Exotic Baryons and Monopole Excitations in a Chiral Soliton Model

We compute the spectra of exotic pentaquarks and monopole excitations of the low--lying ${1/2}^+$ and ${3/2}^+$ baryons in a chiral soliton model. Once the low--lying baryon properties are fit, the other states are predicted without any more adjustable parameters. This approach naturally leads to a scenario in which the mass spectrum of the next to lowest--lying $J^\pi={1/2}^+$ states is fairly well approximated by the ideal mixing pattern of the $\mathbf{8}\oplus\bar{\mathbf{10}}$ representation of flavor SU(3). We compare our results to predictions obtained in other pictures for pentaquarks and speculate about the spin--parity assignment for $\Xi(1690)$ and $\Xi(1950)$Comment: 16 pages, 2 figures, 6 table

The Contribution of CALL to Advanced-Level Foreign/Second Language Instruction

This paper evaluates the contribution of instructional technology to advanced-level foreign/second language learning (AL2) over the past thirty years. It is shown that the most salient feature of AL2 practice and associated Computer-Assisted Language Learning (CALL) research are their rarity and restricted nature. Based on an analysis of four leading CALL journals (CALICO, CALL, LL&T, ReCALL), less than 3% of all CALL publications deal with AL2. Moreover, within this body of research, the range of languages involved is very restricted. Three languages, English, German and French, account for nearly 87% of the studies. Likewise, in nearly 81% of the cases, the learning focus is on the written language. Attention to oral-aural skills accounts for only 18% of all AL2 CALL projects. Whatever the targeted language or linguistic focus, the most striking aspect of advanced-level L2 CALL studies is the lack of information given regarding the competency level of students and the linguistic level of the activities undertaken. The determination of these critical parameters is thus of necessity very much a highly interpretive process. Based on the available evidence, it is estimated that half of the learners in these AL2 studies were in fact within the Common European Framework of Reference (CEFR) B1 range, i.e. below what would generally be considered as advanced-level competency. So, too, half of the assigned tasks were deemed to have been below the B2 level, with 40% of these below the B1 level. This study concludes that both quantitatively and qualitatively the contribution of instructional technology to advanced-level L2 acquisition has been very limited

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

Exclusive photoproduction of pi degrees up to large values of Mandelstam variables s, t, and u with CLAS

Exclusive photoproduction cross sections have been measured for the process $\gamma p \rightarrow p\pi^0(e^+e^-(\gamma))$ with the Dalitz decay final state using tagged photon energies in the range of $E_{\gamma} = 1.275-5.425$ GeV. The complete angular distribution of the final state $\pi^0$, for the entire photon energy range up to large values of $t$ and $u$, has been measured for the first time. The data obtained show that the cross section $d\sigma/dt$, at mid to large angles, decreases with energy as $s^{-6.89\pm 0.26}$. This is in agreement with the perturbative QCD quark counting rule prediction of $s^{-7}$. Paradoxically, the size of angular distribution of measured cross sections is greatly underestimated by the QCD based Generalized Parton Distribution mechanism at highest available invariant energy $s=11$ GeV$^2$. At the same time, the Regge exchange based models for $\pi^0$ photoproduction are more consistent with experimental data.Comment: 7 pages, 6 figure

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

Electroweak measurements in electron–positron collisions at w-boson-pair energies at lep

Contains fulltext : 121524.pdf (preprint version ) (Open Access