Bowhead Whale (Balaena mysticetus) Migration and Calling Behaviour in the Alaskan Beaufort Sea, Autumn 2001–04: An Acoustic Localization Study

The westward migration of bowhead whales (Bering Sea stock) was studied during autumn 2001–04 as part of an oil industry monitoring program. An array of Directional Autonomous Seafloor Acoustic Recorders (DASARs) was deployed northeast of the Northstar oil production island near Prudhoe Bay, Alaska. Underwater sounds were recorded continuously for 24–35 days per year, mainly in September. More than 130 000 bowhead calls were detected, and the directional capability of DASARs allowed triangulation of whale position for ~93 500 calls. The migration pathway was closer to shore in 2003–04 than in 2001–02. Calls were clumped in space and time, and there was significantly more calling at night than by day. From 65% to 82% of calls were simple frequency-modulated calls, and the percentage of complex calls was positively related to the daily number of calls. No songs were detected, but in 2004 there were numerous call sequences consisting of repeated identical calls in series and generally lasting up to a few minutes. The DASAR methodology provides detailed information on the temporal and spatial distribution of calling whales and on their acoustic repertoire.La migration à l’ouest de la baleine boréale (population de la mer de Béring) a été étudiée durant quatre automnes (2001-2004) dans le cadre d’un programme d’étude de l’industrie pétrolière. Un réseau d’enregistreurs sous-marins autonomes et directionnels (DASAR) a été déployé au nord-est de Northstar, une île artificielle d’exploitation pétrolière près de Prudhoe Bay en Alaska. Des enregistrements sous-marins continus ont été récoltés pendant 24 à 35 jours chaque année, principalement pendant le mois de septembre. Plus de 130 000 appels de baleines ont été enregistrés et la capacité directionnelle des DASAR a permis de déterminer par triangulation la position des baleines pour ~ 93 500 de ces appels. Le corridor de migration s’est avéré plus proche de la côte en 2003-2004 qu’en 2001-2002. Les appels des baleines étaient groupés dans le temps et l’espace et il y avait significativement plus d’appels la nuit que le jour. Soixante-cinq à 82 % des appels appartenaient au type dit « simple », et le pourcentage d’appels du type « complexe » était positivement corrélé au nombre journalier d’appels. Aucun chant n’a été détecté, mais les enregistrements de 2004 contenaient de nombreuses séquences d’appels composées de séries d’appels identiques répétés pendant 30 minutes et plus. L’utilisation des DASAR a permis d’obtenir des renseignements détaillés sur la distribution spatiale et temporelle de baleines boréales vocalisant ainsi que sur leur répertoire acoustique

Spin-Polarized Transport Across an La0.7_{0.7}Sr0.3_{0.3}MnO3_{3}/YBa2_{2}Cu3_{3}O7_{7} Interface: Role of Andreev Bound States

Transport across an La$_{0.7}$Sr$_{0.3}MnO$_{3}/YBa$_{2}Cu$_{3}$O$_{7}$(LSMO/YBCO), interface is studied as a function of temperature and surface morphology. For comparison, control measurements are performed in non-magnetic heterostructures of LaNiO$_{3}$/YBCO and Ag/YBCO. In all cases, YBCO is used as bottom layer to eliminate the channel resistance and to minimize thermal effects. The observed differential conductance re ects the role of Andreev bound states in a-b planes, and brings out for the first time the suppression of such states by the spin-polarized transport across the interface. The theoretical analysis of the measured data reveals decay of the spin polarization near the LSMO surface with temperature, consistent with the reported photoemission data.Comment: 5 pages LaTeX, 3 eps figures included, accepted by Physical Review

Quasiclassical description of transport through superconducting contacts

We present a theoretical study of transport properties through superconducting contacts based on a new formulation of boundary conditions that mimics interfaces for the quasiclassical theory of superconductivity. These boundary conditions are based on a description of an interface in terms of a simple Hamiltonian. We show how this Hamiltonian description is incorporated into quasiclassical theory via a T-matrix equation by integrating out irrelevant energy scales right at the onset. The resulting boundary conditions reproduce results obtained by conventional quasiclassical boundary conditions, or by boundary conditions based on the scattering approach. This formalism is well suited for the analysis of magnetically active interfaces as well as for calculating time-dependent properties such as the current-voltage characteristics or as current fluctuations in junctions with arbitrary transmission and bias voltage. This approach is illustrated with the calculation of Josephson currents through a variety of superconducting junctions ranging from conventional to d-wave superconductors, and to the analysis of supercurrent through a ferromagnetic nanoparticle. The calculation of the current-voltage characteristics and of noise is applied to the case of a contact between two d-wave superconductors. In particular, we discuss the use of shot noise for the measurement of charge transferred in a multiple Andreev reflection in d-wave superconductors

Inclusive cross section and double helicity asymmetry for \pi^0 production in p+p collisions at sqrt(s)=200 GeV: Implications for the polarized gluon distribution in the proton

The PHENIX experiment presents results from the RHIC 2005 run with polarized proton collisions at sqrt(s)=200 GeV, for inclusive \pi^0 production at mid-rapidity. Unpolarized cross section results are given for transverse momenta p_T=0.5 to 20 GeV/c, extending the range of published data to both lower and higher p_T. The cross section is described well for p_T < 1 GeV/c by an exponential in p_T, and, for p_T > 2 GeV/c, by perturbative QCD. Double helicity asymmetries A_LL are presented based on a factor of five improvement in uncertainties as compared to previously published results, due to both an improved beam polarization of 50%, and to higher integrated luminosity. These measurements are sensitive to the gluon polarization in the proton, and exclude maximal values for the gluon polarization.Comment: 375 authors, 7 pages, 3 figures. Submitted to Phys. Rev. D, Rapid Communications. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

System Size and Energy Dependence of Jet-Induced Hadron Pair Correlation Shapes in Cu+Cu and Au+Au Collisions at sqrt(s_NN) = 200 and 62.4 GeV

We present azimuthal angle correlations of intermediate transverse momentum (1-4 GeV/c) hadrons from {dijets} in Cu+Cu and Au+Au collisions at sqrt(s_NN) = 62.4 and 200 GeV. The away-side dijet induced azimuthal correlation is broadened, non-Gaussian, and peaked away from \Delta\phi=\pi in central and semi-central collisions in all the systems. The broadening and peak location are found to depend upon the number of participants in the collision, but not on the collision energy or beam nuclei. These results are consistent with sound or shock wave models, but pose challenges to Cherenkov gluon radiation models.Comment: 464 authors from 60 institutions, 6 pages, 3 figures, 2 tables. Submitted to Physical Review Letters. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Measurement of Bottom versus Charm as a Function of Transverse Momentum with Electron-Hadron Correlations in p+p Collisions at sqrt(s)=200 GeV

The momentum distribution of electrons from semi-leptonic decays of charm and bottom for mid-rapidity |y|<0.35 in p+p collisions at sqrt(s)=200 GeV is measured by the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) over the transverse momentum range 2 < p_T < 7 GeV/c. The ratio of the yield of electrons from bottom to that from charm is presented. The ratio is determined using partial D/D^bar --> e^{+/-} K^{-/+} X (K unidentified) reconstruction. It is found that the yield of electrons from bottom becomes significant above 4 GeV/c in p_T. A fixed-order-plus-next-to-leading-log (FONLL) perturbative quantum chromodynamics (pQCD) calculation agrees with the data within the theoretical and experimental uncertainties. The extracted total bottom production cross section at this energy is \sigma_{b\b^bar}= 3.2 ^{+1.2}_{-1.1}(stat) ^{+1.4}_{-1.3}(syst) micro b.Comment: 432 authors, 6 pages text, 3 figures. Submitted to Phys. Rev. Lett. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Scaling properties of azimuthal anisotropy in Au+Au and Cu+Cu collisions at sqrt(s_NN) = 200 GeV

Detailed differential measurements of the elliptic flow for particles produced in Au+Au and Cu+Cu collisions at sqrt(s_NN) = 200 GeV are presented. Predictions from perfect fluid hydrodynamics for the scaling of the elliptic flow coefficient v_2 with eccentricity, system size and transverse energy are tested and validated. For transverse kinetic energies KE_T ~ m_T-m up to ~1 GeV, scaling compatible with the hydrodynamic expansion of a thermalized fluid is observed for all produced particles. For large values of KE_T, the mesons and baryons scale separately. A universal scaling for the flow of both mesons and baryons is observed for the full transverse kinetic energy range of the data when quark number scaling is employed. In both cases the scaling is more pronounced in terms of KE_T rather than transverse momentum.Comment: 422 authors from 58 institutions, 6 pages, 3 figures. Submitted to Physical Review Letters. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Measurement of the top-quark mass in all-jets tt events in pp collisions at root = 7 TeV

The mass of the top quark is measured using a sample of tt¯ candidate events with at least six jets in the final state. The sample is selected from data collected with the CMS detector in pp collisions at s&#8730;=7 TeV in 2011 and corresponds to an integrated luminosity of 3.54 fb&#8722;1 . The mass is reconstructed for each event employing a kinematic fit of the jets to a tt¯ hypothesis. The top-quark mass is measured to be 173.49±0.69(stat.)±1.21(syst.) GeV. A combination with previously published measurements in other decay modes by CMS yields a mass of 173.54±0.33(stat.)±0.96(syst.) GeV

Supplementary Material for: Lambl's Excrescences: Association with Cerebrovascular Disease and Pathogenesis

<p><b><i>Background:</i></b> Lambl's excrescences (LEx) are detected by transesophageal echocardiography (TEE) and are characterized as thin, elongated, and hypermobile structures located at the leaflets' coaptation point of the heart valves. The association of LEx with cerebrovascular disease (CVD) is still undefined and yet patients with LEx and suspected CVD receive unproven effective antiplatelet or anticoagulant therapy or even undergo valve surgery. Also, the association of LEx with aging and atherogenic, inflammatory, or thrombogenic parameters has not been reported. <b><i>Methods:</i></b> Seventy-seven patients with systemic lupus erythematosus (SLE) (71 women, age 37 ± 12 years) and 26 age- and sex-matched healthy controls (22 women, age 34 ± 11 years) prospectively underwent routine history and physical exam, transcranial Doppler, brain MRI, TEE, carotid duplex, and clinical and laboratory evaluations of atherogenesis, inflammation, platelet activity, coagulation, and fibrinolysis. Subjects without stroke/TIA on enrollment (with and without LEx) had a median follow-up of 57 months. <b><i>Results:</i></b> On enrollment, 33 (43%) of 77 patients had CVD manifested as acute stroke/TIA (23 patients), cerebromicroembolism by transcranial Doppler (17 patients), or cerebral infarcts by MRI (14 patients). Mitral or aortic valve LEx were equally frequent in healthy controls (46%) as in patients with and without any CVD (39 and 43%), stroke/TIA (35 and 43%), cerebromicroembolism (41 and 42%), or cerebral infarcts (36 and 43%) (all p ≥ 0.72). Also, other mechanisms for CVD other than LEx such as Libman-Sacks vegetations, patent foramen ovale or interatrial septal aneurysm, aortic or carotid atherosclerosis, or thrombogenesis were found in ≥94% of patients with CVD. In addition, 36 subjects with and 44 without LEx had similar low incidence of stroke/TIA (1 (1.3%) and 2 (2.5%), respectively, p = 1.0) during follow-up. Finally, LEx were not associated with aging, atherogenic risk factors, atherosclerosis, inflammation, or thrombogenesis. <b><i>Conclusions:</i></b> In this study, LEx are similarly prevalent in healthy controls and SLE patients, are not associated with CVD, and are not associated with pathogenic risk factors. Therefore, the study findings suggest that LEx may not be cardioembolic substrates, may not represent pathologic valve structures, and may not require therapy.</p