La peche continentale au lac de Songori (region du Gontougo; Nord-Est de la Cote D'Ivoire): Facteurs de production et niveau d'exploitation halieutique

RESUMEL’étude de l’activité de pêche au lac de Songori (environ 1,5 km²) dans la région du Gontougo (Nord- Est de la Côte d’Ivoire) s’est déroulée de janvier 2013 à décembre 2014. Elle montre que la pêche est essentiellement pratiquée par des ivoiriens (100 %) avec une absence de pêcheurs professionnels. Ces acteurs sont majoritairement des pêcheurs-agriculteurs (80 %) et considèrent la pêche comme une activité secondaire. Ils utilisent généralement les filets maillants (89,66 %) comme engins de pêche. Des pirogues monoxyles (83,33 %) constituent les embarcations les plus couramment utilisées. L’effort de pêche est autour de 2,7 pêcheurs/km². Les captures comprennent des espèces économiquement importantes avec une prédominance de Oreochromis niloticus (68,10 % à 78,89 % de la biomasse annuelle). La production annuelle est comprise entre 13,33 et 13,51 t soit entre 88,9 et 90,1 kg/ha/an. Elle reste inférieure aux captures potentielles (entre 100 et 750 kg/ha/an) indiquées par la FAO pour ces plans d’eau ; ce qui montre qu’il peut exister une marge pour augmenter la biomasse exploitée. Toutefois, le manque de professionnalisme des pêcheurs, la vétusté des engins de pêche et l’occupation du tiers (environ) du volume d’eau exploitable par des plantes aquatiques constituent une entrave majeure au développement de cette activité. ABSTRACTINLAND FISHING AT LAKE SONGORI (GONTOUGO REGION; NORTH-EAST OF THE IVORY COAST): FACTORS OF PRODUCTION AND LEVEL OF FISHING EXPLOITATIONThe study of fishing activity on Lake Songori (about 1.5 km²) in the area of Gontougo (north-east of Ivory Coast) took place from January 2013 to December 2014. It shows that fishing is mainly practiced by Ivorians (100%) with no professional fishermen. These actors are mainly fishermen-farmers (91.67%) and consider fishing as a secondary activity. They generally use gillnets (89.66%) as fishing gear. Monoxyls canoes (83.33%) are the most commonly used boats. The fishing effort is around 2.7 fishermen / km². Catches include economically important species with a predominance of Oreochromis niloticus (68.10% to 78.89% of the annual biomass). The annual production is between 13,33 and 13,51 t or between 88.9 and 90.1 kg / ha / year. It remains lower the potential catches (between 100 and 750 kg / ha / year) reported by FAO for these water bodies; which shows that there may be a margin to increase the exploited biomass. However, the lack of professionalism of fishermen, the obsolescence of fishing gear and the occupation of about one-third of the volume of water exploitable by aquatic plants constitute a major obstacle to the development of this activity

Continuous function optimization using hybrid ant colony approach with orthogonal design scheme

A hybrid Orthogonal Scheme Ant Colony Optimization (OSACO) algorithm for continuous function optimization (CFO) is presented in this paper. The methodology integrates the advantages of Ant Colony Optimization (ACO) and Orthogonal Design Scheme (ODS). OSACO is based on the following principles: a) each independent variable space (IVS) of CFO is dispersed into a number of random and movable nodes; b) the carriers of pheromone of ACO are shifted to the nodes; c) solution path can be obtained by choosing one appropriate node from each IVS by ant; d) with the ODS, the best solved path is further improved. The proposed algorithm has been successfully applied to 10 benchmark test functions. The performance and a comparison with CACO and FEP have been studied

Electron spin as a spectrometer of nuclear spin noise and other fluctuations

This chapter describes the relationship between low frequency noise and coherence decay of localized spins in semiconductors. Section 2 establishes a direct relationship between an arbitrary noise spectral function and spin coherence as measured by a number of pulse spin resonance sequences. Section 3 describes the electron-nuclear spin Hamiltonian, including isotropic and anisotropic hyperfine interactions, inter-nuclear dipolar interactions, and the effective Hamiltonian for nuclear-nuclear coupling mediated by the electron spin hyperfine interaction. Section 4 describes a microscopic calculation of the nuclear spin noise spectrum arising due to nuclear spin dipolar flip-flops with quasiparticle broadening included. Section 5 compares our explicit numerical results to electron spin echo decay experiments for phosphorus doped silicon in natural and nuclear spin enriched samples.Comment: Book chapter in "Electron spin resonance and related phenomena in low dimensional structures", edited by Marco Fanciulli. To be published by Springer-Verlag in the TAP series. 35 pages, 9 figure

Higher levels of (Internet) Gaming Disorder symptoms according to the WHO and APA frameworks associate with lower striatal volume

Background and aims: Growing concerns about the addictive nature of Internet and computer games led to the preliminary recognition of Internet Gaming Disorder (IGD) as an emerging disorder by the American Psychiatric Association (APA) and the official recognition of Gaming Disorder (GD) as a new diagnosis by the World Health Organization (WHO). While the definition of clear diagnostic criteria for (I)GD represents an important step for diagnosis and treatment of the disorder, potential neurobiological correlates of the criteria remain to be explored. Methods: The present study employed a dimensional Magnetic Resonance Imaging (MRI) approach to determine associations between (I)GD symptom-load according to the APA and WHO diagnostic frameworks and brain structure in a comparably large sample of n = 82 healthy subjects. Results: Higher symptom-load on both, the APA and WHO diagnostic frameworks convergently associated with lower volumes of the striatum. Discussion: The results from this exploratory study provide the first initial evidence for a neurobiological foundation of the proposed diagnostic criteria for (I)GD according to both diagnostic classification systems and suggest that the transition from non-disordered to disordered gaming may be accompanied by progressive neuroplastic changes in the striatum, thus resembling progressive changes in other addictive disorders. Conclusions: The proposed (I)GD criteria in both diagnostic systems were associated with neurostructural alterations in the striatum, suggesting an association with progressive changes in the motivational systems of the brain

A population of hypercompact HII regions identified from young HII regions

CONTEXT: The derived physical parameters for young H$\tiny{II}$ regions are normally determined assuming the emission region to be optically-thin. However, this is unlikely to hold for young H$\tiny{II}$ regions such as Hyper-compact H$\tiny{II}$ (HC H$\tiny{II}$) and Ultra-compact H$\tiny{II}$ (UC H$\tiny{II}$) regions and leads to the underestimation of their properties. This can be overcome by fitting the SEDs over a wide range of radio frequencies. AIMS: Two primary goals are (1) determining physical properties from radio SEDs and finding potential HC H$\tiny{II}$ regions; (2) using these physical properties to investigate their evolution. METHODS: We used Karl G. Jansky Very Large Array (VLA) to make observations of X-band and K-band with angular-resolutions of ~ 1:7′′ and ~ 0:7′′, respectively, toward 114 H$\tiny{II}$ regions with rising-spectra $α{5GHz\choose 1.4GHz} > 0$. We complement our observations with VLA archival data and construct SEDs between 1-26 GHz and model them assuming an ionisation-bounded H$\tiny{II}$ region with uniform density. RESULTS: The sample has a mean electron density of n$_e$ = 1.6 x 10$^4$ cm$^{-3}$, diameter diam = 0.14 pc, and emission measure EM = 1.9 x 10$^7$ pc cm$^{-6}$. We identify 16 HC H$\tiny{II}$ region candidates and 8 intermediate objects between the classes of HC H$\tiny{II}$ and UC H$\tiny{II}$ regions. The n$_e$, diam, and EM change as expected, however, the Lyman continuum flux is relatively constant over time. We find that about 67% of Lyman continuum photons are absorbed by dust within these H$\tiny{II}$ regions and the dust absorption fraction tends to be more significant for more compact and younger H$\tiny{II}$ regions. CONCLUSIONS: Young H$\tiny{II}$ regions are commonly located in dusty clumps; HC H$\tiny{II}$ regions and intermediate objects are often associated with various masers, outflows, broad radio recombination lines, and extended green objects, and the accretion at the two stages tends to be quickly reduced or halted

Single-photon Transistors Based on the Interaction of an Emitter and Surface Plasmons

A symmetrical approach is suggested (Chang DE et al. Nat Phys 3:807, 2007) to realize a single-photon transistor, where the presence (or absence) of a single incident photon in a ‘gate’ field is sufficient to allow (prevent) the propagation of a subsequent ‘signal’ photon along the nanowire, on condition that the ‘gate’ field is symmetrically incident from both sides of an emitter simultaneously. We present a scheme for single-photon transistors based on the strong emitter-surface-plasmon interaction. In this scheme, coherent absorption of an incoming ‘gate’ photon incident along a nanotip by an emitter located near the tip of the nanotip results in a state flip in the emitter, which controls the subsequent propagation of a ‘signal’ photon in a nanowire perpendicular to the axis of the nanotip

Genetic variants in anti-Müllerian hormone-related genes and breast cancer risk: results from the AMBER consortium

Purpose: Circulating anti-Müllerian hormone (AMH) levels are positively associated with time to menopause and breast cancer risk. We examined breast cancer associations with single nucleotide polymorphisms (SNPs) in the AMH gene or its receptor genes, ACVR1 and AMHR2, among African American women. Methods: In the AMBER consortium, we tested 65 candidate SNPs, and 1130 total variants, in or near AMH, ACVR1, and AMHR2 and breast cancer risk. Overall, 3649 cases and 4230 controls contributed to analyses. Odds ratios (OR) and 95% confidence intervals (CI) for breast cancer were calculated using multivariable logistic regression. Results: After correction for multiple comparisons (false-discovery rate of 5%), there were no statistically significant associations with breast cancer risk. Without correction for multiple testing, four candidate SNPs in ACVR1 and one near AMH were associated with breast cancer risk. In ACVR1, rs13395576[C] was associated with lower breast cancer risk overall (OR 0.84; 95% CI 0.72, 0.97) and for ER+ disease (OR 0.75; CI 0.62, 0.89) (p < 0.05). Rs1220110[A] and rs1220134[T] each had ORs of 0.89–0.90 for postmenopausal and ER+ breast cancer (p ≤ 0.03). Conversely, rs1682130[T] was associated with higher risk of ER+ breast cancer (OR 1.17; 95% CI 1.04, 1.32). Near AMH, rs6510652[T] had ORs of 0.85–0.90 for breast cancer overall and after menopause (p ≤ 0.02). Conclusions: The present results, from a large study of African American women, provide limited support for an association between AMH-related polymorphisms and breast cancer risk and require replication in other studies

Heavy quarkonium: progress, puzzles, and opportunities

A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the $B$-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b}, and b\bar{c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K. Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D. Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A. Petrov, P. Robbe, A. Vair

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02