Lithium atom interferometer using laser diffraction : description and experiments

We have built and operated an atom interferometer of the Mach-Zehnder type. The atomic wave is a supersonic beam of lithium seeded in argon and the mirrors and beam-splitters for the atomic wave are based on elastic Bragg diffraction on laser standing waves at 671 nm. We give here a detailed description of our experimental setup and of the procedures used to align its components. We then present experimental signals, exhibiting atomic interference effects with a very high visibility, up to 84.5 %. We describe a series of experiments testing the sensitivity of the fringe visibility to the main alignment defects and to the magnetic field gradient.Comment: 8 avril 200

Higher harmonic anisotropic flow measurements of charged particles in Pb-Pb collisions at 2.76 TeV

We report on the first measurement of the triangular $v_3$, quadrangular $v_4$, and pentagonal $v_5$ charged particle flow in Pb-Pb collisions at 2.76 TeV measured with the ALICE detector at the CERN Large Hadron Collider. We show that the triangular flow can be described in terms of the initial spatial anisotropy and its fluctuations, which provides strong constraints on its origin. In the most central events, where the elliptic flow $v_2$ and $v_3$ have similar magnitude, a double peaked structure in the two-particle azimuthal correlations is observed, which is often interpreted as a Mach cone response to fast partons. We show that this structure can be naturally explained from the measured anisotropic flow Fourier coefficients.Comment: 10 pages, 4 figures, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/387

Controversy and consensus on the management of elevated sperm DNA fragmentation in male infertility: A global survey, current guidelines, and expert recommendations

Purpose Sperm DNA fragmentation (SDF) has been associated with male infertility and poor outcomes of assisted reproductive technology (ART). The purpose of this study was to investigate global practices related to the management of elevated SDF in infertile men, summarize the relevant professional society recommendations, and provide expert recommendations for managing this condition. Materials and Methods An online global survey on clinical practices related to SDF was disseminated to reproductive clinicians, according to the CHERRIES checklist criteria. Management protocols for various conditions associated with SDF were captured and compared to the relevant recommendations in professional society guidelines and the appropriate available evidence. Expert recommendations and consensus on the management of infertile men with elevated SDF were then formulated and adapted using the Delphi method. Results A total of 436 experts from 55 different countries submitted responses. As an initial approach, 79.1% of reproductive experts recommend lifestyle modifications for infertile men with elevated SDF, and 76.9% prescribe empiric antioxidants. Regarding antioxidant duration, 39.3% recommend 4–6 months and 38.1% recommend 3 months. For men with unexplained or idiopathic infertility, and couples experiencing recurrent miscarriages associated with elevated SDF, most respondents refer to ART 6 months after failure of conservative and empiric medical management. Infertile men with clinical varicocele, normal conventional semen parameters, and elevated SDF are offered varicocele repair immediately after diagnosis by 31.4%, and after failure of antioxidants and conservative measures by 40.9%. Sperm selection techniques and testicular sperm extraction are also management options for couples undergoing ART. For most questions, heterogenous practices were demonstrated. Conclusions This paper presents the results of a large global survey on the management of infertile men with elevated SDF and reveals a lack of consensus among clinicians. Furthermore, it demonstrates the scarcity of professional society guidelines in this regard and attempts to highlight the relevant evidence. Expert recommendations are proposed to help guide clinicians

macrocarpum

Lomatium macrocarpum (Hook. & Arn.) Coult. & RoseLarge-fruited desert parsleylomatium à gros fruitsCorrals; N of Rd 774T. ChisholmDry S.E. facing sloped meadow1523 mThalictrum venulosum, Selaginella densa, Delphinium bicolor, Amelanchier alnifolia, Primula conjugens, Achillea millefolium, Lupinus sericeus, Erythronium grandiflorum, Calochortus apiculatus, Toxicoscordion venenosum, Sedum lanceolatum, Heuchera cylindric

macrocarpum

Lomatium macrocarpum (Hook. & Arn.) Coult. & Roselomatium à gros fruitsLarge-fruited desert parsleyCorrals; N of Rd 774T. ChisholmDry S.E. facing sloped meadow1523 mThalictrum venulosum, Selaginella densa, Delphinium bicolor, Amelanchier alnifolia, Primula conjugens, Achillea millefolium, Lupinus sericeus, Erythronium grandiflorum, Calochortus apiculatus, Toxicoscordion venenosum, Sedum lanceolatum, Heuchera cylindric

Sedimentary dynamics on isolated highs in Lake Baikal: evidence from detailed high-resolution geophysical data and sediment cores

High- and very-high-resolution seismic data, side-scan sonar mosaics and piston cores from three isolated highs in Lake Baikal (Vydrino Shoulder, Posolsky Bank, Continent Ridge) have allowed to document in unprecedented detail the depositional, re-depositional and tectonic processes and to characterise the overall sedimentary environment on such isolated highs. Our data show that Vydrino Shoulder actually represents a turbidity- or underflow-sourced slope fan, with a distinct channel-levee morphology, and affected by tectonics and stratigraphic unconformities. Sediment cores contain up to 90% of terrigenous material. Posolsky Bank is a major tilted fault block, clearly affected by tectonic activity, by stratigraphic unconformities and by mass wasting along its margins. Sedimentation on its crest is undisturbed, but average sedimentation rates are high due to the influence of the nearby Selenga River. Continent Ridge is also affected by active faulting, stratigraphic unconformities and by mass-wasting along its flanks. The area receives only 30% of terrigenous input. There are no signs of sediment reworking due to bottom-currents. Our study thus shows that in comparison with other environments in Lake Baikal, the isolated highs probably hold the best potential to contain a high-quality, continuous, undisturbed and undiluted sedimentary record suitable for paleoclimate research. (C) 2004 Elsevier B.V. All rights reserved.Continen