2,116 research outputs found

    Strange Particle Production and Elliptic Flow from CERES

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    Elliptic flow measurements as a function of p_T of charged (pi^+- and low-p_T protons) and strange (Lambda and K^0_S) particles from Pb+Au collisions at 158 AGeV/c are presented, together with measurements of phi and K^0_S meson production. A mass ordering effect was observed. Scaling to the number of constituent quarks and transverse rapidity y^fs_T scaling are presented. The results are compared with results from the NA49 and STAR experiments and with hydrodynamical calculations. For the first time in heavy-ion collisions, phi mesons were reconstructed in the same experiment both in the K^+K^- and in the e^+e^- decay channels. The obtained transverse mass distributions of phi mesons are compared with results from the NA49 and NA50 experiments. The yield and the inverse slope parameter of the K^0_S mesons were reconstructed from two independent analyses. Our results are compared with those from the NA49 and NA57 experiments.Comment: Submitted to J. Phys. G (Proceedings of the 9th International Conference on Strangeness in Quark Matter, Los Angeles, USA, March 26-31) 9 pages, 7 figure

    Investigation of Azimuthal Asymmetries in Charged and Strange Particle Distributions from CERES

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    Diese Doktorarbeit stellt die Messung des anisotropen transversalen Flusses v2 geladener und seltsamer Teilchen mit dem CERES Spektrometer vor. Gezeigt werden die elliptischen Fluss Messungen der Teilchen Lambda, K^0_S, geladener Pions und protons in Pb-Au Kollisionen bei hoechsten SPS Energien. Mit einem Pseudorapiditaetsbereich von \eta=2.05-2.70 bei voller azimuthaler Akzeptanz und mit einer pT Sensitivitaet von bis zu 4 GeV/c koennen mit den CERES Daten hydrodynamische Modelle getestet werden. v2 wird als Funktionen der Zentralitaet, Rapiditaet, Pseudorapiditaet und des Transversalimpulses fuer die verschiedenen Teilchensorten diskutiert. Die Messungen werden mit Ergebnissen der NA49 Experimentes und mit hydrodynamischen Rechnungen verglichen.Ferner werden Vergleiche zu den STAR und RHICH Beobachtungen angestellt. Bei kleinem pT wird der Massenordnungseffekt v2(Lambda)<v2(K^0_S)<Pions) beobachtet. Ein entgegengesetztes Verhalten zeigt sich bei hohem pT. Um ein teiferes Verstaendniss fuer die Ursachen des Skalenverhaltens des kollektiven Flusses mit der Anzahl an Konstituentenquarks und mit der transversalen Rapiditaet zu erhalten, wird die von der Hydrodynamiek vorhergesagte y^fs_T Skalierung durchgefuehrt. Vergleiche differentieller Flussmessungen verschiedenster Teilchen mit verschiedenen Szenarien an Skalenverhalten ermoeglicht eine Aussage ueber die Ursachen des Flusses, sowie ueber die fruehesten Stadien der Kollision

    Crime and Punishment in Distributed Byzantine Decision Tasks (Extended Version)

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    A decision task is a distributed input-output problem in which each process starts with its input value and eventually produces its output value. Examples of such decision tasks are broad and range from consensus to reliable broadcast to lattice agreement. A distributed protocol solves a decision task if it enables processes to produce admissible output values despite arbitrary (Byzantine) failures. Unfortunately, it has been known for decades that many decision tasks cannot be solved if the system is overly corrupted, i.e., safety of distributed protocols solving such tasks can be violated in unlucky scenarios. By contrast, only recently did the community discover that some of these distributed protocols can be made accountable by ensuring that correct processes irrevocably detect some faulty processes responsible for any safety violation. This realization is particularly surprising (and positive) given that accountability is a powerful tool to mitigate safety violations in distributed protocols. Indeed, exposing crimes and introducing punishments naturally incentivize exemplarity. In this paper, we propose a generic transformation of any non-synchronous distributed protocol solving a decision task into its accountable version. Our transformation is built upon the well-studied simulation of crash failures on top of Byzantine failures and increases the communication complexity by a quadratic multiplicative factor in the worst case

    UPAYA MENINGKATKAN MOTIVASI BELAJAR SISWA MELALUI MEDIA GAME EDUCATION DALAM PEMBELAJARAN IPS DI MTs HASBUR RACHMAN ALIF DESA LENGKONG WETAN KABUPATEN MAJALENGKA

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    ASEP SAMSUL MA'ARIF : Berdasarkan Observasiawal di kelas VII MTs Hasbur Rachman Alif terlihat proses pembelajaran IPS masih menggunakan media spidol dan papan tulis. Sehingga banyak siswa yang kurang memperhatikan guru pada saat proses pembelajaran., Hal ini berakibat pada kejenuhan dan kebosanan yang berdampak pada hasil belajar siswa yang kurang dari KKM yang diterapkan di MTs Hasbur Rachman Alif yakni 70. Tujuan penelitian ini untuk mengetahui bagaimana penerapan pembelajaran dengan menggunakan media Game Education pada mata pelajaran IPS Terpadu, aktivitas siswa dan kinerja guru dengan pembelajaran dengan menggunakan media Game Education, dan mengetahui motivasi belajar siswa sebelum dan setelah diterapkannya pembelajaran dengan menggunakan media Game education pada mata pelajaran IPS Terpadu di MTs Hasbur Rachman Alif. Pembelajaran dengan menggunakan media Game Education menekankan motivasi siswa untuk berpikir kritis dan menuangkan. Hal ini memudahkan siswa untuk mengakses materi IPS yang banyak dimanapun, serta mempemudah daya ingat siswa tentang apayatgtelah didapatkan selama proses pembelajaran. Penelitian ini menggunakan Penelitian Tindakan Kelas (pTK) yang dilaksanakan selama tiga siklus. Teknik Pengumpulan data menggunakan observasi, tes, dan dokumentasi. Subjek penelitian ini adalah siswa kelas VII MTs Hasbur Rachman Alif sebanyak 31 siswa yang terdiri dari 18 siswa laki-laki dan 13 siswa perempuan. Pembelajaran dengan menggunakan media Game Education dapat meningkatkan motivasi belajar siswa hal ini terlihat dari hasil tes yang telah dilakukan selama tiga siklus, dimana pada pratindakan (pretes) nilai sebesar 65,25 dan ketuntasan belajar 25 yo, siklus I nilai rata-rata sebesar 76,75 dan ketuntasan_ belajar siswa sebesar 65,5%o siklus II nilai rata-rata siswa 85,75 dan nilai ketuntasan belajar sebesar 90% siklus III dengan nilai rata-rata 92,25 dan ketuntasan belajar mengalami peningkatanya itu 97,5yo. Dengan demikian dapat disimpulkan bahwa pembelajaran dengan menggunakan media Game Education merupakan salah satu upaya untuk meningkatkan hasil belajar siswa pada mata pelajaran IPS Terpadu di MTs Hasbur Rachman Alif. Kata Kunci: Game Education, MotivasiBelajar, PTK

    Measurement of quarkonium production at forward rapidity in pp collisions at √s=7 TeV

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    The inclusive production cross sections at forward rapidity of J/ψ , ψ(2S) , Υ (1S) and Υ (2S) are measured in pp collisions at s√=7 TeV with the ALICE detector at the LHC. The analysis is based on a data sample corresponding to an integrated luminosity of 1.35 pb‾¹ . Quarkonia are reconstructed in the dimuon-decay channel and the signal yields are evaluated by fitting the μ+μ− invariant mass distributions. The differential production cross sections are measured as a function of the transverse momentum pT and rapidity y , over the ranges 0<pT<20 GeV/c for J/ψ , 0<pT<12 GeV/c for all other resonances and for \(2.5 . The measured cross sections integrated over pT and y , and assuming unpolarized quarkonia, are: σJ/ψ=6.69±0.04±0.63 μ b, σψ(2S)=1.13±0.07±0.19 μ b, σΥ(1S)=54.2±5.0±6.7 nb and σΥ(2S)=18.4±3.7±2.9 nb, where the first uncertainty is statistical and the second one is systematic. The results are compared to measurements performed by other LHC experiments and to theoretical models

    Event-by-event mean pT fluctuations in pp and Pb–Pb collisions at the LHC

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    Event-by-event fluctuations of the mean transverse momentum of charged particles produced in pp collisions at TeX TeX 0.9, 2.76 and 7 TeV, and Pb–Pb collisions at TeX TeX 2.76 TeV are studied as a function of the charged-particle multiplicity using the ALICE detector at the LHC. Dynamical fluctuations indicative of correlated particle emission are observed in all systems. The results in pp collisions show little dependence on collision energy. The Monte Carlo event generators PYTHIA and PHOJET are in qualitative agreement with the data. Peripheral Pb–Pb data exhibit a similar multiplicity dependence as that observed in pp. In central Pb–Pb, the results deviate from this trend, featuring a significant reduction of the fluctuation strength. The results in Pb–Pb are in qualitative agreement with previous measurements in Au–Au at lower collision energies and with expectations from models that incorporate collective phenomena

    Suppression of ψ(2S) production in p-Pb collisions at √sNN=5.02 TeV .

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    The ALICE Collaboration has studied the inclusive production of the charmonium state ψ(2S) in proton-lead (p-Pb) collisions at the nucleon-nucleon centre of mass energy √sNN = 5.02TeV at the CERN LHC. The measurement was performed at forward (2.03 < ycms < 3.53) and backward (−4.46 < ycms < −2.96) centre of mass rapidities, studying the decays into muon pairs. In this paper, we present the inclusive production cross sections σ (2S), both integrated and as a function of the transverse momentum pT, for the two ycms domains. The results are compared to those obtained for the 1S vector state (J/ψ), by showing the ratios between the production cross sections, as well as the double ratios [σ (2S)/σJ/ ]pPb/[σ (2S)/σJ/ ]pp between p-Pb and proton-proton collisions. Finally, the nuclear modification factor for inclusive ψ(2S) is evaluated and compared to the measurement of the same quantity for J/ψ and to theoretical models including parton shadowing and coherent energy loss mechanisms. The results show a significantly larger suppression of the ψ(2S) compared to that measured for J/ψ and to models. These observations represent a clear indication for sizeable final state effects on ψ(2S) production

    Dehydroepiandrosterone sulfate mediates activation of transcription factors CREB and ATF-1 via a Gα11-coupled receptor in the spermatogenic cell line GC-2

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    AbstractDehydroepiandrosterone sulfate (DHEAS) is a circulating steroid produced in the adrenal cortex, brain, and gonads. Whereas a series of investigations attest to neuroprotective effects of the steroid in the brain, surprisingly little is known about the physiological effects of DHEAS on cells of the reproductive system. Here we demonstrate that DHEAS acting on the spermatogenic cell line GC-2 induces a time- and concentration-dependent phosphorylation of c-Src and Erk1/2 and activates the transcription factors activating transforming factor-1 (ATF-1) and cyclic AMP-responsive element binding protein (CREB). These actions are consistent with the non-classical signaling pathway of testosterone and suggest that DHEAS is a pro-androgen that is converted into testosterone in order to exert its biological activity. The fact, however, that steroid sulfatase mRNA was not detected in the GC-2 cells and the clear demonstration of DHEAS-induced activation of Erk1/2, ATF-1 and CREB after silencing the androgen receptor by small interfering RNA (siRNA) clearly contradict this assumption and make it appear unlikely that DHEAS has to be converted in the cytosol into a different steroid in order to activate the kinases and transcription factors mentioned. Instead, it is likely that the DHEAS-induced signaling is mediated through the interaction of the steroid with a membrane-bound G-protein-coupled receptor, since silencing of Guanine nucleotide-binding protein subunit alpha-11 (Gnα11) leads to the abolition of the DHEAS-induced stimulation of Erk1/2, ATF-1, and CREB. The investigation presented here shows a hormone-like activity of DHEAS on a spermatogenic cell line. Since DHEAS is produced in male and female reproductive organs, these findings could help to define new roles for DHEAS in the physiology of reproduction
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