission when the congested nodes seize the channel. Simulations are performed in NS-2, and results show that the proposed CA-MAC protocol achieves a good performance in terms of the packet delivery ratio (PDR, power consumption, throughput, and average latency.

  14. Exposure histories of lunar meteorites: ALHA81005, MAC88104, MAC88105, and Y791197

    Energy Technology Data Exchange (ETDEWEB)

    Nishiizumi, K.; Arnold, J.R. (Univ. of California, San Diego, (United States)); Klein, J.; Fink, D.; Middleton, R. (Univ. of Pennsylvania, Philadelphia (United States)); Kubik, P.W.; Sharma, P.; Elmore, D. (Univ. of Rochester, NY (United States)); Reedy, R.C. (Los Alamos National Lab., NM (United States))

    1991-11-01

    The cosmogenic radionuclides {sup 41}Ca, {sup 36}Cl, {sup 26}Al, and {sup 10}Be in the Allan Hills 81005, MacAlpine Hills 88104, MacAlpine Hills 88105,and Yamato 791197 meteorites were measured by accelerator mass spectrometry (AMS). {sup 53}Mn in Allan Hills 81005 and Yamato 791197 was measured by activation. These four lunar meteorites experienced similar histories. They were ejected from near the surface of the Moon ranging in depth down to 400 g/cm{sup 2} and had very short transition times (less than 0.1 Ma) from the Moon to the Earth. A comparison of the cosmogenic nuclide concentrations in MacAlpine Hills 88104 and MacAlpine Hills 88105 clearly indicates that they are a pair from the same fall.

  15. 42 CFR 405.1126 - Case remanded by the MAC.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Case remanded by the MAC. 405.1126 Section 405.1126....1126 Case remanded by the MAC. (a) When the MAC may remand a case. Except as specified in § 405.1122(c), the MAC may remand a case in which additional evidence is needed or additional action by the ALJ is...

  16. A class of almost equilibrium states in Robertson-Walker spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Kueskue, Muharrem

    2008-11-06

    In quantum field theory in curved spacetimes the construction of the algebra of observables of linear fields is today well understood. However, it remains a non-trivial task to construct physically meaningful states on the algebra. For instance, we are in the unsatisfactory situation that there exist no examples of states suited to describe local thermal equilibrium in a non-stationary spacetime. In this thesis, we construct a class of states for the Klein-Gordon field in Robertson-Walker spacetimes, which seem to provide the first example of thermal states in a spacetime without time translation symmetry. More precisely, in the setting of real, linear, scalar fields in Robertson-Walker spacetimes we define on the set of homogeneous, isotropic, quasi-free states a free energy functional that is based on the averaged energy density measured by an isotropic observer along his worldline. This functional is well defined and lower bounded by a suitable quantum energy inequality. Subsequently, we minimize this functional and obtain states that we interpret as 'almost equilibrium states'. It turns out that the states of low energy are the ground states of the almost equilibrium states. Finally, we prove that the almost equilibrium states satisfy the Hadamard condition, which qualifies them as physically meaningful states. (orig.)

  17. Lake Robertson hydroelectric project. Construction of a roller compacted concrete dam

    Energy Technology Data Exchange (ETDEWEB)

    Labelle, M.; Robitaille, F. [Hydro-Quebec, Montreal, PQ (Canada)

    1995-12-31

    Construction of the Lake Robertson hydroelectric project on Quebec`s Lower North Shore was discussed in detail. The dam and powerhouse, located on the HaHa River, consists of a 134 m long concrete gravity dam, and a 21 MW powerhouse with two 69 kV transmission lines and four substations. The climate, terrain, and geography of the region, all of them characterized as severe, and the logistics of construction of the dam and power lines, aggravated by the isolation and severe conditions at the site, were described. The roller compacted concrete design and construction were noted, and justification for a concrete dam over an earth-fill dam was provided. Economics, properties, and composition of the roller compacted concrete (RCC) were examined, and control test results for the RCC concrete were provided. The use of RCC for the Lake Robertson development was described as successful in terms of the quality, watertightness, and completion time. The experience gained by the participants will make it possible to offer RCC as an alternative on various other projects. 2 figs.

  18. Opera's neutrinos and the Robertson test theory of the Lorentz transformations

    CERN Document Server

    Vargas, Jose G

    2011-01-01

    The difference in light's travel time from CERN to GPS to Gran Sasso, on the one hand, and light going the direct route in vacuum (mimicked by neutrinos), on the other hand, is analyzed with a modified Robertson test theory of the Lorentz transformations. The modification consists simply in removing the restriction of what Robertson referred to as agreement to equate the to and from speeds of light. For reasons that will be contained in a paper to soon follow, we restrict ourselves, within the new freedom, to the case of preferred frame kinematics with absolute simultaneity. At the level of not assuming any concomitant dynamical changes in this alternative, the analysis yields \\QTR{it}{zero effect}, i.e. no change with respect to special relativity (to be expected). The 60 ns would thus remain unexplained. However, a gravitation related effect that would likely accompany an alternative kinematics yields that value up to uncertainties due to the need to simplify the experimental set up for analysis. The effect...

  19. Reduction in standard MAC and MAC for intubation after clonidine premedication in children.

    Science.gov (United States)

    Inomata, S; Kihara, S; Yaguchi, Y; Baba, Y; Kohda, Y; Toyooka, H

    2000-11-01

    We examined the relative effects of different doses of oral clonidine on the MAC for endotracheal intubation (MACEI) and the MAC for skin incision (MAC) in children. We studied 90 children (15 in each group) (age range 2-8 yr, weight 10-27 kg, height 89-124 cm) who received one of three preanaesthetic medications: placebo (control), oral clonidine 2 micrograms kg-1, or oral clonidine 4 micrograms kg-1 100 min before anaesthesia. Anaesthesia was induced and maintained with sevoflurane in oxygen and air without i.v. anesthetics and neuromuscular relaxants. The end-tidal sevoflurane concentration was kept constant for > or = 15 min before tracheal intubation or skin incision. MACs were determined using Dixon's 'up-and-down method'. Mean (SD) MACEIs of sevoflurane were 2.9 (0.1)%, 2.5 (0.1)% and 1.9 (0.1)% (P clonidine 2 micrograms kg-1 and clonidine 4 micrograms kg-1 groups. The MACEIs and MACs decreased dose-dependently. The MACEI/MAC ratio (1.4) was not affected by clonidine.

  20. CR-MAC: A Multichannel MAC Protocol for Cognitive Radio AD HOC Networks

    Directory of Open Access Journals (Sweden)

    S. M. Kamruzzaman

    2010-09-01

    Full Text Available This paper proposes a cross-layer based cognitive radio multichannel medium access control (MACprotocol with TDMA, which integrate the spectrum sensing at physical (PHY layer and the packetscheduling at MAC layer, for the ad hoc wireless networks. The IEEE 802.11 standard allows for the useof multiple channels available at the PHY layer, but its MAC protocol is designed only for a singlechannel. A single channel MAC protocol does not work well in a multichannel environment, because ofthe multichannel hidden terminal problem. Our proposed protocol enables secondary users (SUs toutilize multiple channels by switching channels dynamically, thus increasing network throughput. In ourproposed protocol, each SU is equipped with only one spectrum agile transceiver, but solves themultichannel hidden terminal problem using temporal synchronization. The proposed cognitive radioMAC (CR-MAC protocol allows SUs to identify and use the unused frequency spectrum in a way thatconstrains the level of interference to the primary users (PUs. Our scheme improves network throughputsignificantly, especially when the network is highly congested. The simulation results show that ourproposed CR-MAC protocol successfully exploits multiple channels and significantly improves networkperformance by using the licensed spectrum band opportunistically and protects PUs from interference,even in hidden terminal situations.

  1. 42 CFR 423.2128 - Action of the MAC.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Action of the MAC. 423.2128 Section 423.2128 Public...) MEDICARE PROGRAM VOLUNTARY MEDICARE PRESCRIPTION DRUG BENEFIT Reopening, ALJ Hearings, MAC review, and Judicial Review § 423.2128 Action of the MAC. (a) After it has reviewed all the evidence in the...

  2. 42 CFR 405.1118 - Obtaining evidence from the MAC.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Obtaining evidence from the MAC. 405.1118 Section... Council Review § 405.1118 Obtaining evidence from the MAC. A party may request and receive a copy of all... these items. If a party requests evidence from the MAC and an opportunity to comment on that evidence...

  3. 42 CFR 405.1128 - Action of the MAC.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Action of the MAC. 405.1128 Section 405.1128 Public... the MAC. (a) After it has reviewed all the evidence in the administrative record and any additional evidence received, subject to the limitations on MAC consideration of additional evidence in § 405.1122...

  4. 42 CFR 422.608 - Medicare Appeals Council (MAC) review.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Medicare Appeals Council (MAC) review. 422.608... and Appeals § 422.608 Medicare Appeals Council (MAC) review. Any party to the hearing, including the MA organization, who is dissatisfied with the ALJ hearing decision, may request that the MAC review...

  5. MAC 700 Wash高亮度灯具

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    马田最新推出的MAC 700 Wash高亮度灯具继承了MAC系列的传统优点.具有与MAC 700 Profile相同的强大功能、模组桔构和出色设计,是MAC 700 Profile的“最佳搭档”。

  6. Isolation and characterisation of human gingival margin-derived STRO-1/MACS1 and MACS2 cell populations

    Institute of Scientific and Technical Information of China (English)

    Karim M Fawzy El-Sayed; Sebastian Paris; Christian Graetz; Neemat Kassem; Mohamed Mekhemar; Hendrick Ungefroren; Fred Fandrich; Christof Dorfer

    2015-01-01

    Recently, gingival margin-derived stem/progenitor cells isolated via STRO-1/magnetic activated cell sorting (MACS) showed remarkable periodontal regenerative potential in vivo. As a second-stage investigation, the present study’s aim was to perform in vitro characterisation and comparison of the stem/progenitor cell characteristics of sorted STRO-1-positive (MACS1) and STRO-1-negative (MACS2) cell populations from the human free gingival margin. Cells were isolated from the free gingiva using a minimally invasive technique and were magnetically sorted using anti-STRO-1 antibodies. Subsequently, the MACS1 and MACS2 cell fractions were characterized by flow cytometry for expression of CD14, CD34, CD45, CD73, CD90, CD105, CD146/MUC18 and STRO-1. Colony-forming unit (CFU) and multilineage differentiation potential were assayed for both cell fractions. Mineralisation marker expression was examined using real-time polymerase chain reaction (PCR). MACS1 and MACS2 cell fractions showed plastic adherence. MACS1 cells, in contrast to MACS2 cells, showed all of the predefined mesenchymal stem/progenitor cell characteristics and a significantly higher number of CFUs (P,0.01). More than 95%of MACS1 cells expressed CD105, CD90 and CD73;lacked the haematopoietic markers CD45, CD34 and CD14, and expressed STRO-1 and CD146/MUC18. MACS2 cells showed a different surface marker expression profile, with almost no expression of CD14 or STRO-1, and more than 95%of these cells expressed CD73, CD90 and CD146/MUC18, as well as the haematopoietic markers CD34 and CD45 and CD105. MACS1 cells could be differentiated along osteoblastic, adipocytic and chondroblastic lineages. In contrast, MACS2 cells demonstrated slight osteogenic potential. Unstimulated MACS1 cells showed significantly higher expression of collagen I (P,0.05) and collagen III (P,0.01), whereas MACS2 cells demonstrated higher expression of osteonectin (P,0.05;Mann–Whitney). The present study is the first to compare gingival

  7. MacBook All-in-One For Dummies

    CERN Document Server

    Chambers, Mark L

    2011-01-01

    Get comfortable and confident with your MacBook! Combining the fun-but-straightforward content of nine minibooks, this new edition of MacBook All-in-One For Dummies delivers helpful coverage of the rich features and essential tools you need to know to use the MacBook to its fullest potential. You'll learn an array of MacBook basics while veteran author Mark Chambers walks you through setting up your MacBook, running programs, finding files with Finder, searching with Spotlight, keeping track with Address Book, enjoying music with iTunes, creating cool multimedia projects with iLife, and more.

  8. Modeling MAC layer for powerline communications networks

    Science.gov (United States)

    Hrasnica, Halid; Haidine, Abdelfatteh

    2001-02-01

    The usage of electrical power distribution networks for voice and data transmission, called Powerline Communications, becomes nowadays more and more attractive, particularly in the telecommunication access area. The most important reasons for that are the deregulation of the telecommunication market and a fact that the access networks are still property of former monopolistic companies. In this work, first we analyze a PLC network and system structure as well as a disturbance scenario in powerline networks. After that, we define a logical structure of the powerline MAC layer and propose the reservation MAC protocols for the usage in the PLC network which provides collision free data transmission. This makes possible better network utilization and realization of QoS guarantees which can make PLC networks competitive to other access technologies.

  9. Seán MacDiarmada

    Directory of Open Access Journals (Sweden)

    Madden

    2016-12-01

    Full Text Available Seán MacDiarmada: Signatory to Proclamation – Executed after the Rising of 1916 - Leitrim to Kilmainham was written by Tom Madden to coincide with the 1916/2016 centenary commemorations. The play was first performed at the Mullagh Arts Festival in Cavan during September 2016 and provides a lively account of the background and activism of one the seven leaders of the Easter Rising of 1916. The action plays out over twelve scenes taking in MacDiarmada's journey from teacher to revolutionary activist culminating in a deeply flawed court-martial and his subsequent execution by a British Army firing squad on May 12th, 1916.

  10. Earth tides in MacDonald's model

    CERN Document Server

    Ferraz-Mello, S

    2013-01-01

    We expand the equations used in MacDonald's 1964 theory and Fourier analyze the tidal variations of the height at one point on the Earth surface, and also the tidal potential at such point. It is shown that no intrinsic law is relating the lag of the tide components to their frequencies. In other words, no simple rheology is being intrinsically fixed by MacDonald's equations. The same is true of the modification proposed by Singer(1968). At variance with these two cases, the modification proposed by Williams and Efroimsky (2012) fix the standard Darwin rheology in which the lags are proportional to the frequencies and their model is, in this sense, equivalent to Mignard's 1979 formulation of Darwin's theory.

  11. MacBook Pro portable genius

    CERN Document Server

    Gruman, Galen

    2013-01-01

    Learn the skills, tools and shortcuts you need in order to make the most of your MacBook Pro This easy-to-use, compact guide skips the fluff and gets right to the essentials so that you can maximize all the latest features of the MacBook Pro. Packed with savvy insights and tips on key tools and shortcuts, this handy book aims to help you increase your productivity and save you time and hassle. From desktop sharing and wireless networking to running Windows applications and more, this book shows you what you want to know. Includes the latest version of OS X, iCloud, FaceTime, and moreCovers al

  12. Performance Analysis of MAC Layer Protocols in Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Hameeza Ahmed

    2014-10-01

    Full Text Available Media Access Control (MAC layer protocols have a critical role in making a typical Wireless Sensor Network (WSN more reliable and efficient. Choice of MAC layer protocol and other factors including number of nodes, mobility, traffic rate and playground size dictates the performance of a particular WSN. In this paper, the performance of an experimental WSN is evaluated using different MAC layer protocols. In this experiment, a WSN is created using OMNeT++ MiXiM network simulator and its performance in terms of packet delivery ratio and mean latency is evaluated. The simulation results show that IEEE 802.11 MAC layer protocol performs better than CSMA, B-MAC and IEEE 802.15.4 MAC layer protocols. In the considered scenario, IEEE 802.15.4 is ranked second in performance, followed by CSMA and B-MAC.

  13. 关于Mac OS X Lion

    Institute of Scientific and Technical Information of China (English)

    饭桶

    2011-01-01

    Lion是Mac OS X操作系统的第七个版本,第一个版本是2001年发布的Cheetah(猎豹).或许很多Windows用户会认为,Lion不过是一次升级,主版本仍然是Mac OSX.那么我不介意稍微解释一下:Mac OS X对应的层次是Windows,Cheetah或者Lion相当于XP,或者7.因此即使从软件工程的角度看,Lion也是一个全新的操作系统.由于重新编译了核心,Lion的安装文件只有3.6GB大小,比上一代(Snow Leopard)减少了近一半的体积,这种比旧版本体积更小的新操作系统在历史上可不多见.

  14. Power Saving MAC Protocols for WSNs and Optimization of S-MAC Protocol

    Directory of Open Access Journals (Sweden)

    Simarpreet Kaur

    2012-11-01

    Full Text Available Low power MAC protocols have received a lot of consideration in the last few years because of their influence on the lifetime of wireless sensor networks. Since, sensors typically operate on batteries, replacement of which is often difficult. A lot of work has been done to minimize the energy expenditure and prolong the sensor lifetime through energy efficient designs, across layers. Meanwhile, the sensor network should be able to maintain a certain throughput in order to fulfill the QoS requirements of the end user, and to ensure the constancy of the network. This paper introduces different types of MAC protocols used for WSNs and proposes S‐MAC, a Medium‐Access Control protocol designed for Wireless Sensor Networks. S‐MAC uses a few innovative techniques to reduce energy consumption and support selfconfiguration. A new protocol is suggested to improve the energy efficiency, latency and throughput of existing MAC protocol for WSNs. A modification of the protocol is then proposed to eliminate the need for some nodes to stay awake longer than the other nodes which improves the energy efficiency, latency and throughput and hence increases the life span of a wireless sensor network.

  15. SR-MAC: A Low Latency MAC Protocol for Multi-Packet Transmissions in Wireless Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    Hong-Wei Tang; Jian-Nong Cao; Xue-Feng Liu; Cai-Xia Sun

    2013-01-01

    Event detection is one of the major applications of wireless sensor networks (WSNs).Most of existing medium access control (MAC) protocols are mainly optimized for the situation under which an event only generates one packet on a single sensor node.When an event generates multiple packets on a single node,the performance of these MAC protocols degrades rapidly.In this paper,we present a new synchronous duty-cycle MAC protocol called SR-MAC for the event detection applications in which multiple packets are generated on a single node.SR-MAC introduces a new scheduling mechanism that reserves few time slots during the SLEEP period for the nodes to transmit multiple packets.By this approach,SR-MAC can schedule multiple packets generated by an event on a single node to be forwarded over multiple hops in one operational cycle without collision.We use event delivery latency (EDL) and event delivery ratio (EDR) to measure the event detection capability of the SR-MAC protocol.Through detailed ns-2 simulation,the results show that SR-MAC can achieve lower EDL,higher EDR and higher network throughput with guaranteed energy efficiency compared with R-MAC,DW-MAC and PR-MAC.

  16. Nonlinear dynamics from the relativistic Boltzmann equation in the Friedmann-Lema\\^itre-Robertson-Walker spacetime

    CERN Document Server

    Bazow, D; Heinz, U; Martinez, M; Noronha, J

    2016-01-01

    The dissipative dynamics of an expanding massless gas with constant cross section in a spatially flat Friedmann-Lema\\^itre-Robertson-Walker (FLRW) universe is studied. The mathematical problem of solving the full nonlinear relativistic Boltzmann equation is recast into an infinite set of nonlinear ordinary differential equations for the moments of the one-particle distribution function. Momentum-space resolution is determined by the number of non-hydrodynamic modes included in the moment hierarchy, i.e., by the truncation order. We show that in the FLRW spacetime the non-hydrodynamic modes decouple completely from the hydrodynamic degrees of freedom. This results in the system flowing as an ideal fluid while at the same time producing entropy. The solutions to the nonlinear Boltzmann equation exhibit transient tails of the distribution function with nontrivial momentum dependence. The evolution of this tail is not correctly captured by the relaxation time approximation nor by the linearized Boltzmann equation...

  17. Phase-plane analysis of Friedmann-Robertson-Walker cosmologies in Brans-Dicke gravity

    CERN Document Server

    Holden, D J; Holden, Damien J.; Wands, David

    1998-01-01

    We present an autonomous phase-plane describing the evolution of Friedmann-Robertson-Walker models containing a perfect fluid (with barotropic index gamma) in Brans-Dicke gravity (with Brans-Dicke parameter omega). We find self-similar fixed points corresponding to Nariai's power-law solutions for spatially flat models and curvature-scaling solutions for curved models. At infinite values of the phase-plane variables we recover O'Hanlon and Tupper's vacuum solutions for spatially flat models and the Milne universe for negative spatial curvature. We find conditions for the existence and stability of these critical points and describe the qualitative evolution in all regions of the (omega,gamma) parameter space for 0-3/2. We show that the condition for inflation in Brans-Dicke gravity is always stronger than the general relativistic condition, gamma<2/3.

  18. Finding revelation in anthropology: Alexander Winchell, William Robertson Smith and the heretical imperative.

    Science.gov (United States)

    Livingstone, David N

    2015-09-01

    Anthropological inquiry has often been considered an agent of intellectual secularization. Not least is this so in the sphere of religion, where anthropological accounts have often been taken to represent the triumph of naturalism. This metanarrative, however, fails to recognize that naturalistic explanations could sometimes be espoused for religious purposes and in defence of confessional creeds. This essay examines two late nineteenth-century figures--Alexander Winchell in the United States and William Robertson Smith in Britain--who found in anthropological analysis resources to bolster rather than undermine faith. In both cases these individuals found themselves on the receiving end of ecclesiastical censure and were dismissed from their positions at church-governed institutions. But their motivation was to vindicate divine revelation, in Winchell's case from the physical anthropology of human origins and in Smith's from the cultural anthropology of Semitic ritual.

  19. On Radiation Pressure and the Poynting-Robertson Effect for Fluffy Dust Particles

    CERN Document Server

    Klacka, J

    2002-01-01

    Equation of motion for real dust particle under the action of electromagnetic radiation is more general than equation of motion corresponding to standardly used Poynting-Robertson effect (P-R effect). As a consequence, orbital evolution of particles may significantly differ from that corresponding to the P-R effect. The paper discusses recently published (Icarus, June 2002) derivation of equation of motion, which is in contradiction with known relativistically covariant formulation. The ``new'' derivation does not respect fundamental physical laws (law of conservation of energy, law of conservation of momentum) which must hold in any frame of reference. Application of the derived ``general'' equation of motion to the special case treated by Einstein in 1905 yields result which is not consistent with Einstein's result. Correct solution is presented.

  20. W-MAC: a workload-aware MAC protocol for heterogeneous convergecast in wireless sensor networks.

    Science.gov (United States)

    Xia, Ming; Dong, Yabo; Lu, Dongming

    2011-01-01

    The power consumption and latency of existing MAC protocols for wireless sensor networks (WSNs) are high in heterogeneous convergecast, where each sensor node generates different amounts of data in one convergecast operation. To solve this problem, we present W-MAC, a workload-aware MAC protocol for heterogeneous convergecast in WSNs. A subtree-based iterative cascading scheduling mechanism and a workload-aware time slice allocation mechanism are proposed to minimize the power consumption of nodes, while offering a low data latency. In addition, an efficient schedule adjustment mechanism is provided for adapting to data traffic variation and network topology change. Analytical and simulation results show that the proposed protocol provides a significant energy saving and latency reduction in heterogeneous convergecast, and can effectively support data aggregation to further improve the performance.

  1. Notas sobre dois livros de MacIntyre Notes on two books by MacIntyre

    Directory of Open Access Journals (Sweden)

    Isabel Ribeiro de Oliveira

    2005-04-01

    Full Text Available Os conceitos centrais da teoria da justiça desenvolvida por Alasdair MacIntyre - prática, narrativa e tradição - ocupam o núcleo da análise feita acerca de dois de seus livros: Depois da Virtude e Justiça de Quem? Qual racionalidade?. O artigo considera a relação, em MacIntyre, entre ética e história, virtude e relativismo, bem como apresenta seu conceito do Eu, como corretivos à anomia contemporânea.The central concepts of MacIntyre's approach to justice - practice, narrative and tradition - constitute the main trust of the analysis of two of his books: After Virtue and Whose justice? Which rationality? The article elaborates on the relationship of ethics to history, of virtues to relativism as well as his conception of the self as correctives to the pervasive anomie in contemporary societies.

  2. Monitored Anaesthesia Care (MAC in antalgic surgery

    Directory of Open Access Journals (Sweden)

    Giovanni Maria Pisanu

    2011-09-01

    Full Text Available The use of surgical techniques for pain relief in the treatment of chronic-persistent pain unresponsive to drug therapy is experiencing a growing spread application in algology. These techniques have set themselves the goal of removing the pain after treatment. Therefore, not always, percutaneous or open procedures are carried out with due precaution necessary to alleviate the patient discomfort and suffering during the surgical intervention. We present our personal experience in the use of this technique Monitored Anaesthesia Care (MAC for patients undergoing surgical treatment of pain management at our Regional Center of Pain Management.

  3. One of the First Portable Macs

    CERN Multimedia

    1989-01-01

    It was one of the first portable macs released. The Portable had many new advances in mobile computing : The display was crispy clear, and looked beautiful when used in daylight ; The Portable came with a Lead-acid gel/cell battery that could run a anywhere from 6 -12 hours ; It supported to internal hard drives, and an external one. The reaction to the laptop was weak because it was slow, it had no capacity for expansion, it weighed heavily, its price was expensive. It has been stayed 1 year and half on the market.

  4. Energy Efficient MAC for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Pekka KOSKELA

    2010-10-01

    Full Text Available This paper considers an overlay solution for asynchronous Medium Access Control (MAC protocols in a duty-cycled wireless sensor network (WSN. The solution extends sleeping times and corrects time drift when the sampling rate is low. The sleeping time is adjusted according to the requisite data sampling rate and the delay requirements of the prevailing application. This and the time drift correction considerably reduced idle listening and thus also decreased power consumption. When the power consumption is reduced, the life of wireless sensor nodes extends.

  5. Implementation of MAC by using Modified Vedic Multiplier

    OpenAIRE

    2013-01-01

    Multiplier Accumulator Unit (MAC) is a part of Digital Signal Processors. The speed of MAC depends on the speed of multiplier. So by using an efficient Vedic multiplier which excels in terms of speed, power and area, the performance of MAC can be increased. For this fast method of multiplication based on ancient Indian Vedic mathematics is proposed in this paper. Among various method of multiplication in Vedic mathematics, Urdhva Tiryagbhyam is used and the multiplication is for 32 X 32 bits....

  6. Essential Mac OS X panther server administration integrating Mac OS X server into heterogeneous networks

    CERN Document Server

    Bartosh, Michael

    2004-01-01

    If you've ever wondered how to safely manipulate Mac OS X Panther Server's many underlying configuration files or needed to explain AFP permission mapping--this book's for you. From the command line to Apple's graphical tools, the book provides insight into this powerful server software. Topics covered include installation, deployment, server management, web application services, data gathering, and more

  7. APC-MAC/TA: Adaptive Power Controlled MAC Protocol with Traffic Awareness for Wireless Sensor Networks

    Science.gov (United States)

    Woo, Seok; Kim, Kiseon

    In this paper, we propose an adaptive power controlled MAC protocol with a traffic-aware scheme specifically designed to reduce both energy and latency in wireless sensor networks. Typically, existing MAC protocols for sensor networks sacrifice latency performance for node energy efficiency. However, some sensor applications for emergencies require rather fast transmissions of sensed data, where we need to consider both energy and latency together. The proposed MAC protocol includes two novel ideas: one is a transmission power control scheme for improving latency in high traffic loads, and the other is a traffic-aware scheme to save more energy in low traffic loads. The transmission power control scheme increases channel utilization by mitigating interference between nodes, and the traffic-aware scheme allows nodes to sleep to reduce idle energy consumption when there are no traffic loads in a network. Simulation results show that the proposed protocol significantly reduces the latency as well as the energy consumption compared to the S-MAC protocol specifically for a large transmission power of nodes and low network traffic.

  8. Mac OS X Snow Leopard Server For Dummies

    CERN Document Server

    Rizzo, John

    2009-01-01

    Making Everything Easier!. Mac OS® X Snow Leopard Server for Dummies. Learn to::;. Set up and configure a Mac network with Snow Leopard Server;. Administer, secure, and troubleshoot the network;. Incorporate a Mac subnet into a Windows Active Directory® domain;. Take advantage of Unix® power and security. John Rizzo. Want to set up and administer a network even if you don't have an IT department? Read on!. Like everything Mac, Snow Leopard Server was designed to be easy to set up and use. Still, there are so many options and features that this book will save you heaps of time and effort. It wa

  9. Energy-efficient MAC protocols for Wireless Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    Li De-liang; Peng Fei

    2009-01-01

    Designing energy-efficient Medium Access Control (MAC) protocols has a significant influence on the energy performance of wireless sensor network (WSN). In this paper we present a survey of the recent typical MAC protocols regarding energy efficiency for WSN. According to channel access policies, we classify these protocols into four categories: contention-based, TDMA-based, hybrid, and cross layer protocols, in which the advantages and disadvantages in each class of MAC protocols are discussed. Finally, we point out open research issues that need to carry on to achieve high energy efficiency for the design of MAC protocols in WSN.

  10. Study on intracellular trafficking of Mac-1 by direct visualization

    Institute of Scientific and Technical Information of China (English)

    YAN Ming; MAO Jifang; WEI Yi; ZHONG Jigen; YANG Shengsheng; XU Renbao

    2004-01-01

    Previously, we constructed DNA vectors containing cDNA of Mac-1 subunits (CD11b or CD18b) fused with fluorescence protein (FP). cDNA fragments and the DNA constructs were then transfected into CHO cells (as CHO-Mac-1-FP). The structure and function of Mac-1-FP obtained from the CHO-Mac-1-FP cells are nearly identical to that expressed in wild type leukocytes. In the present study, the intracellular trafficking of Mac-1 was visualized directly by monitoring the fluorescent intensities of YFP-CD18 and PE-conjugated monoclonal antibody against CD11b under a confocal microscope in CHO-Mac-1-FP cells. The results indicate that: (ⅰ) although Mac-1 was not detected in the cell membrane at resting state, it had been translocated and clustered into the cell membrane by 1 h and internalized 2 h after PMA stimulation, at which point the fluorescence intensity began to diminish gradually, probably due to partial degradation of Mac-1. The fluorescence of CD18 and CD11b reappeared on the cell membrane 1 h after re-treatment with PMA, suggesting the recycling of non-degraded Mac-1. (ⅱ) The adhesion rate of CHO-Mac-1-FP to magnetic beads coupled ICAM-1 increased within 4 h after their initial interaction, accompanied by the clustering of Mac-1-FP. After 8 h,the adhesion rate declined and fluorescence also decreased simultaneously. The pattern of change in fluorescence in CHO-Mac-1-FP cells elicited by ICAM-1 beads was similar to that elicited by PMA, suggesting that endocytosis and degradation of Mac-1 occurred after the interaction with ICAM-1. Thus, we conclude that the intracellular trafficking of Mac-1 after activation is associated with membrane translocation, endocytosis, degradation and recycling. These changes are in parallel with the adhesion of CHO-Mac-1-FP cells with ICAM-1, and may be involved in the adhesion and detachment of leukocytes. The detachment of leukocytes may be caused by endocytosis of Mac-1.

  11. An Energy Efficient Analysis of S-MAC And H-MAC Protocols for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    P.T.Kalaivaani

    2013-04-01

    Full Text Available Wireless Sensor Networks (WSNs is an interesting topic to the researchers because of its variousapplications. The applications are health monitoring and environmental monitoring, Industrial ProcessMonitoring, Target detection, Target tracking, Energy Efficiency, Disaster Management and MilitarySecurity Systems. The wireless medium requires highly optimized medium Access Protocols to avoidinterferences. Limited resources have driven the research towards energy consumption of MACfunctionalities. Two Medium Access Control (MAC protocol performances are analyzed by using the MAClayer frame work for wireless sensor networks. In this paper an energy efficient analysis of S-MAC and HMACprotocols for wireless sensor networks is proposed with spatial correlation concept. Two MACprotocols such as Sensor MAC (S-MAC and Hybrid MAC (H-MAC protocols are proposed to analyze theperformance of Wireless Sensor Network using four different Parameters such as End to End delay, PacketDelivery Ratio, Packet Drop Rate and Energy Consumption. Performance analysis is carried out by usingthe simulation tool NS2.

  12. TreeMAC: Localized TDMA MAC protocol for real-time high-data-rate sensor networks

    Science.gov (United States)

    Song, W.-Z.; Huang, R.; Shirazi, B.; LaHusen, R.

    2009-01-01

    Earlier sensor network MAC protocols focus on energy conservation in low-duty cycle applications, while some recent applications involve real-time high-data-rate signals. This motivates us to design an innovative localized TDMA MAC protocol to achieve high throughput and low congestion in data collection sensor networks, besides energy conservation. TreeMAC divides a time cycle into frames and each frame into slots. A parent node determines the children's frame assignment based on their relative bandwidth demand, and each node calculates its own slot assignment based on its hop-count to the sink. This innovative 2-dimensional frame-slot assignment algorithm has the following nice theory properties. First, given any node, at any time slot, there is at most one active sender in its neighborhood (including itself). Second, the packet scheduling with TreeMAC is bufferless, which therefore minimizes the probability of network congestion. Third, the data throughput to the gateway is at least 1/3 of the optimum assuming reliable links. Our experiments on a 24-node testbed show that TreeMAC protocol significantly improves network throughput, fairness, and energy efficiency compared to TinyOS's default CSMA MAC protocol and a recent TDMA MAC protocol Funneling-MAC. Partial results of this paper were published in Song, Huang, Shirazi and Lahusen [W.-Z. Song, R. Huang, B. Shirazi, and R. Lahusen, TreeMAC: Localized TDMA MAC protocol for high-throughput and fairness in sensor networks, in: The 7th Annual IEEE International Conference on Pervasive Computing and Communications, PerCom, March 2009]. Our new contributions include analyses of the performance of TreeMAC from various aspects. We also present more implementation detail and evaluate TreeMAC from other aspects. ?? 2009 Elsevier B.V.

  13. 42 CFR 405.1122 - What evidence may be submitted to the MAC.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false What evidence may be submitted to the MAC. 405.1122... Council Review § 405.1122 What evidence may be submitted to the MAC. (a) Appeal before the MAC on request for review of ALJ's decision. (1) If the MAC is reviewing an ALJ's decision, the MAC limits its review...

  14. 42 CFR 423.2122 - What evidence may be submitted to the MAC.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false What evidence may be submitted to the MAC. 423.2122..., MAC review, and Judicial Review § 423.2122 What evidence may be submitted to the MAC. (a) Appeal before the MAC on request for review of ALJ's decision. (1) If the MAC is reviewing an ALJ's decision...

  15. Approximate KMS states for scalar and spinor fields in Friedmann-Robertson-Walker spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Dappiaggi, Claudio; Hack, Thomas-Paul [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik; Pinamonti, Nicola [Roma ' ' Tor Vergata' ' Univ. (Italy). Dipt. di Matematica

    2010-09-15

    We construct and discuss Hadamard states for both scalar and Dirac spinor fields in a large class of spatially flat Friedmann-Robertson-Walker spacetimes characterised by an initial phase either of exponential or of power-law expansion. The states we obtain can be interpreted as being in thermal equilibrium at the time when the scale factor a has a specific value a = a{sub 0}. In the case a{sub 0} = 0, these states fulfil a strict KMS condition on the boundary of the spacetime, which is either a cosmological horizon, or a Big Bang hypersurface. Furthermore, in the conformally invariant case, they are conformal KMS states on the full spacetime. However, they provide a natural notion of an approximate KMS state also in the remaining cases, especially for massive fields. On the technical side, our results are based on a bulk-to-boundary reconstruction technique already successfully applied in the scalar case and here proven to be suitable also for spinor fields. The potential applications of the states we find range over a broad spectrum, but they appear to be suited to discuss in particular thermal phenomena such as the cosmic neutrino background or the quantum state of dark matter. (orig.)

  16. A measure on the set of compact Friedmann-Lemaitre-Robertson-Walker models

    Energy Technology Data Exchange (ETDEWEB)

    Roukema, Boudewijn F [Torun Centre for Astronomy, Nicolaus Copernicus University, ul. Gagarina 11, 87-100 Torun (Poland); Blanloeil, Vincent [IRMA, Departement de Mathematiques, Universite de Strasbourg, 7 rue Rene Descartes, 67084 Strasbourg, Cedex (France)

    2010-12-21

    Compact, flat Friedmann-Lemaitre-Robertson-Walker (FLRW) models have recently regained interest as a good fit to the observed cosmic microwave background temperature fluctuations. However, it is generally thought that a globally, exactly flat FLRW model is theoretically improbable. Here, in order to obtain a probability space on the set F of compact, comoving, 3-spatial sections of FLRW models, a physically motivated hypothesis is proposed, using the density parameter {Omega} as a derived rather than fundamental parameter. We assume that the processes that select the 3-manifold also select a global mass-energy and a Hubble parameter. The requirement that the local and global values of {Omega} are equal implies a range in {Omega} that consists of a single real value for any 3-manifold. Thus, the obvious measure over F is the discrete measure. Hence, if the global mass-energy and Hubble parameter are a function of 3-manifold choice among compact FLRW models, then probability spaces parametrized by {Omega} do not, in general, give a zero probability of a flat model. Alternatively, parametrization by a spatial size parameter, the injectivity radius r{sub inj}, suggests the Lebesgue measure. In this case, the probability space over the injectivity radius implies that flat models occur almost surely (a.s.), in the sense of probability theory, and non-flat models a.s. do not occur.

  17. Dispersion, Topological Scattering, and Self-Interference in Multiply Connected Robertson-Walker Cosmologies

    CERN Document Server

    Tomaschitz, R

    1994-01-01

    We investigate scattering effects in open Robertson-Walker cosmologies whose spacelike slices are multiply connected hyperbolic manifolds. We work out an example in which the 3-space is infinite and has the topology of a solid torus. The world-lines in these cosmologies are unstable, and classical probability densities evolving under the horospherical geodesic flow show dispersion, as do the densities of scalar wave packets. The rate of dispersion depends crucially on the expansion factor, and we calculate the time evolution of their widths. We find that the cosmic expansion can confine dispersion: The diameter of the domain of chaoticity in the 3-manifold provides the natural, time-dependent length unit in an infinite, multiply connected universe. In a toroidal 3-space manifold this diameter is just the length of the limit cycle. On this scale we find that the densities take a finite limit width in the late stage of the expansion. In the early stage classical densities and conformally coupled fields approach...

  18. Preserving Information from the Beginning to the End of Time in a Robertson-Walker Universe

    CERN Document Server

    Mancini, Stefano; Wilde, Mark M

    2014-01-01

    Preserving information stored in a physical system subjected to noise can be modeled in a communication-theoretic paradigm, in which storage and retrieval correspond to an input encoding and output decoding, respectively. The encoding and decoding are then constructed in such a way as to protect against the action of a given noisy quantum channel. This paper considers the situation in which the noise is not due to technological imperfections, but rather to the physical laws governing the evolution of the universe. In particular, we consider the dynamics of quantum systems under a Robertson-Walker spacetime and find that the noise imparted to them is equivalent to the well known amplitude damping channel. Since one might be interested in preserving both classical and quantum information in such a scenario, we study trade-off coding strategies and determine a region of achievable rates for the preservation of both kinds of information. As a byproduct we also determine a trade-off between achievable rates of cla...

  19. Bowlby and Robertson revisited: the impact of isolation on hospitalized children during SARS.

    Science.gov (United States)

    Koller, Donna F; Nicholas, David B; Goldie, Robyn Salter; Gearing, Robin; Selkirk, Enid K

    2006-04-01

    Psychosocial issues related to pediatric isolation remain relevant to both clinical practice and research. The early theories of Bowlby and Robertson are central to this discussion for it was predominantly their work that elicited several policy changes aimed at improving psychosocial care in pediatric settings. Recognizing the significant effects of isolating hospitalized children is just as relevant today where serious infectious diseases can lead to separation of family members. An ethnographic, qualitative study examined the experiences and perspectives of children hospitalized because of SARS (severe acute respiratory syndrome), their parents, and pediatric health care providers. The sample included 23 participants: five children, 10 parents, and eight health care providers. Data analyses illuminated a range of perceived experiences for this triadic sample. Themes related to the effects of social isolation on children were predominant. They included emotional upheaval, changes in parental and professional roles, and familial experiences following hospital discharge. Finally, the paper draws on the findings of the present study and other recent work in offering recommendations for effective clinical approaches in the event of future outbreaks.

  20. The Zero Active Mass Condition in Friedmann-Robertson-Walker Cosmologies

    CERN Document Server

    Melia, Fulvio

    2016-01-01

    Many cosmological measurements today suggest that the Universe is expanding at a constant rate. This is inferred from the observed age versus redshift relationship and various distance indicators, all of which point to a cosmic equation of state (EoS) p=-rho/3, where rho and p are, respectively, the total energy density and pressure of the cosmic fluid. It has recently been shown that this result is not a coincidence and simply confirms the fact that the symmetries in the Friedmann-Robertson-Walker (FRW) metric appear to be viable only for a medium with zero active mass, i.e., rho+3p=0. In their latest paper, however, Kim, Lasenby and Hobson have provided what they believe to be a counter argument to this conclusion. Here, we show that these authors are merely repeating the conventional mistake of incorrectly placing the observer simultaneously in a co-moving frame, where the lapse function g_tt is coordinate dependent when rho+3p is not 0, and a supposedly different, free-falling frame, in which g_tt=1, impl...

  1. Simulations of the Poynting--Robertson Cosmic Battery in Resistive Accretion Disks

    CERN Document Server

    Christodoulou, Dimitris M; Kazanas, Demosthenes

    2007-01-01

    We describe the results of numerical "2.5--dimensional" MHD simulations of an initially unmagnetized disk model orbiting a central point--mass and responding to the continual generation of poloidal magnetic field due to a secular source that emulates the Poynting--Robertson (PR) drag on electrons in the vicinity of a luminous stellar or compact accreting object. The fluid in the disk and in the surrounding hotter atmosphere has finite electrical conductivity and allows for the magnetic field to diffuse freely out of the areas where it is generated, while at the same time, the differential rotation of the disk twists the poloidal field and quickly induces a substantial toroidal--field component. The secular PR term has dual purpose in these simulations as the source of the magnetic field and the trigger of a magnetorotational instability (MRI) in the disk. The MRI is especially mild and does not destroy the disk because a small amount of resistivity dampens the instability efficiently. In simulations with mode...

  2. A Physical Basis for the Symmetries in the Friedmann-Robertson-Walker Metric

    CERN Document Server

    Melia, Fulvio

    2016-01-01

    Modern cosmological theory is based on the Friedmann-Robertson-Walker (FRW) metric. Often written in terms of co-moving coordinates, this well-known solution to Einstein's equations owes its elegant and highly practical formulation to the Cosmological principal and Weyl's postulate, upon which it is founded. But there is physics behind such symmetries, and not all of it has yet been recognized. In this paper, we derive the FRW metric coefficients from the general form of the spherically-symmetric line element, and demonstrate that, because the co-moving frame also happens to be in free fall, the symmetries in FRW are valid only for a medium with zero active mass. In other words, the spacetime of a perfect fluid in cosmology may be correctly written as FRW only when its equation-of-state is rho+3p=0, in terms of the total pressure p and total energy density rho. There is now compelling observational support for this conclusion, including the Alcock-Paczynski test, which shows that only an FRW cosmology with ze...

  3. Poynting Robertson Battery and the Chiral Magnetic Fields of AGN Jets

    Science.gov (United States)

    Kazanas, Demosthenes

    2010-01-01

    We propose that the magnetic fields in the accretion disks of active galactic nuclei (AGNs) are generated by azimuthal electric currents due to the difference between the plasma electron and ion velocities that arises when the electrons are retarded by interactions with the AGN photons (the Poynting Robertson battery). This process provides a unique relation between the polarity of the poloidal B field to the angular velocity Omega of the accretion disk (B is parallel to Omega), a relation absent in the more popular dynamo B-field generation. This then leads to a unique direction for the toroidal B field induced by disk rotation. Observations of the toroidal fields of 29 AGN jets revealed by parsec-scale Faraday rotation measurements show a clear asymmetry that is consistent with this model, with the probability that this asymmetry comes about by chance being approx.0.06 %. This lends support to the hypothesis that the universe is seeded by B fields that are generated in AGNs via this mechanism and subsequently injected into intergalactic space by the jet outflows.

  4. Stable motions of charged dust grains subject to solar wind, Poynting-Robertson drag, and the mean interplanetary magnetic field

    Science.gov (United States)

    Lhotka, Christoph; Bourdin, Philippe; Narita, Yasuhito

    2016-10-01

    We investigate the combined effect of solar wind, Poynting-Robertson drag, and the frozen-in interplanetary magnetic field on the motion of charged dust grains in our solar system. It is generally accepted that the combined effects of solar wind and photon absorption and re-emmision (Poynting-Robertson drag) lead to a decrease in semi-major axis on secular time scales. On the contrary, we demonstrate that the interplanetary magnetic field may counteract these drag forces under certain circumstances. We derive a simple relation between the parameters of the magnetic field, the physical properties of the dust grain as well as the shape and orientation of the orbital ellipse of the particle, which is a necessary conditions for the stabilization in semi-major axis.

  5. Class of solutions of the Wheeler-DeWitt equation in the Friedmann-Robertson-Walker universe

    Science.gov (United States)

    Vieira, H. S.; Bezerra, V. B.

    2016-07-01

    We show that the solutions of the Wheeler-DeWitt equation in a homogeneous and isotropic universe are given by triconfluent Heun functions for the spatially closed, flat, and open geometries of the Friedmann-Robertson-Walker universe filled with different forms of energy. In a matter-dominated universe, we find the polynomial solution and the energy density spectrum. In the cases of radiation-dominated and vacuum universes, there are no polynomial solutions as shown.

  6. Quantum cosmology on (k = -1)-Friedmann-Robertson-Walker Universe evolving from stiff matter era to the dust dominated one

    Science.gov (United States)

    Dariescu, Marina-Aura; Dariescu, Ciprian

    2017-01-01

    This work is devoted to the spatially open Friedmann-Robertson-Walker (FRW) Universe evolving from the stiff matter era to the dust dominated one. Within the quantum analysis based on the Wheeler-DeWitt equation, we derive the wave function of the (k = -1)-FRW Universe with combined matter sources. On the classical level, one has to deal with the Friedmann equation which leads on a dependence of the scale function on time generally expressed from functional relations involving elliptic integrals.

  7. Influence of prior determination of baseline minimum alveolar concentration (MAC) of isoflurane on the effect of ketamine on MAC in dogs.

    Science.gov (United States)

    Gianotti, Giacomo; Valverde, Alexander; Johnson, Ron; Sinclair, Melissa; Gibson, Thomas; Dyson, Doris H

    2014-07-01

    The objective of this study was to determine if prior measurement of the minimum alveolar concentration (MAC) of isoflurane influences the effect of ketamine on the MAC of isoflurane in dogs. Eight mixed-breed dogs were studied on 2 occasions. Anesthesia was induced and maintained using isoflurane. In group 1 the effect of ketamine on isoflurane MAC was determined after initially finding the baseline isoflurane MAC. In group 2, the effect of ketamine on isoflurane MAC was determined without previous measure of the baseline isoflurane MAC. In both groups, MAC was determined again 30 min after stopping the CRI of ketamine. Plasma ketamine concentrations were measured during MAC determinations. In group 1, baseline MAC (mean ± SD: 1.18 ± 0.14%) was decreased by ketamine (0.88 ± 0.14%; P MAC after stopping ketamine was similar (1.09 ± 0.16%) to baseline MAC and higher than with ketamine (P MAC with ketamine (0.79 ± 0.11%) was also increased after stopping ketamine (1.10 ± 0.17%; P MAC values with ketamine were different between groups (P MAC determination. The MAC of isoflurane during the CRI of ketamine yielded different results when methods of same day (group-1) versus separate days (group-2) are used, despite similar plasma ketamine concentrations with both methods. However, because the magnitude of this difference was less than 10%, either method of determining MAC is deemed acceptable for research purposes.

  8. On the orthogonality of the MacDonald s functions

    Energy Technology Data Exchange (ETDEWEB)

    Passian, Ali [ORNL; Simpson, Henry [University of Tennessee, Knoxville (UTK); Koucheckian, Sherwin [University of South Florida, Tampa; Yakubovich, Semyon [University of Porto, Portugal

    2009-01-01

    A proof of an orthogonality relation for the MacDonald's functions with identical arguments but unequal complex lower indices is presented. The orthogonality is derived first via a heuristic approach based on the Mehler-Fock integral transform of the MacDonald's functions, and then proved rigorously using a polynomial approximation procedure.

  9. SuperMacLang: Development of an Authoring System.

    Science.gov (United States)

    Frommer, Judith; Foelsche, Otmar K. E.

    1999-01-01

    Describes the development of "SuperMacLang, the 1990s version of the MacLang authoring system. An analysis of various features of the program explains the ways in which certain aspects of collaboration and funding affected developer and programming decisions. (Author/VWL)

  10. Steven MacCall: Winner of LJ's 2010 Teaching Award

    Science.gov (United States)

    Berry, John N., III

    2010-01-01

    This article profiles Steven L. MacCall, winner of "Library Journal's" 2010 Teaching Award. An associate professor at the School of Library and Information Studies (SLIS) at the University of Alabama, Tuscaloosa, MacCall was nominated by Kathie Popadin, known as "Kpop" to the members of her cohort in the online MLIS program at SLIS. Sixteen of…

  11. MAC of xenon and halothane in rhesus monkeys.

    Science.gov (United States)

    Whitehurst, S L; Nemoto, E M; Yao, L; Yonas, H

    1994-10-01

    Local cerebral blood flow (LCBF) maps produced by 33% xenon-enhanced computed tomographic scanning (Xe/CT LCBF) are useful in the clinical diagnosis and management of patients with cerebrovascular disorders. However, observations in humans that 25-35% xenon (Xe) inhalation increases cerebral blood flow (CBF) have raised concerns that Xe/CT LCBF measurements may be inaccurate and that Xe inhalation may be hazardous in patients with decreased intracranial compliance. In contrast, 33% Xe does not increase CBF in rhesus monkeys. To determine whether this interspecies difference in the effect of Xe on CBF correlates with an interspecies difference in the anesthetic potency of Xe, we measured the minimum alveolar concentration (MAC) of Xe preventing movement to a tail-clamp stimulus in rhesus monkeys. Using a standard protocol for the determination of MAC in animals, we first measured the MAC of halothane (n = 5), and then used a combination of halothane and Xe to measure the MAC of Xe (n = 7). The halothane MAC was 0.99 +/- 0.12% (M +/- SD), and the Xe MAC was 98 +/- 15%. These results suggest that the MAC of Xe in rhesus monkeys is higher than the reported human Xe MAC value of 71%. Thus the absence of an effect of 33% Xe on CBF in the rhesus monkey may be related to its lower anesthetic potency.

  12. Intel-Based Mac Computers Improve Teaching and Learning

    Science.gov (United States)

    Technology & Learning, 2007

    2007-01-01

    Today, Mac computers offer schools an easy and powerful way to engage students in learning, foster 21st century skills and leverage existing software assets. Innovative software and hardware built into the Mac allows students to demonstrate their individual strengths--empowering them to be creators of content, rather than just consumers. Judging…

  13. Intel-Based Mac Computers Improve Teaching and Learning

    Science.gov (United States)

    Technology & Learning, 2007

    2007-01-01

    Today, Mac computers offer schools an easy and powerful way to engage students in learning, foster 21st century skills and leverage existing software assets. Innovative software and hardware built into the Mac allows students to demonstrate their individual strengths--empowering them to be creators of content, rather than just consumers. Judging…

  14. Multi-channel MAC Protocol in Cognitive Radio Networks

    Directory of Open Access Journals (Sweden)

    Yongli Sun

    2013-11-01

    Full Text Available Since cognitive wireless network (CRN has the characteristic of secondary use, it can enable the device to dynamically access available spectrum without interference to primary users (PUs, which can effectively alleviate contradiction between the lack of spectrum resources and the growing demand for wireless access. However, Medium Access Control (MAC protocol as CRN core components, can achieve competition access of the licensed spectrum and coordination control, which will maximize spectrum utilization efficiency and network throughput. The contribution of this survey is threefold. First, we analyze the characteristics of the existed multi- channel MAC protocol in CRN; Second, according to the different ways of spectrum access in CRNs, the multi-channel MAC protocols are classified into time-slotted based MAC protocol, control channel based MAC protocol and hybrid MAC protocol, and the paper emphatically analyzed the advantages and disadvantages of these multi-channel MAC protocols; Finally, the paper explores the difficulties and the challenges of multi-channel MAC protocols design in cognitive wireless network.

  15. Steven MacCall: Winner of LJ's 2010 Teaching Award

    Science.gov (United States)

    Berry, John N., III

    2010-01-01

    This article profiles Steven L. MacCall, winner of "Library Journal's" 2010 Teaching Award. An associate professor at the School of Library and Information Studies (SLIS) at the University of Alabama, Tuscaloosa, MacCall was nominated by Kathie Popadin, known as "Kpop" to the members of her cohort in the online MLIS program at SLIS. Sixteen of…

  16. Global Existence of Solutions for the Einstein-Boltzmann System with Cosmological Constant in the Robertson-Walker Space-time

    CERN Document Server

    Takou, E; Takou, Etienne; Noutchegueme, Norbert

    2005-01-01

    We prove a global in time existence theorem for the initial values problem for the Einstein-Boltzmann system with cosmological constant and arbitrarily large initial data, in the spatially homogeneous case, in a Robertson-Walker space-time.

  17. A Sensing Error Aware MAC Protocol for Cognitive Radio Networks

    CERN Document Server

    Hu, Donglin

    2011-01-01

    Cognitive radios (CR) are intelligent radio devices that can sense the radio environment and adapt to changes in the radio environment. Spectrum sensing and spectrum access are the two key CR functions. In this paper, we present a spectrum sensing error aware MAC protocol for a CR network collocated with multiple primary networks. We explicitly consider both types of sensing errors in the CR MAC design, since such errors are inevitable for practical spectrum sensors and more important, such errors could have significant impact on the performance of the CR MAC protocol. Two spectrum sensing polices are presented, with which secondary users collaboratively sense the licensed channels. The sensing policies are then incorporated into p-Persistent CSMA to coordinate opportunistic spectrum access for CR network users. We present an analysis of the interference and throughput performance of the proposed CR MAC, and find the analysis highly accurate in our simulation studies. The proposed sensing error aware CR MAC p...

  18. McCay ("Mac") Vernon (1928-2013).

    Science.gov (United States)

    Sherman, William A

    2014-09-01

    McCay ("Mac") Vernon, the founding and preeminent psychologist in the field of deafness. Mac was born at Walter Reed Hospital in Washington, DC, into a military family on October 14, 1928 and died on August 28, 2013, at the age of 84. Prior to Mac, research and clinical direction in the field were sparse. Mac became the icon for psychological services for deaf people, and his work extended into the education of deaf children, forensic and ethical practices with the deaf, and public understanding of deafness as a disability and of deaf persons as a psychosocial minority group. Mac will also be remembered for his sharp intellect, good humor, compassion, and advocacy for those who are misunderstood.

  19. Alasdair MacIntyre, joven lector de Freud

    Directory of Open Access Journals (Sweden)

    Ramis Barceló, Rafael

    2010-06-01

    Full Text Available This article tries to show the reading of Freud that MacIntyre made from 1955 to 1970. For this purpose, it summarizes the ideas of MacIntyre in the intellectual context, mainly the use of philosophical ideas of Freud against the Enlightenment project. MacIntyre criticises Marxist interpreters and the mixing between Marx and Freud. MacIntyre uses the philosophical ideas of Freud for answering two problems on determinism: the links between determinism and reasons for action and determinism and Marxism. The main conclusion is that MacIntyre used Freud in his own advantage: as an ally in the criticism of the Enlightenment.

    Este artículo trata de mostrar la lectura que MacIntyre hizo de Freud desde 1955 hasta 1970. Con este fin, se resumen las ideas de MacIntyre en el contexto intelectual, principalmente el uso de las ideas filosóficas de Freud contra el proyecto de la Ilustración. MacIntyre critica a los intérpretes de Marx y a la mezcla entre Marx y Freud. MacIntyre usa las ideas filosóficas de Freud para contestar dos problemas sobre el determinismo: los vínculos entre el determinismo y las razones para la acción y el determinismo y el marxismo. La conclusión principal es que MacIntyre usó a Freud en su propio beneficio: como un aliado en la crítica de la Ilustración.

  20. TreeMAC: Localized TDMA MAC protocol for real-time high-data-rate sensor networks

    Science.gov (United States)

    Song, W.-Z.; Huang, R.; Shirazi, B.; Husent, R.L.

    2009-01-01

    Earlier sensor network MAC protocols focus on energy conservation in low-duty cycle applications, while some recent applications involve real-time high-data-rate signals. This motivates us to design an innovative localized TDMA MAC protocol to achieve high throughput and low congestion in data collection sensor networks, besides energy conservation. TreeMAC divides a time cycle into frames and frame into slots. Parent determines children's frame assigmnent based on their relative bandwidth demand, and each node calculates its own slot assignment based on its hop-count to the sink. This innovative 2-dimensional frame-slot assignment algorithm has the following nice theory properties. Firstly, given any node, at any time slot, there is at most one active sender in its neighborhood (includ ing itself). Secondly, the packet scheduling with TreelMAC is bufferless, which therefore minimizes the probability of network congestion. Thirdly, the data throughput to gateway is at least 1/3 of the optimum assuming reliable links. Our experiments on a 24 node test bed demonstrate that TreeMAC protocol significantly improves network throughput and energy efficiency, by comparing to the TinyOS's default CSMA MAC protocol and a recent TDMA MAC protocol Funneling-MAC[8]. ?? 2009 IEEE.

  1. TR-MAC: an energy-efficient MAC protocol exploiting transmitted reference modulation for wireless sensor networks

    NARCIS (Netherlands)

    Morshed, S.; Heijenk, Geert

    2014-01-01

    The medium access control (MAC) protocol determines the energy consumption of a wireless sensor node by specifying the listening, transmitting or sleeping time. Therefore MAC protocols play an important role in minimizing the overall energy consumption in a typical wireless sensor network (WSN).

  2. TR-MAC: an energy-efficient MAC protocol exploiting transmitted reference modulation for wireless sensor networks

    NARCIS (Netherlands)

    Morshed, Sarwar; Heijenk, Geert

    2014-01-01

    The medium access control (MAC) protocol determines the energy consumption of a wireless sensor node by specifying the listening, transmitting or sleeping time. Therefore MAC protocols play an important role in minimizing the overall energy consumption in a typical wireless sensor network (WSN). Usi

  3. Changing attitudes towards the care of children in hospital: a new assessment of the influence of the work of Bowlby and Robertson in the UK, 1940-1970.

    Science.gov (United States)

    van der Horst, Frank C P; van der Veer, René

    2009-03-01

    It is generally believed that the work of Bowlby and Robertson was new and decisive in changing the hospital conditions for young children. The fact that parents in the UK and other European countries can now visit their sick child at any time they wish or even room-in is attributed to an acquaintance with Bowlby's findings and Robertson's well-known films about the potentially detrimental effects of hospital stays for young children. In this paper we shall argue that this picture is incomplete and that, historically, things were rather more intricate. Bowlby and Robertson were neither the first nor the only researchers who tried to change hospital policies. Moreover, the older hospital policies were not uniformly bad. Long before Bowlby and Robertson began their plea for reforms, several individuals and hospitals had already introduced conditions that we now still regard as exemplary. The whole change towards more liberal, flexible, and humane practices in children's wards took place over several decades and was fuelled by both worried medical doctors, pressure groups of parents, sympathetic editors of medical journals, and emerging new research findings such as those provided by Bowlby and Robertson. In that societal debate, the voices of Bowlby and Robertson were influential but not necessarily new or decisive.

  4. The zero active mass condition in Friedmann-Robertson-Walker cosmologies

    Science.gov (United States)

    Melia, Fulvio

    2017-02-01

    Many cosmological measurements today suggest that the Universe is expanding at a constant rate. This is inferred from the observed age versus redshift relationship and various distance indicators, all of which point to a cosmic equation of state (EoS) p = -ρ/3, where ρ and p are, respectively, the total energy density and pressure of the cosmic fluid. It has recently been shown that this result is not a coincidence and simply confirms the fact that the symmetries in the Friedmann-Robertson-Walker (FRW) metric appear to be viable only for a medium with zero active mass, i.e., ρ + 3p = 0. In their latest paper, however, Kim, Lasenby and Hobson (2016) have provided what they believe to be a counter argument to this conclusion. Here, we show that these authors are merely repeating the conventional mistake of incorrectly placing the observer simultaneously in a comoving frame, where the lapse function gtt is coordinate dependent when ρ + 3p ≠ 0, and a supposedly different, freefalling frame, in which g tt = 1, implying no time dilation. We demonstrate that the Hubble flow is not inertial when ρ + 3p ≠ 0, so the comoving frame is generally not in free fall, even though in FRW, the comoving and free-falling frames are supposed to be identical at every spacetime point. So this confusion of frames not only constitutes an inconsistency with the fundamental tenets of general relativity but, additionally, there is no possibility of using a gauge transformation to select a set of coordinates for which g tt = 1 when ρ + 3p ≠ 0.

  5. The minimum alveolar concentration (MAC) of isoflurane in preterm neonates.

    Science.gov (United States)

    LeDez, K M; Lerman, J

    1987-09-01

    Studies in fetal lambs suggested that the minimum alveolar concentration (MAC) in preterm neonates may be less than that in full-term neonates and older infants. To determine the MAC of isoflurane in preterm neonates, 20 patients less than 32 weeks gestation at birth and 16 patients 32-37 weeks gestation at birth, all less than 1 month post-natal age, were studied. Following tracheal intubation, the neonates were anesthetized with a predetermined end-tidal concentration of isoflurane in oxygen and air. The move-no move responses to skin incision were recorded, and MAC was determined using the "up-and-down" technique. Heart rate and systolic arterial pressure were recorded awake, before skin incision, and after skin incision. MAC (mean +/- SD) of isoflurane in preterm neonates less than 32 weeks gestation was 1.28 +/- 0.17%, and MAC in neonates 32-37 weeks gestation was 1.41 +/- 0.18% (P less than 0.05). Although heart rate did not decrease significantly in either group during the study, systolic arterial pressure decreased between 20 and 30% below awake values both before and after skin incision in both age groups (P less than 0.01). We conclude that the MAC of isoflurane in preterm neonates less than 32 weeks gestation is significantly less than that in preterm neonates 32-37 weeks gestation, and that systolic arterial pressure decreases to a similar extent at approximately 1 MAC isoflurane in both age groups.

  6. Increased NMDA receptor inhibition at an increased Sevoflurane MAC

    Directory of Open Access Journals (Sweden)

    Brosnan Robert J

    2012-06-01

    Full Text Available Abstract Background Sevoflurane potently enhances glycine receptor currents and more modestly decreases NMDA receptor currents, each of which may contribute to immobility. This modest NMDA receptor antagonism by sevoflurane at a minimum alveolar concentration (MAC could be reciprocally related to large potentiation of other inhibitory ion channels. If so, then reduced glycine receptor potency should increase NMDA receptor antagonism by sevoflurane at MAC. Methods Indwelling lumbar subarachnoid catheters were surgically placed in 14 anesthetized rats. Rats were anesthetized with sevoflurane the next day, and a pre-infusion sevoflurane MAC was measured in duplicate using a tail clamp method. Artificial CSF (aCSF containing either 0 or 4 mg/mL strychnine was then infused intrathecally at 4 μL/min, and the post-infusion baseline sevoflurane MAC was measured. Finally, aCSF containing strychnine (either 0 or 4 mg/mL plus 0.4 mg/mL dizocilpine (MK-801 was administered intrathecally at 4 μL/min, and the post-dizocilpine sevoflurane MAC was measured. Results Pre-infusion sevoflurane MAC was 2.26%. Intrathecal aCSF alone did not affect MAC, but intrathecal strychnine significantly increased sevoflurane requirement. Addition of dizocilpine significantly decreased MAC in all rats, but this decrease was two times larger in rats without intrathecal strychnine compared to rats with intrathecal strychnine, a statistically significant (P  Conclusions Glycine receptor antagonism increases NMDA receptor antagonism by sevoflurane at MAC. The magnitude of anesthetic effects on a given ion channel may therefore depend on the magnitude of its effects on other receptors that modulate neuronal excitability.

  7. Increased NMDA receptor inhibition at an increased Sevoflurane MAC.

    Science.gov (United States)

    Brosnan, Robert J; Thiesen, Roberto

    2012-06-06

    Sevoflurane potently enhances glycine receptor currents and more modestly decreases NMDA receptor currents, each of which may contribute to immobility. This modest NMDA receptor antagonism by sevoflurane at a minimum alveolar concentration (MAC) could be reciprocally related to large potentiation of other inhibitory ion channels. If so, then reduced glycine receptor potency should increase NMDA receptor antagonism by sevoflurane at MAC. Indwelling lumbar subarachnoid catheters were surgically placed in 14 anesthetized rats. Rats were anesthetized with sevoflurane the next day, and a pre-infusion sevoflurane MAC was measured in duplicate using a tail clamp method. Artificial CSF (aCSF) containing either 0 or 4 mg/mL strychnine was then infused intrathecally at 4 μL/min, and the post-infusion baseline sevoflurane MAC was measured. Finally, aCSF containing strychnine (either 0 or 4 mg/mL) plus 0.4 mg/mL dizocilpine (MK-801) was administered intrathecally at 4 μL/min, and the post-dizocilpine sevoflurane MAC was measured. Pre-infusion sevoflurane MAC was 2.26%. Intrathecal aCSF alone did not affect MAC, but intrathecal strychnine significantly increased sevoflurane requirement. Addition of dizocilpine significantly decreased MAC in all rats, but this decrease was two times larger in rats without intrathecal strychnine compared to rats with intrathecal strychnine, a statistically significant (P MAC. The magnitude of anesthetic effects on a given ion channel may therefore depend on the magnitude of its effects on other receptors that modulate neuronal excitability.

  8. Multichannel MAC Layer In Mobile Ad—Hoc Network

    Science.gov (United States)

    Logesh, K.; Rao, Samba Siva

    2010-11-01

    This paper we presented the design objectives and technical challenges in Multichannel MAC protocols in Mobile Ad-hoc Network. In IEEE 802.11 a/b/g standards allow use of multiple channels, only a single channel is popularly used, due to the lack of efficient protocols that enable use of Multiple Channels. Even though complex environments in ad hoc networks require a combined control of physical (PHY) and medium access control (MAC) layers resources in order to optimize performance. And also we discuss the characteristics of cross-layer frame and give a multichannel MAC approach.

  9. MacRuby Ruby and Cocoa on OS X

    CERN Document Server

    Aimonetti, Matt

    2011-01-01

    Want to build native Mac OS X applications with a sleek, developer-friendly alternative to Objective-C? MacRuby is an ideal choice. This in-depth guide shows you how Apple's implementation of Ruby gives you access to all the features available to Objective-C programmers. You'll get clear, detailed explanations of MacRuby, including quick programming techniques such as prototyping. Perfect for programmers at any level, this book is packed with code samples and complete project examples. If you use Ruby, you can tap your skills to take advantage of Interface Builder, Cocoa libraries, the Objec

  10. Handling Deafness Problem of Scheduled Multi-Channel Polling MACs

    Science.gov (United States)

    Jiang, Fulong; Liu, Hao; Shi, Longxing

    Combining scheduled channel polling with channel diversity is a promising way for a MAC protocol to achieve high energy efficiency and performance under both light and heavy traffic conditions. However, the deafness problem may cancel out the benefit of channel diversity. In this paper, we first investigate the deafness problem of scheduled multi-channel polling MACs with experiments. Then we propose and evaluate two schemes to handle the deafness problem. Our experiment shows that deafness is a significant reason for performance degradation in scheduled multi-channel polling MACs. A proper scheme should be chosen depending on the traffic pattern and the design objective.

  11. Cooperative energy harvesting-adaptive MAC protocol for WBANs.

    Science.gov (United States)

    Esteves, Volker; Antonopoulos, Angelos; Kartsakli, Elli; Puig-Vidal, Manel; Miribel-Català, Pere; Verikoukis, Christos

    2015-05-28

    In this paper, we introduce a cooperative medium access control (MAC) protocol, named cooperative energy harvesting (CEH)-MAC, that adapts its operation to the energy harvesting (EH) conditions in wireless body area networks (WBANs). In particular, the proposed protocol exploits the EH information in order to set an idle time that allows the relay nodes to charge their batteries and complete the cooperation phase successfully. Extensive simulations have shown that CEH-MAC significantly improves the network performance in terms of throughput, delay and energy efficiency compared to the cooperative operation of the baseline IEEE 802.15.6 standard.

  12. A Hybrid MacCormack-type Scheme for Computational Aeroacoustics

    Science.gov (United States)

    Yazdani, Soroush

    A new type of MacCormack scheme, using a modified Low Dissipation and Dispersion Runge-Kutta time marching method, is presented. This scheme is using two stages in every step which implements biased spatial differencing stencils and for the remaining stages uses non-dissipative central differencing stencils. Because of using the MacCormack-type scheme in this method, the new scheme carries an inherent artificial dissipation which uses the ease of implementing boundary condition specifications of a two-stage MacCormack scheme.

  13. iMac G3 Blueberry 350MHz

    CERN Multimedia

    2000-01-01

    The iMac G3 is an all-in-one personal computer, encompassing both the monitor and the computer in one package. It allowed to revitalize the Apple brand that was in decline and close to financial ruin. Originally released in striking bondi blue and later a range of other translucent plastic envelopes in bright colors. The iMac comes with a keyboard and mouse matching the color of the case. The iMac G3 was sold from 1998 to 2003 and has been updated many times.

  14. PAD-MAC: primary user activity-aware distributed MAC for multi-channel cognitive radio networks.

    Science.gov (United States)

    Ali, Amjad; Piran, Md Jalil; Kim, Hansoo; Yun, Jihyeok; Suh, Doug Young

    2015-03-30

    Cognitive radio (CR) has emerged as a promising technology to solve problems related to spectrum scarcity and provides a ubiquitous wireless access environment. CR-enabled secondary users (SUs) exploit spectrum white spaces opportunistically and immediately vacate the acquired licensed channels as primary users (PUs) arrive. Accessing the licensed channels without the prior knowledge of PU traffic patterns causes severe throughput degradation due to excessive channel switching and PU-to-SU collisions. Therefore, it is significantly important to design a PU activity-aware medium access control (MAC) protocol for cognitive radio networks (CRNs). In this paper, we first propose a licensed channel usage pattern identification scheme, based on a two-state Markov model, and then estimate the future idle slots using previous observations of the channels. Furthermore, based on these past observations, we compute the rank of each available licensed channel that gives SU transmission success assessment during the estimated idle slot. Secondly, we propose a PU activity-aware distributed MAC (PAD-MAC) protocol for heterogeneous multi-channel CRNs that selects the best channel for each SU to enhance its throughput. PAD-MAC controls SU activities by allowing them to exploit the licensed channels only for the duration of estimated idle slots and enables predictive and fast channel switching. To evaluate the performance of the proposed PAD-MAC, we compare it with the distributed QoS-aware MAC (QC-MAC) and listen-before-talk MAC schemes. Extensive numerical results show the significant improvements of the PAD-MAC in terms of the SU throughput, SU channel switching rate and PU-to-SU collision rate.

  15. Infecting Windows, Linux & Mac in one go

    CERN Multimedia

    Computer Security Team

    2012-01-01

    Still love bashing on Windows as you believe it is an insecure operating system? Hold on a second! Just recently, a vulnerability has been published for Java 7.   It affects Windows/Linux PCs and Macs, Internet Explorer, Safari and Firefox. In fact, it affects all computers that have enabled the Java 7 plug-in in their browser (Java 6 and earlier is not affected). Once you visit a malicious website (and there are plenty already out in the wild), your computer is infected… That's "Game Over" for you.      And this is not the first time. For a while now, attackers have not been targeting the operating system itself, but rather aiming at vulnerabilities inherent in e.g. your Acrobat Reader, Adobe Flash or Java programmes. All these are standard plug-ins added into your favourite web browser which make your web-surfing comfortable (or impossible when you un-install them). A single compromised web-site, however, is sufficient to prob...

  16. Prior determination of baseline minimum alveolar concentration (MAC) of isoflurane does not influence the effect of ketamine on MAC in rabbits.

    Science.gov (United States)

    Gianotti, Giacomo; Valverde, Alexander; Sinclair, Melissa; Dyson, Doris H; Gibson, Thomas; Johnson, Ron

    2012-10-01

    The objective of this study was to compare the effect on the minimum alveolar concentration (MAC) of isoflurane when ketamine was administered either after or without prior determination of the baseline MAC of isoflurane in rabbits. Using a prospective randomized crossover study, 8 adult, female New Zealand rabbits were allocated to 2 treatment groups. Anesthesia was induced and maintained with isoflurane. Group 1 (same-day determination) had the MAC-sparing effect of ketamine [1 mg/kg bodyweight (BW) bolus followed by a constant rate infusion (CRI) of 40 μg/kg BW per min, given by intravenous (IV)], which was determined after the baseline MAC of isoflurane was determined beforehand. A third MAC determination was started 30 min after stopping the CRI. Group 2 (separate-day determination) had the MAC-sparing effect of ketamine determined without previous determination of the baseline MAC of isoflurane. A second MAC determination was started 30 min after stopping the CRI. In group 1, the MAC of isoflurane (2.15 ± 0.09%) was significantly decreased by ketamine (1.63 ± 0.07%). After stopping the CRI, the MAC was significantly less (2.04 ± 0.11%) than the baseline MAC of isoflurane and significantly greater than the MAC during the CRI. In group 2, ketamine decreased isoflurane MAC (1.53 ± 0.22%) and the MAC increased significantly (1.94 ± 0.25%) after stopping the CRI. Minimum alveolar concentration (MAC) values did not differ significantly between the groups either during ketamine administration or after stopping ketamine. Under the study conditions, prior determination of the baseline isoflurane MAC did not alter the effect of ketamine on MAC. Both methods of determining MAC seemed to be valid for research purposes.

  17. Competition at the Wireless Sensor Network MAC Layer: Low Power Probing interfering with X-MAC

    Science.gov (United States)

    Zacharias, Sven; Newe, Thomas

    2011-08-01

    Wireless Sensor Networks (WSNs) combine sensors with computer networks and enable very dense, in-situ and live measurements of data over a large area. Since this emerging technology has the potential to be embedded almost everywhere for numberless applications, interference between different networks can become a serious issue. For most WSNs, it is assumed today that the network medium access is non-competitive. On the basis of X-MAC interfered by Low Power Probing, this paper shows the danger and the effects of different sensor networks communicating on a single wireless channel of the 2.4 GHz band, which is used by the IEEE 802.15.4 standard.

  18. After MacIntyre : Kaasaegsest vooruseetikast / Meego Remmel

    Index Scriptorium Estoniae

    Remmel, Meego

    2006-01-01

    Alasdair MacIntyre panus 20. sajandi eetikasse. Tema käsitlus vooruseetikast ja vooruseetilisest perspektiivist, mida on võimalik näha komplekselt, vaadeldes voorust, praktikat, narratiivi ja traditsiooni mõisteid

  19. After MacIntyre : Kaasaegsest vooruseetikast / Meego Remmel

    Index Scriptorium Estoniae

    Remmel, Meego

    2006-01-01

    Alasdair MacIntyre panus 20. sajandi eetikasse. Tema käsitlus vooruseetikast ja vooruseetilisest perspektiivist, mida on võimalik näha komplekselt, vaadeldes voorust, praktikat, narratiivi ja traditsiooni mõisteid

  20. Design and Implementation of an Efficient 64 bit MAC

    Directory of Open Access Journals (Sweden)

    Mohammad Shabber Hasan Khan

    2015-08-01

    Full Text Available The design of optimized 64 bit multiplier and accumulator (MAC unit is implemented in this paper. MAC unit plays major role in many of the digital signal processing (DSP applications. The MAC unit is designed with the combinations of multipliers and adders. In the proposed method MAC unit is implemented using Vedic multiplier and the adder is done with ripple carry adder .The components are reduced by implementing Vedic multiplier using the techniques of Vedic mathematics that have been modified to improve performance. a high speed processor depends significantly on the multiplier as it is one of the key hardware blocks in most digital signal processing systems as well as in general processors. The area is optimized effectively using Vedic multiplier .The total design implemented using Xilinx.

  1. Beamforming in Ad Hoc Networks: MAC Design and Performance Modeling

    National Research Council Canada - National Science Library

    Fakih, Khalil; Diouris, Jean-Francois; Andrieux, Guillaume

    2009-01-01

    .... Our proposition performs jointly channel estimation and radio resource sharing. We validate the fruitfulness of the proposed MAC and we evaluate the effects of the channel estimation on the network performance...

  2. Aeronautical Mobile Airport Communications System (AeroMACS)

    Science.gov (United States)

    Budinger, James M.; Hall, Edward

    2011-01-01

    To help increase the capacity and efficiency of the nation s airports, a secure wideband wireless communications system is proposed for use on the airport surface. This paper provides an overview of the research and development process for the Aeronautical Mobile Airport Communications System (AeroMACS). AeroMACS is based on a specific commercial profile of the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard known as Wireless Worldwide Interoperability for Microwave Access or WiMAX (WiMax Forum). The paper includes background on the need for global interoperability in air/ground data communications, describes potential AeroMACS applications, addresses allocated frequency spectrum constraints, summarizes the international standardization process, and provides findings and recommendations from the world s first AeroMACS prototype implemented in Cleveland, Ohio, USA.

  3. Rating of new outlet structures for MacFarlane Reservoir

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Memorandum explaining the new work on the outlet structure at MacFarlane Reservoir. Flow measurements were taken at different staff gage elevations and this data is...

  4. Big Mac arvestab raha ostujõudu / Harli Uljas

    Index Scriptorium Estoniae

    Uljas, Harli

    2005-01-01

    The Economist võrdleb maailma valuutade suhestamiseks Big Mac'i burgeri hindu 120 riigis, kuna see meetod võimaldab saada ülevaate riikide elanikkonna tegelikust ostujõust. Tabel: Hamburgeri standard

  5. Big Mac arvestab raha ostujõudu / Harli Uljas

    Index Scriptorium Estoniae

    Uljas, Harli

    2005-01-01

    The Economist võrdleb maailma valuutade suhestamiseks Big Mac'i burgeri hindu 120 riigis, kuna see meetod võimaldab saada ülevaate riikide elanikkonna tegelikust ostujõust. Tabel: Hamburgeri standard

  6. MAC layer security issues in wireless mesh networks

    Science.gov (United States)

    Reddy, K. Ganesh; Thilagam, P. Santhi

    2016-03-01

    Wireless Mesh Networks (WMNs) have emerged as a promising technology for a broad range of applications due to their self-organizing, self-configuring and self-healing capability, in addition to their low cost and easy maintenance. Securing WMNs is more challenging and complex issue due to their inherent characteristics such as shared wireless medium, multi-hop and inter-network communication, highly dynamic network topology and decentralized architecture. These vulnerable features expose the WMNs to several types of attacks in MAC layer. The existing MAC layer standards and implementations are inadequate to secure these features and fail to provide comprehensive security solutions to protect both backbone and client mesh. Hence, there is a need for developing efficient, scalable and integrated security solutions for WMNs. In this paper, we classify the MAC layer attacks and analyze the existing countermeasures. Based on attacks classification and countermeasures analysis, we derive the research directions to enhance the MAC layer security for WMNs.

  7. Mac OS X : Tiger edition the missing manual

    CERN Document Server

    Pogue, David

    2005-01-01

    You can set your watch to it: As soon as Apple comes out with another version of Mac OS X, David Pogue hits the streets with another meticulous Missing Manual to cover it with a wealth of detail. The new Mac OS X 10.4, better known as Tiger, is faster than its predecessors, but nothing's too fast for Pogue and Mac OS X: The Missing Manual. There are many reasons why this is the most popular computer book of all time. With its hallmark objectivity, the Tiger Edition thoroughly explores the latest features to grace the Mac OS. Which ones work well and which do not? What should you look for? Th

  8. A tribute to Lloyd D. MacLean.

    Science.gov (United States)

    Keith, Roger G

    2015-08-01

    Dr. Lloyd D. MacLean, long-time co-editor of the Canadian Journal of Surgery passed away earlier this year at the age of 90. In order to appreciate the contributions of Dr. MacLean to the journal, this commentary recognizes him as a humble surgeon–scientist who was one of — if not the — most outstanding Canadian ambassadors to academic surgery in North America.

  9. Conformal holonomy in MacDowell-Mansouri gravity

    Energy Technology Data Exchange (ETDEWEB)

    Reid, James A., E-mail: j.a.reid@abdn.ac.uk [SUPA Department of Physics, University of Aberdeen, Aberdeen, AB24 3UE (United Kingdom); Wang, Charles H.-T., E-mail: c.wang@abdn.ac.uk [SUPA Department of Physics, University of Aberdeen, Aberdeen, AB24 3UE (United Kingdom); STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX (United Kingdom)

    2014-03-15

    The MacDowell-Mansouri formulation of general relativity is based on a gauge theory whose gauge algebra depends on the sign of the cosmological constant. In this article, we show that the gauge algebra is uniquely determined by the conformal structure of spacetime itself. Specifically, we show that in vacuum: the spacetime conformal holonomy algebra coincides with the MacDowell-Mansouri gauge algebra for both signs of the cosmological constant, in both Lorentzian and Euclidean metric signatures.

  10. Some Problems of Alasdair MacIntyre’s "Emotivism Thesis"

    OpenAIRE

    2016-01-01

    In this article Alasdair MacIntyre’s thesis concerning emotivist use of moral utterances in contemporary liberal societies is analysed. One tries to show that it needs further clarification since at least three elements of MacIntyre’s argument seem to pose certain problems; these are: ‘discussion halt’ as the source of emotivism, comprehensive doctrines as premises of respective arguments in liberal debates and the problem of incommensurability. These three problematic eleme...

  11. 42 CFR 423.2102 - Request for MAC review when ALJ issues decision or dismissal.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Request for MAC review when ALJ issues decision or... Reopening, ALJ Hearings, MAC review, and Judicial Review § 423.2102 Request for MAC review when ALJ issues decision or dismissal. (a)(1) An enrollee to the ALJ hearing may request a MAC review if the enrollee files...

  12. 42 CFR 423.2062 - Applicability of policies not binding on the ALJ and MAC.

    Science.gov (United States)

    2010-10-01

    ... and MAC. 423.2062 Section 423.2062 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT... BENEFIT Reopening, ALJ Hearings, MAC review, and Judicial Review § 423.2062 Applicability of policies not binding on the ALJ and MAC. (a) ALJs and the MAC are not bound by CMS program guidance, such as program...

  13. 42 CFR 423.2110 - MAC reviews on its own motion.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false MAC reviews on its own motion. 423.2110 Section 423... (CONTINUED) MEDICARE PROGRAM VOLUNTARY MEDICARE PRESCRIPTION DRUG BENEFIT Reopening, ALJ Hearings, MAC review, and Judicial Review § 423.2110 MAC reviews on its own motion. (a) General rule. The MAC may decide on...

  14. 42 CFR 423.2050 - Removal of a hearing request from an ALJ to the MAC.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Removal of a hearing request from an ALJ to the MAC..., ALJ Hearings, MAC review, and Judicial Review § 423.2050 Removal of a hearing request from an ALJ to the MAC. If a request for hearing is pending before an ALJ, the MAC may assume responsibility for...

  15. 42 CFR 423.2108 - MAC Actions when request for review is filed.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false MAC Actions when request for review is filed. 423... Hearings, MAC review, and Judicial Review § 423.2108 MAC Actions when request for review is filed. (a) General. Except as specified in paragraph (c) of this section, when an enrollee requests that the MAC...

  16. A Mac Protocol Implementation for Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Jamila Bhar

    2015-01-01

    Full Text Available IEEE 802.15.4 is an important standard for Low Rate Wireless Personal Area Network (LRWPAN. The IEEE 802.15.4 presents a flexible MAC protocol that provides good efficiency for data transmission by adapting its parameters according to characteristics of different applications. In this research work, some restrictions of this standard are explained and an improvement of traffic efficiency by optimizing MAC layer is proposed. Implementation details for several blocks of communication system are carefully modeled. The protocol implementation is done using VHDL language. The analysis gives a full understanding of the behavior of the MAC protocol with regard to backoff delay, data loss probability, congestion probability, slot effectiveness, and traffic distribution for terminals. Two ideas are proposed and tested to improve efficiency of CSMA/CA mechanism for IEEE 802.15.4 MAC Layer. Primarily, we dynamically adjust the backoff exponent (BE according to queue level of each node. Secondly, we vary the number of consecutive clear channel assessment (CCA for packet transmission. We demonstrate also that slot compensation provided by the enhanced MAC protocol can greatly avoid unused slots. The results show the significant improvements expected by our approach among the IEEE 802.15.4 MAC standards. Synthesis results show also hardware performances of our proposed architecture.

  17. Connectivity-Based Reliable Multicast MAC Protocol for IEEE 802.11 Wireless LANs

    Directory of Open Access Journals (Sweden)

    Woo-Yong Choi

    2009-01-01

    Full Text Available We propose the efficient reliable multicast MAC protocol based on the connectivity information among the recipients. Enhancing the BMMM (Batch Mode Multicast MAC protocol, the reliable multicast MAC protocol significantly reduces the RAK (Request for ACK frame transmissions in a reasonable computational time and enhances the MAC performance. By the analytical performance analysis, the throughputs of the BMMM protocol and our proposed MAC protocol are derived. Numerical examples show that our proposed MAC protocol increases the reliable multicast MAC performance for IEEE 802.11 wireless LANs.

  18. Anaesthesia with sevoflurane in pigeons: minimal anaesthetic concentration (MAC) determination and investigation of cardiorespiratory variables at 1 MAC.

    Science.gov (United States)

    Botman, J; Gabriel, F; Dugdale, A H A; Vandeweerd, J-M

    2016-05-28

    The objective of the study was to determine the minimal anaesthetic concentration (MAC) of sevoflurane (SEVO) in pigeons and investigate the effects of 1 MAC SEVO anaesthesia on cardiovascular and respiratory variables compared with the awake state. This is a prospective, experimental study. Animals were seven healthy adult pigeons. After acclimatisation to handling, heart rate (HR), heart rhythm, respiratory rate (fR), end-expired carbon dioxide tension (PE'CO2), inspired CO2 tension, indirect systolic arterial blood pressure (SAP) and cloacal temperature were measured to determine baseline, 'awake' values. Pigeons were then anaesthetised with SEVO and MAC was determined by the 'bracketing' method. The same variables were monitored during a 40 minute period at 1.0 MAC SEVO for each bird. Mean MAC was 3.0±0.6 per cent for SEVO. During maintenance of anaesthesia at 1.0 MAC, SAP decreased significantly (Pawake PE'CO2 values were unexpectedly low. Sinus arrhythmias were detected in two birds under SEVO anaesthesia. The times to tracheal intubation and to recovery were 2.5±0.7 and 6.4±1.7 minutes, respectively. Recovery was rapid and uneventful in all birds. In conclusion, SEVO is suitable for anaesthesia in pigeons. British Veterinary Association.

  19. Learning Unix for Mac OS X Tiger Unlock the Power of Unix

    CERN Document Server

    Taylor, Dave

    2005-01-01

    Thoroughly revised and updated for Mac OS X Tiger, this new edition introduces Mac users to the Terminal application and shows you how to navigate the command interface, explore hundreds of Unix applications that come with the Mac, and, most importantly, how to take advantage of both the Mac and Unix interfaces. If you want to master the command-line, this gentle guide to using Unix on Mac OS X Tiger is well worth its cover price

  20. Charged dust grain dynamics subject to solar wind, Poynting-Robertson drag, and the interplanetary magnetic field

    CERN Document Server

    Lhotka, Christoph; Narita, Yasuhito

    2016-01-01

    We investigate the combined effect of solar wind, Poynting-Robertson drag, and the frozen-in interplanetary magnetic field on the motion of charged dust grains in our solar system. For this reason we derive a secular theory of motion by the means of averaging method and validate it with numerical simulations of the un-averaged equations of motions. The theory predicts that the secular motion of charged particles is mainly affected by the z-component of the solar magnetic axis, or the normal component of the interplanetary magnetic field. The normal component of the interplanetary magnetic field leads to an increase or decrease of semi-major axis depending on its functional form and sign of charge of the dust grain. It is generally accepted that the combined effects of solar wind and photon absorption and re-emmision (Poynting-Robertson drag) lead to a decrease in semi-major axis on secular time scales. On the contrary, we demonstrate that the interplanetary magnetic field may counteract these drag forces unde...

  1. The University of Toronto's lasting contribution to war surgery: how Maj. L. Bruce Robertson fundamentally transformed thinking toward blood transfusion during the First World War.

    Science.gov (United States)

    Tien, Abigail; Beckett, Andrew; Pannell, Dylan

    2017-06-01

    During the Great War, Canadian military surgeons produced some of the greatest innovations to improve survival on the battlefield. Arguably, the most important was bringing blood transfusion practice close to the edge of the battlefield to resuscitate the many casualties dying of hemorrhagic shock. Dr. L. Bruce Robertson of the Canadian Army Medical Corps was the pioneering surgeon from the University of Toronto who was able to demonstrate the benefit of blood transfusions near the front line and counter the belief that saline was the resuscitation fluid of choice in military medicine. Robertson would go on to survive the Great War, but would be taken early in life by influenza. Despite his life and career being cut short, Robertson's work is still carried on today by many military medical organizations who strive to bring blood to the wounded in austere and dangerous settings. This article has an Appendix, available at canjsurg.ca.

  2. C-MAC compared with direct laryngoscopy for intubation in patients with cervical spine immobilization: A manikin trial.

    Science.gov (United States)

    Smereka, Jacek; Ladny, Jerzy R; Naylor, Amanda; Ruetzler, Kurt; Szarpak, Lukasz

    2017-08-01

    The aim of this study was to compare C-MAC videolaryngoscopy with direct laryngoscopy for intubation in simulated cervical spine immobilization conditions. The study was designed as a prospective randomized crossover manikin trial. 70 paramedics with MAC and C-MAC on the first attempt (95.7% MAC vs. 100% C-MAC), with similar intubation times (16.5s MAC vs. 18s C-MAC). Scenario B: The results with C-MAC were significantly better than those with MAC (pMAC vs. 19 s C-MAC), success of the first intubation attempt (88.6% MAC vs. 100% C-MAC), Cormack-Lehane grade, POGO score, severity of dental compression, device difficulty score, and preferred airway device. Scenario C: The results with C-MAC were significantly better than those with MAC (pMAC vs. 100% C-MAC), overall success rate, intubation time (27 s MAC vs. 20.5 s C-MAC), Cormack-Lehane grade, POGO score, dental compression, device difficulty score and the preferred airway device. The C-MAC videolaryngoscope is an excellent alternative to the MAC laryngoscope for intubating manikins with cervical spine immobilization. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Victor Bérard et la Macédoine

    Directory of Open Access Journals (Sweden)

    Ivan Savev

    2011-01-01

    Full Text Available Un helléniste convaincu, Victor Bérard, en vient, au début du XXe siècle à soutenir l’existence de « Macédoniens » et le slogan « la Macédoine aux Macédoniens”.Le Congrès de Berlin en 1878 avait laissé la Macédoine aux mains des Ottomans. La Grèce, la Serbie et la Bulgarie, parvenues à ses limites et prévoyant le retrait futur des Ottomans peaufinent les arguments linguistiques et historiques qui justifieront leurs revendications territoriales. Victor Bérard, un helléniste respecté et bon connaisseur de la région sud balkanique, effectue des enquêtes en Macédoine en 1896 et 1903 qu’il publie à Paris.Cette étude montre comment, dans le contexte de la propagande nationaliste des prétendants à la possession de la Macédoine, Victor Bérard en vient progressivement à affirmer qu’il existe une population autochtone, les Macédoniens. Il soutient leur programme pour la constitution d’une fédération ou confédération avec le slogan « la Macédoine aux Macédoniens » ce qui fait toute l’actualité de ses ouvrages.In 1878, the Congress of Berlin had left Macedonia in the hands of the Ottomans. Greece, Serbia and Bulgaria had reached its limits. Anticipating the Ottoman retreat, they polish language and historical arguments that will justify their territorial claims. Victor Bérard, a respected Hellenist and a good expert of the southern Balkans, is doing researches in Macedonia in 1896 and 1903. These will be later published in Paris.This study shows how, in the context of the nationalist propaganda build-up made by the candidates for the possession of Macedonia, Victor Bérard comes progressively to assert the existence of a native population: the Macedonians. He supports their program for the forming of a federation or confederation which slogan would be “Macedonia to Macedonians”. This makes his works very topical.

  4. The many faces of Mac-1 in autoimmune disease.

    Science.gov (United States)

    Rosetti, Florencia; Mayadas, Tanya N

    2016-01-01

    Mac-1 (CD11b/CD18) is a β2 integrin classically regarded as a pro-inflammatory molecule because of its ability to promote phagocyte cytotoxic functions and enhance the function of several effector molecules such as FcγR, uPAR, and CD14. Nevertheless, recent reports have revealed that Mac-1 also plays significant immunoregulatory roles, and genetic variants in ITGAM, the gene that encodes CD11b, confer risk for the autoimmune disease systemic lupus erythematosus (SLE). This has renewed interest in the physiological roles of this integrin and raised new questions on how its seemingly opposing biological functions may be regulated. Here, we provide an overview of the CD18 integrins and how their activation may be regulated as this may shed light on how the opposing roles of Mac-1 may be elicited. We then discuss studies that exemplify Mac-1's pro-inflammatory versus regulatory roles particularly in the context of IgG immune complex-mediated inflammation. This includes a detailed examination of molecular mechanisms that could explain the risk-conferring effect of rs1143679, a single nucleotide non-synonymous Mac-1 polymorphism associated with SLE.

  5. Dolphin natures, human virtues: MacIntyre and ethical naturalism.

    Science.gov (United States)

    Glackin, Shane Nicholas

    2008-09-01

    Can biological facts explain human morality? Aristotelian 'virtue' ethics has traditionally assumed so. In recent years Alasdair MacIntyre has reintroduced a form of Aristotle's 'metaphysical biology' into his ethics. He argues that the ethological study of dependence and rationality in other species--dolphins in particular--sheds light on how those same traits in the typical lives of humans give rise to the moral virtues. However, some goal-oriented dolphin behaviour appears both dependent and rational in the precise manner which impresses MacIntyre, yet anything but ethically 'virtuous'. More damningly, dolphin ethologists consistently refuse to evaluate such behaviour in the manner MacIntyre claims is appropriate to moral judgement. In light of this, I argue that virtues--insofar as they name a biological or ethological category--do not name a morally significant one.

  6. An Energy Efficient MAC Proto col for Linear WSNs

    Institute of Scientific and Technical Information of China (English)

    DAI Guoyong; MIAO Chunyu; YING Kezhen; WANG Kai; CHEN Qingzhang

    2015-01-01

    Wireless sensor networks (WSNs) have been employed as an ideal solution in many applications for data gathering in harsh environment. Energy consumption is a key issue in wireless sensor networks since nodes are often battery operated. Medium access control (MAC) pro-tocol plays an important role in energy efficiency in wire-less sensor networks because nodes’ access to the shared medium is coordinated by the MAC layer. An energy ef-ficient MAC protocol is designed for data gathering in linear wireless sensor networks. In order to enhance the performance, when a source node transmits data to the sink, proper relay nodes are selected for forwarding data according to the energy consumption factor and residual energy balance factor. Some simulation experiments are conducted and the results show that, the proposed proto-col provides better energy efficiency and long lifetime than the existing DMAC protocol.

  7. A Fair-Priority MAC design in Networked Control System

    Directory of Open Access Journals (Sweden)

    Hongjun Li

    2009-10-01

    Full Text Available Media Access Control (MAC protocols in Wireless Networked Control System (WNCS must minimize the radio energy costs in sensor nodes. Latency and throughput are also important design features for MAC protocols in the applications. But most of them cannot guarantee quality for real-time traffic. This paper studies the state of the art of current real-time MAC protocols, and then introduces a medium access control protocol and a improved protocol that provide multiple priority levels and hard real-time transmission. The channel is accessed by sensors according to their priorities. Sensors send frames in a round manner with same priority. The fairness between different priorities is provided. The channel access procedure is divided into two stages: broadcast period and transmission period. Simulation and experiment results indicate that our protocol provides high channel utilization and bounded delays for real-time communication and can be well applied in the many fields especially the dynamic wireless sensor networks.

  8. Implementation of MAC by using Modified Vedic Multiplier

    Directory of Open Access Journals (Sweden)

    Sreelekshmi M. S.

    2013-09-01

    Full Text Available Multiplier Accumulator Unit (MAC is a part of Digital Signal Processors. The speed of MAC depends on the speed of multiplier. So by using an efficient Vedic multiplier which excels in terms of speed, power and area, the performance of MAC can be increased. For this fast method of multiplication based on ancient Indian Vedic mathematics is proposed in this paper. Among various method of multiplication in Vedic mathematics, Urdhva Tiryagbhyam is used and the multiplication is for 32 X 32 bits. Urdhva Tiryagbhyam is a general multiplication formula applicable to all cases of multiplication. Adder used is Carry Look Ahead adder. The proposed design shows improvement over carry save adder.

  9. Cognitive MAC Protocols for General Primary Network Models

    CERN Document Server

    Mehanna, Omar; Gamal, Hesham El

    2009-01-01

    We consider the design of cognitive Medium Access Control (MAC) protocols enabling a secondary (unlicensed) transmitter-receiver pair to communicate over the idle periods of a set of primary (licensed) channels. More specifically, we propose cognitive MAC protocols optimized for both slotted and un-slotted primary networks. For the slotted structure, the objective is to maximize the secondary throughput while maintaining synchronization between the secondary pair and not causing interference to the primary network. Our investigations differentiate between two sensing scenarios. In the first, the secondary transmitter is capable of sensing all the primary channels, whereas it senses only a subset of the primary channels in the second scenario. In both cases, we propose blind MAC protocols that efficiently learn the statistics of the primary traffic on-line and asymptotically achieve the throughput obtained when prior knowledge of primary traffic statistics is available. For the un-slotted structure, the object...

  10. Synthesizing Existing CSMA and TDMA Based MAC Protocols for VANETs.

    Science.gov (United States)

    Huang, Jiawei; Li, Qi; Zhong, Shaohua; Liu, Lianhai; Zhong, Ping; Wang, Jianxin; Ye, Jin

    2017-02-10

    Many Carrier Sense Multiple Access (CSMA) and Time Division Multiple Access (TDMA) based medium access control (MAC) protocols for vehicular ad hoc networks (VANETs) have been proposed recently. Contrary to the common perception that they are competitors, we argue that the underlying strategies used in these MAC protocols are complementary. Based on this insight, we design CTMAC, a MAC protocol that synthesizes existing strategies; namely, random accessing channel (used in CSMA-style protocols) and arbitral reserving channel (used in TDMA-based protocols). CTMAC swiftly changes its strategy according to the vehicle density, and its performance is better than the state-of-the-art protocols. We evaluate CTMAC using at-scale simulations. Our results show that CTMAC reduces the channel completion time and increases the network goodput by 45% for a wide range of application workloads and network settings.

  11. ETEEM- Extended Traffic Aware Energy Efficient MAC Scheme for WSNs

    Directory of Open Access Journals (Sweden)

    Younas Khan

    2016-11-01

    Full Text Available Idle listening issue arises when a sensor node listens to medium despite the absence of data which results in consumption of energy. ETEEM is a variant of Traffic Aware Energy Efficient MAC protocol (TEEM which focuses on energy optimization due to reduced idle listening time and much lesser overhead on energy sources. It uses a novel scheme for using idle listening time of sensor nodes. The nodes are only active for small amount of time and most of the time, will be in sleep mode when no data is available. ETEEM reduces energy at byte level and uses a smaller byte packet called FLAG replacing longer byte SYNC packets of S-MAC and SYNCrts of TEEM respectively. It also uses a single acknowledgement packet per data set hence reducing energy while reducing frequency of the acknowledgment frames sent. The performance of ETEEM is 70% better comparative to other under-consideration MAC protocols.

  12. Office for iPad and Mac for dummies

    CERN Document Server

    Weverka, Peter

    2015-01-01

    The easy way to work with Office on your iPad or Mac Are you a Mac user who isn't accustomed to working with Microsoft Office? Consider this friendly guide your go-to reference! Written in plain English and packed with easy-to-follow, step-by-step instructions, Office for iPad and Mac For Dummies walks you through every facet of Office, from installing the software and opening files to working with Word, Excel, PowerPoint, and Outlook-and beyond. Plus, you'll discover how to manage files, share content and collaborate online through social media, and find help when you need it. Two things a

  13. SACRB-MAC: A High-Capacity MAC Protocol for Cognitive Radio Sensor Networks in Smart Grid.

    Science.gov (United States)

    Yang, Zhutian; Shi, Zhenguo; Jin, Chunlin

    2016-03-31

    The Cognitive Radio Sensor Network (CRSN) is considered as a viable solution to enhance various aspects of the electric power grid and to realize a smart grid. However, several challenges for CRSNs are generated due to the harsh wireless environment in a smart grid. As a result, throughput and reliability become critical issues. On the other hand, the spectrum aggregation technique is expected to play an important role in CRSNs in a smart grid. By using spectrum aggregation, the throughput of CRSNs can be improved efficiently, so as to address the unique challenges of CRSNs in a smart grid. In this regard, we proposed Spectrum Aggregation Cognitive Receiver-Based MAC (SACRB-MAC), which employs the spectrum aggregation technique to improve the throughput performance of CRSNs in a smart grid. Moreover, SACRB-MAC is a receiver-based MAC protocol, which can provide a good reliability performance. Analytical and simulation results demonstrate that SACRB-MAC is a promising solution for CRSNs in a smart grid.

  14. SACRB-MAC: A High-Capacity MAC Protocol for Cognitive Radio Sensor Networks in Smart Grid

    Directory of Open Access Journals (Sweden)

    Zhutian Yang

    2016-03-01

    Full Text Available The Cognitive Radio Sensor Network (CRSN is considered as a viable solution to enhance various aspects of the electric power grid and to realize a smart grid. However, several challenges for CRSNs are generated due to the harsh wireless environment in a smart grid. As a result, throughput and reliability become critical issues. On the other hand, the spectrum aggregation technique is expected to play an important role in CRSNs in a smart grid. By using spectrum aggregation, the throughput of CRSNs can be improved efficiently, so as to address the unique challenges of CRSNs in a smart grid. In this regard, we proposed Spectrum Aggregation Cognitive Receiver-Based MAC (SACRB-MAC, which employs the spectrum aggregation technique to improve the throughput performance of CRSNs in a smart grid. Moreover, SACRB-MAC is a receiver-based MAC protocol, which can provide a good reliability performance. Analytical and simulation results demonstrate that SACRB-MAC is a promising solution for CRSNs in a smart grid.

  15. AMPA receptor competitive antagonism reduces halothane MAC in rats.

    Science.gov (United States)

    McFarlane, C; Warner, D S; Todd, M M; Nordholm, L

    1992-12-01

    Various subtypes of receptors have been identified for glutamate, an excitatory neurotransmitter. Previous studies have shown that antagonism of glutamate at the NMDA receptors reduces minimum alveolar concentration (MAC) for volatile anesthetics. NBQX (2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(f)quinoxaline) is a selective antagonist at the glutamatergic AMPA receptor. The purpose of this experiment was to determine whether AMPA receptor antagonism influences halothane MAC in the rat. Sprague-Dawley rats were anesthetized with halothane in 50% O2/balance N2, tracheally intubated and the lungs were mechanically ventilated. Increasing doses of NBQX were intravenously infused in three groups while the control group was infused with vehicle (D5W). Halothane MAC was then determined by the tail-clamp method. Halothane MAC was log-linearly related to plasma NBQX concentrations (MAC = 0.125 (In plasma concentration NBQX) + 1.035, r2 = 0.77). A maximal 58% reduction of halothane MAC was achieved with an NBQX loading dose of 42 mg/kg followed by a continuous infusion rate of 36 mg x kg-1 x h-1 (control = 1.02 +/- 0.07%; NBQX = 0.43 +/- 0.12%; P awake rats were randomly assigned to groups based on the dose of NBQX infused. Pa(CO2) and mean arterial pressure were measured at time 0 and at 5 and 30 min after start of NBQX infusion. The infusion was then stopped. Time until recovery of the righting reflex was recorded.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Vehicle Health Management Communications Requirements for AeroMACS

    Science.gov (United States)

    Kerczewski, Robert J.; Clements, Donna J.; Apaza, Rafael D.

    2012-01-01

    As the development of standards for the aeronautical mobile airport communications system (AeroMACS) progresses, the process of identifying and quantifying appropriate uses for the system is progressing. In addition to defining important elements of AeroMACS standards, indentifying the systems uses impacts AeroMACS bandwidth requirements. Although an initial 59 MHz spectrum allocation for AeroMACS was established in 2007, the allocation may be inadequate; studies have indicated that 100 MHz or more of spectrum may be required to support airport surface communications. Hence additional spectrum allocations have been proposed. Vehicle health management (VHM) systems, which can produce large volumes of vehicle health data, were not considered in the original bandwidth requirements analyses, and are therefore of interest in supporting proposals for additional AeroMACS spectrum. VHM systems are an emerging development in air vehicle safety, and preliminary estimates of the amount of data that will be produced and transmitted off an aircraft, both in flight and on the ground, have been prepared based on estimates of data produced by on-board vehicle health sensors and initial concepts of data processing approaches. This allowed an initial estimate of VHM data transmission requirements for the airport surface. More recently, vehicle-level systems designed to process and analyze VHM data and draw conclusions on the current state of vehicle health have been undergoing testing and evaluation. These systems make use of vehicle system data that is mostly different from VHM data considered previously for airport surface transmission, and produce processed system outputs that will be also need to be archived, thus generating additional data load for AeroMACS. This paper provides an analysis of airport surface data transmission requirements resulting from the vehicle level reasoning systems, within the context of overall VHM data requirements.

  17. Link-layer jamming attacks on S-MAC

    OpenAIRE

    Law, Yee Wei; Hartel, Pieter; Hartog, den, D.N.; Havinga, Paul

    2005-01-01

    We argue that among denial-of-service (DoS) attacks, link-layer jamming is a more attractive option to attackers than radio jamming is. By exploiting the semantics of the link-layer protocol (aka MAC protocol), an attacker can achieve better efficiency than blindly jamming the radio signals alone. In this paper, we investigate some jamming attacks on S-MAC, the level of effectiveness and efficiency the attacks can potentially achieve, and a countermeasure that can be implemented against one o...

  18. Rand and MacIntyre on moral agency

    OpenAIRE

    Beadle, Ron

    2008-01-01

    This paper contrasts the work of Ayn Rand and Alasdair MacIntyre on moral agency. Both argue that moral agency requires the application of a consistent moral code across relationships with others and that such consistency is rarely evident in the modern social order. However, while MacIntyre holds this failure to be a defining feature of the modern social order, Rand holds this to be a failure of individuals and a marker of a wider cultural confusion. While Rand sees selfishness and capitalis...

  19. Alasdair MacIntyre: relatividad conceptual, tomismo y liberalismo

    Directory of Open Access Journals (Sweden)

    Carlos Isler S.

    2011-01-01

    Full Text Available Influenciado por Thomas Kuhn, Alasdair MacIntyre presenta una teoría conceptualmente relativista sobre las tradiciones de investigación, la cual pretende no sólo describir la estructura de las distintas tradiciones, sino también encontrar un principioque permita resolver las disputas entre ellas. Se expone esta teoría y se analiza su compatibilidad con el tomismo, tradición a la que MacIntyre dice pertenecer, y con el liberalismo, tradición a la que critica con vigor.

  20. Mac Lane method in the investigation of magnetic translation groups

    OpenAIRE

    Florek, Wojciech

    1998-01-01

    Central extensions of the three-dimensional translation group T=Z^3 by the unitary group U(1) (a group of factors) are considered within the frame of the Mac~Lane method. All nonzero vectors t in T are considered to be generators of T. This choice leads to very illustrative relations between the Mac~Lane method and Zak's approach to magnetic translation groups. It is shown that factor systems introduced by Zak and Brown can be realized only for the unitary group U(1) and for some of its finit...

  1. Generalized Robertson-Walker Space-Time Admitting Evolving Null Horizons Related to a Black Hole Event Horizon

    Science.gov (United States)

    2016-01-01

    A new technique is used to study a family of time-dependent null horizons, called “Evolving Null Horizons” (ENHs), of generalized Robertson-Walker (GRW) space-time (M¯,g¯) such that the metric g¯ satisfies a kinematic condition. This work is different from our early papers on the same issue where we used (1 + n)-splitting space-time but only some special subcases of GRW space-time have this formalism. Also, in contrast to previous work, we have proved that each member of ENHs is totally umbilical in (M¯,g¯). Finally, we show that there exists an ENH which is always a null horizon evolving into a black hole event horizon and suggest some open problems. PMID:27722202

  2. Approximation methods in Loop Quantum Cosmology: From Gowdy cosmologies to inhomogeneous models in Friedmann-Robertson-Walker geometries

    CERN Document Server

    Martín-Benito, Mercedes; Marugán, Guillermo A Mena

    2013-01-01

    We develop approximation methods in the hybrid quantization of the Gowdy model with linear polarization and a massless scalar field, for the case of three-torus spatial topology. The loop quantization of the homogeneous gravitational sector of the Gowdy model (according to the improved dynamics prescription) and the presence of inhomogeneities lead to a very complicated Hamiltonian constraint. Therefore, the extraction of physical results calls for the introduction of well justified approximations. We first show how to approximate the homogeneous part of the Hamiltonian constraint, corresponding to Bianchi I geometries, as if it described a Friedmann-Robertson-Walker (FRW) model corrected with anisotropies. This approximation is valid in the high-energy sector of the FRW geometry (concerning its contribution to the constraint) and for anisotropy profiles that are sufficiently smooth. In addition, for certain families of states associated to regimes of physical interest, with negligible effects of the anisotro...

  3. 'DIRTY WORK', BUT SOMEONE HAS TO DO IT: HOWARD P. ROBERTSON AND THE REFEREEING PRACTICES OF PHYSICAL REVIEW IN THE 1930S.

    Science.gov (United States)

    Lalli, Roberto

    2016-06-20

    In the 1930s the mathematical physicist Howard P. Robertson was the main referee of the journal Physical Review for papers concerning general relativity and related subjects. The rich correspondence between Robertson and the editors of the journal enables a historical investigation of the refereeing process of Physical Review at the time that it was becoming one of the most influential physics periodicals in the world. By focusing on this case study, the paper investigates two complementary aspects of the evolution of the refereeing process: first, the historical evolution of the refereeing practices in connection with broader contextual changes, and second, the attempts to define the activity of the referee, including the epistemic virtues required and the journal's functions according to the participants' categories. By exploring the tension between Robertson's idealized picture about how the referee should behave and the desire to promote his intellectual agenda, I show that the evaluation criteria that Robertson employed were contextually dependent and I argue that, in the 1930s, through his reports the referee had an enormous power in defining what direction future research should take.

  4. Catalogue of the sub-Saharan species of the genus Seladonia Robertson, 1918, with description of two new species (Hymenoptera: Apoidea: Halictidae)

    NARCIS (Netherlands)

    Pauly, A.

    2008-01-01

    This paper is a synonymic catalogue of the 18 species of the genus Seladonia Robertson, 1918 (Apoidea: Halictidae) from sub-Saharan Africa. Two new species are described: S. cyanella spec. nov., a small blue endemic species of the Yemeno-Erythrean area^S. kuhlmanni spec. nov., an endemic species of

  5. Muusikamaailm : Ateena konkurss tuleb esinduslik. Kaks raamatut juubilar-lauljatest. David Robertson lahkub Pariisist. Jean-Pierre Rampal surnud / Priit Kuusk

    Index Scriptorium Estoniae

    Kuusk, Priit, 1938-

    2000-01-01

    Septembris Ateenas toimuvast D. Mitropoulose nim. rahvusvahelisest noorte dirigentide konkursist. Saksamaal ilmus kaks raamatut nimekatelt lauljatelt ئ D. Fischer-Dieskau "Zeit eines Lebens. Auf Fährtensuche" ja J. King'i "Nun sollt Ihr mich befragen". D. Robertson lahkub Ensemble InterContemporaini kunstilise juhi kohalt, dirigendi edasisest tegevuskavast. J.-P. Rampal'i muusikuteest

  6. Muusikamaailm : Ateena konkurss tuleb esinduslik. Kaks raamatut juubilar-lauljatest. David Robertson lahkub Pariisist. Jean-Pierre Rampal surnud / Priit Kuusk

    Index Scriptorium Estoniae

    Kuusk, Priit, 1938-

    2000-01-01

    Septembris Ateenas toimuvast D. Mitropoulose nim. rahvusvahelisest noorte dirigentide konkursist. Saksamaal ilmus kaks raamatut nimekatelt lauljatelt ئ D. Fischer-Dieskau "Zeit eines Lebens. Auf Fährtensuche" ja J. King'i "Nun sollt Ihr mich befragen". D. Robertson lahkub Ensemble InterContemporaini kunstilise juhi kohalt, dirigendi edasisest tegevuskavast. J.-P. Rampal'i muusikuteest

  7. Directional Medium Access Control (MAC Protocols in Wireless Ad Hoc and Sensor Networks: A Survey

    Directory of Open Access Journals (Sweden)

    David Tung Chong Wong

    2015-06-01

    Full Text Available This survey paper presents the state-of-the-art directional medium access control (MAC protocols in wireless ad hoc and sensor networks (WAHSNs. The key benefits of directional antennas over omni-directional antennas are longer communication range, less multipath interference, more spatial reuse, more secure communications, higher throughput and reduced latency. However, directional antennas lead to single-/multi-channel directional hidden/exposed terminals, deafness and neighborhood, head-of-line blocking, and MAC-layer capture which need to be overcome. Addressing these problems and benefits for directional antennas to MAC protocols leads to many classes of directional MAC protocols in WAHSNs. These classes of directional MAC protocols presented in this survey paper include single-channel, multi-channel, cooperative and cognitive directional MACs. Single-channel directional MAC protocols can be classified as contention-based or non-contention-based or hybrid-based, while multi-channel directional MAC protocols commonly use a common control channel for control packets/tones and one or more data channels for directional data transmissions. Cooperative directional MAC protocols improve throughput in WAHSNs via directional multi-rate/single-relay/multiple-relay/two frequency channels/polarization, while cognitive directional MAC protocols leverage on conventional directional MAC protocols with new twists to address dynamic spectrum access. All of these directional MAC protocols are the pillars for the design of future directional MAC protocols in WAHSNs.

  8. Link-layer jamming attacks on S-MAC

    NARCIS (Netherlands)

    Law, Yee Wei; Hartel, Pieter; Hartog, den Jerry; Havinga, Paul

    2005-01-01

    We argue that among denial-of-service (DoS) attacks, link-layer jamming is a more attractive option to attackers than radio jamming is. By exploiting the semantics of the link-layer protocol (aka MAC protocol), an attacker can achieve better efficiency than blindly jamming the radio signals alone. W

  9. Listening, Looking, and Learning with MacLang.

    Science.gov (United States)

    Frommer, Judith

    1989-01-01

    Describes how the capabilities of the MacLang authoring system allow foreign language teachers to develop computer-assisted instruction that meets the listening skill objectives of foreign language courses. Examples are given of the use of audio and video interfaces that facilitate listening comprehension. (Author/CB)

  10. Beamforming in Ad Hoc Networks: MAC Design and Performance Modeling

    Directory of Open Access Journals (Sweden)

    Khalil Fakih

    2009-01-01

    Full Text Available We examine in this paper the benefits of beamforming techniques in ad hoc networks. We first devise a novel MAC paradigm for ad hoc networks when using these techniques in multipath fading environment. In such networks, the use of conventional directional antennas does not necessarily improve the system performance. On the other hand, the exploitation of the potential benefits of smart antenna systems and especially beamforming techniques needs a prior knowledge of the physical channel. Our proposition performs jointly channel estimation and radio resource sharing. We validate the fruitfulness of the proposed MAC and we evaluate the effects of the channel estimation on the network performance. We then present an accurate analytical model for the performance of IEEE 802.11 MAC protocol. We extend the latter model, by introducing the fading probability, to derive the saturation throughput for our proposed MAC when the simplest beamforming strategy is used in real multipath fading ad hoc networks. Finally, numerical results validate our proposition.

  11. God, Sport Philosophy, Kinesiology: A MacIntyrean Examination

    Science.gov (United States)

    Twietmeyer, Gregg

    2015-01-01

    Sport philosophy is in crisis. This subdiscipline of kinesiology garners little to no respect and few tenure track lines in kinesiology departments. Why is this the case? Why isn't philosophy held in greater esteem? Is it possible that philosopher Alasdair MacIntyre's (2009) diagnosis found in "God, Philosophy, Universities" could…

  12. MAC Support for High Density Wireless Sensor Networks

    NARCIS (Netherlands)

    Taddia, C.; Meratnia, Nirvana; van Hoesel, L.F.W.; Mazzini, G.; Havinga, Paul J.M.

    Large scale and high density networks of tiny sensor nodes offer promising solutions for event detection and actuating applications. In this paper we address the effect of high density of wireless sensor network performance with a specific MAC protocol, the Lightweight Medium Access Control (LMAC).

  13. God, Sport Philosophy, Kinesiology: A MacIntyrean Examination

    Science.gov (United States)

    Twietmeyer, Gregg

    2015-01-01

    Sport philosophy is in crisis. This subdiscipline of kinesiology garners little to no respect and few tenure track lines in kinesiology departments. Why is this the case? Why isn't philosophy held in greater esteem? Is it possible that philosopher Alasdair MacIntyre's (2009) diagnosis found in "God, Philosophy, Universities" could…

  14. Roles of Mac-1 and glycoprotein IIb/IIIa integrins in leukocyte-platelet aggregate formation: stabilization by Mac-1 and inhibition by GpIIb/IIIa blockers.

    Science.gov (United States)

    Patko, Zsofia; Csaszar, Albert; Acsady, Gyorgy; Peter, Karlheinz; Schwarz, Meike

    2012-01-01

    Circulating platelet-leukocyte hetero-aggregates play an important role in acute cardiovascular events and hypersensitivity reactions. The association involves the receptor families of selectins and integrin. The objective of this study was to investigate the role of CD11b/CD18 integrin (Mac-1) in hetero-aggregate formation and search for a counter-receptor on platelets ready to interact with Mac-1. As a model of leukocytes, Mac-1 presenting Chinese hamster ovary (CHO) cells were used to evaluate the role of Mac-1 in hetero-aggregate formation. The amount of CHO cell-bound active and inactive platelets was measured by flow cytometry, while the counter-receptors on platelets were identified via using blocking antibodies. We observed significant platelet adhesion on Mac-1-bearing cells when platelet-rich plasma or activated platelets were present. Inactive platelets did not adhere to Mac-1-bearing cells. Addition of fibrinogen, a ligand of Mac-1 significantly increased platelet binding. CD40L was demonstrated to act similarly on Mac-1. Inhibition of platelet GpIIb/IIIa completely abolished CHO cell-platelet aggregation. In our study, we have shown for the first time that Mac-1 mediates the formation of hetero-aggregates without selectin tethering when Mac-1 ligands such as fibrinogen or CD40L are present and blockers of platelet GpIIb/IIIa are able to diminish this interaction.

  15. Pyrogen testing of lipid-based TPN using Mono Mac 6 monocyte cell line and DELFIA

    DEFF Research Database (Denmark)

    Moesby, Lise; Hansen, E W; Christensen, J D

    1997-01-01

    Measurement of lipopolysaccharide (LPS) induced interleukin-6 (IL-6) secretion in Mono Mac 6 cells.......Measurement of lipopolysaccharide (LPS) induced interleukin-6 (IL-6) secretion in Mono Mac 6 cells....

  16. MAC: identifying and correcting annotation for multi-nucleotide variations.

    Science.gov (United States)

    Wei, Lei; Liu, Lu T; Conroy, Jacob R; Hu, Qiang; Conroy, Jeffrey M; Morrison, Carl D; Johnson, Candace S; Wang, Jianmin; Liu, Song

    2015-08-01

    Next-Generation Sequencing (NGS) technologies have rapidly advanced our understanding of human variation in cancer. To accurately translate the raw sequencing data into practical knowledge, annotation tools, algorithms and pipelines must be developed that keep pace with the rapidly evolving technology. Currently, a challenge exists in accurately annotating multi-nucleotide variants (MNVs). These tandem substitutions, when affecting multiple nucleotides within a single protein codon of a gene, result in a translated amino acid involving all nucleotides in that codon. Most existing variant callers report a MNV as individual single-nucleotide variants (SNVs), often resulting in multiple triplet codon sequences and incorrect amino acid predictions. To correct potentially misannotated MNVs among reported SNVs, a primary challenge resides in haplotype phasing which is to determine whether the neighboring SNVs are co-located on the same chromosome. Here we describe MAC (Multi-Nucleotide Variant Annotation Corrector), an integrative pipeline developed to correct potentially mis-annotated MNVs. MAC was designed as an application that only requires a SNV file and the matching BAM file as data inputs. Using an example data set containing 3024 SNVs and the corresponding whole-genome sequencing BAM files, we show that MAC identified eight potentially mis-annotated SNVs, and accurately updated the amino acid predictions for seven of the variant calls. MAC can identify and correct amino acid predictions that result from MNVs affecting multiple nucleotides within a single protein codon, which cannot be handled by most existing SNV-based variant pipelines. The MAC software is freely available and represents a useful tool for the accurate translation of genomic sequence to protein function.

  17. Generation of MAC waves by convection in Earth's core

    Science.gov (United States)

    Jaupart, Etienne; Buffett, Bruce

    2017-05-01

    Convection in Earth's core is a viable mechanism for generating MAC waves when the top of the core is stably stratified. We quantify the generation mechanism by extending the physical description of MAC waves to include a source term due to buoyancy forces in the convecting part of the core. Solutions for the forced motion are obtained using a Green's function, which is constructed from the eigenfunctions for the unforced motion. When the source term is evaluated using the output of a numerical geodynamo model, the largest excitation occurs at even spherical harmonic degrees, corresponding to waves with symmetric azimuthal flow about the equator. We also find that the magnitude of the source term decreases at periods shorter than about 60 yr. As a result most of the wave generation is confined to waves with periods of 60 yr or longer. Quantitative predictions for the wave amplitudes depend on the projection of the source term into the eigenfunction of the waves. Strong stratification limits the penetration of density anomalies into the stratified layer, which means that the source term is confined to the lowermost part of the layer. Overtones of MAC waves with large amplitudes in the lower part of the stratified layer are more effectively generated by convection, even though these waves are heavily damped by magnetic diffusion. Generation of MAC waves by convection establishes a physical link between observable wave motion and deeper convective processes. Detection of changes in the amplitude and phase of MAC waves would constrain the generation processes and offer insights into the nature of the convection.

  18. 42 CFR 405.1110 - MAC reviews on its own motion.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false MAC reviews on its own motion. 405.1110 Section 405....1110 MAC reviews on its own motion. (a) General rule. The MAC may decide on its own motion to review a decision or dismissal issued by an ALJ. CMS or any of its contractors may refer a case to the MAC for it to...

  19. Minimum Alveolar Concentration for Blunting Adrenergic Responses (MAC-BAR) of Sevoflurane in Dogs

    OpenAIRE

    YAMASHITA, Kazuto; FURUKAWA, Erika; ITAMI, Takaharu; ISHIZUKA, Tomohito; TAMURA, Jun; MIYOSHI, Kenjirou

    2012-01-01

    It is well known that heart rate or arterial blood pressure may increase in response to surgical stimulation despite the absence of a purposeful movement. However, there is limited information regarding anesthetic requirement for blunting adrenergic response in dogs. This study was designed to compare the minimum alveolar concentrations of sevoflurane required to prevent autonomic response (MAC-BAR) and purposeful movement (MAC) in dogs. Sevoflurane MAC-BAR and MAC were determined in 5 beagle...

  20. MDS-Mac: a scheduled MAC for localization, time-synchronisation and communication in underwater acoustic networks

    NARCIS (Netherlands)

    Kleunen, van Wouter; Meratnia, Nirvana; Havinga, Paul J.M.

    2012-01-01

    In this paper we describe a design for an underwater MAC protocol which combines localization, time-synchronisation and communication. This protocol is designed for small-scale clustered networks in which all nodes are able to ommunicate with each other. We consider an integrated design of localizat

  1. TR-MAC: an energy-efficient MAC protocol for wireless sensor networks exploiting noise-based transmitted reference modulation

    NARCIS (Netherlands)

    Morshed, S.; Dimitrova, D.C.; Brogle, M.; Braun, T.; Heijenk, Gerhard J.

    Energy-constrained behavior of sensor nodes is one of the most important criteria for successful deployment of wireless sensor net- works. The medium access control (MAC) protocol determines the time a sensor node transceiver spends listening or transmitting, and hence the energy consumption of the

  2. CoR-MAC: Contention over Reservation MAC Protocol for Time-Critical Services in Wireless Body Area Sensor Networks.

    Science.gov (United States)

    Yu, Jeongseok; Park, Laihyuk; Park, Junho; Cho, Sungrae; Keum, Changsup

    2016-05-09

    Reserving time slots for urgent data, such as life-critical information, seems to be very attractive to guarantee their deadline requirements in wireless body area sensor networks (WBASNs). On the other hand, this reservation imposes a negative impact on performance for the utilization of a channel. This paper proposes a new channel access scheme referred to as the contention over reservation MAC (CoR-MAC) protocol for time-critical services in wireless body area sensor networks. CoR-MAC uses the dual reservation; if the reserved time slots are known to be vacant, other nodes can access the time slots by contention-based reservation to maximize the utilization of a channel and decrease the delay of the data. To measure the effectiveness of the proposed scheme against IEEE 802.15.4 and IEEE 802.15.6, we evaluated their performances with various performance indexes. The CoR-MAC showed 50% to 850% performance improvement in terms of the delay of urgent and time-critical data according to the number of nodes.

  3. Library Signage: Applications for the Apple Macintosh and MacPaint.

    Science.gov (United States)

    Diskin, Jill A.; FitzGerald, Patricia

    1984-01-01

    Describes specific applications of the Macintosh computer at Carnegie-Mellon University Libraries, where MacPaint was used as a flexible, easy to use, and powerful tool to produce informational, instructional, and promotional signage. Profiles of system hardware and software, an evaluation of the computer program MacPaint, and MacPaint signage…

  4. 42 CFR 405.1050 - Removal of a hearing request from an ALJ to the MAC.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Removal of a hearing request from an ALJ to the MAC... Removal of a hearing request from an ALJ to the MAC. If a request for hearing is pending before an ALJ, the MAC may assume responsibility for holding a hearing by requesting that the ALJ send the hearing...

  5. 42 CFR 405.1108 - MAC actions when request for review or escalation is filed.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false MAC actions when request for review or escalation...) Medicare Appeals Council Review § 405.1108 MAC actions when request for review or escalation is filed. (a) Except as specified in paragraphs (c) and (d) of this section, when a party requests that the MAC review...

  6. Traffic-adaptive duty cycle adaptation in TR-MAC protocol for wireless sensor networks

    NARCIS (Netherlands)

    Morshed, Sarwar; Baratchi, Mitra; Heijenk, Geert

    2016-01-01

    The Medium Access Control (MAC) layer can influence the energy consumption of a wireless sensor network (WSN) to a significant level. TR-MAC is an energy-efficient preamble sampling based MAC protocol for low power WSNs suitable for low data rate and low duty cycle scenario. However, low data rate i

  7. 42 CFR 405.1102 - Request for MAC review when ALJ issues decision or dismissal.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Request for MAC review when ALJ issues decision or...) Medicare Appeals Council Review § 405.1102 Request for MAC review when ALJ issues decision or dismissal. (a)(1) A party to the ALJ hearing may request a MAC review if the party files a written request for...

  8. The minimum alveolar concentration (MAC) and hemodynamic effects of halothane, isoflurane, and sevoflurane in newborn swine.

    Science.gov (United States)

    Lerman, J; Oyston, J P; Gallagher, T M; Miyasaka, K; Volgyesi, G A; Burrows, F A

    1990-10-01

    To determine the minimum alveolar concentration (MAC) and hemodynamic responses to halothane, isoflurane, and sevoflurane in newborn swine, 36 fasting swine 4-10 days of age were anesthetized with one of the three volatile anesthetics in 100% oxygen. MAC was determined for each swine. Carotid artery and internal jugular catheters were inserted and each swine was allowed to recover for 48 h. After recovery, heart rate (HR), systemic systolic arterial pressure (SAP), and cardiac index (CI) were measured awake and then at 0.5, 1.0, and 1.5 MAC of the designated anesthetic in random sequence. The (mean +/- SD) MAC for halothane was 0.90 +/- 0.12%; the MAC for isoflurane was 1.48 +/- 0.21%; and the MAC for sevoflurane was 2.12 +/- 0.39%. Awake (mean +/- SD) measurements of HR, SAP, and CI did not differ significantly among the three groups. Compared to the awake HR, the mean HR decreased 35% at 1.5 MAC halothane (P less than 0.001), 19% at 1.5 MAC isoflurane (P less than 0.005), and 31% at 1.5 MAC sevoflurane (P less than 0.005). Compared to awake SAP, mean SAP measurements decreased 46% at 1.5 MAC halothane (P less than 0.001), 43% at 1.5 MAC isoflurane (P less than 0.001), and 36% at 1.5 MAC sevoflurane (P less than 0.005). Mean SAP at 1.0 and 1.5 MAC halothane and isoflurane were significantly less than those measured at equipotent concentrations of sevoflurane (P less than 0.005). Compared to awake CI, mean CI measurements decreased 53% at 1.5 MAC halothane (P less than 0.001) and 43% at 1.5 MAC isoflurane (P less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

  9. MAC-awake of isoflurane, enflurane and halothane evaluated by slow and fast alveolar washout.

    Science.gov (United States)

    Gaumann, D M; Mustaki, J P; Tassonyi, E

    1992-01-01

    End-tidal anaesthetic concentrations at first eye opening in response to a verbal command during recovery from anaesthesia (MAC-awake), were measured for isoflurane (n = 16), enflurane (n = 16) and halothane (n = 14). MAC-awake was measured during either slow or fast alveolar washout. Slow washout was obtained by decreasing anaesthetic concentrations in predetermined steps of 15 min, assuming equilibration between brain and alveolar partial pressures. Fast alveolar washout was obtained by discontinuation of the inhalation anaesthetic, which had been maintained at 1 MAC for at least 15 min. Mean MAC-awake obtained with slow alveolar washout was similar for isoflurane (0.25 (SD 0.03) MAC), and enflurane (0.27 (0.04) MAC) and significantly greater than values obtained by fast alveolar washout (isoflurane: 0.19 (0.03) MAC; enflurane: 0.20 (0.03) MAC). The MAC-awake of isoflurane and enflurane was significantly less than that of halothane, which was 0.59 (0.10) MAC as evaluated by the slow and 0.50 (0.05) MAC as evaluated by the fast alveolar washout method. Recovery time from anaesthesia with fast alveolar washout was 8.8 (4.0) min for halothane, which was not different from isoflurane (15 (2.5) min), but significantly shorter than for enflurane (22 (10) min), reflecting differences in the anaesthetic concentration gradient between MAC and MAC-awake values. These data do not support the hypothesis of a uniform ratio between MAC and MAC-awake values.

  10. Una lectura interpretativa de Tras la virtud, de Alasdair MacIntyre - An Interpretive Reading of After Virtue, by Alasdair MacIntyre

    Directory of Open Access Journals (Sweden)

    Fernando Fernández-Llebrez

    2010-12-01

    Full Text Available This article centers on the thought of Alasdair MacIntyre, whose most prominente work, After Virtue, is considered a classic of political science. In contrast with other reviews, this article will examine After Virtue within the broader context of MacIntyre’s thinking and publications. An overview of MacIntyre’s literary corpus and the evolution of his thinking will shed light on the volume examined and trace certain ideas that are characteristic of this Scottish political philosopher. Matters that remained unsettled in After Virtue have become over time more defined in MacIntyre’s thinking, such as the influence exerted upon him by Thomas Aquinas.

  11. Distinguishing and Second-Preimage Attacks on CBC-Like MACs

    Science.gov (United States)

    Jia, Keting; Wang, Xiaoyun; Yuan, Zheng; Xu, Guangwu

    This paper first presents a new distinguishing attack on the CBC-MAC structure based on block ciphers in cipher block chaining (CBC) mode. This attack detects a CBC-like MAC from random functions. The second result of this paper is a second-preimage attack on the CBC-MAC, which is an extension of the attack of Brincat and Mitchell. The attack also covers MT-MAC, PMAC and MACs with three-key enciphered CBC mode. Instead of exhaustive search, both types of attacks are of birthday attack complexity.

  12. Magnetic activated cell sorting (MACS): utility in assisted reproduction.

    Science.gov (United States)

    Makker, Kartikeya; Agarwal, Ashok; Sharma, Rakesh K

    2008-07-01

    Assisted reproductive techniques (ART) have now been extensively incorporated in the management of infertile couples. But even after rapid methodological and technological advances the success rates of these procedures have been below expectations. This has led to development of many sperm preparation protocols to obtain an ideal semen sample for artificial reproduction. Sperm apoptosis has been heavily linked to failures in reproductive techniques. One of the earliest changes shown by apoptotic spermatozoa is externalization of phosphatidyl serine. Magnetic activated cell sorting (MACS) is a novel sperm preparation technique that separates apoptotic and non-apoptotic spermatozoa based on the expression of phosphatidylserine. This has led to the incorporation of MACS as a sperm preparation technique. The review highlights the principle and mechanism of this novel technique and enumerates its advantages as a sperm preparation technique. Its utility in ART as an efficient tool for sperm recovery and its application in cryopreservation of semen samples is also explained.

  13. Secure MAC for Wireless Sensor Networks through RBFNN

    Directory of Open Access Journals (Sweden)

    P.Sankara Rao

    2010-08-01

    Full Text Available This paper discusses an application of a neural network in wireless sensor network security. It presents a Radial Basic Function Neural Network based media access control protocol (MAC to secure a CSMA-based wireless sensor network against the denial-of-service attacks launched by adversaries. The Radial Basic Function Neural Network enhances the security of a WSN by constantly monitoring the parameters that exhibit unusual variations in case of an attack. The RBFN shuts down the MAC layer and the physical layer of the sensor node when the suspicion factor, the output of the MLP, exceeds a preset threshold level. The MLP-guarded secure WSN is implemented using the Prowler simulator. Simulation results show that the MLP helps in extending the lifetime of the WSN.

  14. On the Development of Low Power MAC Protocol for WBANs

    CERN Document Server

    Ullah, Sana; Kwak, Kyung Sup

    2009-01-01

    Current advances in wireless communication, microelectronics, semiconductor technologies, and intelligent sensors have contributed to the development of unobtrusive WBANs. These networks provide long term health monitoring of patients without any constraint in their normal activities. Traditional MAC protocols do not accommodate the assorted WBAN traffic requirements in a power efficient manner. In this paper, we present a brief discussion on the development process of a low power MAC protocol for WBANs. We observe the behavior of a beacon-enabled IEEE 802.15.4 for on-body sensor networks. We further propose a low power technique called traffic based wakeup mechanism for a WBAN that exploits the traffic patterns of the BAN Nodes to ensure power efficient and reliable communication.

  15. Activity Modelling and Comparative Evaluation of WSN MAC Security Attacks

    DEFF Research Database (Denmark)

    Pawar, Pranav M.; Nielsen, Rasmus Hjorth; Prasad, Neeli R.

    2012-01-01

    and initiate security attacks that disturb the normal functioning of the network in a severe manner. Such attacks affect the performance of the network by increasing the energy consumption, by reducing throughput and by inducing long delays. Of all existing WSN attacks, MAC layer attacks are considered....... The second aim of the paper is to simulate these attacks on hybrid MAC mechanisms, which shows the performance degradation of aWSN under the considered attacks. The modelling and implementation of the security attacks give an actual view of the network which can be useful in further investigating secure......Applications of wireless sensor networks (WSNs) are growing tremendously in the domains of habitat, tele-health, industry monitoring, vehicular networks, home automation and agriculture. This trend is a strong motivation for malicious users to increase their focus on WSNs and to develop...

  16. Gravitational Duality in MacDowell-Mansouri Gauge Theory

    CERN Document Server

    García-Compéan, H; Ramírez, C

    1998-01-01

    Strong-weak duality invariance can only be defined for particular sectors of supersymmetric Yang-Mills theories. Nevertheless, for full non-Abelian non-supersymmetric theories, dual theories with inverted couplings, have been found. We show that an analogous procedure allows to find the dual action to the gauge theory of gravity constructed by the MacDowell-Mansouri model plus the superposition of a $\\Theta$ term.

  17. Mac OS X Server Snow Leopard 雪豹

    Institute of Scientific and Technical Information of China (English)

    王炳晨

    2010-01-01

    日前,苹果公司宣布推出Mac OSX Server Snow Leopard服务器系统。这是一个真正意义的全64位操作系统,为充分发挥多核心处理器和内存的性能而设计,且完全兼容32位应用程序。

  18. LHC@home online tutorial for Mac users - recording

    CERN Document Server

    CERN. Geneva

    2016-01-01

    A step-by-step online tutorial about LHC@home for Mac users by Alexandre Racine. It contains detailed instructions on how-to-join this volunteer computing project.  There are 3 screen capture videos with the real installation process accelerated attached to the event page. This 5' video is linked from http://lhcathome.web.cern.ch/join-us Also from the CDS e-learning category.

  19. On the Selection of MAC Optimised Routing Protocol for VANET

    Directory of Open Access Journals (Sweden)

    Kanu Priya

    2017-02-01

    Full Text Available In today‘s era of modernization, the concept of smart vehicles, smart cities and automated vehicles is trending day by day. VANET (Vehicular Adhoc Network has also been emerging as a potential applicant to enable these smart applications. Though VANET is very much similar to MANET (Mobile Adhoc Network but VANET has more severe challenges as compared to MANET due to hostile channel conditions and high degree of mobility. So lot of work related to MAC and Network Layer need attention from the network designers. In this paper MAC Layer has been optimised in terms of Queue Size by using QoS Parameters namely Packet Collision Rate, Packet Drop Rate, Throughput Rate and Broadcast Rate. In doing so, simulative investigations have been done to find out optimum queue size. For this purpose various routing protocols namely DSDV, AODV, ADV and GOD have been considered and optimum queue length for each of these have been obtained. Further the most efficient routing protocol has also been identified. Moreover this paper also compares the performance of most efficient Routing Protocols selected in terms of QoS parameters for different MAC Interfaces.

  20. Nonlinear dynamics from the relativistic Boltzmann equation in the Friedmann-Lemaître-Robertson-Walker spacetime

    Science.gov (United States)

    Bazow, D.; Denicol, G. S.; Heinz, U.; Martinez, M.; Noronha, J.

    2016-12-01

    The dissipative dynamics of an expanding massless gas with constant cross section in a spatially flat Friedmann-Lemaître-Robertson-Walker (FLRW) universe is studied. The mathematical problem of solving the full nonlinear relativistic Boltzmann equation is recast into an infinite set of nonlinear ordinary differential equations for the moments of the one-particle distribution function. Momentum-space resolution is determined by the number of nonhydrodynamic modes included in the moment hierarchy, i.e., by the truncation order. We show that in the FLRW spacetime the nonhydrodynamic modes decouple completely from the hydrodynamic degrees of freedom. This results in the system flowing as an ideal fluid while at the same time producing entropy. The solutions to the nonlinear Boltzmann equation exhibit transient tails of the distribution function with nontrivial momentum dependence. The evolution of this tail is not correctly captured by the relaxation time approximation nor by the linearized Boltzmann equation. However, the latter probes additional high-momentum details unresolved by the relaxation time approximation. While the expansion of the FLRW spacetime is slow enough for the system to move towards (and not away from) local thermal equilibrium, it is not sufficiently slow for the system to actually ever reach complete local equilibrium. Equilibration is fastest in the relaxation time approximation, followed, in turn, by kinetic evolution with a linearized and a fully nonlinear Boltzmann collision term.

  1. Equilibration and freeze-out of an expanding gas in a transport approach in a Friedmann-Robertson-Walker metric

    Science.gov (United States)

    Tindall, J.; Torres-Rincon, J. M.; Rose, J. B.; Petersen, H.

    2017-07-01

    Motivated by a recent finding of an exact solution of the relativistic Boltzmann equation in a Friedmann-Robertson-Walker spacetime, we implement this metric into the newly developed transport approach Simulating Many Accelerated Strongly-interacting Hadrons (SMASH). We study the numerical solution of the transport equation and compare it to this exact solution for massless particles. We also compare a different initial condition, for which the transport equation can be independently solved numerically. Very nice agreement is observed in both cases. Having passed these checks for the SMASH code, we study a gas of massive particles within the same spacetime, where the particle decoupling is forced by the Hubble expansion. In this simple scenario we present an analysis of the freeze-out times, as function of the masses and cross sections of the particles. The results might be of interest for their potential application to relativistic heavy-ion collisions, for the characterization of the freeze-out process in terms of hadron properties.

  2. An integrated geologic and engineering reservoir characterization of the North Robertson (Clearfork) unit: A case study, part 1

    Energy Technology Data Exchange (ETDEWEB)

    Doublet, L.E.; Blasingame, T.A. [Texas A and M Univ., College Station, TX (United States); Pande, P.K.; Clark, M.B.; Nevans, J.W.

    1995-12-31

    Infill drilling of wells on a uniform spacing, without regard to reservoir performance and characterization, must become a process of the past. Such efforts do not optimize reservoir development as they fail to account for the complex nature of reservoir heterogeneities present in many low permeability carbonate reservoirs. New and emerging technologies such as cross-borehole tomography, geostatistical modeling, and rigorous decline type curve analysis can be used to quantify reservoir quality and the degree of interwell communication. These results can be used to develop a 3-D simulation model for prediction of infill locations. In this work, the authors will demonstrate the application of reservoir surveillance techniques to identify additional reservoir ``pay`` zones, and to monitor pressure and preferential fluid movement in the reservoir. These techniques are: long-term production and injection data analysis, pressure transient analysis, and advanced open and cased hole well log analysis. The major contribution of this paper is the summary of cost effective reservoir characterization and management tools that will be helpful to both independent and major operators for the optimal development of heterogeneous, low permeability carbonate reservoirs such as the North Robertson (Clearfork) Unit.

  3. Casimir energy-momentum tensor for a quantized bulk scalar field in Friedmann-Robertson-Walker space-time

    CERN Document Server

    Pejhan, Hamed

    2016-01-01

    In a previous work [S. Rahbardehghan et al. in Phys. Lett. B 750, 627 (2015)], we considered a simple brane-world model; a single $4$-dimensional brane embedded in a $5$-dimensional de Sitter (dS) space-time. Then, by including a conformally coupled scalar field in the bulk, we studied the induced Casimir energy-momentum tensor. Technically, the Krein-Gupta-Bleuler (KGB) quantization scheme as a covariant and renormalizable quantum field theory in dS space was used to perform the calculations. In the present paper, we generalize this study to a less idealized, but physically motivated, scenario, namely we consider Friedmann-Robertson-Walker (FRW) space-time which behaves asymptotically as a dS space-time. More precisely, we evaluate Casimir energy-momentum tensor for a system with two $D$-dimensional curved branes on background of $D+1$-dimensional FRW space-time with negative spatial curvature and a bulk conformally coupled scalar field that satisfies Dirichlet boundary condition on the branes.

  4. 42 CFR 423.2140 - MAC Review of ALJ decision in a case remanded by a Federal District Court.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false MAC Review of ALJ decision in a case remanded by a... BENEFIT Reopening, ALJ Hearings, MAC review, and Judicial Review § 423.2140 MAC Review of ALJ decision in..., when a case is remanded by a Federal District Court for further consideration and the MAC remands the...

  5. Leukocyte integrin Mac-1 regulates thrombosis via interaction with platelet GPIbα.

    Science.gov (United States)

    Wang, Yunmei; Gao, Huiyun; Shi, Can; Erhardt, Paul W; Pavlovsky, Alexander; A Soloviev, Dmitry; Bledzka, Kamila; Ustinov, Valentin; Zhu, Liang; Qin, Jun; Munday, Adam D; Lopez, Jose; Plow, Edward; Simon, Daniel I

    2017-05-30

    Inflammation and thrombosis occur together in many diseases. The leukocyte integrin Mac-1 (also known as integrin αMβ2, or CD11b/CD18) is crucial for leukocyte recruitment to the endothelium, and Mac-1 engagement of platelet GPIbα is required for injury responses in diverse disease models. However, the role of Mac-1 in thrombosis is undefined. Here we report that mice with Mac-1 deficiency (Mac-1(-/-)) or mutation of the Mac-1-binding site for GPIbα have delayed thrombosis after carotid artery and cremaster microvascular injury without affecting parameters of haemostasis. Adoptive wild-type leukocyte transfer rescues the thrombosis defect in Mac-1(-/-) mice, and Mac-1-dependent regulation of the transcription factor Foxp1 contributes to thrombosis as evidenced by delayed thrombosis in mice with monocyte-/macrophage-specific overexpression of Foxp1. Antibody and small-molecule targeting of Mac-1:GPIbα inhibits thrombosis. Our data identify a new pathway of thrombosis involving leukocyte Mac-1 and platelet GPIbα, and suggest that targeting this interaction has anti-thrombotic therapeutic potential with reduced bleeding risk.

  6. Characteristics of Mycobacterium avium complex (MAC) pulmonary disease in previously treated lung cancer patients.

    Science.gov (United States)

    Meier, Erin; Pennington, Kelly; Gallo de Moraes, Alice; Escalante, Patricio

    2017-01-01

    Mycobacterium avium complex (MAC) is responsible for a large portion of non-tuberculous mycobacterial (NTM) infections worldwide. Host factors such as active malignancy, immunosuppression, chronic obstructive pulmonary disease (COPD) and bronchiectasis increase the risk of MAC infection. However, the relationship between previously treated lung cancer with subsequent development of MAC pulmonary disease and treatment outcomes have not been previously studied. We retrospectively identified all patients with lung cancer and MAC pulmonary disease documented in medical records at Mayo Clinic between January 2005 and October 2016. Patients who were diagnosed with MAC pulmonary disease before or at the time of lung cancer diagnosis were excluded. Patients meeting all inclusion criteria underwent chart review for prior oncologic treatments, clinical characteristics, and MAC treatment response. We identified 13 patients with MAC pulmonary disease and prior lung cancer, including 4 men and 9 women. Eight patients had structural lung disease that can predispose to MAC pulmonary disease, including bronchiectasis (23.0%) and COPD (46.2%). Four (30.8%) had no apparent immunosuppression or other risk factor(s) for MAC pulmonary disease. Primary pulmonary malignancies included pulmonary carcinoid, adenocarcinoma, and squamous cell carcinoma. Ten (76.9%) patients were started on antimicrobial treatment for MAC, and 8 (61.5%) patients completed MAC treatment with 6 (46.1%) patients achieving symptomatic improvement. MAC pulmonary disease in previously treated lung cancer can occur without apparent risk factors for this NTM infection. Symptomatic improvement with MAC antimicrobial therapy appears to be lower than expected but comorbidities might influence outcomes in this patient population.

  7. Design of High Speed Architecture of Parallel MAC Based On Radix-2 MBA

    Directory of Open Access Journals (Sweden)

    Syed Anwar Ahmed,

    2014-05-01

    Full Text Available The multiplier and multiplier-and-accumulator (MAC are the essential elements of the digital signal processing such as filtering, convolution, transformations and Inner products. Parallel MAC is frequently used in digital signal processing and video/graphics applications. Fast multipliers are essential parts of digital signal processing systems. The speed of multiply operation is of great importance in digital signal processing as well as in the general purpose processors today, especially since the media processing took off. The MAC provides high speed multiplication and multiplication with accumulative addition. This paper presents a combined process of multiplication and accumulation based on radix-4 & radix-8 booth encodings. In this Paper, we investigate the method of implementing the Parallel MAC with the smallest possible delay. Enhancing the speed of operation of the parallel MAC is a major design issue. This has been achieved by developing a CLA adder for parallel MAC.

  8. TMAC: Timestamp-Ordered MAC Protocol for Wireless Mesh Networks

    KAUST Repository

    Nawab, Faisal

    2011-05-01

    Wireless Mesh Networks (WMNs) have emerged to meet a need for a self-organized and self-configured multi-hop wireless network infrastructure. Low cost infrastructure and ease of deployment have made WMNs an attractive technology for last mile access. However, 802.11 based WMNs are subject to serious fairness issues. With backlogged TCP traffic, nodes which are two or more hops away from the gateway are subject to starvation, while the one-hop away node saturates the channel with its own local traffic. We study the interactions of TCP and IEEE 802.11 MAC in WMNs to aid us in understanding and overcoming the unfairness problem. We propose a Markov chain to capture the behavior of TCP sessions, particularly the impact on network throughput performance due to the effect of queue utilization and packet relaying. A closed form solution is derived to numerically derive the throughput. Based on the developed model, we propose a distributed MAC protocol called Timestamp-ordered MAC (TMAC), aiming to alleviate the unfairness problem in WMNs via a manipulative per-node scheduling mechanism which takes advantage of the age of each packet as a priority metric. Simulation is conducted to validate our model and to illustrate the fairness characteristics of TMAC. Our results show that TMAC achieves excellent resource allocation fairness while maintaining above 90% of maximum link capacity in parking lot and large grid topologies. Our work illuminates the factors affecting TCP fairness in WMNs. Our theoretical and empirical findings can be used in future research to develop more fairness-aware protocols for WMNs.

  9. Tournament MAC with Constant Size Congestion Window for WLAN

    CERN Document Server

    Galtier, Jerome

    2007-01-01

    In the context of radio distributed networks, we present a generalized approach for the Medium Access Control (MAC) with fixed congestion window. Our protocol is quite simple to analyze and can be used in a lot of different situations. We give mathematical evidence showing that our performance is tight, in the sense that no protocol with fixed congestion window can do better. We also place ourselves in the WiFi/WiMAX framework, and show experimental results enlightening collision reduction of 14% to 21% compared to the best known other methods. We show channel capacity improvement, and fairness considerations.

  10. Dual Description of Supergravity MacDowell-Mansouri Theory

    CERN Document Server

    García-Compéan, H; Obregón, O; Ramírez, C

    1999-01-01

    In the context of field theory two elements seem to be necessary to search for strong-weak coupling duality. First, one needs a gauge theory and second, it should be supersymmetric. For gravitation these two elements are present in MacDowell-Mansouri supergravity. The search for an "effective duality" in this theory presents technical and conceptual problems that we discuss. Nevertheless, by means of a field theoretical approach, which in the abelian case coincides with $S$-duality, we exhibit a dual theory for supergravity, with inverted couplings. This results in a supersymmetric non-linear sigma model of the Freedman-Townsend type.

  11. Mac configuration management at the Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Marcus, Allan B [Los Alamos National Laboratory

    2010-01-01

    The Los Alamos National Laboratory (LANL) had a need for central configuration management of non-Windows computers. LANL has three to five thousand Macs and an equal number of Linux based systems. The primary goal was to be able to inventory all non-windows systems and patch Mc OS X systems. LANL examined a number of commercial and open source solutions and ultimately selected Puppet. This paper will discuss why we chose Puppet, how we implemented it, and some lessons we learned along the way.

  12. Proximate analysis of coal by Leco MAC-400

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, S.T. (British Steel Corporation, London (UK). Ravenscraig Works)

    1988-01-01

    Discussion is presented of the use of the Leco Mac-400 Proximate Analyser at the Ravenscraig Steel Works, UK. It is used for the analysis of in-plant coals and the determination of ash in coke. The instrument does not meet the British Standard requirement for repeatability, so is not used for 'value in use' coal analysis. It has recently been overhauled, however, and will be re-evaluated to see if the overhaul has brought an improvement in performance. 6 figs., 7 tabs.

  13. Intelligent Cooperative MAC Protocol for Balancing Energy Consumption

    Science.gov (United States)

    Wu, S.; Liu, K.; Huang, B.; Liu, F.

    To extend the lifetime of wireless sensor networks, we proposed an intelligent balanced energy consumption cooperative MAC protocol (IBEC-CMAC) based on the multi-node cooperative transmission model. The protocol has priority to access high-quality channels for reducing energy consumption of each transmission. It can also balance the energy consumption among cooperative nodes by using high residual energy nodes instead of excessively consuming some node's energy. Simulation results show that IBEC-CMAC can obtain longer network lifetime and higher energy utilization than direct transmission.

  14. Minimum alveolar concentration (MAC) for sevoflurane and xenon at normothermia and hypothermia in newborn pigs.

    Science.gov (United States)

    Liu, X; Dingley, J; Elstad, M; Scull-Brown, E; Steen, P A; Thoresen, M

    2013-05-01

    Neuroprotection from therapeutic hypothermia increases when combined with the anaesthetic gas xenon in animal studies. A clinical feasibility study of the combined treatment has been successfully undertaken in asphyxiated human term newborns. It is unknown whether xenon alone would be sufficient for sedation during hypothermia eliminating or reducing the need for other sedative or analgesic infusions in ventilated sick infants. Minimum alveolar concentration (MAC) of xenon is unknown in any neonatal species. Eight newborn pigs were anaesthetised with sevoflurane alone and then sevoflurane plus xenon at two temperatures. Pigs were randomised to start at either 38.5°C or 33.5°C. MAC for sevoflurane was determined using the claw clamp technique at the preset body temperature. For xenon MAC determination, a background of 0.5 MAC sevoflurane was used, and 60% xenon added to the gas mixture. The relationship between sevoflurane and xenon MAC is assumed to be additive. Xenon concentrations were changed in 5% steps until a positive clamp reaction was noted. Pigs' temperature was changed to the second target, and two MAC determinations for sevoflurane and 0.5 MAC sevoflurane plus xenon were repeated. MAC for sevoflurane was 4.1% [95% confidence interval (CI): 3.65-4.50] at 38.5°C and 3.05% (CI: 2.63-3.48) at 33.5°C, a significant reduction. MAC for xenon was 120% at 38.5°C and 116% at 33.5°C, not different. In newborn swine sevoflurane, MAC was temperature dependent, while xenon MAC was independent of temperature. There was large individual variability in xenon MAC, from 60% to 120%. © 2013 The Acta Anaesthesiologica Scandinavica Foundation.

  15. MQ-MAC: A Multi-Constrained QoS-Aware Duty Cycle MAC for Heterogeneous Traffic in Wireless Sensor Networks

    Science.gov (United States)

    Monowar, Muhammad Mostafa; Rahman, Md. Obaidur; Hong, Choong Seon; Lee, Sungwon

    2010-01-01

    Energy conservation is one of the striking research issues now-a-days for power constrained wireless sensor networks (WSNs) and hence, several duty-cycle based MAC protocols have been devised for WSNs in the last few years. However, assimilation of diverse applications with different QoS requirements (i.e., delay and reliability) within the same network also necessitates in devising a generic duty-cycle based MAC protocol that can achieve both the delay and reliability guarantee, termed as multi-constrained QoS, while preserving the energy efficiency. To address this, in this paper, we propose a Multi-constrained QoS-aware duty-cycle MAC for heterogeneous traffic in WSNs (MQ-MAC). MQ-MAC classifies the traffic based on their multi-constrained QoS demands. Through extensive simulation using ns-2 we evaluate the performance of MQ-MAC. MQ-MAC provides the desired delay and reliability guarantee according to the nature of the traffic classes as well as achieves energy efficiency. PMID:22163439

  16. MQ-MAC: a multi-constrained QoS-aware duty cycle MAC for heterogeneous traffic in wireless sensor networks.

    Science.gov (United States)

    Monowar, Muhammad Mostafa; Rahman, Md Obaidur; Hong, Choong Seon; Lee, Sungwon

    2010-01-01

    Energy conservation is one of the striking research issues now-a-days for power constrained wireless sensor networks (WSNs) and hence, several duty-cycle based MAC protocols have been devised for WSNs in the last few years. However, assimilation of diverse applications with different QoS requirements (i.e., delay and reliability) within the same network also necessitates in devising a generic duty-cycle based MAC protocol that can achieve both the delay and reliability guarantee, termed as multi-constrained QoS, while preserving the energy efficiency. To address this, in this paper, we propose a Multi-constrained QoS-aware duty-cycle MAC for heterogeneous traffic in WSNs (MQ-MAC). MQ-MAC classifies the traffic based on their multi-constrained QoS demands. Through extensive simulation using ns-2 we evaluate the performance of MQ-MAC. MQ-MAC provides the desired delay and reliability guarantee according to the nature of the traffic classes as well as achieves energy efficiency.

  17. MQ-MAC: A Multi-Constrained QoS-Aware Duty Cycle MAC for Heterogeneous Traffic in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Sungwon Lee

    2010-11-01

    Full Text Available Energy conservation is one of the striking research issues now-a-days for power constrained wireless sensor networks (WSNs and hence, several duty-cycle based MAC protocols have been devised for WSNs in the last few years. However, assimilation of diverse applications with different QoS requirements (i.e., delay and reliability within the same network also necessitates in devising a generic duty-cycle based MAC protocol that can achieve both the delay and reliability guarantee, termed as multi-constrained QoS, while preserving the energy efficiency. To address this, in this paper, we propose a Multi-constrained QoS-aware duty-cycle MAC for heterogeneous traffic in WSNs (MQ-MAC. MQ-MAC classifies the traffic based on their multi-constrained QoS demands. Through extensive simulation using ns-2 we evaluate the performance of MQ-MAC. MQ-MAC provides the desired delay and reliability guarantee according to the nature of the traffic classes as well as achieves energy efficiency.

  18. Sevoflurane decreases bispectral index values more than does halothane at equal MAC multiples.

    Science.gov (United States)

    Schwab, Hildebrand S; Seeberger, Manfred D; Eger, Edmond I; Kindler, Christoph H; Filipovic, Miodrag

    2004-12-01

    At the minimum alveolar concentration (MAC) of inhaled anesthetics, 50% of subjects move in response to noxious stimulation. Similarly, at MAC-awake, 50% of subjects respond appropriately to command. The bispectral index (BIS) nominally measures the effect of anesthetics on wakefulness or consciousness. We postulated that the use of halothane with a larger MAC-awake/MAC ratio than sevoflurane would produce higher BIS values at comparable levels of MAC. We studied 33 unpremedicated patients anesthetized by inhalation, 18 with sevoflurane and 15 with halothane. We measured BIS before and during anesthesia at 1 MAC, both before and after tracheal intubation facilitated by fentanyl and rocuronium and then at 1.5 MAC. BIS measurements were made after meeting steady-state conditions. No surgery was performed during this study. BIS values in awake patients did not differ between the sevoflurane and halothane groups (96 +/- 2 and 96 +/- 2, mean +/- sd, respectively). At 1 MAC without and with neuromuscular blockade and at 1.5 MAC, BIS values for patients anesthetized with halothane (54 +/- 7, 56 +/- 7, and 49 +/- 7, respectively) exceeded those for patients anesthetized with sevoflurane (34 +/- 6, 34 +/- 6, and 29 +/- 5, respectively) (P < 0.0001). This finding adds to other evidence indicating that BIS is drug specific.

  19. Power-Controlled MAC Protocols with Dynamic Neighbor Prediction for Ad hoc Networks

    Institute of Scientific and Technical Information of China (English)

    LI Meng; ZHANG Lin; XIAO Yong-kang; SHAN Xiu-ming

    2004-01-01

    Energy and bandwidth are the scarce resources in ad hoc networks because most of the mobile nodes are battery-supplied and share the exclusive wireless medium. Integrating the power control into MAC protocol is a promising technique to fully exploit these precious resources of ad hoc wireless networks. In this paper, a new intelligent power-controlled Medium Access Control (MAC) (iMAC) protocol with dynamic neighbor prediction is proposed. Through the elaborate design of the distributed transmit-receive strategy of mobile nodes, iMAC greatly outperforms the prevailing IEEE 802.11 MAC protocols in not only energy conservation but also network throughput. Using the Dynamic Neighbor Prediction (DNP), iMAC performs well in mobile scenes. To the best of our knowledge, iMAC is the first protocol that considers the performance deterioration of power-controlled MAC protocols in mobile scenes and then proposes a solution. Simulation results indicate that DNP is important and necessary for power-controlled MAC protocols in mobile ad hoc networks.

  20. An Empirical Study and some Improvements of the MiniMac Protocol for Secure Computation

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Lauritsen, Rasmus; Toft, Tomas

    2014-01-01

    (nicknamed MiniMac). While TinyOT has already been implemented, we present in this paper the first implementation of MiniMac, using the same platform as the existing TinyOT implementation. We also suggest several improvements of MiniMac, both on the protocol design and implementation level. In particular, we...... suggest a modification of MiniMac that achieves increased parallelism at no extra communication cost. This gives an asymptotic improvement of the original protocol as well as an 8-fold speed-up of our implementation. We compare the resulting protocol to TinyOT for the case of secure computation in parallel...

  1. PA-MAC:A Passive Asynchronous MAC Protocol for Low Duty-Cycled Wireless Sensor Networks%PA-MAC:一种被动的异步低占空比无线传感器网络MAC协议

    Institute of Scientific and Technical Information of China (English)

    唐震洲; 施晓秋; 金可仲

    2011-01-01

    空闲侦听是无线传感器网络能耗的主要原因之一,而占空比机制是减少空闲侦听能量损耗最主要的方法之一.提出了一种新的无线传感器网络异步MAC协议,称为PA-MAC(Passive Asynchronous MAC),即被动异步MAC.PA-MAC通过采用接收方发起数据传输机制、异步占空比机制以及节点唤醒时间估计机制,降低了节点的工作占空比,提高了网络的能量有效性.在NS2网络仿真平台上对PA-MAC的性能进行了评估.仿真结果表明,在保持网络性能的前提下,PA-MAC能够进一步降低节点工作的占空比,进而减少节点的能耗.%The problem of idle listening is one of the most concerned issues in wireless sensor networks, and the duty cycling mechanism is widely used to reduce energy consumption. We present a new asynchronous MAC protocol, called Passive-Asynchronous MAC (PA-MAC). PA-MAC uses receiver-initiated data transmission scheme, asynchronous duty cycling mechanism and awakening time estimation scheme to achieve low duty cycle and high energy efficiency. Simulations have been done to evaluate the performance of the proposed new protocol, by which we can find out that,on the premise of keeping the network performance,PA-MAC can further reduce the nodes' duty cycle ,thereby reduce the energy consumption.

  2. Autonomous Power Control MAC Protocol for Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Battery energy limitation has become a performance bottleneck for mobile ad hoc networks. IEEE 802.11 has been adopted as the current standard MAC protocol for ad hoc networks. However, it was developed without considering energy efficiency. To solve this problem, many modifications on IEEE 802.11 to incorporate power control have been proposed in the literature. The main idea of these power control schemes is to use a maximum possible power level for transmitting RTS/CTS and the lowest acceptable power for sending DATA/ACK. However, these schemes may degrade network throughput and reduce the overall energy efficiency of the network. This paper proposes autonomous power control MAC protocol (APCMP, which allows mobile nodes dynamically adjusting power level for transmitting DATA/ACK according to the distances between the transmitter and its neighbors. In addition, the power level for transmitting RTS/CTS is also adjustable according to the power level for DATA/ACK packets. In this paper, the performance of APCMP protocol is evaluated by simulation and is compared with that of other protocols.

  3. Learning Microsoft Excel 2011 for Mac video training DVD

    CERN Document Server

    Vaccaro, Guy

    2011-01-01

    In this video tutorial for Microsoft Excel 2011 For Mac, expert author Guy Vaccaro teaches you to effectively utilize the features and functions of Excel through project based learning. You will complete various projects, and along they way learn to leverage the power of the most important features Excel 2011 has to offer the Mac user. Starting your training course with the creation of a spreadsheet to record and monitor sales data, you will learn the basics of what you can do with a spreadsheet. You will then move on to creating a Profit and Loss report, learning formulas along the way. Moving to score sheets for a sports day, you will discover conditional based formatting, lookups, and more. You then create a functional expense claim form, advancing your Excel expertise. Moving on to a sales contact management sheet, you will discover how you can manipulate text, and even create mail merges from Excel. Finally, you will utilize all your knowledge thus far to create a sales report, including charts, pivot ta...

  4. MAC Layer Resource Allocation for Wireless Body Area Networks

    Institute of Scientific and Technical Information of China (English)

    Qinghua Shen; Xuemin Sherman Shen; Tom HLuan; Jing Liu

    2014-01-01

    Wireless body area networks (WBANs) can provide low-cost, timely healthcare services and are expected to be widely used for e-healthcare in hospitals. In a hospital, space is often limited and multiple WBANs have to coexist in an area and share the same channel in order to provide healthcare services to different patients. This causes severe interference between WBANs that could significantly reduce the network throughput and increase the amount of power consumed by sensors placed on the body. There-fore, an efficient channel-resource allocation scheme in the medium access control (MAC) layer is crucial. In this paper, we devel-op a centralized MAC layer resource allocation scheme for a WBAN. We focus on mitigating the interference between WBANs and reducing the power consumed by sensors. Channel and buffer state are reported by smartphones deployed in each WBAN, and channel access allocation is performed by a central controller to maximize network throughput. Sensors have strict limitations in terms of energy consumption and computing capability and cannot provide all the necessary information for channel allocation in a timely manner. This deteriorates network performance. We exploit the temporal correlation of the body area channel in order to minimize the number of channel state reports necessary. We view the network design as a partly observable optimization prob-lem and develop a myopic policy, which we then simulate in Matlab.

  5. A Review of MAC Scheduling Algorithms in LTE System

    Directory of Open Access Journals (Sweden)

    Satheesh Monikandan B

    2017-06-01

    Full Text Available The recent wireless communication networks rely on the new technology named Long Term Evolution (LTE to offer high data rate real-time (RT traffic with better Quality of Service (QoS for the increasing demand of customer requirement. LTE provide low latency for real-time services with high throughput, with the help of two-level packet retransmission. Hybrid Automatic Repeat Request (HARQ retransmission at the Medium Access Control (MAC layer of LTE networks achieves error-free data transmission. The performance of the LTE networks mainly depends on how effectively this HARQ adopted in the latest communication standard, Universal Mobile Telecommunication System (UMTS. The major challenge in LTE is to balance QoS and fairness among the users. Hence, it is very essential to design a down link scheduling scheme to get the expected service quality to the customers and to utilize the system resources efficiently. This paper provides a comprehensive literature review of LTE MAC layer and six types of QoS/Channel-aware downlink scheduling algorithms designed for this purpose. The contributions of this paper are to identify the gap of knowledge in the downlink scheduling procedure and to point out the future research direction. Based on the comparative study of algorithms taken for the review, this paper is concluded that the EXP Rule scheduler is most suited for LTE networks due to its characteristics of less Packet Loss Ratio (PLR, less Packet Delay (PD, high throughput, fairness and spectral efficiency.

  6. Mac-1 deficiency induces respiratory failure by affecting type I alveolar epithelial cells.

    Science.gov (United States)

    Wang, J; Ci, Y B; Liu, C L; Sun, H M

    2017-08-31

    As a β2 integrin family member, Mac-1 plays an important role in the inflammatory response. Inflammation and lung injury are closely associated, but the involvement of Mac-1 in the occurrence and development of such pathologies remains poorly understood. We aimed to investigate the relationship between Mac-1 deficiency and respiratory failure in Mac-1 knockout {Mac-1(-/-)} mice, using C57BL/6J mice as a control. The newborn survival rate of Mac-1(-/-) mice was calculated, and mouse lung tissue was treated with hematoxylin and eosin and subjected to immunofluorescent staining. Moreover, western blotting and immunohistochemistry were used to detect the expression of molecules specific to type I and type II alveolar epithelial cells, as well as alveolar surfactant proteins secreted by the latter. Survival of Mac-1(-/-) pups was significantly lower than that of newborn C57BL/6J mice. In a float test, lung tissues from C57BL/6J mice were buoyant, whereas those of Mac-1(-/-) mice were not. Compared with C57BL/6J mice, expression of proSP-C {specific to type II alveolar epithelial cells} and alveolar surfactant proteins in Mac-1(-/-) mice was not significantly different, implying that type II cell function was unaltered. However, western blotting revealed expression of T1α, Aqp5, and Snx5 {type I alveolar epithelial cell markers} in Mac-1(-/-) mice to be significantly decreased {P Mac-1 may play an important role in respiratory failure. Its absence leads to this condition not by influencing type II alveolar epithelial cells or their secreted surfactant proteins, but rather by reducing type I alveolar cell numbers.

  7. Land Cover

    Data.gov (United States)

    Kansas Data Access and Support Center — The Land Cover database depicts 10 general land cover classes for the State of Kansas. The database was compiled from a digital classification of Landsat Thematic...

  8. Land acquisition

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a summary of lands acquired by Neal Smith National Wildlife Refuge between 1991 and 2009. Lists of acres and locations of land acquired are provided for...

  9. Application of HollySys MACS DCS to PET plant%HollySys MACS DCS在PET装置中的应用

    Institute of Scientific and Technical Information of China (English)

    霍卫

    2015-01-01

    介绍了HollySys MACS DCS在PET装置中的应用,简要说明了PET装置的生产工艺和MACS系统的主要特点,介绍了该装置控制系统的软硬件构成,阐述了HollySys MACS DCS在PET装置中应用的控制方案.

  10. Mulighedernes land?

    DEFF Research Database (Denmark)

    Munck Petersen, Rikke

    2001-01-01

    Kommentar om arbejde med det åbne land i forlængelse af konfencen "Mulighedernes land" og vigtigheden af at landskabsarkitekter går aktivt ind i debatten og arbejdet med landskabets forandring i Danmark.......Kommentar om arbejde med det åbne land i forlængelse af konfencen "Mulighedernes land" og vigtigheden af at landskabsarkitekter går aktivt ind i debatten og arbejdet med landskabets forandring i Danmark....

  11. 78 FR 26711 - Federal Agricultural Mortgage Corporation Funding and Fiscal Affairs; Farmer Mac Liquidity...

    Science.gov (United States)

    2013-05-08

    ...; Farmer Mac Liquidity Management ACTION: Proposed rule; reopening of comment period. SUMMARY: The Farm... amend its liquidity management regulations for the Federal Agricultural Mortgage Corporation (Farmer Mac... liquidity by addressing four definitions in Sec. 652.5,\\3\\ liquidity management in Sec. 652.35, and the...

  12. Optimization and verification of the TR-MAC protocol for wireless sensor networks

    NARCIS (Netherlands)

    Morshed, Sarwar; Heijenk, Geert

    2015-01-01

    Energy-efficiency is an important requirement in the design of communication protocols for wireless sensor networks (WSN). TR-MAC is an energy-efficient medium access control (MAC) layer protocol for low power WSN that exploits transmitted-reference (TR) modulation in the physical layer. The underly

  13. Official Portrait of STS-52 Canadian Payload Specialist Steve G. MacLean

    Science.gov (United States)

    1992-01-01

    STS-52 Canadian Payload Specialist Steven G. MacLean, wearing a launch and entry suit (LES), poses with a launch and entry helmet (LEH) and Canadian flag for his Official portrait. MacLean representing the Canadian Space Agency (CSA) will fly aboard Columbia, Orbiter Vehicle (OV) 102, for the STS-52 mission.

  14. Transcriptomic microarray analysis of BoMac cells after infection with bovine foamy virus

    NARCIS (Netherlands)

    Rola-Luszczak, M.; Materniak, M.; Pluta, A.; Hulst, M.M.; Kuz'mak, J.

    2014-01-01

    Bovine foamy virus (BFV) infections are highly prevalent among cattle worldwide. However, relatively little is known about the impact of this virus on the host immune system. In our study, we focused on a bovine macrophage cell line (BoMac) and examined changes in the BoMac transcriptome after in vi

  15. Scheduled MAC in Beacon Overlay Networks for Underwater Localization and Time-Synchronization

    NARCIS (Netherlands)

    van Kleunen, W.A.P.; Meratnia, Nirvana; Havinga, Paul J.M.

    2011-01-01

    In this article we introduce a MAC protocol designed for underwater localization and time-synchronisation. The MAC protocol assumes a network of static reference nodes and allows blind nodes to be localized by listening-only to the beacon messages. Such a system is known to be very scalable. We show

  16. Simulation of 64-bit MAC Unit using Kogge Stone Adder and Ancient Indian Mathematics

    Directory of Open Access Journals (Sweden)

    Aapurva Kaul

    2016-05-01

    Full Text Available This paper describes that multiply and accumulate (MAC unit plays a very vital role in various Digital Signal Processing applications. Speed of these applications depends on the speed of these three sub units of MAC multiply unit, adder unit and accumulator unit. In this paper the delay of 64-bit MAC unit is decreased as compared to the previous MAC units. In this Kogge Stone Adder is used as adder in design Vedic Multiplier using Urdhva Tiryakbhyam sutra. The designing of MAC unit is done under VIRTEX-4 family, XC4VFX140 device, FF1517 package and -11 speed and comparison of proposed MAC unit design is done under SPARTAN- 3E family, XC3S500 device, FG320 package and -5 speed in Xilinx ISE 8.1i. The combinational path delay of the 64-bit MAC unit is 59.705ns in SPARTAN-3E family. Ancient Indian mathematics is being used for designing of multiplier unit to decrease the overall delay of the MAC unit.

  17. A concurrent access MAC protocol for cognitive radio ad hoc networks without common control channel

    Science.gov (United States)

    Timalsina, Sunil K.; Moh, Sangman; Chung, Ilyong; Kang, Moonsoo

    2013-12-01

    Cognitive radio ad hoc networks (CRAHNs) consist of autonomous nodes that operate in ad hoc mode and aim at efficient utilization of spectrum resources. Usually, the cognitive nodes in a CRAHN exploit a number of available channels, but these channels are not necessarily common to all nodes. Such a network environment poses the problem of establishing a common control channel (CCC) as there might be no channel common to all the network members at all. In designing protocols, therefore, it is highly desirable to consider the network environment with no CCC. In this article, we propose a MAC protocol called concurrent access MAC (CA-MAC) that operates in the network environment with no CCC. The two devices in a communication pair can communicate with each other even if they have only one common channel available. Therefore, the problems with CCC (such as channel saturation and denial of service attacks) can also be resolved. In CA-MAC, channel accesses are distributed over communication pairs, resulting in increased network connectivity. In addition, CA-MAC allows different communication pairs to access multiple channels concurrently. According to our performance study, CA-MAC provides higher network connectivity with shorter channel access delay compared to SYN-MAC, which is the conventional key MAC protocol for the network environment with no CCC, resulting in better network throughput.

  18. Investigation of Mycobacterium avium complex (MAC) in Australian commercial milk using qPCR.

    Science.gov (United States)

    Adhikari, Shraddha; Caro Tohme, Tanya; Whiley, Harriet

    2017-02-01

    This technical research communication describes the first study to use quantitative polymerase chain reaction (qPCR) to investigate the presence of Mycobacterium avium complex (MAC) in Australian pasteurised milk. MAC is the most common NTM responsible for human illnesses and includes M. avium subspecies paratuberculosis (MAP). MAC is a causative agent of lymphadenitis in children, with contaminated food and water considered as a likely source. As such the presence of MAC in milk would have public health significance. MAP has been linked to Crohn's disease and is also the causative agent of Johne's disease in cattle. Previous studies have detected MAP in pasteurised milk from Brazil, India, Czech Republic, USA, Argentina, UK, Iran, Ireland and the United Kingdom. This study investigated a total of 180 commercially available Australian pasteurised milk samples which were tested for MAC DNA in triplicate using PCR. All samples were negative for MAC DNA. An additional 14 milk samples were tested, incubated for 3 weeks at 37 °C to potentially increase the concentration of any viable MAC that may be present and then retested. All samples were again negative for MAC DNA. This could be due to concentrations below the limit of detection, limited sample size or could be reflective of the Australian biosecurity control protocols and surveillance of Johne's disease in ruminant animals.

  19. An update on the side channel cryptanalysis of MACs based on cryptographic hash functions

    DEFF Research Database (Denmark)

    Gauravaram, Praveen; Okeya, Katsuyuki

    2007-01-01

    into consideration. Next, we propose new hybrid NMAC/HMAC schemes for security against side channel attacks assuming that their underlying block cipher is ideal. We then show that M-NMAC, MDx-MAC and a variant of the envelope MAC scheme based on DM with an ideal block cipher are secure against DPA attacks....

  20. THE EFFECT OF TEMPERATURE ON THE GROWTH OF MYCOBACTERIUM AVIUM COMPLEX (MAC) ORGANISMS

    Science.gov (United States)

    MAC organisms are able to grow, persist, and colonize in water distribution systems and may amplify in hospital hot water systems. This study examined the response of MAC organisms (M. avium, M. intracellulare, and MX) to a range of temperatures commonly associated with drinking...

  1. Sevoflurane at 1 MAC provides optimal myocardial protection during off-pump CABG.

    Science.gov (United States)

    Wang, Jiang; Zheng, Hong; Chen, Chun-Ling; Lu, Wei; Zhang, Yong-Qiang

    2013-06-01

    We investigated the myocardial protective effect of sevoflurane in patients receiving off-pump coronary artery bypass grafting (OPCABG) and the role of brain natriuretic peptide (BNP). Forty-eight patients receiving elective OPCABG were randomly assigned to a control group, and to 0.75 MAC, 1.0 MAC and 1.5 MAC sevoflurane groups. Blood samples were collected and levels of BNP and cardiac troponin I (cTnI) were measured before anesthesia, and immediately, 24, 48 and 72 h after surgery. Dopamine was necessary to maintain blood pressure in the sevoflurane groups, but not in the control group (p MAC sevoflurane significantly decreased post-surgical cTnI levels (p MAC had no significant effect, and increasing sevoflurane concentrations to 1.5 MAC caused no further decrease in cTnI concentrations. There was no significant difference in BNP level among the groups (p = 0.227) or between any two groups, although values of BNP showed a significant correlation with cTnI values in control subjects immediately after (r = 0.847) and 24 h after (r = 0.661) surgery. Our results demonstrated that 1.0 MAC and 1.5 MAC sevoflurane can exert a significant myocardial protective effect. BNP cannot be used to predict the myocardial protective effect of sevoflurane in OPCABG.

  2. Self-Admitted Pretensions of Mac Users on a Predominantly PC University Campus

    Science.gov (United States)

    Firmin, Michael W.; Wood, Whitney L. Muhlenkamp; Firmin, Ruth L.; Wood, Jordan C.

    2010-01-01

    The present qualitative research study addressed the overall research question of college students' pretention dynamics in the context of a university setting. Thirty-five Mac users were interviewed on a university campus that exclusively supports PC machines. Mac users shared four self-admitted pretensions related to using Macintosh computers.…

  3. THE EFFECT OF TEMPERATURE ON THE GROWTH OF MYCOBACTERIUM AVIUM COMPLEX (MAC) ORGANISMS

    Science.gov (United States)

    MAC organisms are able to grow, persist, and colonize in water distribution systems and may amplify in hospital hot water systems. This study examined the response of MAC organisms (M. avium, M. intracellulare, and MX) to a range of temperatures commonly associated with drinking...

  4. Self-Admitted Pretensions of Mac Users on a Predominantly PC University Campus

    Science.gov (United States)

    Firmin, Michael W.; Wood, Whitney L. Muhlenkamp; Firmin, Ruth L.; Wood, Jordan C.

    2010-01-01

    The present qualitative research study addressed the overall research question of college students' pretention dynamics in the context of a university setting. Thirty-five Mac users were interviewed on a university campus that exclusively supports PC machines. Mac users shared four self-admitted pretensions related to using Macintosh computers.…

  5. Poincaré-MacMillan Equations of Motion for a Nonlinear Nonholonomic Dynamical System

    Institute of Scientific and Technical Information of China (English)

    Amjad Hussain; Syed Tauseef Mohyud-Din; Ahmet Yildirim

    2012-01-01

    MacMillan's equations are extended to Poincaré's formalism,and MacMillan's equations for nonlinear nonholonomic systems are obtained in terms of Poincaré parameters.The equivalence of the results obtained here with other forms of equations of motion is demonstrated.An illustrative example of the theory is provided as well.

  6. On PHY and MAC Performance in Body Sensor Networks

    Directory of Open Access Journals (Sweden)

    Sana Ullah

    2009-01-01

    Full Text Available This paper presents an empirical investigation on the performance of body implant communication using radio frequency (RF technology. In body implant communication, the electrical properties of the body influence the signal propagation in several ways. We use a Perspex body model (30 cm diameter, 80 cm height and 0.5 cm thickness filled with a liquid that mimics the electrical properties of the basic body tissues. This model is used to observe the effects of body tissue on the RF communication. We observe best performance at 3cm depth inside the liquid. We further present a simulation study of several low-power MAC protocols for an on-body sensor network and discuss the derived results. Also, the traditional preamble-based TMDA protocol is extended towards a beacon-based TDMA protocol in order to avoid preamble collision and to ensure low-power communication.

  7. Self and Otherness in Norman MacCaig’s Poetry

    Directory of Open Access Journals (Sweden)

    Dominique DELMAIRE

    2004-10-01

    Full Text Available No other Scottish poet has concerned himself more thoroughly than Norman MacCaig (1910-1996 — the author of such poems as “Ego,” “Other Self,” “Other self, same self,” and many more in the same vein — with the problematic issue of the subject and his relations to both reality and to his own multiple avatars or projections. “Other self” (Collected Poems 95 is such a case in point that it deserves full quoting:       My inmost creature, Caliban perhaps,      Perhaps St Francis (at least, a s...

  8. A Distributed MAC Protocol for Cooperation in Random Access Networks

    CERN Document Server

    Böcherer, Georg

    2008-01-01

    WLAN is one of the most successful applications of wireless communications in daily life because of low cost and ease of deployment. The enabling technique for this success is the use of random access schemes for the wireless channel. Random access requires minimal coordination between the nodes, which considerably reduces the cost of the infrastructure. Recently, cooperative communication in wireless networks has been of increasing interest because it promises higher rates and reliability. An additional MAC overhead is necessary to coordinate the nodes to allow cooperation and this overhead can possibly cancel out the cooperative benefits. In this work, a completely distributed protocol is proposed that allows nodes in the network to cooperate via Two-Hop and Decode-and-Forward for transmitting their data to a common gateway node. It is shown that high throughput gains are obtained in terms of the individual throughput that can be guaranteed to any node in the network. These results are validated by Monte Ca...

  9. Analysis and improvement of the MAC shaping mechanism in RPR

    Science.gov (United States)

    Li, Jing; Xu, Zhanqi; Yu, Shaohua

    2005-11-01

    Resilient Packet Ring (RPR) specified by IEEE 802.17 is a new standard for Metropolitan Area Networks (MANs). One of RPR's characteristics is that it can support three priorities traffic in a single datapath, i.e., class A, class B and class C, ranging from high priority to low priority, respectively. Different entities such as shaping, scheduling, fairness, topology and protection coordinate to guarantee the Quality of Service (QoS) for different services. Various pieces of the datapath in RPR are tied together through logical queues, thus we investigate the datapath from the view of logical queues in this paper. With a detailed analysis of the MAC shaping mechanism in RPR, we propose some improvement to achieve better transport performance for RPR's three priorities traffic. Simulation results show that our improvement is efficient.

  10. Marielle Macé, Le genre littéraire

    OpenAIRE

    2012-01-01

    Pour des termes génériques associés à une longue tradition et plusieurs écoles de pensée, la collection Corpus s’engage à présenter un panorama de définitions. Tel a été le cas, entre autres notions, pour celles d’auteur, de lecteur… L’ouvrage de Marielle Macé traite lui aussi d’une notion clé qui est au cœur d’une histoire plus que millénaire de la réflexion littéraire, mais aussi philosophique, voire linguistique et rhétorique, exposée aux vagues successives de remise en cause de la moderni...

  11. [Materials for the substantiation of the biological MAC of benzene].

    Science.gov (United States)

    Ulanova, I P; Avilova, G G; Karpukhina, E A; Karimova, L K; Boĭko, V I; Makar'eva, L M

    1990-09-01

    Relatively great amount of benzene-originated phenol, the presence of a definite relationship between phenol amount in the urine and benzene content in the air indicate that it is reasonable to use a phenol sample as an exposure test. To determine the intensity of benzene exposure, data on phenol content in the urine of people working at some big-tonnage enterprises has been analyzed. On the basis of the national and foreign literature data on the correlation between the phenol urine concentration and the level of benzene exposure a regression equation was deduced, which has made it possible to calculate phenol content in the urine on the level of average working day benzene concentration adopted in the USSR. This value equals 15 mg/l, which was proposed as a biological benzene MAC.

  12. MacBurn's cylinder test problem

    Energy Technology Data Exchange (ETDEWEB)

    Shestakov, Aleksei I. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-02-29

    This note describes test problem for MacBurn which illustrates its performance. The source is centered inside a cylinder with axial-extent-to-radius ratio s.t. each end receives 1/4 of the thermal energy. The source (fireball) is modeled as either a point or as disk of finite radius, as described by Marrs et al. For the latter, the disk is divided into 13 equal area segments, each approximated as a point source and models a partially occluded fireball. If the source is modeled as a single point, one obtains very nearly the expected deposition, e.g., 1/4 of the flux on each end and energy is conserved. If the source is modeled as a disk, both conservation and energy fraction degrade. However, errors decrease if the source radius to domain size ratio decreases. Modeling the source as a disk increases run-times.

  13. Sabine MacCormack, On the Wings of Time. Rome,

    OpenAIRE

    Rey, Sarah

    2011-01-01

    Que vient faire une antiquisante sur les hauteurs andines ? Sabine MacCormack, spécialiste de l’art romain, n’a pas à se justifier. Dans cette étude, l’abondante littérature qu’elle offre au lecteur suffit à prouver l’intérêt de sa démarche qui consiste à quêter les formes, les mots et les images de l’Antiquité apposés sur l’espace inca au moment de sa découverte. L’historienne donne une suite à son étude de 1991, Religion in the Andes  : Vision and Imagination in Early Colonial Peru. Pour re...

  14. MACS low-background doubly focusing neutron monochromator

    CERN Document Server

    Smee, S A; Scharfstein, G A; Qiu, Y; Brand, P C; Anand, D K; Broholm, C L

    2002-01-01

    A novel doubly focusing neutron monochromator has been developed as part of the Multi-Analyzer Crystal Spectrometer (MACS) at the NIST Center for Neutron Research. The instrument utilizes a unique vertical focusing element that enables active vertical and horizontal focusing with a large, 357-crystal (1428 cm sup 2), array. The design significantly reduces the amount of structural material in the beam path as compared to similar instruments. Optical measurements verify the excellent focal performance of the device. Analytical and Monte Carlo simulations predict that, when mounted at the NIST cold-neutron source, the device should produce a monochromatic beam (DELTA E=0.2 meV) with flux phi>10 sup 8 n/cm sup 2 s. (orig.)

  15. Antimoulting Activity of Eremanthus erythropappus (DC. MacLeisch

    Directory of Open Access Journals (Sweden)

    Danielle Barbosa

    2012-06-01

    Resumo. Os extratos e metabólitos secundários de plantas podem agir como agentes tóxicos e inibidores do da alimentação e do desenvolvimento em insetos. Neste estudo foi utilizado Oncopeltus fasciatus (Dallas (Hemiptera como modelo experimental a fim de avaliar as atividades do extrato etanólico bruto e frações obtidos das flores ou caules de Eremanthus erythropappus (DC. MacLeisch (Asteraceae, na mortalidade e sobre o desenvolvimento do inseto. A fração butanólica obtida do extrato etanólico mostrou toxidade sobre as ninfas de O. fasciatus, bem como atividade de inibição do crescimento. Os resultados sugerem que a fração butanólica de E. erythropappus possui substâncias ativas sobre a fisiologia, crescimento e desenvolvimento de insetos.

  16. On PHY and MAC Performance in Body Sensor Networks

    Directory of Open Access Journals (Sweden)

    Higgins Henry

    2009-01-01

    Full Text Available Abstract This paper presents an empirical investigation on the performance of body implant communication using radio frequency (RF technology. In body implant communication, the electrical properties of the body influence the signal propagation in several ways. We use a Perspex body model (30 cm diameter, 80 cm height and 0.5 cm thickness filled with a liquid that mimics the electrical properties of the basic body tissues. This model is used to observe the effects of body tissue on the RF communication. We observe best performance at 3cm depth inside the liquid. We further present a simulation study of several low-power MAC protocols for an on-body sensor network and discuss the derived results. Also, the traditional preamble-based TMDA protocol is extended towards a beacon-based TDMA protocol in order to avoid preamble collision and to ensure low-power communication.

  17. MAC Protocols for GSP in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Maria Calle

    2008-06-01

    Full Text Available The Gossip-based Sleep Protocol (GSP is a routing protocol designed to save energy in Wireless Sensor Networks. This work presents two MAC protocols designed to complement the characteristics of GSP: MACGSP1 and MACGSP2 were evaluated in combination with GSP on square grids of 100, 400 and 900 simulated nodes. Both protocols show increased energy savings compared to GSP by itself. MACGSP1 provided the greatest energy savings, however MACGSP2 exhibited the best trade off between overhead, delay and packet reception probability. MACGSP2 reduces the duplicate packets generated by GSP, with no significant difference in end-to end delay and a reduced GSP packet reception probability of 10%.

  18. Interference Analysis Status and Plans for Aeronautical Mobile Airport Communications System (AeroMACS)

    Science.gov (United States)

    Kerczewski, Robert J.; Wilson, Jeffrey D.

    2010-01-01

    Interference issues related to the operation of an aeronautical mobile airport communications system (AeroMACS) in the C-Band (specifically 5091-5150 MHz) is being investigated. The issue of primary interest is co-channel interference from AeroMACS into mobile-satellite system (MSS) feeder uplinks. The effort is focusing on establishing practical limits on AeroMACS transmissions from airports so that the threshold of interference into MSS is not exceeded. The analyses are being performed with the software package Visualyse Professional, developed by Transfinite Systems Limited. Results with omni-directional antennas and plans to extend the models to represent AeroMACS more accurately will be presented. These models should enable realistic analyses of emerging AeroMACS designs to be developed from NASA Test Bed, RTCA 223, and European results.

  19. Reliable Multicast MAC Protocol for IEEE 802.11 Wireless LANs with Extended Service Range

    Science.gov (United States)

    Choi, Woo-Yong

    2011-11-01

    In this paper, we propose the efficient reliable multicast MAC protocol by which the AP (Access Point) can transmit reliably its multicast data frames to the recipients in the AP's one-hop or two-hop transmission range. The AP uses the STAs (Stations) that are directly associated with itself as the relays for the data delivery to the remote recipients that cannot be reached directly from itself. Based on the connectivity information among the recipients, the reliable multicast MAC protocol optimizes the number of the RAK (Request for ACK) frame transmissions in a reasonable computational time. Numerical examples show that our proposed MAC protocol significantly enhances the MAC performance compared with the BMMM (Batch Mode Multicast MAC) protocol that is extended to support the recipients that are in the AP's one-hop or two-hop transmission range in IEEE 802.11 wireless LANs.

  20. The identification of MacSe in Streptococcus equi ssp. equi

    Institute of Scientific and Technical Information of China (English)

    Jiande YANG; Yanfei LIU; Jun XU; Jifei MA

    2009-01-01

    Streptococcus equi subsp, equi (S. equi ssp. equi) causes equine strangles, a highly contagious and widespread purulent lymphadenitis of the head and neck. We have identified MacSe, a novel protein of S. equi, by screening a phage library of 3-8 kb random DNA fragments of S. equi CF32. MacSe shares 62% and 67.5% amino acid homology with Mac5005 and Mac8345 of S. pyogenes respectively. Expression during infection was shown by strong reactivity of the protein with convalescent sera and mucosal wash IgA of ponies infected by commingling exposure. Release into the culture medium was detected during the log phase of growth. Dose dependent anti-phagocytic activity for equine neutrophils involved interaction of MacSe with C3 and neutrophils.

  1. Self-Adaptive and Energy-Efficient MAC Protocol Based on Event-Driven

    Directory of Open Access Journals (Sweden)

    Xin Hou

    2013-01-01

    Full Text Available Combined with WSN MAC layer protocol characteristics and design requirements, according to the characteristic of WSN monitoring application requirements, this paper puts forward a method based on event driven MAC protocol. The agreement algorithm is to solve the problem of network congestion and node energy unnecessary consumption cause by a large number of redundant monitoring data transceiver. It is a kind of adaptive low power consumption of the MAC layer protocol, which is pointed out based on theoretical foundation of S_MAC protocol, made use of the event driven mechanism system theory, combined with event driven mechanism and the characteristics of the WSN. It has the periodic dormancy mechanism of S_MAC protocol, in the premise of the reliability data, to reduce data redundancy and communication delay time, improve the overall network throughput, to ensure the safety and reliability of the network, which can greatly extends  the node of working time.

  2. Energy efficient TDMA-based MAC protocol associated with GAF for wireless sensor networks

    Institute of Scientific and Technical Information of China (English)

    XIAO Xiao; ZHENG Bao-yu; YAN Zhen-ya; CHEN Chao

    2007-01-01

    The design of media access control (MAC) protocol for wireless sensor networks (WSNs) with the idea of cross layer attracts more and more attention. People can improve the MAC protocol by obtaining certain information regarding the network layer and physical layer. This article synthesizes and optimizes certain cross-layer protocols which have existed. On the basis of the routing, topology information in the network layer, and transmission power information in the physical layer, the time slot assignment algorithm has been improved in the MAC layer.By using geographical adaptive fidelity algorithm (GAF) to divide the grids, controlling of transmission power and scheduling the work/sleep duty cycle for sensor nodes, a new MAC protocol has been proposed to decrease energy consumption and enlarge the lifetime of WSNs. Simulation results show that the MAC protocol functions well.

  3. Research on low-latency MAC protocols for wireless sensor networks

    Science.gov (United States)

    He, Chenguang; Sha, Xuejun; Lee, Chankil

    2007-11-01

    Energy-efficient should not be the only design goal in MAC protocols for wireless sensor networks, which involve the use of battery-operated computing and sensing devices. Low-latency operation becomes the same important as energy-efficient in the case that the traffic load is very heavy or the real-time constrain is used in applications like tracking or locating. This paper introduces some causes of traditional time delays which are inherent in a multi-hops network using existing WSN MAC protocols, illuminates the importance of low-latency MAC design for wireless sensor networks, and presents three MACs as examples of low-latency protocols designed specially for sleep delay, wait delay and wakeup delay in wireless sensor networks, respectively. The paper also discusses design trade-offs with emphasis on low-latency and points out their advantages and disadvantages, together with some design considerations and suggestions for MAC protocols for future applications and researches.

  4. An Energy-Efficient, Application-Oriented Control Algorithm for MAC Protocols in WSN

    Science.gov (United States)

    Li, Deliang; Peng, Fei; Qian, Depei

    Energy efficiency has been a main concern in wireless sensor networks where Medium Access Control (MAC) protocol plays an important role. However, current MAC protocols designed for energy saving have seldom considered multiple applications coexisting in WSN with variation of traffic load dynamics and different QoS requirements. In this paper, we propose an adaptive control algorithm at MAC layer to promote energy efficiency. We focus on the tradeoff relation between collisions and control overhead as a reflection of traffic load and propose to balance the tradeoff under the constraints of QoS options. We integrate the algorithm into S-MAC and verify it through NS-2 platform. The results demonstrate the algorithm achieves observable improvement in energy performance while meeting QoS requirement for different coexisting applications in comparison with S-MAC.

  5. MAQF/MAC:A New QoS Provisioning MAC Mechanism for MANET

    Institute of Scientific and Technical Information of China (English)

    YAOYinxion; WANGHaoxing; WANXiang

    2003-01-01

    QoS provisioning is not an easy problem under the time varying and dynamic environment of MANET.Based on MANET Adaptive QoS Framework(MAQF)and through improving the scheme of MACA/PR,a new mechanism MAQF/MAC that can provide MAC layer QoS guarantees for MANET has been presented.MAQF/MAC can measure the variation of resource in real time,change the channel access policy and adapt the amount of resource captured by trafflc.In addition,this paper also concerns some key components of MAQF/MAC,including reservation table(RT),QoS routing,resource compression algorithm and etc.Simulation result show that MAQF/MAC ls superior to MACA/PR in the aspects of multi-level trafflc QoS provisioning and resource utilization.

  6. MicMac GIS application: free open source

    Science.gov (United States)

    Duarte, L.; Moutinho, O.; Teodoro, A.

    2016-10-01

    The use of Remotely Piloted Aerial System (RPAS) for remote sensing applications is becoming more frequent as the technologies on on-board cameras and the platform itself are becoming a serious contender to satellite and airplane imagery. MicMac is a photogrammetric tool for image matching that can be used in different contexts. It is an open source software and it can be used as a command line or with a graphic interface (for each command). The main objective of this work was the integration of MicMac with QGIS, which is also an open source software, in order to create a new open source tool applied to photogrammetry/remote sensing. Python language was used to develop the application. This tool would be very useful in the manipulation and 3D modelling of a set of images. The main objective was to create a toolbar in QGIS with the basic functionalities with intuitive graphic interfaces. The toolbar is composed by three buttons: produce the points cloud, create the Digital Elevation Model (DEM) and produce the orthophoto of the study area. The application was tested considering 35 photos, a subset of images acquired by a RPAS in the Aguda beach area, Porto, Portugal. They were used in order to create a 3D terrain model and from this model obtain an orthophoto and the corresponding DEM. The code is open and can be modified according to the user requirements. This integration would be very useful in photogrammetry and remote sensing community combined with GIS capabilities.

  7. Mac-1 Regulates IL-13 Activity in Macrophages by Directly Interacting with IL-13Rα1.

    Science.gov (United States)

    Cao, Chunzhang; Zhao, Juanjuan; Doughty, Emily K; Migliorini, Mary; Strickland, Dudley K; Kann, Maricel G; Zhang, Li

    2015-08-28

    Mac-1 exhibits a unique inhibitory activity toward IL-13-induced JAK/STAT activation and thereby regulates macrophage to foam cell transformation. However, the underlying molecular mechanism is unknown. In this study, we report the identification of IL-13Rα1, a component of the IL-13 receptor (IL-13R), as a novel ligand of integrin Mac-1, using a co-evolution-based algorithm. Biochemical analyses demonstrated that recombinant IL-13Rα1 binds Mac-1 in a purified system and supports Mac-1-mediated cell adhesion. Co-immunoprecipitation experiments revealed that endogenous Mac-1 forms a complex with IL-13Rα1 in solution, and confocal fluorescence microscopy demonstrated that these two receptors co-localize with each other on the surface of macrophages. Moreover, we found that genetic inactivation of Mac-1 promotes IL-13-induced JAK/STAT activation in macrophages, resulting in enhanced polarization along the alternative activation pathway. Importantly, we observed that Mac-1(-/-) macrophages exhibit increased expression of foam cell differentiation markers including 15-lipoxygenase and lectin-type oxidized LDL receptor-1 both in vitro and in vivo. Indeed, we found that Mac-1(-/-)LDLR(-/-) mice develop significantly more foam cells than control LDLR(-/-) mice, using an in vivo model of foam cell formation. Together, our data establish for the first time a molecular mechanism by which Mac-1 regulates the signaling activity of IL-13 in macrophages. This newly identified IL-13Rα1/Mac-1-dependent pathway may offer novel targets for therapeutic intervention in the future.

  8. Mac-1 Regulates IL-13 Activity in Macrophages by Directly Interacting with IL-13Rα1*

    Science.gov (United States)

    Cao, Chunzhang; Zhao, Juanjuan; Doughty, Emily K.; Migliorini, Mary; Strickland, Dudley K.; Kann, Maricel G.; Zhang, Li

    2015-01-01

    Mac-1 exhibits a unique inhibitory activity toward IL-13-induced JAK/STAT activation and thereby regulates macrophage to foam cell transformation. However, the underlying molecular mechanism is unknown. In this study, we report the identification of IL-13Rα1, a component of the IL-13 receptor (IL-13R), as a novel ligand of integrin Mac-1, using a co-evolution-based algorithm. Biochemical analyses demonstrated that recombinant IL-13Rα1 binds Mac-1 in a purified system and supports Mac-1-mediated cell adhesion. Co-immunoprecipitation experiments revealed that endogenous Mac-1 forms a complex with IL-13Rα1 in solution, and confocal fluorescence microscopy demonstrated that these two receptors co-localize with each other on the surface of macrophages. Moreover, we found that genetic inactivation of Mac-1 promotes IL-13-induced JAK/STAT activation in macrophages, resulting in enhanced polarization along the alternative activation pathway. Importantly, we observed that Mac-1−/− macrophages exhibit increased expression of foam cell differentiation markers including 15-lipoxygenase and lectin-type oxidized LDL receptor-1 both in vitro and in vivo. Indeed, we found that Mac-1−/−LDLR−/− mice develop significantly more foam cells than control LDLR−/− mice, using an in vivo model of foam cell formation. Together, our data establish for the first time a molecular mechanism by which Mac-1 regulates the signaling activity of IL-13 in macrophages. This newly identified IL-13Rα1/Mac-1-dependent pathway may offer novel targets for therapeutic intervention in the future. PMID:26160172

  9. Gambia Land Use Land Cover

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This series of three-period land use land cover (LULC) datasets (1975, 2000, and 2013) aids in monitoring change in West Africa’s land resources (exception is...

  10. History-based MAC Protocol for Low Duty-Cycle Wireless Sensor Networks: the SLACK-MAC Protocol

    Directory of Open Access Journals (Sweden)

    Affoua Thérèse Aby

    2016-06-01

    Full Text Available Wireless sensor networks (WSNs are increasingly used in environmental monitoring applications. They are designed to operate for several months by featuring low activity cycles in order to save energy. In this paper, we propose a Medium Access Control (MAC protocol for suchWSNs with very low duty-cycles of 1% and less. Nodes are activated randomly and use a history of previous successful frame exchanges to decide their next activation time. We study the choice of the history size, and we compare the performance of our protocol with other protocols from the literature. We show by simulations and real experiments that with a limited history size of only six entries, our protocol achieves better performance than other protocols from the literature, while keeping the advantages of fully asynchronous protocols.

  11. Environmental Assessment for Construction of Security Forces Facility/Demolition of Existing Building 528 MacDill AFB, Florida

    Science.gov (United States)

    2005-08-01

    Gennarro and Tish Maddy MacDill Air Force Base Environmental Restoration Program 7621 Hillsborough Loop Dr. MacDill AFB, FL 33621-5207 Bryan...MacDill Air Force Base Maddy, Tish Lead-based Paint and Asbestos Records, Building 528. Verbal correspondence, February 1, 2005. Naval

  12. 42 CFR 405.1140 - MAC review of ALJ decision in a case remanded by a Federal district court.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false MAC review of ALJ decision in a case remanded by a...) Medicare Appeals Council Review § 405.1140 MAC review of ALJ decision in a case remanded by a Federal... district court for further consideration and the MAC remands the case to an ALJ, a decision subsequently...

  13. 42 CFR 405.1062 - Applicability of local coverage determinations and other policies not binding on the ALJ and MAC.

    Science.gov (United States)

    2010-10-01

    ... other policies not binding on the ALJ and MAC. 405.1062 Section 405.1062 Public Health CENTERS FOR... of local coverage determinations and other policies not binding on the ALJ and MAC. (a) ALJs and the MAC are not bound by LCDs, LMRPs, or CMS program guidance, such as program memoranda and manual...

  14. A Priority-Based Adaptive MAC Protocol for Wireless Body Area Networks

    Directory of Open Access Journals (Sweden)

    Sabin Bhandari

    2016-03-01

    Full Text Available In wireless body area networks (WBANs, various sensors and actuators are placed on/inside the human body and connected wirelessly. WBANs have specific requirements for healthcare and medical applications, hence, standard protocols like the IEEE 802.15.4 cannot fulfill all the requirements. Consequently, many medium access control (MAC protocols, mostly derived from the IEEE 802.15.4 superframe structure, have been studied. Nevertheless, they do not support a differentiated quality of service (QoS for the various forms of traffic coexisting in a WBAN. In particular, a QoS-aware MAC protocol is essential for WBANs operating in the unlicensed Industrial, Scientific, and Medical (ISM bands, because different wireless services like Bluetooth, WiFi, and Zigbee may coexist there and cause severe interference. In this paper, we propose a priority-based adaptive MAC (PA-MAC protocol for WBANs in unlicensed bands, which allocates time slots dynamically, based on the traffic priority. Further, multiple channels are effectively utilized to reduce access delays in a WBAN, in the presence of coexisting systems. Our performance evaluation results show that the proposed PA-MAC outperforms the IEEE 802.15.4 MAC and the conventional priority-based MAC in terms of the average transmission time, throughput, energy consumption, and data collision ratio.

  15. A Priority-Based Adaptive MAC Protocol for Wireless Body Area Networks.

    Science.gov (United States)

    Bhandari, Sabin; Moh, Sangman

    2016-03-18

    In wireless body area networks (WBANs), various sensors and actuators are placed on/inside the human body and connected wirelessly. WBANs have specific requirements for healthcare and medical applications, hence, standard protocols like the IEEE 802.15.4 cannot fulfill all the requirements. Consequently, many medium access control (MAC) protocols, mostly derived from the IEEE 802.15.4 superframe structure, have been studied. Nevertheless, they do not support a differentiated quality of service (QoS) for the various forms of traffic coexisting in a WBAN. In particular, a QoS-aware MAC protocol is essential for WBANs operating in the unlicensed Industrial, Scientific, and Medical (ISM) bands, because different wireless services like Bluetooth, WiFi, and Zigbee may coexist there and cause severe interference. In this paper, we propose a priority-based adaptive MAC (PA-MAC) protocol for WBANs in unlicensed bands, which allocates time slots dynamically, based on the traffic priority. Further, multiple channels are effectively utilized to reduce access delays in a WBAN, in the presence of coexisting systems. Our performance evaluation results show that the proposed PA-MAC outperforms the IEEE 802.15.4 MAC and the conventional priority-based MAC in terms of the average transmission time, throughput, energy consumption, and data collision ratio.

  16. A tale of two mitochondrial channels, MAC and PTP, in apoptosis.

    Science.gov (United States)

    Kinnally, Kathleen W; Antonsson, Bruno

    2007-05-01

    The crucial step in the intrinsic, or mitochondrial, apoptotic pathway is permeabilization of the mitochondrial outer membrane. Permeabilization triggers release of apoptogenic factors, such as cytochrome c, from the mitochondrial intermembrane space into the cytosol where these factors ensure propagation of the apoptotic cascade and execution of cell death. However, the mechanism(s) underlying permeabilization of the outer membrane remain controversial. Two mechanisms, involving opening of two different mitochondrial channels, have been proposed to be responsible for the permeabilization; the permeability transition pore (PTP) in the inner membrane and the mitochondrial apoptosis-induced channel (MAC) in the outer membrane. Opening of PTP would lead to matrix swelling, subsequent rupture of the outer membrane, and an unspecific release of intermembrane proteins into the cytosol. However, many believe PTP opening is a consequence of apoptosis and this channel is thought to principally play a role in necrosis, not apoptosis. Activation of MAC is exquisitely regulated by Bcl-2 family proteins, which are the sentinels of apoptosis. MAC provides specific pores in the outer membrane for the passage of intermembrane proteins, in particular cytochrome c, to the cytosol. The electrophysiological characteristics of MAC are very similar to Bax channels and depletion of Bax significantly diminishes MAC activity, suggesting that Bax is an essential constituent of MAC in some systems. The characteristics of various mitochondrial channels and Bax are compared. The involvement of MAC and PTP activities in apoptosis of disease and their pharmacology are discussed.

  17. A cross-layer duty cycle MAC protocol supporting a pipeline feature for wireless sensor networks.

    Science.gov (United States)

    Tong, Fei; Xie, Rong; Shu, Lei; Kim, Young-Chon

    2011-01-01

    Although the conventional duty cycle MAC protocols for Wireless Sensor Networks (WSNs) such as RMAC perform well in terms of saving energy and reducing end-to-end delivery latency, they were designed independently and require an extra routing protocol in the network layer to provide path information for the MAC layer. In this paper, we propose a new cross-layer duty cycle MAC protocol with data forwarding supporting a pipeline feature (P-MAC) for WSNs. P-MAC first divides the whole network into many grades around the sink. Each node identifies its grade according to its logical hop distance to the sink and simultaneously establishes a sleep/wakeup schedule using the grade information. Those nodes in the same grade keep the same schedule, which is staggered with the schedule of the nodes in the adjacent grade. Then a variation of the RTS/CTS handshake mechanism is used to forward data continuously in a pipeline fashion from the higher grade to the lower grade nodes and finally to the sink. No extra routing overhead is needed, thus increasing the network scalability while maintaining the superiority of duty-cycling. The simulation results in OPNET show that P-MAC has better performance than S-MAC and RMAC in terms of packet delivery latency and energy efficiency.

  18. DLD-MAC:A Diffserv-based Low-delay MAC Protocol for WSNs%DLD-MAC:一种区分服务的低时延传感器网络MAC协议

    Institute of Scientific and Technical Information of China (English)

    舒俊浩; 白光伟; 沈航

    2012-01-01

    针对现有无线传感器网络MAC协议不能提供区分服务和传输时廷较大的问题,在经典多跳传输协议DW-MAC的基础上,提出了一种具有区分服务功能的低时延MAC协议—DLD-MAC(Diffserv-based Low-Delay MAC).其基本思路是让高优先级数据选择更小的竞争窗口,以降低时延和能耗.Markov建模分析表明,DLD-MAC能对不同优先级的业务流进行很好的服务区分,而且相较于传统的无线传感器网络MAC协议,其在时延性能上有显著优势,能更有效地保障服务质量.%Considering that most of the existing MAC protocols in wireless sensor networks do not support any priority scheme,this paper proposed a novel,Diffserv-based low-delay MAC mechanismCDLD-MAC),on the basis of the existing DW-MAC protocol. The main idea is that, by introducing differentiated services, the high priority data chooses smaller back-off window, so that it can achieve much more chance to be delivered, and its packet transmission latency and energy consumption can be reduced significantly compared with low priority data. On the other hand, a Markov chain model was designed in this work, to analyze and evaluate the mechanism performance. Our analytical analyses show that the proposed DLD-MAC can effectively make the high priority data achieve higher QoS over the low priority data, and achieve much lower transmission latency than traditional MAC protocol as well,which is adequate to serve delay-sensitive data flow.

  19. An extended smart utilization medium access control (ESU-MAC) protocol for ad hoc wireless systems

    Science.gov (United States)

    Vashishtha, Jyoti; Sinha, Aakash

    2006-05-01

    The demand for spontaneous setup of a wireless communication system has increased in recent years for areas like battlefield, disaster relief operations etc., where a pre-deployment of network infrastructure is difficult or unavailable. A mobile ad-hoc network (MANET) is a promising solution, but poses a lot of challenges for all the design layers, specifically medium access control (MAC) layer. Recent existing works have used the concepts of multi-channel and power control in designing MAC layer protocols. SU-MAC developed by the same authors, efficiently uses the 'available' data and control bandwidth to send control information and results in increased throughput via decreasing contention on the control channel. However, SU-MAC protocol was limited for static ad-hoc network and also faced the busy-receiver node problem. We present the Extended SU-MAC (ESU-MAC) protocol which works mobile nodes. Also, we significantly improve the scheme of control information exchange in ESU-MAC to overcome the busy-receiver node problem and thus, further avoid the blockage of control channel for longer periods of time. A power control scheme is used as before to reduce interference and to effectively re-use the available bandwidth. Simulation results show that ESU-MAC protocol is promising for mobile, ad-hoc network in terms of reduced contention at the control channel and improved throughput because of channel re-use. Results show a considerable increase in throughput compared to SU-MAC which could be attributed to increased accessibility of control channel and improved utilization of data channels due to superior control information exchange scheme.

  20. An Economic Analysis of MAC Versus WALANT: A Trigger Finger Release Surgery Case Study.

    Science.gov (United States)

    Codding, Jason L; Bhat, Suneel B; Ilyas, Asif M

    2017-07-01

    There has been recent interest in wide awake hand surgery, also referred to as "wide awake local anesthesia with no tourniquet" (WALANT) surgery. Using a model of single trigger finger release (TFR) surgery, a hypothesis was made that WALANT would result in decreased hospital time and cost than patients receiving sedation with monitored anesthetic care (MAC). Consecutive cases of single TFR surgery with MAC were compared with WALANT. All surgeries were performed in the same manner, at the same facility, and by the same surgeon. Total operating room (OR) time, surgical time, recovery time, and anesthesia costs were analyzed. There were 78 patients: 31 MAC and 47 WALANT. The MAC group averaged 27.2 minutes of OR time; the WALANT group averaged 25.2 minutes. The MAC group surgical time was 10.2 minutes versus WALANT of 10.4 minutes. Post-operatively, the MAC group averaged 72.3 minutes in the recovery room compared with WALANT group of 30.2 minutes. Each case performed under MAC had a minimum of excess charges from anesthesia of approximately $105. Patients undergoing single TFR surgery under WALANT trended toward less time in the OR, had similar surgical times, and spent significantly less time in the recovery room, compared with MAC, thereby resulting in less indirect costs. Each MAC case also had minimum direct excess anesthesia charges of $105, which knowingly underestimates overall charges as it excludes material and fixed costs associated with the delivery of anesthesia. Avoiding sedation for high-volume procedures such as TFR may result in significant systemic savings to payers, and in the future with bundling and episode-based payments can become increasingly important to patients, facilities, and surgeons.

  1. PLEIOTROPHIN, A MULTIFUNCTIONAL CYTOKINE AND GROWTH FACTOR, INDUCES LEUKOCYTE RESPONSES THROUGH THE INTEGRIN MAC-1.

    Science.gov (United States)

    Shen, Di; Podolnikova, Nataly P; Yakubenko, Valentin P; Ardell, Christopher L; Balabiyev, Arnat; Ugarova, Tatiana P; Wang, Xu

    2017-09-22

    Pleiotrophin (PTN) is a multifunctional, cationic, glycosaminoglycan-binding cytokine and growth factor involved in numerous physiological and pathological processes, including tissue repair and inflammation-related diseases. PTN has been shown to promote leukocyte responses by inducing their migration and expression of inflammatory cytokines. However, the mechanisms through which PTN mediates these responses remain unclear. Here, we identified the integrin Mac-1 (αMβ2, CD11b/CD18) as the receptor mediating macrophage adhesion and migration to PTN. We also found that expression of Mac-1 on the surface of human embryonic kidney (HEK) 293 cells induced their adhesion and migration to PTN. Accordingly, PTN promoted Mac-1-dependent cell spreading and initiated intracellular signaling manifested in phosphorylation of Erk1/2. While binding to PTN, Mac-1 on Mac-1-expressing HEK293 cells appear to cooperate with cell-surface proteoglycans, since both anti-Mac-1 function-blocking mAb and heparin were required to block adhesion. Moreover, biolayer interferometry and NMR indicated a direct interaction between the αMI domain, the major ligand-binding region of Mac-1, and PTN. Using peptide libraries, we found that in PTN, the αMI domain bound sequences enriched in basic and hydrophobic residues, indicating that PTN conforms to the general principle of ligand-recognition specificity of the αMI domain toward cationic proteins/peptides. Finally, using recombinant PTN-derived fragments, we show that PTN contains two distinct Mac-1-binding sites in each of its constitutive domains. Collectively, these results identify PTN as a ligand for the integrin Mac-1 on the surface of leukocytes and suggest that this interaction may play a role in inflammatory responses. Copyright © 2017, The American Society for Biochemistry and Molecular Biology.

  2. Measurements of the Sunyaev-Zel'dovich Effect in MACS J0647.7+7015 and MACS J1206.2-0847 at High Angular Resolution with MUSTANG

    CERN Document Server

    Young, Alexander H; Romero, Charles; Sayers, Jack; Balestra, Italo; Clarke, Tracy E; Czakon, Nicole; Devlin, Mark; Dicker, Simon R; Ferrari, Chiara; Girardi, Marisa; Golwala, Sunil; Intema, Huib; Korngut, Phillip M; Mason, Brian S; Mercurio, Amata; Nonino, Mario; Reese, Erik D; Rosati, Piero; Sarazin, Craig; Umetsu, Keiichi

    2014-01-01

    We present high resolution (9$^{\\prime \\prime}$) imaging of the Sunyaev-Zel'dovich Effect (SZE) toward two massive galaxy clusters, MACS J0647.7+7015 ($z=0.591$) and MACS J1206.2-0847 ($z=0.439$). We compare these 90 GHz measurements, taken with the MUSTANG receiver on the Green Bank Telescope, with generalized Navarro-Frenk-White (gNFW) models derived from Bolocam 140 GHz SZE data as well as maps of the thermal gas derived from {\\it Chandra} X-ray observations. For MACS J0647.7+7015, we find a gNFW profile with core slope parameter $\\gamma= 0.9$ fits the MUSTANG image with $\\chi^{2}_{red}=1.005$ and probability to exceed (PTE) = 0.34. For MACS J1206.2-0847, we find $\\gamma=0.7$, $\\chi^{2}_{red}=0.993$, and PTE = 0.70. In addition, we find a significant ($>$3-$\\sigma$) residual SZE feature in MACS J1206.2-0847 coincident with a group of galaxies identified in VLT data and filamentary structure found in a weak-lensing mass reconstruction. We suggest the detected sub-structure may be the SZE decrement from a lo...

  3. A Study on the Distributed Antenna Based Heterogeneous Cognitive Wireless Network Synchronous MAC Protocol

    Directory of Open Access Journals (Sweden)

    Lian-Fen Huang

    2015-01-01

    Full Text Available This paper introduces distributed antennas into a cognitive radio network and presents a heterogeneous network. The best contribution of this paper is that it designs a synchronous cognitive MAC protocol (DAHCWNS-MAC protocol: distributed antenna based heterogeneous cognitive wireless network synchronous MAC protocol. The novel protocol aims at combining the advantages of cognitive radio and distributed antennas to fully utilize the licensed spectrum, broaden the communication range, and improve throughput. This paper carries out the mathematical modeling and performance simulation to demonstrate its superiority in improving the network throughput at the cost of increasing antenna hardware costs.

  4. Approximate discrete time analysis of the hybrid Token-CDMA MAC system

    CSIR Research Space (South Africa)

    Liu, YS

    2007-09-01

    Full Text Available of the Hybrid Token-CDMA MAC System Yi Sheng Liu, Student Member, IEEE, Fambirai Takawira, Member, IEEE , and Hong Jun Xu, Member, IEEE Abstract— In this paper a hybrid Token-CDMA based medium access control (MAC) protocol is considered. The MAC scheme...Zulu-Natal, Howard College Campus. He received the BSc degree in 1984 from the University of Guilin Technology and the MSc degree from the Institute of Telecontrol and Telemeasure in Shi Jian Zhuang, 1989, and the PhD degree from the Beijing University...

  5. Learn AppleScript The Comprehensive Guide to Scripting and Automation on MAC OS X

    CERN Document Server

    Rosenthal, Hanaan

    2009-01-01

    AppleScript is an English-like, easy-to-understand scripting language built into every Mac. AppleScript can automate hundreds of AppleScriptable applications, performing tasks both large and small, complex and simple. Learn AppleScript: The Comprehensive Guide to Scripting and Automation on Mac OS X, Third Edition has been completely updated for Mac OS X Snow Leopard. It's all here, with an emphasis on practical information that will help you solve any automation problem-from the most mundane repetitive tasks to highly integrated workflows of complex systems. * Friendly enough for beginners, d

  6. MAC Protocol for Ad Hoc Networks Using a Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Omar Elizarraras

    2014-01-01

    Full Text Available The problem of obtaining the transmission rate in an ad hoc network consists in adjusting the power of each node to ensure the signal to interference ratio (SIR and the energy required to transmit from one node to another is obtained at the same time. Therefore, an optimal transmission rate for each node in a medium access control (MAC protocol based on CSMA-CDMA (carrier sense multiple access-code division multiple access for ad hoc networks can be obtained using evolutionary optimization. This work proposes a genetic algorithm for the transmission rate election considering a perfect power control, and our proposition achieves improvement of 10% compared with the scheme that handles the handshaking phase to adjust the transmission rate. Furthermore, this paper proposes a genetic algorithm that solves the problem of power combining, interference, data rate, and energy ensuring the signal to interference ratio in an ad hoc network. The result of the proposed genetic algorithm has a better performance (15% compared to the CSMA-CDMA protocol without optimizing. Therefore, we show by simulation the effectiveness of the proposed protocol in terms of the throughput.

  7. Pliable Cognitive MAC for Heterogeneous Adaptive Cognitive Radio Sensor Networks.

    Directory of Open Access Journals (Sweden)

    Mohammed Al-Medhwahi

    Full Text Available The rapid expansion of wireless monitoring and surveillance applications in several domains reinforces the trend of exploiting emerging technologies such as the cognitive radio. However, these technologies have to adjust their working concepts to consider the common characteristics of conventional wireless sensor networks (WSNs. The cognitive radio sensor network (CRSN, still an immature technology, has to deal with new networks that might have different types of data, traffic patterns, or quality of service (QoS requirements. In this paper, we design and model a new cognitive radio-based medium access control (MAC algorithm dealing with the heterogeneous nature of the developed networks in terms of either the traffic pattern or the required QoS for the node applications. The proposed algorithm decreases the consumed power on several fronts, provides satisfactory levels of latency and spectrum utilization with efficient scheduling, and manages the radio resources for various traffic conditions. An intensive performance evaluation is conducted to study the impact of key parameters such as the channel idle time length, node density, and the number of available channels. The performance evaluation of the proposed algorithm shows a better performance than the comparable protocols. Moreover, the results manifest that the proposed algorithm is suitable for real time monitoring applications.

  8. MAC to VAX Connectivity: Heartrate Spectral Analysis System

    Science.gov (United States)

    Rahman, Hasan H.; Faruque, Monazer

    1993-01-01

    The heart rate Spectral Analysis System (SAS) acquires and analyzes, in real-time, the Space Shuttle onboard electrocardiograph (EKG) experiment signals, calculates the heartrate, and applies a Fast Fourier Transformation (FFT) to the heart rate. The system also calculates other statistical parameters such as the 'mean heart rate' over specific time period and heart rate histogram. This SAS is used by NASA Principal Investigators as a research tool to determine the effects of weightlessness on the human cardiovascular system. This is also used to determine if Lower Body Negative Pressure (LBNP) is an effective countermeasure to the orthostatic intolerance experienced by astronauts upon return to normal gravity. In microgravity, astronauts perform the LBNP experiment in the mid deck of the Space Shuttle. The experiment data are downlinked by the orbiter telemetry system, then processed and analyzed in real-time by the integrated Life Sciences Data Acquisition (LSDS) - Spectral Analysis System. The data system is integrated within the framework of two different computer systems, VAX and Macintosh (Mac), using the networking infrastructure to assist the investigators in further understanding the most complex machine on Earth--the human body.

  9. Tracing the merger history of MACS clusters using the GMRT

    CERN Document Server

    Paul, S; Intema, H T

    2014-01-01

    Galaxy-cluster merger shocks efficiently accelerate the ambient electrons through diffusive shock acceleration and amplify magnetic field by compressing the Inter Cluster Medium. As a result, such objects produce a significant amount of synchrotron radio emission. Radio halo and Mpc scale peripheral radio relics thus help us to trace back the cluster formation history. To study the dynamical state of the galaxy clusters and their relation to the merging scenario, as a pilot project, we thus observed four suitable candidates from the MACS (Massive Cluster Survey) cluster sample. Observations were carried out simultaneously at 610 and 235 MHz with the GMRT. We observed a rare phenomena in the cluster MACSJ0014.3-3022, which hosts both a peripheral spectacular radio relic and an unusually flat spectrum central giant radio halo of more than 1.5 Mpc dimension. We also report that another cluster MACSJ0152.5-2852 is possibly showing the sign of one of the earliest and young merging system where, we saw a faint 0.5 ...

  10. A MAC Protocol to Support Monitoring of Underwater Spaces †

    Science.gov (United States)

    Santos, Rodrigo; Orozco, Javier; Ochoa, Sergio F.; Meseguer, Roc; Eggly, Gabriel; Pistonesi, Marcelo F.

    2016-01-01

    Underwater sensor networks are becoming an important field of research, because of their everyday increasing application scope. Examples of their application areas are environmental and pollution monitoring (mainly oil spills), oceanographic data collection, support for submarine geolocalization, ocean sampling and early tsunamis alert. The challenge of performing underwater communications is well known, provided that radio signals are useless in this medium, and a wired solution is too expensive. Therefore, the sensors in these networks transmit their information using acoustic signals that propagate well under water. This data transmission type not only brings an opportunity, but also several challenges to the implementation of these networks, e.g., in terms of energy consumption, data transmission and signal interference. In order to help advance the knowledge in the design and implementation of these networks for monitoring underwater spaces, this paper proposes a MAC protocol for acoustic communications between the nodes, based on a self-organized time division multiple access mechanism. The proposal was evaluated using simulations of a real monitoring scenario, and the obtained results are highly encouraging. PMID:27355950

  11. A MAC Protocol to Support Monitoring of Underwater Spaces

    Directory of Open Access Journals (Sweden)

    Rodrigo Santos

    2016-06-01

    Full Text Available Underwater sensor networks are becoming an important field of research, because of their everyday increasing application scope. Examples of their application areas are environmental and pollution monitoring (mainly oil spills, oceanographic data collection, support for submarine geolocalization, ocean sampling and early tsunamis alert. The challenge of performing underwater communications is well known, provided that radio signals are useless in this medium, and a wired solution is too expensive. Therefore, the sensors in these networks transmit their information using acoustic signals that propagate well under water. This data transmission type not only brings an opportunity, but also several challenges to the implementation of these networks, e.g., in terms of energy consumption, data transmission and signal interference. In order to help advance the knowledge in the design and implementation of these networks for monitoring underwater spaces, this paper proposes a MAC protocol for acoustic communications between the nodes, based on a self-organized time division multiple access mechanism. The proposal was evaluated using simulations of a real monitoring scenario, and the obtained results are highly encouraging.

  12. A MAC Protocol to Support Monitoring of Underwater Spaces.

    Science.gov (United States)

    Santos, Rodrigo; Orozco, Javier; Ochoa, Sergio F; Meseguer, Roc; Eggly, Gabriel; Pistonesi, Marcelo F

    2016-01-01

    Underwater sensor networks are becoming an important field of research, because of their everyday increasing application scope. Examples of their application areas are environmental and pollution monitoring (mainly oil spills), oceanographic data collection, support for submarine geolocalization, ocean sampling and early tsunamis alert. The challenge of performing underwater communications is well known, provided that radio signals are useless in this medium, and a wired solution is too expensive. Therefore, the sensors in these networks transmit their information using acoustic signals that propagate well under water. This data transmission type not only brings an opportunity, but also several challenges to the implementation of these networks, e.g., in terms of energy consumption, data transmission and signal interference. In order to help advance the knowledge in the design and implementation of these networks for monitoring underwater spaces, this paper proposes a MAC protocol for acoustic communications between the nodes, based on a self-organized time division multiple access mechanism. The proposal was evaluated using simulations of a real monitoring scenario, and the obtained results are highly encouraging.

  13. Emergency Handling for MAC Protocol in Human Body Communication

    Directory of Open Access Journals (Sweden)

    Kwon Youngmi

    2011-01-01

    Full Text Available The human body communication (HBC is a technology that enables short range data communication using the human body as a medium, like an electrical wire. Thus it removes the need for a traditional antenna. HBC may be used as a type of data communication in body area network (BAN, while the devices are being in contact with body. One of important issues in BAN is an emergency alarm because it may be closely related to human life. For emergency data communication, the most critical factor is the time constraint. IEEE 802.15.6 specifies that the emergency alarm for the BAN must be notified in less than 1 sec and must provide prioritization mechanisms for emergency traffic and notification. As one type of BAN, the HBC must follow this recommendation, too. Existing emergency handling methods in BAN are based on the carrier sensing capability on radio frequencies to detect the status of channels. However, PHY protocol in HBC does not provide the carrier sensing. So the previous methods are not well suitable for HBC directly. Additionally, in the environment that the emergency rate is very low, the allocation of dedicated slot(s for emergency in each superframe is very wasteful. In this work, we proposed specific emergency handling operation for human body communication's medium access control (HBC-MAC protocol to meet the emergency requirements for BAN. We also showed the optimal number of emergency slots for the various combinations of beacon intervals and emergency rates.

  14. LAMAN: Load Adaptable MAC for Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Realp Marc

    2005-01-01

    Full Text Available In mobile ad hoc radio networks, mechanisms on how to access the radio channel are extremely important in order to improve network efficiency. In this paper, the load adaptable medium access control for ad hoc networks (LAMAN protocol is described. LAMAN is a novel decentralized multipacket MAC protocol designed following a cross-layer approach. Basically, this protocol is a hybrid CDMA-TDMA-based protocol that aims at throughput maximization in multipacket communication environments by efficiently combining contention and conflict-free protocol components. Such combination of components is used to adapt the nodes' access priority to changes on the traffic load while, at the same time, accounting for the multipacket reception (MPR capability of the receivers. A theoretical analysis of the system is developed presenting closed expressions of network throughput and packet delay. By simulations the validity of our analysis is shown and the performances of a LAMAN-based system and an Aloha-CDMA-based one are compared.

  15. Design and Analysis of an Asynchronous Zero Collision MAC Protocol

    CERN Document Server

    Lee, Jiwoong

    2008-01-01

    This paper proposes and analyzes a distributed MAC protocol that achieves zero collision with no control message exchange nor synchronization. ZC (ZeroCollision) is neither reservation-based nor dynamic TDMA; the protocol supports variable-length packets and does not lose efficiency when some of the stations do not transmit. At the same time, ZC is not a CSMA; in its steady state, it is completely collision-free. The stations transmit repeatedly in a round-robin order once the convergence state is reached. If some stations skip their turn, their transmissions are replaced by idle $20 \\mu$-second mini-slots that enable the other stations to keep track of their order. Because of its short medium access delay and its efficiency, the protocol supports both real-time and elastic applications. The protocol allows for nodes leaving and joining the network; it can allocate more throughput to specific nodes (such as an access point). The protocol is robust against carrier sensing errors or clock drift. While collision...

  16. Pliable Cognitive MAC for Heterogeneous Adaptive Cognitive Radio Sensor Networks.

    Science.gov (United States)

    Al-Medhwahi, Mohammed; Hashim, Fazirulhisyam; Ali, Borhanuddin Mohd; Sali, Aduwati

    2016-01-01

    The rapid expansion of wireless monitoring and surveillance applications in several domains reinforces the trend of exploiting emerging technologies such as the cognitive radio. However, these technologies have to adjust their working concepts to consider the common characteristics of conventional wireless sensor networks (WSNs). The cognitive radio sensor network (CRSN), still an immature technology, has to deal with new networks that might have different types of data, traffic patterns, or quality of service (QoS) requirements. In this paper, we design and model a new cognitive radio-based medium access control (MAC) algorithm dealing with the heterogeneous nature of the developed networks in terms of either the traffic pattern or the required QoS for the node applications. The proposed algorithm decreases the consumed power on several fronts, provides satisfactory levels of latency and spectrum utilization with efficient scheduling, and manages the radio resources for various traffic conditions. An intensive performance evaluation is conducted to study the impact of key parameters such as the channel idle time length, node density, and the number of available channels. The performance evaluation of the proposed algorithm shows a better performance than the comparable protocols. Moreover, the results manifest that the proposed algorithm is suitable for real time monitoring applications.

  17. Modified pterional craniotomy without "MacCarty keyhole".

    Science.gov (United States)

    Moscovici, Samuel; Mizrahi, Cezar José; Margolin, Emil; Spektor, Sergey

    2016-02-01

    Pterional craniotomy is one of the most widely used approaches in neurosurgery. The MacCarty keyhole has remained the preferred means of beginning the craniotomy to achieve a low access point; however, the bone opening may result in a residual defect and an aesthetically unpleasant depression in the periorbital area. We present our modification of the traditional technique. Instead of drilling the keyhole in the frontoperiorbital area, the classical location, we perform a 5 × 15 mm strip craniectomy at the lowest accessible point in the infratemporal fossa, corresponding to the projection of the most lateral point of the sphenoid ridge. The anterior half of this opening exposes the basal frontal dura, while the posterior half brings the temporal dura into view. This modified technique was applied in 48 pterional craniotomies performed for removal of a variety of neoplasms during 2014-2015. There were no approach-related complications. Aesthetic outcomes and patient acceptance have been good; no patient developed skin depression in the periorbital area. In our experience, craniotomy for a pterional approach with the lowest possible access to the frontotemporal skull base may be performed by drilling a narrow oblong opening, without the use of any keyhole or burr hole, to create a smaller skull defect and achieve optimal aesthetic outcomes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Analysis of an Adaptive P-Persistent MAC Scheme for WLAN Providing Delay Fairness

    Science.gov (United States)

    Yen, Chih-Ming; Chang, Chung-Ju; Chen, Yih-Shen; Huang, Ching Yao

    The paper proposes and analyzes an adaptive p-persistent-based (APP) medium access control (MAC) scheme for IEEE 802.11 WLAN. The APP MAC scheme intends to support delay fairness for every station in each access, denoting small delay variance. It differentiates permission probabilities of transmission for stations which are incurred with various packet delays. This permission probability is designed as a function of the numbers of retransmissions and re-backoffs so that stations with larger packet delay are endowed with higher permission probability. Also, the scheme is analyzed by a Markov-chain analysis, where the collision probability, the system throughput, and the average delay are successfully obtained. Numerical results show that the proposed APP MAC scheme can attain lower mean delay and higher mean throughput. In the mean time, simulation results are given to justify the validity of the analysis, and also show that the APP MAC scheme can achieve more delay fairness than conventional algorithms.

  19. Corrections to "Connectivity-Based Reliable Multicast MAC Protocol for IEEE 802.11 Wireless LANs"

    Directory of Open Access Journals (Sweden)

    Choi Woo-Yong

    2010-01-01

    Full Text Available We have found the errors in the throughput formulae presented in our paper "Connectivity-based reliable multicast MAC protocol for IEEE 802.11 wireless LANs". We provide the corrected formulae and numerical results.

  20. Evaluation of video transmission of MAC protocols in wireless sensor network

    Science.gov (United States)

    Maulidin, Mahmuddin, M.; Kamaruddin, L. M.; Elsaikh, Mohamed

    2016-08-01

    Wireless Sensor Network (WSN) is a wireless network which consists of sensor nodes scattered in a particular area which are used to monitor physical or environment condition. Each node in WSN is also scattered in sensor field, so an appropriate scheme of MAC protocol should have to develop communication link for data transferring. Video transmission is one of the important applications for the future that can be transmitted with low aspect in side of cost and also power consumption. In this paper, comparison of five different MAC WSN protocol for video transmission namely IEEE 802.11 standard, IEEE 802.15.4 standard, CSMA/CA, Berkeley-MAC, and Lightweight-MAC protocol are studied. Simulation experiment has been conducted in OMNeT++ with INET network simulator software to evaluate the performance. Obtained results indicate that IEEE 802.11 works better than other protocol in term of packet delivery, throughput, and latency.

  1. Adaptive low-power listening MAC protocol based on transmission rates.

    Science.gov (United States)

    Hwang, Kwang-il; Yi, Gangman

    2014-01-01

    Even though existing low-power listening (LPL) protocols have enabled ultra-low-power operation in wireless sensor networks (WSN), they do not address trade-off between energy and delay, since they focused only on energy aspect. However, in recent years, a growing interest in various WSN applications is requiring new design factors, such as minimum delay and higher reliability, as well as energy efficiency. Therefore, in this paper we propose a novel sensor multiple access control (MAC) protocol, transmission rate based adaptive low-power listening MAC protocol (TRA-MAC), which is a kind of preamble-based LPL but is capable of controlling preamble sensing cycle adaptively to transmission rates. Through experiments, it is demonstrated that TRA-MAC enables LPL cycle (LC) and preamble transmission length to adapt dynamically to varying transmission rates, compensating trade-off between energy and response time.

  2. Four new species of Adicella MacLachlan (Trichoptera: Leptoceridae: Triaenodini) from Sabah, East Malaysia

    NARCIS (Netherlands)

    Huisman, J.; Andersen, T.

    1997-01-01

    Four new species of Adicella MacLachlan, 1877, A. anakpanah spec, nov., A. bavanga spec, nov., A. danumensis spec, nov., and A. gada spec, nov., from Sabah (Borneo), East Malaysia, are described and figured.

  3. MacMath 92 a dynamical systems software package for the Macintosh

    CERN Document Server

    Hubbard, John H

    1993-01-01

    MacMath is a scientific toolkit for the Macintosh computer consisting of twelve graphics programs. It supports mathematical computation and experimentation in dynamical systems, both for differential equations and for iteration. The MacMath package was designed to accompany the textbooks Differential Equations: A Dynamical Systems Approach Part I & II. The text and software was developed for a junior-senior level course in applicable mathematics at Cornell University, in order to take advantage of excellent and easily accessible graphics. MacMath addresses differential equations and iteration such as: analyzer, diffeq, phase plane, diffeq 3D views, numerical methods, periodic differential equations, cascade, 2D iteration, eigenfinder, jacobidraw, fourier, planets. These versatile programs greatly enhance the understanding of the mathematics in these topics. Qualitative analysis of the picture leads to quantitative results and even to new mathematics. This new edition includes the latest version of the Mac...

  4. An Improved MAC Scheme of HORNET Based on Node Structure with Variable Optical Buffer

    Institute of Scientific and Technical Information of China (English)

    Nian Fang; Lutang Wang; Zhaoming Huang

    2003-01-01

    An improved unslotted CSMA/CA MAC scheme of HORNET based on the node structure with variable optical buffer is reported. It can be used for transmitting high effectively all variable IP packets in the WDM network.

  5. Industrial WSN Based on IR-UWB and a Low-Latency MAC Protocol

    Science.gov (United States)

    Reinhold, Rafael; Underberg, Lisa; Wulf, Armin; Kays, Ruediger

    2016-07-01

    Wireless sensor networks for industrial communication require high reliability and low latency. As current wireless sensor networks do not entirely meet these requirements, novel system approaches need to be developed. Since ultra wideband communication systems seem to be a promising approach, this paper evaluates the performance of the IEEE 802.15.4 impulse-radio ultra-wideband physical layer and the IEEE 802.15.4 Low Latency Deterministic Network (LLDN) MAC for industrial applications. Novel approaches and system adaptions are proposed to meet the application requirements. In this regard, a synchronization approach based on circular average magnitude difference functions (CAMDF) and on a clean template (CT) is presented for the correlation receiver. An adapted MAC protocol titled aggregated low latency (ALL) MAC is proposed to significantly reduce the resulting latency. Based on the system proposals, a hardware prototype has been developed, which proves the feasibility of the system and visualizes the real-time performance of the MAC protocol.

  6. Side channel analysis of some hash based MACs:A response to SHA-3 requirements

    DEFF Research Database (Denmark)

    function which is more resistant to known side channel attacks (SCA) when plugged into HMAC, or that has an alternative MAC mode which is more resistant to known SCA than the other submitted alternatives. In response to this, we perform differential power analysis (DPA) on the possible smart card...... implementations of some of the recently proposed MAC alternatives to NMAC (a fully analyzed variant of HMAC) and HMAC algorithms and NMAC/HMAC versions of some recently proposed hash and compression function modes. We show that the recently proposed BNMAC and KMDP MAC schemes are even weaker than NMAC....../HMAC against the DPA attacks, whereas multi-lane NMAC, EMD MAC and the keyed wide-pipe hash have similar security to NMAC against the DPA attacks. Our DPA attacks do not work on the NMAC setting of MDC-2, Grindahl and MAME compression functions. This talk outlines our results....

  7. A Multi-Channel Diversity Based MAC Protocol for Power-Constrained Cognitive Ad Hoc Networks

    CERN Document Server

    Wang, Yichen; Du, Qinghe; Zhang, Chao

    2011-01-01

    One of the major challenges in the medium access control (MAC) protocol design over cognitive Ad Hoc networks (CAHNs) is how to efficiently utilize multiple opportunistic channels, which vary dynamically and are subject to limited power resources. To overcome this challenge, in this paper we first propose a novel diversity technology called \\emph{Multi-Channel Diversity} (MCD), allowing each secondary node to use multiple channels simultaneously with only one radio per node under the upperbounded power. Using the proposed MCD, we develop a MCD based MAC (MCD-MAC) protocol, which can efficiently utilize available channel resources through joint power-channel allocation. Particularly, we convert the joint power-channel allocation to the Multiple-Choice Knapsack Problem, such that we can obtain the optimal transmission strategy to maximize the network throughput through dynamic programming. Simulation results show that our proposed MCD-MAC protocol can significantly increase the network throughput as compared to...

  8. 78 FR 2879 - Federal Agricultural Mortgage Corporation Funding and Fiscal Affairs; Farmer Mac Investment...

    Science.gov (United States)

    2013-01-15

    ..., 2012 (77 FR 66375) is effective December 31, 2012. FOR FURTHER INFORMATION CONTACT: Joseph T. Connor... 3052-AC56 Federal Agricultural Mortgage Corporation Funding and Fiscal Affairs; Farmer Mac...

  9. AN EFFICIENT MAC PROTOCOL BASED ON HYBRID SUPERFRAME FOR WIRELESS SENSOR NETWORKS

    Directory of Open Access Journals (Sweden)

    Ge Ma

    2009-07-01

    Full Text Available Designing low energy consumption, high efficiency Media Access Control (MAC protocols are one ofthe most important directions in wireless sensor networks (WSN. In this paper, we proposed a newcontention reserve MAC protocol, named CRMAC, under the inspiration of IEEE 802.15.4’s superframestructure. CRMAC is a MAC protocol suitable for intra-cluster WSN that combines the advantages ofcontention and schedule-based MAC protocols. We introduce the mechanism and superframe structure ofCRMAC in detail and verified the performance of this protocol through simulations. Our results showthat CRMAC performs better than IEEE 802.15.4 in energy consumption, system delay and networkthroughput. CRMAC is especially suitable for short packet transmission under low load networks, whichis the main situation in WSN.

  10. Experimental Evaluation of Simulation Abstractions for Wireless Sensor Network MAC Protocols

    Directory of Open Access Journals (Sweden)

    G. P. Halkes

    2010-01-01

    Full Text Available The evaluation of MAC protocols for Wireless Sensor Networks (WSNs is often performed through simulation. These simulations necessarily abstract away from reality in many ways. However, the impact of these abstractions on the results of the simulations has received only limited attention. Moreover, many studies on the accuracy of simulation have studied either the physical layer and per link effects or routing protocol effects. To the best of our knowledge, no other work has focused on the study of the simulation abstractions with respect to MAC protocol performance. In this paper, we present the results of an experimental study of two often used abstractions in the simulation of WSN MAC protocols. We show that a simple SNR-based reception model can provide quite accurate results for metrics commonly used to evaluate MAC protocols. Furthermore, we provide an analysis of what the main sources of deviation are and thereby how the simulations can be improved to provide even better results.

  11. Mac-2 binding protein is a novel E-selectin ligand expressed by breast cancer cells.

    Science.gov (United States)

    Shirure, Venktesh S; Reynolds, Nathan M; Burdick, Monica M

    2012-01-01

    Hematogenous metastasis involves the adhesion of circulating tumor cells to vascular endothelium of the secondary site. We hypothesized that breast cancer cell adhesion is mediated by interaction of endothelial E-selectin with its glycoprotein counter-receptor(s) expressed on breast cancer cells. At a hematogenous wall shear rate, ZR-75-1 breast cancer cells specifically adhered to E-selectin expressing human umbilical vein endothelial cells when tested in parallel plate flow chamber adhesion assays. Consistent with their E-selectin ligand activity, ZR-75-1 cells expressed flow cytometrically detectable epitopes of HECA-452 mAb, which recognizes high efficiency E-selectin ligands typified by sialofucosylated moieties. Multiple E-selectin reactive proteins expressed by ZR-75-1 cells were revealed by immunoprecipitation with E-selectin chimera (E-Ig chimera) followed by Western blotting. Mass spectrometry analysis of the 72 kDa protein, which exhibited the most prominent E-selectin ligand activity, corresponded to Mac-2 binding protein (Mac-2BP), a heretofore unidentified E-selectin ligand. Immunoprecipitated Mac-2BP expressed sialofucosylated epitopes and possessed E-selectin ligand activity when tested by Western blot analysis using HECA-452 mAb and E-Ig chimera, respectively, demonstrating that Mac-2BP is a novel high efficiency E-selectin ligand. Furthermore, silencing the expression of Mac-2BP from ZR-75-1 cells by shRNA markedly reduced their adhesion to E-selectin expressing cells under physiological flow conditions, confirming the functional E-selectin ligand activity of Mac-2BP on intact cells. In addition to ZR-75-1 cells, several other E-selectin ligand positive breast cancer cell lines expressed Mac-2BP as detected by Western blot and flow cytometry, suggesting that Mac-2BP may be an E-selectin ligand in a variety of breast cancer types. Further, invasive breast carcinoma tissue showed co-localized expression of Mac-2BP and HECA-452 antigens by

  12. Achievable rates for transmission of discrete constellations over the Gaussian MAC channe

    CERN Document Server

    Ghaffar, Rizwan; Lee, Jungwon

    2011-01-01

    In this paper we consider the achievable rate region of the Gaussian Multiple Access Channel (MAC) when suboptimal transmission schemes are employed. Focusing on the two-user MAC and assuming uncoded Pulse Amplitude Modulation (PAM), we derive a rate region that is a pentagon, and propose a strategy with which it can be achieved. We also compare the region with outer bounds and with orthogonal transmission.

  13. Performance evaluation of MAC transmission power control in wireless sensor networks.

    OpenAIRE

    Egea López, Estebán

    2007-01-01

    In this paper we provide a method to analytically compute the energy saving provided by the use of Transmission Power Control (TPC) at the MAC layer in Wireless Sensor Networks (WSN). We consider a classical TPC mechanism: data packets are transmitted with the minimum required power to achieve a given packet error probability, whereas the additional MAC control packets are transmitted with the nominal (maximum) power. This scheme has been chosen because it does not modify the network to...

  14. John MacCulloch, MD (1773-1835): a dedicated geologist.

    Science.gov (United States)

    Hull, Gillian

    2007-11-01

    The teaching in Scottish medical schools in the second half of the 18th century had a reputation that stretched far beyond Britain. Edinburgh attracted students not only for its high academic standards but also for its freedom from religious constraints and its developing interest in the sciences. John MacCulloch was taught at Edinburgh by Joseph Black (1728-99) who had chosen chemistry as a career rather than medicine. Already MacCulloch's enquiring mind ranged over many subjects.

  15. TraPy-MAC: Traffic Priority Aware Medium Access Control Protocol for Wireless Body Area Network.

    Science.gov (United States)

    Ullah, Fasee; Abdullah, Abdul Hanan; Kaiwartya, Omprakash; Cao, Yue

    2017-06-01

    Recently, Wireless Body Area Network (WBAN) has witnessed significant attentions in research and product development due to the growing number of sensor-based applications in healthcare domain. Design of efficient and effective Medium Access Control (MAC) protocol is one of the fundamental research themes in WBAN. Static on-demand slot allocation to patient data is the main approach adopted in the design of MAC protocol in literature, without considering the type of patient data specifically the level of severity on patient data. This leads to the degradation of the performance of MAC protocols considering effectiveness and traffic adjustability in realistic medical environments. In this context, this paper proposes a Traffic Priority-Aware MAC (TraPy-MAC) protocol for WBAN. It classifies patient data into emergency and non-emergency categories based on the severity of patient data. The threshold value aided classification considers a number of parameters including type of sensor, body placement location, and data transmission time for allocating dedicated slots patient data. Emergency data are not required to carry out contention and slots are allocated by giving the due importance to threshold value of vital sign data. The contention for slots is made efficient in case of non-emergency data considering threshold value in slot allocation. Moreover, the slot allocation to emergency and non-emergency data are performed parallel resulting in performance gain in channel assignment. Two algorithms namely, Detection of Severity on Vital Sign data (DSVS), and ETS Slots allocation based on the Severity on Vital Sign (ETS-SVS) are developed for calculating threshold value and resolving the conflicts of channel assignment, respectively. Simulations are performed in ns2 and results are compared with the state-of-the-art MAC techniques. Analysis of results attests the benefit of TraPy-MAC in comparison with the state-of-the-art MAC in channel assignment in realistic medical

  16. FPGA IMPLEMENTATION OF MAC HEADER BLOCK OF TRANSMITTER FOR Wi-Fi

    Directory of Open Access Journals (Sweden)

    A.M.BHAVIKATTI,

    2011-04-01

    Full Text Available For the wireless communication, IEEE 802.11 is one of the protocols available. The IEEE 802.11b uses the medium access control layer (MAC for wireless local area network. These wireless local area networks use Carrier Sense multiple access with collision avoidance (CSMA/CS for the MAC layer .But only the MAC layer for transmitter is considered here for simulation. So, the Wi-Fi transmitter module is divided into 5 blocks i.e. Data Unit Interface block, Controller block, Pay Load Data Storage, MAC Header Register block and Data Processing block. In this paper we consider only the simulation of MAC header register blocks. So, other blocks i.e. Data unit interface block, Controller block, pay load Data Storage block & Data Processing block are not discussed further in this paper. A field programmable gate array (FPGA device has been used as the hardware implementation platform. The proposed MAC-layer hardware is implemented with Xilinx xcv300e Virtex E FPGA.

  17. FPGA IMPLEMENTATION OF MAC HEADER BLOCK OF TRANSMITTER FOR Wi-Fi

    Directory of Open Access Journals (Sweden)

    A.M.BHAVIKATTI,

    2011-04-01

    Full Text Available For the wireless communication, IEEE 802.11 is one of the protocols available. The IEEE 802.11b uses the medium access control layer (MAC for wireless local area network. These wireless local area networks use Carrier Sense multiple access with collision avoidance (CSMA/CS for the MAC layer .But only the MAC layer for transmitter is considered here for simulation. So, the Wi-Fi transmitter module is divided into 5 blocks i.e. Data Unit Interface block, Controller block, Pay Load Data Storage, MAC Header Register block and Data Processing block. In this paper we consider only the simulation of MAC header register blocks. So, other blocks i.e. Data unit interface block, Controller block, pay load Data Storage block & Data Processing block are not discussed further in this paper. A field programmable gate array (FPGA device has been used as the hardware implementation platform. The proposed MAC-layer hardware is implemented with Xilinx xcv300e Virtex E FPGA

  18. Performance of a Wireless Sensor Network MAC Protocol with a Variable Sleep Interval

    Directory of Open Access Journals (Sweden)

    M.K. Kirubakaran

    2014-02-01

    Full Text Available A MAC protocol specifies how nodes in a sensor network access a shared communication channel. Medium access control protocols for wireless sensor networks are almost always designed to be energy efficient. Desired properties of such MAC protocol are: it should be distributed and contention-free. This study addresses low power MAC protocols utilize energy in efficient manner in wireless sensor networks. We are interested in the trade-off between power consumption and transmission delay, focusing on low traffic in EM-MAC. In EM-MAC, a significant proportion of the nodes may have to stay awake much longer than envisaged. We describe RRMAC protocol (Receiver-Reservation MAC protocol, a new protocol for the Collision avoidance and energy loss due to retransmissions and increase the life span of a wireless sensor networks. This study concludes with the result of simulation studies which indicate that the use of the proposed RRMAC protocol is expected to increase the life time of wireless sensor networks significantly.

  19. HARVESTED ENERGY-ADAPTIVE MAC PROTOCOL FOR ENERGY HARVESTING IOT NETWORKS

    Directory of Open Access Journals (Sweden)

    Hyeong-Kyu Lee

    2015-12-01

    Full Text Available In energy harvesting IoT networks, an energy queue state of an IoT device will change dynamically and the number of IoT devices that transmit data to the IoT AP will vary in a frame. So we need a MAC protocol to adjust the frame length taking the amount of energy of IoT devices into consideration. Since the existing Framed slotted ALOHA (F-ALOHA Medium Access Control (MAC protocol utilizes the fixed frame size, the resource efficiency can be reduced. In this paper, we propose a Harvested Energy-adaptive Medium Access Control (HEMAC protocol where an IoT Access Point (AP allocates slots in accordance with the number of IoT devices that try to transmit data in a frame. The proposed HE-MAC protocol improves the resource efficiency of the F-ALOHA MAC protocol. We show that the resource efficiency of the HE-MAC protocol is superior to those of the F-ALOHA MAC protocol through simulations.

  20. An Analysis on Decentralized Adaptive MAC Protocols for Cognitive Radio Networks

    Institute of Scientific and Technical Information of China (English)

    Munam Ali Shah; Sijing Zhang; Carsten Maple

    2013-01-01

    The scarcity of bandwidth in the radio spectrum has become more vital since the demand for more and more wireless applications has increased.Most of the spectrum bands have been allocated although many studies have shown that these bands are significantly underutilized most of the time.The problem of unavailability of spectrum and inefficiency in its utilization has been smartly addressed by the cognitive radio (CR) technology which is an opportunistic network that senses the environment,observes the network changes,and then uses knowledge gained from the prior interaction with the network to make intelligent decisions by dynamically adapting their transmission characteristics.In this paper,some of the decentralized adaptive medium access control (MAC) protocols for CR networks have been critically analyzed,and a novel adaptive MAC protocol for CR networks,decentralized non-global MAC (DNG-MAC),has been proposed.The results show the DNG-MAC outperforms other CR-MAC protocols in termsof time and energy efficiency.

  1. Federal Lands

    Data.gov (United States)

    Department of Homeland Security — This map layer consists of federally owned or administered lands of theUnited States, Puerto Rico, and the U.S. Virgin Islands. Only areas of 640 acres or more are...

  2. Land Resources

    Science.gov (United States)

    Young, Anthony

    1998-08-01

    Unless action is taken, the developing world will face recurrent problems of food security and conflict. This volume provides a summary and perspective of the field of land resources and suggests improvements needed to conserve resources for future generations. Coverage provides an authoritative review of the resources of soils, water, climate, forests and pastures on which agriculture depends. It assesses the interactions between land resources and wider aspects of development, including population and poverty. It provides a strong critique of current methods of assessing land degradation and placing an economic value on land. It should be read by all involved in rural development, including scientists, economists, geographers, sociologists, planners, and students of development studies.

  3. Research on MAC Protocol Simulation Analysis of Underwater Acoustic Communication%水声通信环境下MAC协议仿真分析研究

    Institute of Scientific and Technical Information of China (English)

    张文健; 王美茜; 刘旻; 刘广钟

    2015-01-01

    Deployed underwater sensor nodes can be promptly transferred the data to the land,to achieve accurate,real-time,continuous space and time underwater surveillance. In order to implement the stable communication between nodes deployed underwater and land, need to solve a series of problems. According to the characteristics of underwater sensor networks,describe the principle and basic idea of RC-MAC protocol with the receiver as the center,and the underwater simulation scene is built on the network simulation platform for the specialty of underwater environment. Simulate RC-MAC protocol,analyze and compare the throughput and energy consumption of RC-MAC protocol in diverse underwater scene. The results show that the throughput of the channel is better when the RC-MAC protocol has small number of nodes with relatively broad distribution,when the nodes distribution is shallow,the number of nodes is less than 4,saving better.%部署在水下的传感器节点可以将数据及时传送到陆地,来实现精确的、实时的、时间空间连续的水下监视。为了实现部署在水下的节点与陆地实现稳定通信,需要解决一系列问题。针对水下传感器网络的特性,首先阐述了以接收者为中心的RC-MAC协议的原理以及基本思想,并在网络仿真平台上针对水声环境特殊性搭建了水下仿真场景,对RC-MAC协议进行模拟仿真,分析比较在各种不同水声场景中RC-MAC协议的吞吐量、能量消耗等数据。通过仿真实验发现,RC-MAC协议在水下节点数量比较少、节点分布范围比较广时信道的吞吐量更高,节点分布较浅、数量小于4时节点节能效果较好。

  4. Use of MAC-ELISA for evaluation of yellow fever vaccination Uso do MAC-ELISA para avaliação de vacinados contra febre amarela

    Directory of Open Access Journals (Sweden)

    Rita M. Ribeiro Nogueira

    1992-10-01

    Full Text Available An evaluation of the IgM antibody immune response against yellow fever using strain 17D was carried out by MAC-ELISA and PRNT. The results showed an agreement of 97% between both tests and the authors conclude that MAC-ELISA can be used as a specific and sensitive asssay to replace the PRNT for detecting yellow fever antibodies in human sera, after vaccination programs.Foi avaliada a resposta imune de anticorpos IgM em vacinados contra febre amarela usando a amostra 17D empregando-se provas de captura de anticorpos IgM (MAC-ELISA e teste de neutralização por redução de placas (PRNT. Os resulta-dos mostraram uma concordância de 97% entre ambas as provas e os autores concluem que o MAC-ELISA pode ser utilizado como um método específico e sensível para substituir o teste de neutralização para detecção de anticorpos IgM em vacinados contra febre amarela.

  5. On Proper Selection of Multihop Relays for Future Enhancement of AeroMACS Networks

    Science.gov (United States)

    Kamali, Behnam; Kerczewski, Robert J.; Apaza, Rafael D.

    2015-01-01

    As the Aeronautical Mobile Airport Communications System (AeroMACS) has evolved from a technology concept to a deployed communications network over major US airports, it is now time to contemplate whether the existing capacity of AeroMACS is sufficient to meet the demands set forth by all fixed and mobile applications over the airport surface given the AeroMACS constraints regarding bandwidth and transmit power. The underlying idea in this article is to present IEEE 802.16j-based WiMAX as a technology that can address future capacity enhancements and therefore is most feasible for AeroMACS applications. The principal argument in favor IEEE 802.16j technology is the flexible and cost effective extension of radio coverage that is afforded by relay fortified networks, with virtually no increase in the power requirements and virtually no rise in interference levels to co-allocated applications. The IEEE 802.16j-based multihop relay systems are briefly described. The focus is on key features of this technology, frame structure, and its architecture. Next, AeroMACS is described as a WiMAX-based wireless network. The two major relay modes supported by IEEE 802.16j amendment, i.e., transparent and non-transparent are described. The benefits of employing multihop relays are listed. Some key challenges related to incorporating relays into AeroMACS networks are discussed. The selection of relay type in a broadband wireless network affects a number of network parameters such as latency, signal overhead, PHY (Scalable Physical Layer) and MAC (Media Access Layer) layer protocols, consequently it can alter key network quantities of throughput and QoS (Quality of Service).

  6. Characterization of the murine myeloid precursor cell line MuMac-E8.

    Science.gov (United States)

    Fricke, Stephan; Pfefferkorn, Cathleen; Wolf, Doris; Riemschneider, Sina; Kohlschmidt, Janine; Hilger, Nadja; Fueldner, Christiane; Knauer, Jens; Sack, Ulrich; Emmrich, Frank; Lehmann, Jörg

    2014-01-01

    Starting point for the present work was the assumption that the cell line MuMac-E8 represents a murine cell population with stem cell properties. Preliminary studies already pointed to the expression of stem-cell associated markers and a self-regenerative potential of the cells. The cell line MuMac-E8 should be examined for their differential stage within stem cell hierarchy. MuMac-E8 cells were derived from a chimeric mouse model of arthritis. It could be shown that MuMac-E8 cells express mRNA of some genes associated with pluripotent stem cells (Nanog, Nucleostemin), of genes for hematopoietic markers (EPCR, Sca-1, CD11b, CD45), for the mesenchymal marker CD105 and of genes for the neural markers Pax-6 and Ezrin. In methylcellulose and May-Grünwald-Giemsa staining, hematopoietic colonies were obtained but the hematopoietic system of lethally irradiated mice could not be rescued. Osteogenic differentiation was not detectable. Thus, it became evident that MuMac-E8 represents not a stem cell line. However, MuMac-E8 cells expressed several myeloid surface markers (i.e. CD11b, F4/80, CD14, CD64), showed phagocytosis and is capable of producing nitric oxide. Thus, this cell line seems to be arrested an advanced stage of myeloid differentiation. Adherence data measured by impedance-based real-time cell analysis together with cell morphology data suggested that MuMac-E8 represents a new macrophage precursor cell line exhibiting weak adherence. This cell line is suitable as an in-vitro model for testing of macrophage functions. Moreover, it might be also useful for differentiation or reprogramming studies.

  7. Characterization of the murine myeloid precursor cell line MuMac-E8.

    Directory of Open Access Journals (Sweden)

    Stephan Fricke

    Full Text Available Starting point for the present work was the assumption that the cell line MuMac-E8 represents a murine cell population with stem cell properties. Preliminary studies already pointed to the expression of stem-cell associated markers and a self-regenerative potential of the cells. The cell line MuMac-E8 should be examined for their differential stage within stem cell hierarchy. MuMac-E8 cells were derived from a chimeric mouse model of arthritis. It could be shown that MuMac-E8 cells express mRNA of some genes associated with pluripotent stem cells (Nanog, Nucleostemin, of genes for hematopoietic markers (EPCR, Sca-1, CD11b, CD45, for the mesenchymal marker CD105 and of genes for the neural markers Pax-6 and Ezrin. In methylcellulose and May-Grünwald-Giemsa staining, hematopoietic colonies were obtained but the hematopoietic system of lethally irradiated mice could not be rescued. Osteogenic differentiation was not detectable. Thus, it became evident that MuMac-E8 represents not a stem cell line. However, MuMac-E8 cells expressed several myeloid surface markers (i.e. CD11b, F4/80, CD14, CD64, showed phagocytosis and is capable of producing nitric oxide. Thus, this cell line seems to be arrested an advanced stage of myeloid differentiation. Adherence data measured by impedance-based real-time cell analysis together with cell morphology data suggested that MuMac-E8 represents a new macrophage precursor cell line exhibiting weak adherence. This cell line is suitable as an in-vitro model for testing of macrophage functions. Moreover, it might be also useful for differentiation or reprogramming studies.

  8. An energy-efficient MAC protocol using dynamic queue management for delay-tolerant mobile sensor networks.

    Science.gov (United States)

    Li, Jie; Li, Qiyue; Qu, Yugui; Zhao, Baohua

    2011-01-01

    Conventional MAC protocols for wireless sensor network perform poorly when faced with a delay-tolerant mobile network environment. Characterized by a highly dynamic and sparse topology, poor network connectivity as well as data delay-tolerance, delay-tolerant mobile sensor networks exacerbate the severe power constraints and memory limitations of nodes. This paper proposes an energy-efficient MAC protocol using dynamic queue management (EQ-MAC) for power saving and data queue management. Via data transfers initiated by the target sink and the use of a dynamic queue management strategy based on priority, EQ-MAC effectively avoids untargeted transfers, increases the chance of successful data transmission, and makes useful data reach the target terminal in a timely manner. Experimental results show that EQ-MAC has high energy efficiency in comparison with a conventional MAC protocol. It also achieves a 46% decrease in packet drop probability, 79% increase in system throughput, and 25% decrease in mean packet delay.

  9. 42 CFR 405.1104 - Request for MAC review when an ALJ does not issue a decision timely.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Request for MAC review when an ALJ does not issue a...) Medicare Appeals Council Review § 405.1104 Request for MAC review when an ALJ does not issue a decision... under § 405.1016 may request MAC review if— (1) The appellant files a written request with the ALJ to...

  10. Eliminating the Heart from the Curcumin Molecule: Monocarbonyl Curcumin Mimics (MACs

    Directory of Open Access Journals (Sweden)

    Dinesh Shetty

    2014-12-01

    Full Text Available Curcumin is a natural product with several thousand years of heritage. Its traditional Asian application to human ailments has been subjected in recent decades to worldwide pharmacological, biochemical and clinical investigations. Curcumin’s Achilles heel lies in its poor aqueous solubility and rapid degradation at pH ~ 7.4. Researchers have sought to unlock curcumin’s assets by chemical manipulation. One class of molecules under scrutiny are the monocarbonyl analogs of curcumin (MACs. A thousand plus such agents have been created and tested primarily against cancer and inflammation. The outcome is clear. In vitro, MACs furnish a 10–20 fold potency gain vs. curcumin for numerous cancer cell lines and cellular proteins. Similarly, MACs have successfully demonstrated better pharmacokinetic (PK profiles in mice and greater tumor regression in cancer xenografts in vivo than curcumin. The compounds reveal limited toxicity as measured by murine weight gain and histopathological assessment. To our knowledge, MAC members have not yet been monitored in larger animals or humans. However, Phase 1 clinical trials are certainly on the horizon. The present review focuses on the large and evolving body of work in cancer and inflammation, but also covers MAC structural diversity and early discovery for treatment of bacteria, tuberculosis, Alzheimer’s disease and malaria.

  11. Cooperative Defense Against Pollution Attacks in Network Coding Using SpaceMac

    CERN Document Server

    Le, Anh

    2011-01-01

    Intra-session network coding is known to be vulnerable to pollution attacks. In this work, first, we introduce a novel homomorphic MAC scheme called SpaceMac, which allows an intermediate node to verify if its received packets belong to a specific subspace, even if the subspace is expanding over time. Then, we use SpaceMac as a building block to design a cooperative scheme that provides complete defense against pollution attacks: (i) it can detect polluted packets early at intermediate nodes and (ii) it can identify the exact location of all, even colluding, attackers, thus making it possible to eliminate them. Our scheme is cooperative: parents and children of any node cooperate to detect any corrupted packets sent by the node, and nodes in the network cooperate with a central controller to identify the exact location of all attackers. We implement SpaceMac in both C/C++ and Java as a library, and we make the library available online. Our evaluation on both a PC and an Android device shows that (i) SpaceMac'...

  12. Silicon Nanostructures Produced by Modified MacEtch Method for Antireflective Si Surface.

    Science.gov (United States)

    Nichkalo, Stepan; Druzhinin, Anatoly; Evtukh, Anatoliy; Bratus', Oleg; Steblova, Olga

    2017-12-01

    This work pertains to the method for modification of silicon (Si) wafer morphology by metal-assisted chemical etching (MacEtch) technique suitable for fabrication of antireflective Si surfaces. For this purpose, we made different Au catalyst patterns on the surface of Si substrate. This modification allowed to obtain the close-packed Au nanodrop (ND) pattern that generates the nanowires (NWs) and the well-separated Au NDs, which induce the nanopore (NP) formation. The antireflective properties of these structures in comparison with NWs produced by the conventional Ag-MacEtch method were analysed. The total surface reflectance of 1~7% for SiNWs and ~17% for SiNPs was observed over the entire Si-absorbing region. Moreover, SiNWs prepared by Au-MacEtch demonstrate better antireflective properties in contrast to those formed by conventional Ag-assisted chemical etching. So, the use of SiNWs produced by the modified Au-MacEtch method as the antireflective material is favored over those prepared by Ag-MacEtch due to their higher light absorption and lower reflectance. The possible reason of these findings is discussed.

  13. Halothane concentrations required to block the cardiovascular responses to incision (MAC CVR) in infants and children.

    Science.gov (United States)

    Ishizawa, Y; Dohi, S

    1993-01-01

    The purpose of this study was to determine the halothane concentration in N2O required to block the cardiovascular responses to skin incision (MAC CVR) in infants and children. We studied 64 unpremedicated ASA 1 infants and children (one month to seven years). In each infant or child, anaesthesia was induced slowly with halothane and N2O, and an endotracheal tube was placed. The MAC CVR was assessed, after a steady state end-tidal halothane concentration had been established for ten minutes, by the "up and down technique" of Dixon. Positive responses were defined as an increase in MAP or HR > 10%. The MAC CVR50 values of halothane with 60% N2O were 1.16 +/- 0.23% at 1-6 mo, 1.17 +/- 0.18% at 7-12 mo, 0.95 +/- 0.26% at 1-3 yr, and 1.12 +/- 0.16% at 4-7 yr. The value at 1-3 years children was less than those in the other age groups (P values of MAC CVR50 of halothane in infants and children are higher than those required to block motor responses (MAC). The halothane requirement to block cardiovascular responses is lowest in the children aged one to three years.

  14. Efficient MAC Protocol for Hybrid Wireless Network with Heterogeneous Sensor Nodes

    Directory of Open Access Journals (Sweden)

    Md. Nasre Alam

    2016-01-01

    Full Text Available Although several Directional Medium Access Control (DMAC protocols have been designed for use with homogeneous networks, it can take a substantial amount of time to change sensor nodes that are equipped with an omnidirectional antenna for sensor nodes with a directional antenna. Thus, we require a novel MAC protocol for use with an intermediate wireless network that consists of heterogeneous sensor nodes equipped with either an omnidirectional antenna or a directional antenna. The MAC protocols that have been designed for use in homogeneous networks are not suitable for use in a hybrid network due to deaf, hidden, and exposed nodes. Therefore, we propose a MAC protocol that exploits the characteristics of a directional antenna and can also work efficiently with omnidirectional nodes in a hybrid network. In order to address the deaf, hidden, and exposed node problems, we define RTS/CTS for the neighbor (RTSN/CTSN and Neighbor Information (NIP packets. The performance of the proposed MAC protocol is evaluated through a numerical analysis using a Markov model. In addition, the analytical results of the MAC protocol are verified through an OPNET simulation.

  15. A macrophage activation switch (MAcS)-index for assessment of monocyte/macrophage activation

    DEFF Research Database (Denmark)

    Maniecki, Maciej Bogdan; Lauridsen, Mette; Knudsen, Troels Bygum

    2008-01-01

    of inflammatory markers (IL-1β, IL-6, IL-8, IL-10, and TNF-α) was determined by RT-qPCR. Normalized values of sCD163 and mCD163 were calculated by dividing each value by the median value of the healthy population. The MAcS-index was then calculated as the ratio between normalized sCD163 and normalized mCD163....... A MAcS-index > 1 indicates relative increase in sCD163 as compared to mCD163, suggested to reflect a predominant M1 activation.   RESULTS AND DISCUSSION: The MAcS-index of healthy individuals clustered around 1 (2.5-97.5 percentile: 0.28-3.11), whereas the MAcS-index of the patients varied from 0.......06 to 5139, with 4% below the 2.5 % limit of healthy individuals, and 60% above the 97.5 upper limit of healthy individuals.  The MAcS-index in infected patients (with assumed M1 activation) was clearly elevated. The index was significantly higher in patients with clinical signs of infection (median: 9...

  16. MAP, MAC, and vortex-rings configurations in the Weinberg-Salam model

    Science.gov (United States)

    Teh, Rosy; Ng, Ban-Loong; Wong, Khai-Ming

    2015-11-01

    We report on the presence of new axially symmetric monopoles, antimonopoles and vortex-rings solutions of the SU(2)×U(1) Weinberg-Salam model of electromagnetic and weak interactions. When the ϕ-winding number n = 1, and 2, the configurations are monopole-antimonopole pair (MAP) and monopole-antimonopole chain (MAC) with poles of alternating sign magnetic charge arranged along the z-axis. Vortex-rings start to appear from the MAP and MAC configurations when the winding number n = 3. The MAP configurations possess zero net magnetic charge whereas the MAC configurations possess net magnetic charge of 4 πn / e. In the MAP configurations, the monopole-antimonopole pair is bounded by the Z0 field flux string and there is an electromagnetic current loop encircling it. The monopole and antimonopole possess magnetic charges ± 4πn/e sin2θW respectively. In the MAC configurations there is no string connecting the monopole and the adjacent antimonopole and they possess magnetic charges ± 4 πn/e respectively. The MAC configurations possess infinite total energy and zero magnetic dipole moment whereas the MAP configurations which are actually sphalerons possess finite total energy and magnetic dipole moment. The configurations were investigated for varying values of Higgs self-coupling constant 0 ≤ λ ≤ 40 at Weinberg angle θW = π/4.

  17. A network architecture for precision formation flying using the IEEE 802.11 MAC Protocol

    Science.gov (United States)

    Clare, Loren P.; Gao, Jay L.; Jennings, Esther H.; Okino, Clayton

    2005-01-01

    Precision Formation Flying missions involve the tracking and maintenance of spacecraft in a desired geometric formation. The strong coupling of spacecraft in formation flying control requires inter-spacecraft communication to exchange information. In this paper, we present a network architecture that supports PFF control, from the initial random deployment phase to the final formation. We show that a suitable MAC layer for the application protocol is IEEE's 802.11 MAC protocol. IEEE 802.11 MAC has two modes of operations: DCF and PCF. We show that DCF is suitable for the initial deployment phase while switching to PCF when the spacecraft are in formation improves jitter and throughput. We also consider the effect of routing on protocol performance and suggest when it is profitable to turn off route discovery to achieve better network performance.

  18. MAC-layer protocol for TCP fairness in Wireless Mesh Networks

    KAUST Repository

    Nawab, Faisal

    2012-08-01

    In this paper we study the interactions of TCP and IEEE 802.11 MAC in Wireless Mesh Networks (WMNs). We use a Markov chain to capture the behavior of TCP sessions, particularly the impact on network throughput performance due to the effect of queue utilization and packet relaying. A closed form solution is derived to numerically determine the throughput. Based on the developed model, we propose a distributed MAC protocol to alleviate the unfairness problem in WMNs. Our protocol uses the age of packet as a priority metric for packet scheduling. Simulation is conducted to validate our model and to illustrate the fairness characteristics of our proposed MAC protocol. We conclude that we can achieve fairness with only little impact on network capacity.

  19. RMAC: A Reliable MAC Protocol Supporting Multicast for Wireless Ad Hoc Networks

    Institute of Scientific and Technical Information of China (English)

    Wei-Sheng Si; Cheng-Zhi Li

    2005-01-01

    This paper presents a new reliable MAC protocol called "RMAC" supporting reliable multicast for wireless ad hoc networks. By utilizing the busy tones to realize the multicast reliability, RMAC has three novelties: (1) it uses a variablelength control frame to stipulate an order for the receivers to respond, thus solving the feedback collision problem; (2) it extends the usage of busy tone for preventing data frame collisions into the multicast scenario; and (3) it introduces a new usage of busy tone for acknowledging data frames positively. In addition, RMAC is generalized into a comprehensive MAC protocol that provides both reliable and unreliable services for all the three modes of communications: unicast, multicast,and broadcast, making it capable of supporting various upper-layer protocols. The evaluation shows that RMAC achieves high reliability with very limited overhead. RMAC is also compared with other reliable MAC protocols, showing that RMAC not only provides higher reliability but also involves lower cost.

  20. The international epidemiology of disseminated Mycobacterium avium complex infection in AIDS. International MAC Study Group.

    Science.gov (United States)

    Fordham von Reyn, C; Arbeit, R D; Tosteson, A N; Ristola, M A; Barber, T W; Waddell, R; Sox, C H; Brindle, R J; Gilks, C F; Ranki, A; Bartholomew, C; Edwards, J; Falkinham, J O; O'Connor, G T

    1996-08-01

    To determine rates of disseminated Mycobacterium avium complex (MAC) infection among AIDS patients in developed and developing countries, and to determine whether different rates reflect differences in exposure or immunity, or both. Prospective cohort study. University hospitals and outpatient AIDS programs. HIV-infected subjects with CD4 counts or = 5 mm were present in 20% of patients from Kenya compared to 1% at other sites (P swimming in an indoor pool, history of bronchoscopy, regular consumption of raw or partially cooked fish/shellfish and treatment with granulocyte colony-stimulating factor. Rates of disseminated MAC in AIDS are higher in developed than developing countries and are due to both differences in exposure and differences in immunity. These data provide a rationale for prevention of MAC through both active immunization and reduction in exposure to the organism.

  1. Performance evaluation of IEEE 802.11 MAC layer in supporting delay sensitive services

    Directory of Open Access Journals (Sweden)

    Jyotsna Sengupta

    2010-02-01

    Full Text Available Providing QoS requirements like good throughput and minimum access delay are challenging tasks with regard to 802.11 WLAN protocols and Medium Access Control (MAC functions. IEEE 802.11 MAC layer supports two main protocols: DCF (Distributed Coordination Function and EDCF (Enhanced Distributed Coordination Function. During the evaluation of EDCF, the performance of various access categories was thedetermining factor. Two scenarios, with same Physical and MAC parameters, one implementing the DCF and other EDCF, were created in the network simulation tool (OPNET MODELER [5] to obtain the results. The results showed that the performance of EDCF was better in providing QoS for real-time interactive services (like video conferencing as compared to DCF, because of its ability to differentiate and prioritize various services. Whereas the DCF’s overall performance was marginally better for all kinds of services taken together.

  2. A MAC protocol for medical monitoring applications of wireless body area networks.

    Science.gov (United States)

    Shu, Minglei; Yuan, Dongfeng; Zhang, Chongqing; Wang, Yinglong; Chen, Changfang

    2015-06-03

    Targeting the medical monitoring applications of wireless body area networks (WBANs), a hybrid medium access control protocol using an interrupt mechanism (I-MAC) is proposed to improve the energy and time slot utilization efficiency and to meet the data delivery delay requirement at the same time. Unlike existing hybrid MAC protocols, a superframe structure with a longer length is adopted to avoid unnecessary beacons. The time slots are mostly allocated to nodes with periodic data sources. Short interruption slots are inserted into the superframe to convey the urgent data and to guarantee the real-time requirements of these data. During these interruption slots, the coordinator can break the running superframe and start a new superframe. A contention access period (CAP) is only activated when there are more data that need to be delivered. Experimental results show the effectiveness of the proposed MAC protocol in WBANs with low urgent traffic.

  3. An Approach to Analyze Physical Memory Image File of Mac OS X

    Institute of Scientific and Technical Information of China (English)

    LiJuan Xu; LianHai Wang

    2014-01-01

    Memory analysis is one of the key techniques in computer live forensics. Especially, the analysis of a Mac OS X operating system’ s memory image file plays an important role in identifying the running status of an apple computer. However, how to analyze the image file without using extra”mach-kernel” file is one of the unsolved difficulties. In this paper, we firstly compare several approaches for physical memory acquisition and analyze the effects of each approach on physical memory. Then, we discuss the traditional methods for the physical memory file analysis of Mac OS X. A novel physical memory image file analysis approach without using extra“mach-kernel” file is proposed base on the discussion. We verify the performance of the new approach on Mac OS X 10�8�2. The experimental results show that the proposed approach is simpler and more practical than previous ones.

  4. Optimization of listening time of S-MAC for wireless sensor networks

    Institute of Scientific and Technical Information of China (English)

    LI Cheng; WANG Kui-ru; ZHANG Jin-long; ZHAO De-xin; LI Wang

    2009-01-01

    In wireless sensor networks, sensor nodes are usually battery-operated computing and sensing devices, hence operations are limited by the initially equipped batteries, which are hard to be recharged or replaced. In this sense, saving energy consumption becomes significant. As most energy waste is from the always-on wireless interface, S-MAC is suggested to reduce energy consumption by introducing periodic listen/sleep scheme. However, when designing the listening time, S-MAC fails to consider the traffic distribution factor. In this article, an optimization for this scheme is proposed based on the distribution model. Evaluations show that the optimized S-MAC achieves considerable improvement in energy and latency.

  5. Optimal sensor placement for maximum area coverage (MAC) for damage localization in composite structures

    Science.gov (United States)

    Thiene, M.; Sharif Khodaei, Z.; Aliabadi, M. H.

    2016-09-01

    In this paper an optimal sensor placement algorithm for attaining the maximum area coverage (MAC) within a sensor network is presented. The proposed novel approach takes into account physical properties of Lamb wave propagation (attenuation profile, direction dependant group velocity due to material anisotropy) and geometrical complexities (boundary reflections, presence of openings) of the structure. A feature of the proposed optimization approach lies in the fact that it is independent of characteristics of the damage detection algorithm (e.g. probability of detection) making it readily up-scalable to large complex composite structures such as aircraft stiffened composite panel. The proposed fitness function (MAC) is independent of damage parameters (type, severity, location). Statistical analysis carried out shows that the proposed optimum sensor network with MAC results in high probability of damage localization. Genetic algorithm is coupled with the fitness function to provide an efficient optimization strategy.

  6. Learn Objective-C on the Mac for OS X and iOS

    CERN Document Server

    Knaster, Scott; Malik, Waqar

    2012-01-01

    Learn to write apps for some of today's hottest technologies, including the iPhone and iPad (using iOS), as well as the Mac (using OS X). It starts with Objective-C, the base language on which the native iOS software development kit (SDK) and the OS X are based. Learn Objective-C on the Mac: For OS X and iOS, Second Edition updates a best selling book and is an extensive, newly updated guide to Objective-C. Objective-C is a powerful, object-oriented extension of C, making this update the perfect follow-up to Dave Mark's bestselling Learn C on the Mac. Whether you're an experienced C programmer

  7. LFA-1 and Mac-1 integrins bind to the serine/threonine-rich domain of thrombomodulin

    Energy Technology Data Exchange (ETDEWEB)

    Kawamoto, Eiji [Department of Molecular Pathobiology and Cell Adhesion Biology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie 514-8507 (Japan); Emergency and Critical Care Center, Mie University Hospital, 2-174 Edobashi, Tsu 514-8507 (Japan); Okamoto, Takayuki, E-mail: okamotot@doc.medic.mie-u.ac.jp [Department of Molecular Pathobiology and Cell Adhesion Biology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie 514-8507 (Japan); Takagi, Yoshimi [Department of Molecular Pathobiology and Cell Adhesion Biology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie 514-8507 (Japan); Honda, Goichi [Medical Affairs Department, Asahi Kasei Pharma Corporation, 1-105 Kanda Jinbo-cho, Chiyoda-ku, Tokyo 101-8101 (Japan); Suzuki, Koji [Faculty of Pharmaceutical Science, Suzuka University of Medical Science, 3500-3, Minamitamagaki-cho, Suzuka, Mie 513-8679 (Japan); Imai, Hiroshi [Emergency and Critical Care Center, Mie University Hospital, 2-174 Edobashi, Tsu 514-8507 (Japan); Shimaoka, Motomu, E-mail: shimaoka@doc.medic.mie-u.ac.jp [Department of Molecular Pathobiology and Cell Adhesion Biology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie 514-8507 (Japan)

    2016-05-13

    LFA-1 (αLβ2) and Mac-1 (αMβ2) integrins regulate leukocyte trafficking in health and disease by binding primarily to IgSF ligand ICAM-1 and ICAM-2 on endothelial cells. Here we have shown that the anti-coagulant molecule thrombomodulin (TM), found on the surface of endothelial cells, functions as a potentially new ligand for leukocyte integrins. We generated a recombinant extracellular domain of human TM and Fc fusion protein (TM-domains 123-Fc), and showed that pheripheral blood mononuclear cells (PBMCs) bind to TM-domains 123-Fc dependent upon integrin activation. We then demonstrated that αL integrin-blocking mAb, αM integrin-blocking mAb, and β2 integrin-blocking mAb inhibited the binding of PBMCs to TM-domains 123-Fc. Furthermore, we show that the serine/threonine-rich domain (domain 3) of TM is required for the interaction with the LFA-1 (αLβ2) and Mac-1 (αMβ2) integrins to occur on PBMCs. These results demonstrate that the LFA-1 and Mac-1 integrins on leukocytes bind to TM, thereby establishing the molecular and structural basis underlying LFA-1 and Mac-1 integrin interaction with TM on endothelial cells. In fact, integrin-TM interactions might be involved in the dynamic regulation of leukocyte adhesion with endothelial cells. - Highlights: • LFA-1 and Mac-1 integrins bind to the anti-coagulant molecule thrombomodulin. • The serine/threonine-rich domain of thrombomodulin is essential to interact with the LFA-1 and Mac-1 integrins on PBMCs. • Integrin-TM interactions might be involved in the dynamic regulation of leukocyte adhesion with endothelial cells.

  8. Comparison of the C-MAC video laryngoscope with direct Macintosh laryngoscopy in the emergency department.

    Science.gov (United States)

    Vassiliadis, John; Tzannes, Alex; Hitos, Kerry; Brimble, Jessica; Fogg, Toby

    2015-04-01

    To investigate the first pass success rate, airway grade and complications in two tertiary EDs with the C-MAC video laryngoscope (VL), when compared with standard direct laryngoscopy (DL). This was a retrospective analysis of prospectively collected data entered into an airway registry database in the EDs of Royal North Shore and St George Hospitals (SGH) over a 30 month period. Doctors had the choice of using either DL using a Macintosh or Miller blade or a C-MAC VL for the intubation. Six hundred and nineteen consecutive patients were recruited. There was no statistical difference between VL and DL in grade of view obtained, P = 0.526. Chance of intubation success increased by more than threefold by using a C-MAC VL in the setting of a grade III/IV (total of 109) on DL (OR = 3.06; 95% CI: 1.52-6.17; P = 0.002). This is the first observational study of airway management comparing the C-MAC VL with DL blades in an Australian ED population. Our findings revealed that although the C-MAC VL overall did not provide an enhanced view of the larynx over the Macintosh DL, it was superior to DL when the grade was at least grade III. Currently we are unable to reliably predict the grade by any algorithm prior to intubation. Findings from this study suggest that the C-MAC VL should be considered as the first line laryngoscope in all ED intubations not just the ones predicted to be difficult. © 2015 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

  9. GlideScope vs. C-MAC for Awake Upright Laryngoscopy.

    Science.gov (United States)

    Drenguis, Andrea Skye; Carlson, Jestin N

    2015-09-01

    Combining video laryngoscopy with awake upright intubation may provide an alternative modality of endotracheal intubation (ETI) that avoids pitfalls associated with traditional ETI. We compared laryngoscopic views and time intervals between the GlideScope (GVL) and C-MAC video laryngoscopes using a face-to-face technique in awake, upright volunteers. We performed a prospective, randomized, crossover study performing awake upright laryngoscopy on healthy volunteers. Under local anesthesia, participants had awake upright laryngoscopy performed by a resident and attending physician, both operating GVL and C-MAC in random order. We recorded times to first view of the glottis and best view of the glottis, percentage of glottic opening (POGO) score, Cormack-Lehane grade, and number of attempts needed to visualize the glottis. We enrolled 26 subjects, 10 male and 16 female (mean age of 31.9 years). GVL had shorter time to first view of the glottis than the CMAC (median 7 s; interquartile range [IQR]: 6.5-18 s vs. 9 s; IQR: 8-13; p = 0.005). However, time to best view of the glottis was similar between devices (GVL 10.25 s; IQR: 8.5-15 s; CMAC 13 s; IQR: 10-16 s; p = 0.238). GVL had higher POGO median scores (61.25; IQR: 45.5-87.5) compared to C-MAC (5; IQR: 2.5-20.5) (p MAC (median 2 views; IQR: 2-3 views; p = 0.001). Number of attempts were similar across devices (median 1; IQR, 1-1.5) for both GVL and C-MAC (p = 0.764). GlideScope provides superior views to C-MAC in awake upright laryngoscopy in healthy volunteers. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Conformational stability analyses of alpha subunit I domain of LFA-1 and Mac-1.

    Directory of Open Access Journals (Sweden)

    Debin Mao

    Full Text Available β₂ integrin of lymphocyte function-associated antigen-1 (LFA-1 or macrophage-1 antigen (Mac-1 binds to their common ligand of intercellular adhesion molecule-1 (ICAM-1 and mediates leukocyte-endothelial cell (EC adhesions in inflammation cascade. Although the two integrins are known to have distinct functions, the corresponding micro-structural bases remain unclear. Here (steered-molecular dynamics simulations were employed to elucidate the conformational stability of α subunit I domains of LFA-1 and Mac-1 in different affinity states and relevant I domain-ICAM-1 interaction features. Compared with low affinity (LA Mac-1, the LA LFA-1 I domain was unstable in the presence or absence of ICAM-1 ligand, stemming from diverse orientations of its α₇-helix with different motifs of zipper-like hydrophobic junction between α₁- and α₇-helices. Meanwhile, spontaneous transition of LFA-1 I domain from LA state to intermediate affinity (IA state was first visualized. All the LA, IA, and high affinity (HA states of LFA-1 I domain and HA Mac-1 I domain were able to bind to ICAM-1 ligand effectively, while LA Mac-1 I domain was unfavorable for binding ligand presumably due to the specific orientation of S144 side-chain that capped the MIDAS ion. These results furthered our understanding in correlating the structural bases with their functions of LFA-1 and Mac-1 integrins from the viewpoint of I domain conformational stability and of the characteristics of I domain-ICAM-1 interactions.

  11. Casimir energy-momentum tensor for a quantized bulk scalar field in the geometry of two curved branes on Friedmann-Robertson-Walker background

    Science.gov (United States)

    Pejhan, Hamed; Rahbardehghan, Surena

    2016-09-01

    In a previous work [S. Rahbardehghan and H. Pejhan, Phys. Lett. B 750, 627 (2015)], we considered a simple brane-world model: a single four-dimensional brane embedded in a five-dimensional de Sitter (dS) space-time. Then, by including a conformally coupled scalar field in the bulk, we studied the induced Casimir energy-momentum tensor. Technically, the Krein-Gupta-Bleuler quantization scheme as a covariant and renormalizable quantum field theory in dS space was used to perform the calculations. In the present paper, we generalize this study to a less idealized, but physically motivated, scenario; namely, we consider Friedmann-Robertson-Walker (FRW) space-time which behaves asymptotically as a dS space-time. More precisely, we evaluate a Casimir energy-momentum tensor for a system with two D -dimensional curved branes on background of D +1 -dimensional FRW space-time with negative spatial curvature and a conformally coupled bulk scalar field that satisfied the Dirichlet boundary condition on the branes.

  12. Kinematical and gravitational analysis of the rocket-borne clock experiment by Vessot and Levine using the revised Robertson's test theory of specimen relativity

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, J.G.

    1986-10-01

    The kinematic aspects of the rocket-borne clock experiment by Vessot and Levine are analyzed with the revised Robertson's test theory of special relativity (Found. Phys. 14, 625 (1984)). Besides the expected time-dilation, it is found that the intermediate steps of this experiment yield in principle Michelson-Morley type information (a relation between longitudinal and transverse length contractions) in the third order of the velocities involved, but no relativity-of-simultaneity related effects. The flat space-time test theory induces a family of ''spherically symmetric'' line elements that become the Schwarzchild line element in the relativistic case and also in the abinito rest frame of the theory. These line elements represent the same space-time manifold, but pertain in a one-to-one correspondence to the different flat space-time coordinate transformations of the test theory. The conserved energy is related to the family of local energies in the tangent plane. No deviations from the orthodoxy appear at the pertinent levels of approximation. Hence the unexplained residuals of the Vessot-Levine experiment are not due in obvious ways to kinematic and gravitational frequency shifts caused by deviations of the ''real'' coordinate transformations from the Lorentz transformations.

  13. A Critique of MacIntyrean Morality From a Kantian Perspective

    Directory of Open Access Journals (Sweden)

    Krishna Mani Pathak

    2014-04-01

    Full Text Available This article is a critical examination of MacIntyre’s notion of morality in reference to Kant’s deontological moral theory. The examination shows that MacIntyre (a criticizes Kant’s moral theory to defend virtue ethics or neo-Aristotelian ethics with a weak notion of morality; (b favors the idea of local morality, which does not leave any room for moral assessment and reciprocity in an intercultural domain; and (c fails to provide good arguments for his moral historicism and against Kant’s moral universalism.

  14. Learn Xcode Tools for Mac OS X and iPhone Development

    CERN Document Server

    Piper, I

    2010-01-01

    This book will give you a thorough grounding in the principal and supporting tools and technologies that make up the Xcode Developer Tools suite. Apple has provided a comprehensive collection of developer tools, and this is the first book to examine the complete Apple programming environment for both Mac OS X and iPhone. * Comprehensive coverage of all the Xcode developer tools * Additional coverage of useful third-party development tools* Not just a survey of features, but a serious examination of the complete development process for Mac OS X and iPhone applications What you'll learn* The boo

  15. Relationship of DUI recidivism to moral reasoning, sensation seeking, and MacAndrew alcoholism scores.

    Science.gov (United States)

    Little, G L; Robinson, K D

    1989-12-01

    115 convicted male DUI offenders were treated with Moral Reconation Therapy during their incarceration. Postrelease recidivism status (arrests) was correlated with the pretest, posttest, and change scores on the MacAndrew Alcoholism Scale, Sensation Seeking Scale, Life-purpose scores, and Moral Reasoning scores. Analysis showed that recidivism correlated positively and significantly with the pretest scores on the MacAndrew scale and approached significance with both pre- and posttest scores on the Sensation Seeking Scale. Recidivism status correlated negatively and significantly with scores on the highest levels of moral reasoning (Scale 6 pretest and posttest and Principled Reasoning pretest).

  16. Prototyping and Performance Analysis of a QoS MAC Layer for Industrial Wireless Network

    CERN Document Server

    Bossche, Adrien Van Den; Campo, Eric

    2008-01-01

    Today's industrial sensor networks require strong reliability and guarantees on messages delivery. These needs are even more important in real time applications like control/command, such as robotic wireless communications where strong temporal constraints are critical. For these reasons, classical random-based Medium Access Control (MAC) protocols present a non-null frame collision probability. In this paper we present an original full deterministic MAC-layer for industrial wireless network and its performance evaluation thanks to the development of a material prototype.

  17. A Multi-Channel MAC Protocol For Wireless Hospital Sensor Networks

    CERN Document Server

    Slimane, Jamila Ben; Frikha, Mounir; Koubâa, Anis

    2008-01-01

    Both IEEE 802.15.4 and 802.15.4a standards allow for dynamic channel allocation and use of multiple channels available at their physical layers but its MAC protocols are designed only for single channel. Also, sensor's transceivers such as CC2420 provide multiple channels and channel switch latency of CC2420 transceiver is very short just about 200 micro seconds. In order to enhance both energy efficiency and to shorten end to end delay, we propose, in this report, a new MAC protocol allowing multi-channel allocation for 802.15.4a compliant devices.

  18. Conception and FPGA implementation of IEEE 802.11s mesh network MAC layer transmitter

    CERN Document Server

    Chaari, Lamia; Kamoun, Lotfi

    2010-01-01

    This paper proposes, a hardware implementation of Wireless Mesh Networks (WMN) medium Access Controller (MAC) layer transmitter. In the literature a lot of works are focused on WMN routing protocol as well as performance analysis and software integration of WMN units, however few works deals with WMN hardware implementation. In this field our contribution is to conceive and to implements on FPGA a WMN MAC transmitter module. Our implementation, written in hardware description language (HDL) is based on the IEEE 802.11 s standard. The hardware implementation retains a good performance in speed.

  19. Apple推出配备Retina显示屏的全新MacBook Pro

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Apple推出了全新15英寸MacBook Pro,将Retina显示屏、全闪存架构和强大的四核处理器融于之中。全新MacBookPro薄至1.8厘米、轻至2.02千克,在笔记本电脑高级用户的心中树立了性能与便携性的全新标准。

  20. Additive contribution of nitrous oxide to halothane MAC in infants and children.

    Science.gov (United States)

    Murray, D J; Mehta, M P; Forbes, R B; Dull, D L

    1990-08-01

    Fifty-one infants and small children (14.7 +/- 7.2 mo) were studied to determine the MAC of halothane in O2 (n = 11) and in the presence of three different nitrous oxide (N2O) concentrations (25% [n = 13], 50% [n = 13], and 75% [n = 14]). In the three N2O groups, after randomly assigning patients to an N2O group, anesthesia was induced with halothane and N2O using a pediatric circle system. After endotracheal intubation, halothane and N2O end-expired concentrations were adjusted to predetermined concentrations. The initial halothane concentrations in each group were based on the assumption that each percent N2O reduced halothane concentrations by 0.01 vol % (assumed halothane MAC = 1.0 vol %). Based on the response of the preceding subject in each group, halothane concentrations were increased or decreased depending on whether the response was to move or not to move, respectively, in response to the surgical incision. The mean duration of constant end-tidal concentrations before skin incision was 10 min. End-tidal gases were sampled and measured from a separate distal sampling port of an endotracheal tube during controlled ventilation (Perkin-Elmer Mass Spectrometer). The MAC value for halothane in O2 was 0.94 +/- 0.08 vol % (mean +/- SD). The MAC values of halothane in the presence of 25%, 50%, and 75% N2O were 0.78 +/- 0.12 vol %, 0.44 +/- 0.10 vol %, and 0.29 +/- 0.06 vol %, respectively. All concentrations of N2O significantly reduced the MAC of halothane. A regression analysis through all four data points yielded a linear relationship (r2 = 0.87) with a predicted MAC for N2O of 105 vol %. Unlike halothane and isoflurane, the predicted MAC of N2O in infants and children is similar to that reported by others in adults. Similar to the results of clinical studies in adults, the contribution of N2O to halothane MAC in children is additive.

  1. A DUAL RESERVATION CDMA-BASED MAC PROTOCOL WITH POWER CONTROL FOR AD HOC NETWORKS

    Institute of Scientific and Technical Information of China (English)

    Jia Min; Chen Huimin; Yuan Yuhua

    2007-01-01

    This paper proposes a new multi-channel Medium Access Control (MAC) protocol named as Dual Reservation Code Division Multiple Access (CDMA) based MAC protocol with Power Control (DRCPC). The code channel is divided into common channel, broadcast channel and several data channels. And dynamic power control mechanism is implemented to reduce near-far interference. Compared with IEEE 802.11 Distributed Coordination Function (DCF) protocol, the results show that the proposed mechanism improves the average throughput and limits the transmission delay efficiently.

  2. Computing the Chern–Schwartz–MacPherson class of complete simplical toric varieties

    DEFF Research Database (Denmark)

    Helmer, Martin

    2017-01-01

    Topological invariants such as characteristic classes are an important tool to aid in understanding and categorizing the structure and properties of algebraic varieties. In this note, we consider the problem of computing a particular characteristic class, the Chern–Schwartz–MacPherson class......, of a complete simplicial toric variety X∑ defined by a fan ∑ from the combinatorial data contained in the fan ∑. Specifically, we give an effective combinatorial algorithm to compute the Chern–Schwartz–MacPherson class of X∑, in the Chow ring (or rational Chow ring) of X∑. This method is formulated by combining...

  3. POD/MAC-Based Modal Basis Selection for a Reduced Order Nonlinear Response Analysis

    Science.gov (United States)

    Rizzi, Stephen A.; Przekop, Adam

    2007-01-01

    A feasibility study was conducted to explore the applicability of a POD/MAC basis selection technique to a nonlinear structural response analysis. For the case studied the application of the POD/MAC technique resulted in a substantial improvement of the reduced order simulation when compared to a classic approach utilizing only low frequency modes present in the excitation bandwidth. Further studies are aimed to expand application of the presented technique to more complex structures including non-planar and two-dimensional configurations. For non-planar structures the separation of different displacement components may not be necessary or desirable.

  4. The Mac'OS X command line Unix under the hood

    CERN Document Server

    McElhearn, Kirk

    2006-01-01

    The Mac command line offers a faster, easier way to accomplish many tasks. It''s also the medium for many commands that aren''t accessible using the GUI. The Mac OS X Command Line is a clear, concise, tutorial-style introduction to all the major functionality provided by the command line. It''s also packed with information the experienced users need, including little-known shortcuts and several chapters devoted to advanced topics. This is a book to get you started, but also a book you won't soon outgrow.

  5. The MacNew Heart Disease health-related quality of life instrument: A summary

    Directory of Open Access Journals (Sweden)

    Guyatt Gordon

    2004-01-01

    Full Text Available Abstract Background The measurement of health, the effects of disease, and the impact of health care include not only an indication of changes in disease frequency and severity but also an estimate of patients' perception of health status before and after treatment. One of the more important developments in health care in the past decade may be the recognition that the patient's perspective is as legitimate and valid as the clinician's in monitoring health care outcomes. This has lead to the development of instruments to quantify the patients' perception of their health status before and after treatment. Methods We review evidence supporting the measurement properties of the MacNew Heart Disease Health-related Quality of Life [MacNew] Questionnaire which was designed to evaluate how daily activities and physical, emotional, and social functioning are affected by coronary heart disease and its treatment. Results Reliability was demonstrated by using internal consistency and the intraclass correlation coefficients for the three domains in the Dutch, English, Farsi, German, and Spanish versions of the MacNew. With internal consistency and intraclass correlation coefficients =>0.73, reliability is high. Validity of the MacNew was examined with factor analysis and three core underlying factors, physical, emotional, and social, were identified, explaining 63.0 – 66.5% of the observed variance and replicated in the translations with psychometric data. Construct validity of the MacNew was further demonstrated by extensive substantiation of the logical relationships, defined a priori, between items and other comparison tools. The MacNew is responsive and sensitive to changes in HRQL following various interventions for patients with heart disease with 11 of 13 effect size statistics >0.80. Taking an average of 10 minutes or less to complete, the respondent-burden for the MacNew is low and its acceptability is demonstrated by response rates of over 90

  6. Ultrasonication of pyrogenic microorganisms improves the detection of pyrogens in the Mono Mac 6 assay

    DEFF Research Database (Denmark)

    Moesby, Lise; Hansen, E W; Christensen, J D

    2000-01-01

    of the assay. The interleukin-6 inducing capacity of a broad spectrum of UV-killed and ultrasonicated microorganisms is examined in Mono Mac 6 cells. The interleukin-6 secretion is determined in a sandwich immunoassay (DELFIA). The Mono Mac 6 assay is able to detect UV-killed Bacillus subtilis, Staphylococcus...... aureus and Salmonella typhimurium, but neither Candida albicans nor Aspergillus niger. After ultrasonication of the microorganisms it is possible to detect C. albicans and A. niger. The interleukin-6 inducing ability of the examined microorganisms is in no case reduced after ultrasonic treatment. However...

  7. Living Lands

    DEFF Research Database (Denmark)

    Christensen, Suna Møller

    2014-01-01

    , hunters attended to questions like safe-journeying on ice or the role of natural surroundings in children’s education, in ways revealing a relational perception of ‘nature’ and dissolving culture-nature dualisms. Hunters’ experiences in living the land afforded children a dwelling position from which...... of the social world pushes questions about education and life, disregarding being educated as human control of nature....

  8. Education for Personal Life: John MacMurray on Why Learning to Be Human Requires Emotional Discipline

    Science.gov (United States)

    MacAllister, James

    2014-01-01

    In this article I discuss the philosophy of John MacMurray, and in particular, his little-examined writings on discipline and emotion education. It is argued that discipline is a vital element in the emotion education MacMurray thought central to learning to be human, because for him it takes concerted effort to overcome the human tendency toward…

  9. A hybrid path-oriented code assignment CDMA-based MAC protocol for underwater acoustic sensor networks.

    Science.gov (United States)

    Chen, Huifang; Fan, Guangyu; Xie, Lei; Cui, Jun-Hong

    2013-11-04

    Due to the characteristics of underwater acoustic channel, media access control (MAC) protocols designed for underwater acoustic sensor networks (UWASNs) are quite different from those for terrestrial wireless sensor networks. Moreover, in a sink-oriented network with event information generation in a sensor field and message forwarding to the sink hop-by-hop, the sensors near the sink have to transmit more packets than those far from the sink, and then a funneling effect occurs, which leads to packet congestion, collisions and losses, especially in UWASNs with long propagation delays. An improved CDMA-based MAC protocol, named path-oriented code assignment (POCA) CDMA MAC (POCA-CDMA-MAC), is proposed for UWASNs in this paper. In the proposed MAC protocol, both the round-robin method and CDMA technology are adopted to make the sink receive packets from multiple paths simultaneously. Since the number of paths for information gathering is much less than that of nodes, the length of the spreading code used in the POCA-CDMA-MAC protocol is shorter greatly than that used in the CDMA-based protocols with transmitter-oriented code assignment (TOCA) or receiver-oriented code assignment (ROCA). Simulation results show that the proposed POCA-CDMA-MAC protocol achieves a higher network throughput and a lower end-to-end delay compared to other CDMA-based MAC protocols.

  10. Current evidence for the use of C-MAC videolaryngoscope in adult airway management: a review of the literature.

    Science.gov (United States)

    Xue, Fu-Shan; Li, Hui-Xian; Liu, Ya-Yang; Yang, Gui-Zhen

    2017-01-01

    The C-MAC videolaryngoscope is the first Macintosh-typed videolaryngoscope. Since the advent of its original version video Macintosh system in 1999, this device has been modified several times. A unique feature of C-MAC device is its ability to provide the 2 options of direct and video laryngoscopy with the same device. The available evidence shows that in patients with normal airways, C-MAC videolaryngoscope compared with direct laryngoscopy can provide comparable or better laryngeal views and exerts less force on maxillary incisors, but does not offer conclusive benefits with regard to intubation time, intubation success, number of intubation attempts, the use of adjuncts, and hemodynamic responses to intubation. In patients with predicted or known difficult airways, C-MAC videolaryngoscope can achieve a better laryngeal view, a higher intubation success rate and a shorter intubation time than direct laryngoscopy. Furthermore, the option to perform direct and video laryngoscopy with the same device makes C-MAC videolaryngoscope exceptionally useful for emergency intubation. In addition, the C-MAC videolaryngoscope is a very good tool for tracheal intubation teaching. However, tracheal intubation with C-MAC videolaryngoscope may occasionally fail and introduction of C-MAC videolaryngoscope in clinical practice must be accompanied by formal training programs in normal and difficult airway managements.

  11. Serum Mac-2 binding protein levels as a novel diagnostic biomarker for prediction of disease severity and nonalcoholic steatohepatitis.

    Science.gov (United States)

    Kamada, Yoshihiro; Fujii, Hideki; Fujii, Hironobu; Sawai, Yoshiyuki; Doi, Yoshinori; Uozumi, Naofumi; Mizutani, Kayo; Akita, Maaya; Sato, Motoya; Kida, Sachiho; Kinoshita, Noriaki; Maruyama, Nobuhiro; Yakushijin, Takayuki; Miyazaki, Masanori; Ezaki, Hisao; Hiramatsu, Naoki; Yoshida, Yuichi; Kiso, Shinichi; Imai, Yasuharu; Kawada, Norifumi; Takehara, Tetsuo; Miyoshi, Eiji

    2013-10-01

    Mac-2 binding protein (Mac-2 bp) is one of the major fucosylated glycoproteins, which we identified with glycol-proteomic analyses. We previously reported that fucosylated glycoproteins are secreted into bile, but scarcely secreted into sera in normal liver and hypothesized that the fucosylation-based sorting machinery would be disrupted in ballooning hepatocytes due to the loss of cellular polarity. In the present study, we investigated the availability of Mac-2 bp for differential diagnosis of nonalcoholic steatohepatitis (NASH) from nonalcoholic fatty liver disease (NAFLD) as a biomarker. Serum Mac-2 bp levels were determined with our developed ELISA kit. Our cohort of 127 patients with NAFLD had liver biopsy to make a histological diagnosis of NASH and simple fatty liver. Mac-2 bp levels were significantly elevated in NASH patients compared with non-NASH (simple steatosis) patients (2.132 ± 1.237 vs. 1.103 ± 0.500 μg/mL, p Mac-2 bp was 0.816. Moreover, multivariate logistic regression analyses showed Mac-2 bp levels could predict the fibrosis stage and the presence of ballooning hepatocytes in NAFLD patients. These results support the potential usefulness of measuring Mac-2 bp levels in clinical practice as a biomarker for NASH. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Beoordelen van beroepsmatige blootstelling aan chronische toxische stoffen met of zonder drempeldosis via een 8-uurs MAC

    NARCIS (Netherlands)

    Marquart, J.; Scheffers, T.M.L.

    2001-01-01

    Bij beoordeling aan chronisch toxische stoffen negeert de huidige toetsing aan de MAC de cumulatieve dosis waarop de MAC over het algemeen is gebaseerd. Zelfs indien er een overschrijdingskans van maximaal 5% wordt aangehouden. De meest voorzichtige methode om hier wel rekening mee te houden is via

  13. A Hybrid Path-Oriented Code Assignment CDMA-Based MAC Protocol for Underwater Acoustic Sensor Networks

    Directory of Open Access Journals (Sweden)

    Huifang Chen

    2013-11-01

    Full Text Available Due to the characteristics of underwater acoustic channel, media access control (MAC protocols designed for underwater acoustic sensor networks (UWASNs are quite different from those for terrestrial wireless sensor networks. Moreover, in a sink-oriented network with event information generation in a sensor field and message forwarding to the sink hop-by-hop, the sensors near the sink have to transmit more packets than those far from the sink, and then a funneling effect occurs, which leads to packet congestion, collisions and losses, especially in UWASNs with long propagation delays. An improved CDMA-based MAC protocol, named path-oriented code assignment (POCA CDMA MAC (POCA-CDMA-MAC, is proposed for UWASNs in this paper. In the proposed MAC protocol, both the round-robin method and CDMA technology are adopted to make the sink receive packets from multiple paths simultaneously. Since the number of paths for information gathering is much less than that of nodes, the length of the spreading code used in the POCA-CDMA-MAC protocol is shorter greatly than that used in the CDMA-based protocols with transmitter-oriented code assignment (TOCA or receiver-oriented code assignment (ROCA. Simulation results show that the proposed POCA-CDMA-MAC protocol achieves a higher network throughput and a lower end-to-end delay compared to other CDMA-based MAC protocols.

  14. Medicinal, Aromatic and Cosmetic (MAC) plants for community health and bio-cultural diversity conservation in Bali, Indonesia

    NARCIS (Netherlands)

    Leurs, Liesbeth Nathalie

    2010-01-01

    The general aim of this ethno-botanical study is to document, describe and analyse the Balinese community members’ knowledge, belief and practices with regard to medicinal, aromatic and cosmetic (MAC) plants in relation to community health and bio-cultural diversity conservation of MAC plants. This

  15. The Concurrent and Construct Validity of the MacAndrew Alcoholism Scale among At-Risk Adolescent Males.

    Science.gov (United States)

    Moore, Richard H.

    1984-01-01

    Investigated the empirical validity of the MacAndrew Alcoholism Scale in adolescent male offenders (N=160). Results supported the concurrent validity of the MacAndrew Scale as a measure of alcohol abuse among young at-risk males and was also sensitive to polydrug use among youth who abuse alcohol. (LLL)

  16. Detecting DIF in Polytomous Items Using MACS, IRT and Ordinal Logistic Regression

    Science.gov (United States)

    Elosua, Paula; Wells, Craig

    2013-01-01

    The purpose of the present study was to compare the Type I error rate and power of two model-based procedures, the mean and covariance structure model (MACS) and the item response theory (IRT), and an observed-score based procedure, ordinal logistic regression, for detecting differential item functioning (DIF) in polytomous items. A simulation…

  17. Clustering and OFDMA-based MAC protocol (COMAC for vehicular ad hoc networks

    Directory of Open Access Journals (Sweden)

    Abdel Hafeez Khalid

    2011-01-01

    Full Text Available Abstract The IEEE community is working on the wireless access in vehicular environments as a main technology for vehicular ad hoc networks. The medium access control (MAC protocol of this system known as IEEE 802.11p is based on the distributed coordination function (DCF of the IEEE 802.11 and enhanced DCF of the IEEE 802.11e that have low performance especially in high-density networks with nodes of high mobility. In this paper, we propose a novel MAC protocol where nodes dynamically organize themselves into clusters. Cluster heads are elected based on their stability on the road with minimal overhead since all clustering information is embedded in control channel's safety messages. The proposed MAC protocol is adaptable to drivers' behavior on the road and has learning mechanism for predicting the future speed and position of all cluster members using the fuzzy logic inference system. By using OFDMA, each cluster will use a set of subcarriers that are different from the neighboring clusters to eliminate the hidden terminal problem. Increasing the system reliability, reducing the time delay for vehicular safety applications and efficiently clustering vehicles in highly dynamic and dense networks in a distributed manner are the main contributions of our proposed MAC protocol.

  18. Scalable Video Streaming Adaptive to Time-Varying IEEE 802.11 MAC Parameters

    Science.gov (United States)

    Lee, Kyung-Jun; Suh, Doug-Young; Park, Gwang-Hoon; Huh, Jae-Doo

    This letter proposes a QoS control method for video streaming service over wireless networks. Based on statistical analysis, the time-varying MAC parameters highly related to channel condition are selected to predict available bitrate. Adaptive bitrate control of scalably-encoded video guarantees continuity in streaming service even if the channel condition changes abruptly.

  19. Foreign Language Authoring Systems: Judith Frommer's MacLang Spoken Here.

    Science.gov (United States)

    Frommer, Judith

    1987-01-01

    MacLang, a user-friendly authoring system for the Macintosh computer, helps second language teachers prepare and tailor computer exercises and activities; is usable with any Roman-alphabet language, Russian, and Greek; gives students intelligent feedback; and allows students to control computer activity in order to individualize learning.…

  20. Dependence of AeroMACS Interference on Airport Radiation Pattern Characteristics

    Science.gov (United States)

    Wilson, Jeffrey D.

    2012-01-01

    AeroMACS (Aeronautical Mobile Airport Communications System), which is based upon the IEEE 802.16e mobile wireless standard, is expected to be implemented in the 5091 to 5150 MHz frequency band. As this band is also occupied by Mobile Satellite Service (MSS) feeder uplinks, AeroMACS must be designed to avoid interference with this incumbent service. The aspects of AeroMACS operation that present potential interference are under analysis in order to enable the definition of standards that assure that such interference will be avoided. In this study, the cumulative interference power distribution at low earth orbit from AeroMACS transmitters at the 497 major airports in the contiguous United States was simulated with the Visualyse Professional software. The dependence of the interference power on the number of antenna beams per airport, gain patterns, and beam direction orientations was simulated. As a function of these parameters, the simulation results are presented in terms of the limitations on transmitter power required to maintain the cumulative interference power under the established threshold.