Creat membership Creat membership
Sign in

Forgot password?

Confirm
  • Forgot password?
    Sign Up
  • Confirm
    Sign In
home > search

Now showing items 1 - 16 of 576

  • Treatise on Zoology: Anatomy, Taxonomy, Biologyby J. Forest; J. C. von Vaupel Klein; F. R. Schram

    Review by: Les Watling  

    Download Collect
  • New constraints on mantle carbon from Mid-Atlantic Ridge popping rocks

    Jones, M.R.   Wanless, V.D.   Soule, S.A.   Kurz, M.D.   Mittelstaedt, E.   Fornari, D.J.   Curtice, J.   Klein, F.   Le Roux, V.   Brodsky, H.   Péron, S.   Schwartz, D.M.  

    Download Collect
  • Properties of flavour-singlet pseudoscalar mesons from lattice QCD

    Urbach, Carsten   Klein, F.   Meißner, U.-G.   Thoma, U.  

    Download Collect
  • Evaluation of the high temperature oxidation of W-Cr-Zr self-passivating alloys

    Tan, X.Y.   Klein, F.   Litnovsky, A.   Wegener, T.   Schmitz, J.   Linsmeier, Ch.   Coenen, J.W.   Breuer, U.   Rasinski, M.   Li, P.   Luo, L.M.   Wu, Y.C.  

    Download Collect
  • XML3D and Xflow: Combining Declarative 3D for the Web with Generic Data Flows

    Klein, F.   Sons, K.   Rubinstein, D.   Slusallek, P.  

    Researchers have combined XML3D, which provides declarative, interactive 3D scene descriptions based on HTML5, with Xflow, a language for declarative, high-performance data processing. The result lets Web developers combine a 3D scene graph with data flows for dynamic meshes, animations, image processing, and postprocessing.
    Download Collect
  • A Multi-Model Engine for High-Level Power Estimation Accuracy Optimization

    Klein, F.   Leao, R.   Araujo, G.   Santos, L.   Azevedo, R.  

    Register transfer level (RTL) power macromodeling is a mature research topic with a variety of equation and table-based approaches. Despite its maturity, macromodeling is not yet widely accepted as a de facto industrial standard for power estimation at the RT level. Each approach has many variants depending upon the parameters chosen to capture power variation. Every macromodeling technique has some intrinsic limitation affecting either its performance or its accuracy. Therefore, alternative macromodeling methods can be envisaged as part of a power modeling toolkit from which multiple models for a given component could be exploited so as to reduce the estimation errors resulting from conventional single-model approaches. This paper describes two different approaches for a new multi-model power estimation engine. The first one selects the macromodeling technique that leads to the least estimation error, for a given system component, depending on the properties of its input-vector stream. A proper selection function is built after component characterization and used during estimation. Though simple, this approach has revealed a substantial improvement in estimation accuracy. The second one builds a power estimate function that captures the correlation between individual macromodel estimates and input-stream properties. Experimental results show that our multi-model engine improves the robustness of power analysis with negligible usage overhead. Accuracy becomes seven times better on average, as compared to conventional single-model estimators, while the overall maximum estimation error is divided by 9.
    Download Collect
  • Fe-Ni-Co-O-S Phase Relations in Peridotite-Seawater Interactions

    Klein, F.   Bach, W.  

    Serpentinization of abyssal peridotites is known to produce extremely reducing conditions as a result of dihydrogen (H(2),aq) release upon oxidation of ferrous iron in primary phases to ferric iron in secondary minerals by H(2)O. We have compiled and evaluated thermodynamic data for FeNiCoOS phases and computed phase relations in fO(2),gfS(2),g and aH(2),aqaH(2)S,aq diagrams for temperatures between 150 and 400C at 50 MPa. We use the relations and compositions of FeNiCoOS phases to trace changes in oxygen and sulfur fugacities during progressive serpentinization and steatitization of peridotites from the Mid-Atlantic Ridge in the 1520N Fracture Zone area (Ocean Drilling Program Leg 209). Petrographic observations suggest a systematic change from awaruitemagnetitepentlandite and heazlewooditemagnetitepentlandite assemblages forming in the early stages of serpentinization to milleritepyritepolydymite-dominated assemblages in steatized rocks. Awaruite is observed in all brucite-bearing partly serpentinized rocks. Apparently, buffering of silica activities to low values by the presence of brucite facilitates the formation of large amounts of hydrogen, which leads to the formation of awaruite. Associated with the prominent desulfurization of pentlandite, sulfide is removed from the rock during the initial stage of serpentinization. In contrast, steatitization indicates increased silica activities and that high-sulfur-fugacity sulfides, such as polydymite and pyritevaesite solid solution, form as the reducing capacity of the peridotite is exhausted and H(2) activities drop. Under these conditions, sulfides will not desulfurize but precipitate and the sulfur content of the rock increases. The co-evolution of fO(2),gfS(2),g in the system follows an isopotential of H(2)S,aq, indicating that H(2)S in vent fluids is buffered. In contrast, H(2) in vent fluids is not buffered by FeNiCoOS phases, which merely monitor the evolution of H(2) activities in the fluids in the course of progressive rock alteration. The co-occurrence of pentlanditeawaruitemagnetite indicates H(2),aq activities in the interacting fluids near the stability limit of water. The presence of a hydrogen gas phase would add to the catalyzing capacity of awaruite and would facilitate the abiotic formation of organic compounds.
    Download Collect
  • Enhanced HIV-1 immunotherapy by commonly arising antibodies that target virus escape variants

    Klein, F.   Nogueira, L.   Nishimura, Y.   Phad, G.   West, A. P.   Halper-Stromberg, A.   Horwitz, J. A.   Gazumyan, A.   Liu, C.   Eisenreich, T. R.   Lehmann, C.   Fatkenheuer, G.   Williams, C.   Shingai, M.   Martin, M. A.   Bjorkman, P. J.   Seaman, M. S.   Zolla-Pazner, S.   Karlsson Hedestam, G. B.   Nussenzweig, M. C.  

    Antibody-mediated immunotherapy is effective in humanized mice when combinations of broadly neutralizing antibodies (bNAbs) are used that target nonoverlapping sites on the human immunodeficiency virus type 1 (HIV-1) envelope. In contrast, single bNAbs can control simian-human immunodeficiency virus (SHIV) infection in immune-competent macaques, suggesting that the host immune response might also contribute to the control of viremia. Here, we investigate how the autologous antibody response in intact hosts can contribute to the success of immunotherapy. We find that frequently arising antibodies that normally fail to control HIV-1 infection can synergize with passively administered bNAbs by preventing the emergence of bNAb viral escape variants.
    Download Collect
  • Kaluza–Klein string cosmological model in f ( R, T ) theory of gravity

    Pawar D.D.   Bhuttampalle G.G.   Agrawal P.K.  

    Download Collect
  • Analytische Probleme in der Diagnostik des Gestationsdiabetes – Vergleich von 6 Analytikmethoden

    Klein, F.   Groten, T.   Schleu?ner, E.   Wolf, G.   Battefeld, W.  

    Download Collect
  • Antibodies in HIV-1 Vaccine Development and Therapy

    Klein, F.   Mouquet, H.   Dosenovic, P.   Scheid, J. F.   Scharf, L.   Nussenzweig, M. C.  

    Despite 30 years of study, there is no HIV-1 vaccine and, until recently, there was little hope for a protective immunization. Renewed optimism in this area of research comes in part from the results of a recent vaccine trial and the use of single-cell antibody-cloning techniques that uncovered naturally arising, broad and potent HIV-1-neutralizing antibodies (bNAbs). These antibodies can protect against infection and suppress established HIV-1 infection in animal models. The finding that these antibodies develop in a fraction of infected individuals supports the idea that new approaches to vaccination might be developed by adapting the natural immune strategies or by structure-based immunogen design. Moreover, the success of passive immunotherapy in small-animal models suggests that bNAbs may become a valuable addition to the armamentarium of drugs that work against HIV-1.
    Download Collect
  • Experimental constraints on fluid-rock reactions during incipient serpentinization of harzburgite

    Klein, F.   Grozeva, N. G.   Seewald, J. S.   McCollom, T. M.   Humphris, S. E.   Moskowitz, B.   Berquo, T. S.   Kahl, W.-A.  

    The exposure of mantle peridotite to water at crustal levels leads to a cascade of interconnected dissolution-precipitation and reduction-oxidation reactions a process referred to as serpentinization. These reactions have major implications for microbial life through the provision of hydrogen (H-2). To simulate incipient serpentinization under well-constrained conditions, we reacted centimeter-sized pieces of uncrushed harzburgite with chemically modified seawater at 300 degrees C and 35 MPa for ca. 1.5 yr (13441 h), monitored changes in fluid chemistry over time, and examined the secondary mineralogy at the termination of the experiment. Approximately 4 mol% of the protolith underwent alteration forming serpentine, accessory magnetite, chlorite, and traces of calcite and heazlewoodite. Alteration textures bear remarkable similarities to those found in partially serpentinized abyssal peridotites. Neither brucite nor talc precipitated during the experiment. Given that the starting material contained similar to 4 times more olivine than orthopyroxene on a molar basis, mass balance requires that dissolution of orthopyroxene was significantly faster than dissolution of olivine. Coupled mass transfer of dissolved Si, Mg, and H+ between olivine and orthopyroxene reaction fronts was driven by steep activity gradients and facilitated the precipitation of serpentine. Hydrogen was released in significant amounts throughout the entire experiment; however, the H-2 release rate decreased with time. Serpentinization consumed water but did not release significant amounts of dissolved species (other than H-2) suggesting that incipient hydration reactions involved a volume increase of similar to 40%. The reduced access of water to fresh olivine surfaces due to filling of fractures and coating of primary minerals with alteration products led to decreased rates of serpentinization and H-2 release. While this concept might seem at odds with completely serpentinized seafloor peridotites, reaction-driven fracturing offers an intriguing solution to the seemingly self-limiting nature of serpentinization. Indeed, the reacted sample revealed several textural features diagnostic of incipient reaction-driven fracturing. We conclude that fracturing must have far reaching impacts on the rates of serpentinization and H-2 release in peridotite-hosted hydrothermal systems.
    Download Collect
  • Kaluza–Klein cosmological model in f(R,?T) gravity with Λ(T)

    Sahoo, P. K.   Mishra, B.   Tripathy, S. K.  

    A class of Kaluza–Klein cosmological models in f(R, T) theory of gravity have been investigated. In the work, we have considered the functional f(R, T) to be in the form \(f(R,T)=f(R)+f(T)\) with \(f(R)=\lambda R\) and \(f(T)=\lambda T\). Such a choice of the functional f(R, T) leads to an evolving effective cosmological constant \(\Lambda \) which depends on the stress energy tensor. The source of the matter field is taken to be a perfect cosmic fluid. The exact solutions of the field equations are obtained by considering a constant deceleration parameter which leads to two different aspects of the volumetric expansion, namely a power law and an exponential volumetric expansion. Keeping an eye on the accelerating nature of the universe in the present epoch, the dynamics and physical behaviour of the models have been discussed. From statefinder diagnostic pair, we have found that the model with exponential volumetric expansion behaves more like a lambda cold dark matter model.
    Download Collect
  • The Impact of Simultaneous Liver Resection for Occult Liver Metastases of Pancreatic Adenocarcinoma

    Klein, F.   Puhl, G.   Guckelberger, O.   Pelzer, U.   Pullankavumkal, J. R.   Guel, S.   Neuhaus, P.   Bahra, M.  

    Download Collect
  • Numerical Simulation of the Solidification of Zinc Die Castings

    Klein, F.   Pokora, E.   Dúl, J.  

    Download Collect
  • Spin structure of the nucleon (theory)

    Meißner, Ulf-G.   Rusetsky, Akaki   Klein, F.   Meißner, U.-G.   Thoma, U.  

    Download Collect
1 2 3 4 5 6 7 8 9 10

Contact

If you have any feedback, Please follow the official account to submit feedback.

Turn on your phone and scan

Submit Feedback