24 research outputs found

    Comparative population genomics of manta rays has global implications for management

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    Understanding population connectivity and genetic diversity is of fundamental importance to conservation. However, in globally threatened marine megafauna, challenges remain due to their elusive nature and wide-ranging distributions. As overexploitation continues to threaten biodiversity across the globe, such knowledge gaps compromise both the suitability and effectiveness of management actions. Here, we use a comparative framework to investigate genetic differentiation and diversity of manta rays, one of the most iconic yet vulnerable groups of elasmobranchs on the planet. Despite their recent divergence, we show how oceanic manta rays (Mobula birostris) display significantly higher heterozygosity than reef manta rays (Mobula alfredi) and that M. birostris populations display higher connectivity worldwide. Through inferring modes of colonisation, we reveal how both contemporary and historical forces have likely influenced these patterns, with important implications for population management. Our findings highlight the potential for fisheries to disrupt population dynamics at both local and global scales and therefore have direct relevance for international conservation of marine species

    A factor analysis of the SSQ (Speech, Spatial, and Qualities of Hearing Scale)

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    OBJECTIVE: The speech, spatial, and qualities of hearing questionnaire (SSQ) is a self-report test of auditory disability. The 49 items ask how well a listener would do in many complex listening situations illustrative of real life. The scores on the items are often combined into the three main sections or into 10 pragmatic subscales. We report here a factor analysis of the SSQ that we conducted to further investigate its statistical properties and to determine its structure. DESIGN: Statistical factor analysis of questionnaire data, using parallel analysis to determine the number of factors to retain, oblique rotation of factors, and a bootstrap method to estimate the confidence intervals. STUDY SAMPLE: 1220 people who have attended MRC IHR over the last decade. RESULTS: We found three clear factors, essentially corresponding to the three main sections of the SSQ. They are termed "speech understanding", "spatial perception", and "clarity, separation, and identification". Thirty-five of the SSQ questions were included in the three factors. There was partial evidence for a fourth factor, "effort and concentration", representing two more questions. CONCLUSIONS: These results aid in the interpretation and application of the SSQ and indicate potential methods for generating average scores

    Intraspecific differences in short- and long-term foraging strategies of reef manta ray (Mobula alfredi) in the Chagos Archipelago

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    Assessing the foraging ecology of a threatened species is necessary to understand their movement behaviour and habitat use patterns, which are essential for developing effective protection strategies. Here, the foraging ecology of reef manta rays (Mobula alfredi) in the Chagos Archipelago, a region encompassed by a vast no-take marine protected area (MPA), was investigated using stable isotope analysis of skin and muscle tissue. Enriched δ13C values suggest the population predominantly forages in nearshore environments. Skin δ13C values increased with increased rainfall, likely associated with the boosts in primary production and zooplankton biomass due to the coastal advection of seabird guano. Annual variations in δ13C values of skin and muscle were observed and are consistent with reduced nutrient transport associated with the effects of Indian Ocean Dipole oscillations, including a deepening of the thermocline, a suppression of cold-water upwelling, and reduced rainfall. Short- and long-term foraging strategies and locations were identified by applying hierarchical clustering, isotopic niche analysis, and Bayesian stable isotope mixing models to δ13C and δ15N of paired skin and muscle tissue samples. Two isotopically distinct groups of M. alfredi were identified, employing either local foraging strategies restricted to specific locations or wide-ranging strategies that likely mean they engage in regular migrations throughout the archipelago. Ninety-eight percent of M. alfredi were estimated to switch between strategies utilising and connecting multiple discrete nearshore habitats, emphasising their role in ecosystem functioning by facilitating the transport of nutrients across ecosystem boundaries. However, illegal, unreported, and unregulated fishing and lost or abandoned fishing gear commonly occur within the MPA. Locations of particular concern are Egmont Atoll as it is a highly active aggregation location and Peros Banhos Atoll where IUU frequently occurs and M. alfredi are estimated to be heavily reliant upon for foraging. Frequent migrations between atolls by M. alfredi also raises concern over their vulnerability to these activities along migration corridors. This research bridges current knowledge gaps in this population's foraging ecology and concomitant movement patterns, which should inform conservation strategies in the region

    Videos to BEH 3835

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    Video 1: Breaching behaviour by Mobula alfredi equipped with a Crittercam in Raa Atoll, Maldives.Video 2: Surface feeding behaviour by Mobula alfredi equipped with a Crittercam in Raa Atoll, Maldives.Video 3: Courtship behaviour as recorded Mobula alfredi equipped with a Crittercam in Raa Atoll, Maldives.Video 4: A reef manta ray (Mobula alfredi) equipped with a Crittercam approaches a cleaning station. Species of cleaner wrasse (Labroides dimidiatus, Thalassoma amblycephalum, Thalassoma Lunare) can be observed cleaning the mantas.Video 5: Cleaning behaviour by Clarion Angelfish (Holacanthus clarionensis) as recorded by Mobula birostris equipped with a Crittercam in Revillagigedo Archipelago, Mexico.Video 6: Social cruising behaviour as recorded by Mobula alfredi in Raa Atoll, Maldives.Video 7: Solitary cruising along the seabed by Mobula birostris in Revillagigedo Archipelago, Mexico.Video 8: Crittercam recording of spinetail devil rays (Mobula mobular) interacting with Mobula alfredi in Raa Atoll, Maldives.Video 9: A crittercam recording of trevally (Caranx ignobilis) interacting with Mobula alfredi in Raa Atoll, Maldives, possibly as an abrasive surface to scratch themselves to remove parasites.</p

    Human health risk assessment for aluminium, aluminium oxide, and aluminium hydroxide.

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    International audienc

    Search for the rare hadronic decay Bs0ppˉB_s^0\to p \bar{p}

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    A search for the rare hadronic decay Bs0→pp¯ is performed using proton-proton collision data recorded by the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 6  fb-1. No evidence of the decay is found and an upper limit on its branching fraction is set at B(Bs0→pp¯)&lt;4.4(5.1)×10-9 at 90% (95%) confidence level; this is currently the world’s best upper limit. The decay mode B0→pp¯ is measured with very large significance, confirming the first observation by the LHCb experiment in 2017. The branching fraction is determined to be B(B0→pp¯)=(1.27±0.15±0.05±0.04)×10-8, where the first uncertainty is statistical, the second is systematic and the third is due to the external branching fraction of the normalization channel B0→K+π-. The combination of the two LHCb measurements of the B0→pp¯ branching fraction yields B(B0→pp¯)=(1.27±0.13±0.05±0.03)×10-8.A search for the rare hadronic decay Bs0ppˉB_s^0\to p \bar{p} is performed using proton-proton collision data recorded by the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 6 fb1^{-1}. No evidence of the decay is found and an upper limit on its branching fraction is set at B(Bs0ppˉ)<4.4 (5.1)×109{\cal B}(B_s^0\to p \bar{p}) < 4.4~(5.1) \times 10^{-9} at 90% (95%) confidence level; this is currently the world's best upper limit. The decay mode B0ppˉB^0\to p \bar{p} is measured with very large significance, confirming the first observation by the LHCb experiment in 2017. The branching fraction is determined to be B(B0ppˉ)=(1.27±0.15±0.05±0.04)×108{\cal B}(B^0\to p \bar{p}) = \rm (1.27 \pm 0.15 \pm 0.05 \pm 0.04) \times 10^{-8}, where the first uncertainty is statistical, the second is systematic and the third is due to the external branching fraction of the normalization channel B0K+πB^0\to K^+\pi^-. The combination of the two LHCb measurements of the B0ppˉB^0\to p \bar{p} branching fraction yields B(B0ppˉ)=(1.27±0.13±0.05±0.03)×108{\cal B}(B^0\to p \bar{p}) = \rm (1.27 \pm 0.13 \pm 0.05 \pm 0.03) \times 10^{-8}

    Nuclear modification factor of neutral pions in the forward and backward regions in ppPb collisions

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    The nuclear modification factor of neutral pions is measured in proton-lead collisions collected at a center-of-mass energy per nucleon of 8.168.16 TeV with the LHCb detector. The π0\pi^0 production cross section is measured differentially in transverse momentum (pTp_{T}) for 1.5π0 production cross section is measured differentially in transverse momentum (pT) for 1.5<pT<10.0  GeV and in center-of-mass pseudorapidity (ηc.m.) regions 2.5<ηc.m.<3.5 (forward) and -4.0<ηc.m.<-3.0 (backward) defined relative to the proton beam direction. The forward measurement shows a sizable suppression of π0 production, while the backward measurement shows the first evidence of π0 enhancement in proton-lead collisions at the LHC. Together, these measurements provide precise constraints on models of nuclear structure and particle production in high-energy nuclear collisions.The nuclear modification factor of neutral pions is measured in proton-lead collisions collected at a center-of-mass energy per nucleon of 8.16~{\rm TeV}withtheLHCbdetector.The with the LHCb detector. The \pi^0productioncrosssectionismeasureddifferentiallyintransversemomentum( production cross section is measured differentially in transverse momentum (p_{\rm T})for) for 1.5<p_{\rm T}<10.0~{\rm GeV}andincenterofmasspseudorapidity( and in center-of-mass pseudorapidity (\eta_{\rm c.m.})regions) regions 2.5<\eta_{\rm c.m.}<3.5(forward)and (forward) and -4.0<\eta_{\rm c.m.}<-3.0(backward)definedrelativetotheprotonbeamdirection.Theforwardmeasurementshowsasizablesuppressionof (backward) defined relative to the proton beam direction. The forward measurement shows a sizable suppression of \pi^0production,whilethebackwardmeasurementshowsthefirstevidenceof production, while the backward measurement shows the first evidence of \pi^0$ enhancement in proton-lead collisions at the LHC. Together, these measurements provide precise constraints on models of nuclear structure and particle production in high-energy nuclear collisions

    Observation of sizeable ω\omega contribution to χc1(3872)π+πJ/ψ\chi_{c1}(3872) \to \pi^+\pi^- J/\psi decays

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    Resonant structures in the dipion mass spectrum from χc1(3872)π+πJ/ψ\chi_{c1}(3872)\to\pi^+\pi^- J/\psi decays, produced via B+K+χc1(3872)B^+\to K^+\chi_{c1}(3872) decays, are analyzed using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb1^{-1}. A sizeable contribution from the isospin conserving χc1(3872)ωJ/ψ\chi_{c1}(3872)\to\omega J/\psi decay is established for the first time, (21.4±2.3±2.0)%(21.4\pm2.3\pm2.0)\%, with a significance of more than 7.1σ7.1\sigma. The amplitude of isospin violating decay, χc1(3872)ρ0J/ψ\chi_{c1}(3872)\to\rho^0 J/\psi, relative to isospin conserving decay, χc1(3872)ωJ/ψ\chi_{c1}(3872)\to\omega J/\psi, is properly determined, and it is a factor of six larger than expected for a pure charmonium state.Resonant structures in the dipion mass spectrum from χc1(3872)→π+π-J/ψ decays, produced via B+→K+χc1(3872) decays, are analyzed using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9  fb-1. A sizeable contribution from the isospin conserving χc1(3872)→ωJ/ψ decay is established for the first time, (21.4±2.3±2.0)%, with a significance of more than 7.1σ. The amplitude of isospin violating decay, χc1(3872)→ρ0J/ψ, relative to isospin conserving decay, χc1(3872)→ωJ/ψ, is properly determined, and it is a factor of 6 larger than expected for a pure charmonium state.Resonant structures in the dipion mass spectrum from χc1(3872)π+πJ/ψ\chi_{c1}(3872)\to\pi^+\pi^- J/\psi decays, produced via B+K+χc1(3872)B^+\to K^+\chi_{c1}(3872) decays, are analyzed using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb1fb^{-1}. A sizeable contribution from the isospin conserving χc1(3872)ωJ/ψ\chi_{c1}(3872)\to\omega J/\psi decay is established for the first time, (21.4±2.3±2.0)%(21.4\pm2.3\pm2.0)\%, with a significance of more than 7.1σ7.1\sigma. The amplitude of isospin violating decay, χc1(3872)ρ0J/ψ\chi_{c1}(3872)\to\rho^0 J/\psi, relative to isospin conserving decay, χc1(3872)ωJ/ψ\chi_{c1}(3872)\to\omega J/\psi, is properly determined, and it is a factor of six larger than expected for a pure charmonium state

    Measurement of CP asymmetries in D(s)+ηπ+ {D}_{(s)}^{+}\to \eta {\pi}^{+} and D(s)+ηπ+ {D}_{(s)}^{+}\to {\eta}^{\prime }{\pi}^{+} decays

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    Searches for CP violation in the decays D(s)+ηπ+ {D}_{(s)}^{+}\to \eta {\pi}^{+} and D(s)+ηπ+ {D}_{(s)}^{+}\to {\eta}^{\prime }{\pi}^{+} are performed using pp collision data corresponding to 6 fb1^{−1} of integrated luminosity collected by the LHCb experiment. The calibration channels D(s)+ϕπ+ {D}_{(s)}^{+}\to \phi {\pi}^{+} are used to remove production and detection asymmetries. The resulting CP-violating asymmetries areACP=(D+ηπ+)=(0.34±0.66±0.16±0.05)%,ACP=(Ds+ηπ+)=(0.32±0.51±0.12)%,ACP=(D+ηπ+)=(0.49±0.18±0.06±0.05)%,ACP=(Ds+ηπ+)=(0.01±0.12±0.08)%, {\displaystyle \begin{array}{l}{\mathcal{A}}^{CP}=\left({D}^{+}\to \eta {\pi}^{+}\right)=\left(0.34\pm 0.66\pm 0.16\pm 0.05\right)\%,\\ {}{\mathcal{A}}^{CP}=\left({D}_s^{+}\to \eta {\pi}^{+}\right)=\left(0.32\pm 0.51\pm 0.12\right)\%,\\ {}\begin{array}{l}{\mathcal{A}}^{CP}=\left({D}^{+}\to {\eta}^{\prime }{\pi}^{+}\right)=\left(0.49\pm 0.18\pm 0.06\pm 0.05\right)\%,\\ {}{\mathcal{A}}^{CP}=\left({D}_s^{+}\to {\eta}^{\prime }{\pi}^{+}\right)=\left(0.01\pm 0.12\pm 0.08\right)\%,\end{array}\end{array}} where the first uncertainty is statistical, the second is systematic and the third, relevant for the D+^{+} channels, is due to the uncertainty on ACP=(D+ϕπ+) {\mathcal{A}}^{CP}=\left({D}^{+}\to \phi {\pi}^{+}\right) . These measurements, currently the most precise for three of the four channels considered, are consistent with the absence of CP violation. A combination of these results with previous LHCb measurements is presented.[graphic not available: see fulltext]Searches for CPCP violation in the decays D(s)+ηπ+D^+_{(s)}\rightarrow \eta \pi^+ and D(s)+ηπ+D^+_{(s)}\rightarrow \eta^{\prime} \pi^+ are performed using pppp collision data corresponding to 6 fb1^{-1} of integrated luminosity collected by the LHCb experiment. The calibration channels D(s)+ϕπ+D^+_{(s)}\rightarrow \phi \pi^+ are used to remove production and detection asymmetries. The resulting CPCP-violating asymmetries are ACP(D+ηπ+)=(0.34±0.66±0.16±0.05)%A^{CP}(D^+ \rightarrow \eta \pi^+) = (0.34 \pm 0.66 \pm 0.16 \pm 0.05)\%, ACP(Ds+ηπ+)=(0.32±0.51±0.12)%A^{CP}(D^+_s \rightarrow \eta \pi^+) = (0.32 \pm 0.51 \pm 0.12)\%, ACP(D+ηπ+)=(0.49±0.18±0.06±0.05)%A^{CP}(D^+ \rightarrow \eta^{\prime} \pi^+) = (0.49 \pm 0.18 \pm 0.06 \pm 0.05)\%, ACP(Ds+ηπ+)=(0.01±0.12±0.08)%A^{CP}(D^+_s \rightarrow \eta^{\prime} \pi^+) = (0.01 \pm 0.12 \pm 0.08)\%, where the first uncertainty is statistical, the second is systematic and the third, relevant for the D+D^+ channels, is due to the uncertainty on ACP(D+ϕπ+)A^{CP}(D^+ \to \phi \pi^+). These measurements, currently the most precise for three of the four channels considered, are consistent with the absence of CPCP violation. A combination of these results with previous LHCb measurements is presented

    Amplitude analysis of the Λc+pKπ+\Lambda^+_c\to pK^-\pi^+ decay and Λc+\Lambda^+_c baryon polarization measurement in semileptonic beauty hadron decays

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    An amplitude analysis of Λc+pKπ+\Lambda^+_c \to pK^-\pi^+ decays together with a measurement of the Λc+\Lambda^+_c polarization vector in semileptonic beauty hadron decays is presented. A sample of 400000400\,000 candidates is selected from proton-proton collisions recorded by the LHCb detector at a center-of-mass energy of 13 TeV. An amplitude model is developed and the resonance fractions as well as two- and three-body decay parameters are reported. The mass and width of the Λ(2000)\Lambda(2000) state are also determined. A significant Λc+\Lambda^+_c polarization is found. A large sensitivity of the Λc+pKπ+\Lambda^+_c \to pK^-\pi^+ decay to the polarization is seen, making the amplitude model suitable for Λc+\Lambda^+_c polarization measurements in other systems.An amplitude analysis of Λc+→pK-π+ decays together with a measurement of the Λc+ polarization vector in semiōleptonic beauty hadron decays is presented. A sample of 400 000 candidates is selected from proton-proton collisions recorded by the LHCb detector at a center-of-mass energy of 13 TeV. An amplitude model is developed and the resonance fractions as well as two- and three-body decay parameters are reported. The mass and width of the Λ(2000) state are also determined. A significant Λc+ polarization is found. A large sensitivity of the Λc+→pK-π+ decay to the polarization is seen, making the amplitude model suitable for Λc+ polarization measurements in other systems.An amplitude analysis of Λc+pKπ+\Lambda^+_c \to pK^-\pi^+ decays together with a measurement of the Λc+\Lambda^+_c polarization vector in semileptonic beauty hadron decays is presented. A sample of 400000400\,000 candidates is selected from proton-proton collisions recorded by the LHCb detector at a center-of-mass energy of 13 TeV. An amplitude model is developed and the resonance fractions as well as two- and three-body decay parameters are reported. The mass and width of the Λ(2000)\Lambda(2000) state are also determined. A significant Λc+\Lambda^+_c polarization is found. A large sensitivity of the Λc+pKπ+\Lambda^+_c \to pK^-\pi^+ decay to the polarization is seen, making the amplitude model suitable for Λc+\Lambda^+_c polarization measurements in other systems
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