256 research outputs found

    Data cooperatives as catalysts for collaboration, data sharing, and the (trans)formation of the digital commons

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    Network effects, economies of scale, and lock-in-effects increasingly lead to a concentration of digital resources and capabilities, hindering the free and equitable development of digital entrepreneurship (SDG9), new skills, and jobs (SDG8), especially in small communities (SDG11) and their small and medium-sized enterprises (“SMEs”). To ensure the affordability and accessibility of technologies, promote digital entrepreneurship and community well-being (SDG3), and protect digital rights, we propose data cooperatives [1,2] as a vehicle for secure, trusted, and sovereign data exchange [3,4]. In post-pandemic times, community/SME-led cooperatives can play a vital role by ensuring that supply chains to support digital commons are uninterrupted, resilient, and decentralized [5]. Digital commons and data sovereignty provide communities with affordable and easy access to information and the ability to collectively negotiate data-related decisions. Moreover, cooperative commons (a) provide access to the infrastructure that underpins the modern economy, (b) preserve property rights, and (c) ensure that privatization and monopolization do not further erode self-determination, especially in a world increasingly mediated by AI. Thus, governance plays a significant role in accelerating communities’/SMEs’ digital transformation and addressing their challenges. Cooperatives thrive on digital governance and standards such as open trusted Application Programming Interfaces (APIs) that increase the efficiency, technological capabilities, and capacities of participants and, most importantly, integrate, enable, and accelerate the digital transformation of SMEs in the overall process. This policy paper presents and discusses several transformative use cases for cooperative data governance. The use cases demonstrate how platform/data-cooperatives, and their novel value creation can be leveraged to take digital commons and value chains to a new level of collaboration while addressing the most pressing community issues. The proposed framework for a digital federated and sovereign reference architecture will create a blueprint for sustainable development both in the Global South and North

    Retrotransposons Are the Major Contributors to the Expansion of the Drosophila ananassae Muller F Element

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    The discordance between genome size and the complexity of eukaryotes can partly be attributed to differences in repeat density. The Muller F element (∌5.2 Mb) is the smallest chromosome in Drosophila melanogaster, but it is substantially larger (>18.7 Mb) in D. ananassae. To identify the major contributors to the expansion of the F element and to assess their impact, we improved the genome sequence and annotated the genes in a 1.4-Mb region of the D. ananassae F element, and a 1.7-Mb region from the D element for comparison. We find that transposons (particularly LTR and LINE retrotransposons) are major contributors to this expansion (78.6%), while Wolbachia sequences integrated into the D. ananassae genome are minor contributors (0.02%). Both D. melanogaster and D. ananassae F-element genes exhibit distinct characteristics compared to D-element genes (e.g., larger coding spans, larger introns, more coding exons, and lower codon bias), but these differences are exaggerated in D. ananassae. Compared to D. melanogaster, the codon bias observed in D. ananassae F-element genes can primarily be attributed to mutational biases instead of selection. The 5â€Č ends of F-element genes in both species are enriched in dimethylation of lysine 4 on histone 3 (H3K4me2), while the coding spans are enriched in H3K9me2. Despite differences in repeat density and gene characteristics, D. ananassae F-element genes show a similar range of expression levels compared to genes in euchromatic domains. This study improves our understanding of how transposons can affect genome size and how genes can function within highly repetitive domains

    Neutron emission in ultraperipheral Pb-Pb collisions at sNN\sqrt {s_{NN}} = 5.02 TeV

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    In ultraperipheral collisions (UPCs) of relativistic nuclei without overlap of nuclear densities, the two nuclei are excited by the Lorentz-contracted Coulomb fields of their collision partners. In these UPCs, the typical nuclear excitation energy is below a few tens of MeV, and a small number of nucleons are emitted in electromagnetic dissociation (EMD) of primary nuclei, in contrast to complete nuclear fragmentation in hadronic interactions. The cross sections of emission of given numbers of neutrons in UPCs of 208^{208}Pb nuclei at sNN=5.02\sqrt{s_{\mathrm{NN}}}=5.02~TeV were measured with the neutron zero degree calorimeters (ZDCs) of the ALICE detector at the LHC, exploiting a similar technique to that used in previous studies performed at sNN=2.76\sqrt{s_{\mathrm{NN}}}=2.76~TeV. In addition, the cross sections for the exclusive emission of 1, 2, 3, 4 and 5 forward neutrons in the EMD, not accompanied by the emission of forward protons, and thus mostly corresponding to the production of 207,206,205,204,203^{207,206,205,204,203}Pb, respectively, were measured for the first time. The predictions from the available models describe the measured cross sections well. These cross sections can be used for evaluating the impact of secondary nuclei on the LHC components, in particular, on superconducting magnets, and also provide useful input for the design of the Future Circular Collider (FCC-hh).In ultraperipheral collisions (UPCs) of relativistic nuclei without overlap of nuclear densities, the two nuclei are excited by the Lorentz-contracted Coulomb fields of their collision partners. In these UPCs, the typical nuclear excitation energy is below a few tens of MeV, and a small number of nucleons are emitted in electromagnetic dissociation (EMD) of primary nuclei, in contrast to complete nuclear fragmentation in hadronic interactions. The cross sections of emission of given numbers of neutrons in UPCs of Pb208 nuclei at sNN=5.02 TeV were measured with the neutron zero degree calorimeters (ZDCs) of the ALICE detector at the LHC, exploiting a similar technique to that used in previous studies performed at sNN=2.76 TeV. In addition, the cross sections for the exclusive emission of one, two, three, four, and five forward neutrons in the EMD, not accompanied by the emission of forward protons, and thus mostly corresponding to the production of Pb207,206,205,204,203, respectively, were measured for the first time. The predictions from the available models describe the measured cross sections well. These cross sections can be used for evaluating the impact of secondary nuclei on the LHC components, in particular, on superconducting magnets, and also provide useful input for the design of the Future Circular Collider (FCC-hh).In ultraperipheral collisions (UPCs) of relativistic nuclei without overlap of nuclear densities, the two nuclei are excited by the Lorentz-contracted Coulomb fields of their collision partners. In these UPCs, the typical nuclear excitation energy is below a few tens of MeV, and a small number of nucleons are emitted in electromagnetic dissociation (EMD) of primary nuclei, in contrast to complete nuclear fragmentation in hadronic interactions. The cross sections of emission of given numbers of neutrons in UPCs of 208^{208}Pb nuclei at sNN=5.02\sqrt{s_{\mathrm{NN}}}=5.02 TeV were measured with the neutron zero degree calorimeters (ZDCs) of the ALICE detector at the LHC, exploiting a similar technique to that used in previous studies performed at sNN=2.76\sqrt{s_{\mathrm{NN}}}=2.76 TeV. In addition, the cross sections for the exclusive emission of one, two, three, four, and five forward neutrons in the EMD, not accompanied by the emission of forward protons, and thus mostly corresponding to the production of 207,206,205,204,203^{207,206,205,204,203}Pb, respectively, were measured for the first time. The predictions from the available models describe the measured cross sections well. These cross sections can be used for evaluating the impact of secondary nuclei on the LHC components, in particular, on superconducting magnets, and also provide useful input for the design of the Future Circular Collider (FCC-hh)

    Measurement of the lifetime and Λ\Lambda separation energy of Λ3H^{3}_{\Lambda}\mathrm H

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    The most precise measurements to date of the Λ3H^{3}_{\Lambda}\mathrm H lifetime τ\tau and Λ\Lambda separation energy BΛ{\rm B}_{\Lambda} are obtained using the data sample of Pb-Pb collisions at sNN=\sqrt{s_{\mathrm{NN}}}= 5.02 TeV collected by ALICE at the LHC. The Λ3H^{3}_{\Lambda}\mathrm H is reconstructed via its charged two-body mesonic decay channel (Λ3H→^{3}_{\Lambda}\mathrm{H} \rightarrow 3^3He + π−\pi^- and the charge-conjugate process). The measured values τ=[253±11 (stat.)±6 (syst.)]\tau = [253 \pm 11 \text{ (stat.)} \pm 6 \text{ (syst.)}] ps and BΛ=[72±63 (stat.)±36 (syst.)]{\rm B}_{\Lambda}= [72 \pm 63 \text{ (stat.)} \pm 36 \text{ (syst.)}] keV are compatible with predictions from effective field theories and conclusively confirm that the Λ3H^{3}_{\Lambda}\mathrm H is a weakly-bound system.The most precise measurements to date of the HΛ3 lifetime τ and Λ separation energy BΛ are obtained using the data sample of Pb-Pb collisions at sNN=5.02  TeV collected by ALICE at the LHC. The HΛ3 is reconstructed via its charged two-body mesonic decay channel (HΛ3→He3+π- and the charge-conjugate process). The measured values τ=[253±11(stat)±6(syst)]  ps and BΛ=[102±63(stat)±67(syst)]  keV are compatible with predictions from effective field theories and confirm that the HΛ3 structure is consistent with a weakly bound system.The most precise measurements to date of the Λ3H^{3}_{\Lambda}\mathrm H lifetime τ\tau and Λ\Lambda separation energy BΛ{\rm B}_{\Lambda} are obtained using the data sample of Pb-Pb collisions at sNN=\sqrt{s_{\mathrm{NN}}}= 5.02 TeV collected by ALICE at the LHC. The Λ3H^{3}_{\Lambda}\mathrm H is reconstructed via its charged two-body mesonic decay channel (Λ3H→^{3}_{\Lambda}\mathrm{H} \rightarrow3^3He + π−\pi^- and the charge-conjugate process). The measured values τ=[253±11 (stat.)±6 (syst.)]\tau = [253 \pm 11 \text{ (stat.)} \pm 6 \text{ (syst.)}] ps and BΛ=[102±63 (stat.)±67 (syst.)]{\rm B}_{\Lambda}= [102 \pm 63 \text{ (stat.)} \pm 67 \text{ (syst.)}] keV are compatible with predictions from effective field theories and confirm that the Λ3H^{3}_{\Lambda}\mathrm H structure is consistent with a weakly-bound system

    Measurements of azimuthal anisotropies at forward and backward rapidity with muons in high-multiplicity p–Pb collisions at <math altimg="si1.svg"><msqrt><mrow><msub><mrow><mi>s</mi></mrow><mrow><mi mathvariant="normal">NN</mi></mrow></msub></mrow></msqrt><mo linebreak="goodbreak" linebreakstyle="after">=</mo><mn>8.16</mn></math> TeV

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    International audienceThe study of the azimuthal anisotropy of inclusive muons produced in p–Pb collisions at sNN=8.16 TeV, using the ALICE detector at the LHC is reported. The measurement of the second-order Fourier coefficient of the particle azimuthal distribution, v2, is performed as a function of transverse momentum pT in the 0–20% high-multiplicity interval at both forward (2.03&lt;yCMS&lt;3.53) and backward (−4.46&lt;yCMS&lt;−2.96) rapidities over a wide pT range, 0.5&lt;pT&lt;10 GeV/c, in which a dominant contribution of muons from heavy-flavour hadron decays is expected at pT&gt;2 GeV/c. The v2 coefficient of inclusive muons is extracted using two different techniques, namely two-particle cumulants, used for the first time for heavy-flavour measurements, and forward–central two-particle correlations. Both techniques give compatible results. A positive v2 is measured at both forward and backward rapidities with a significance larger than 4.7σ and 7.6σ, respectively, in the interval 2&lt;pT&lt;6 GeV/c. Comparisons with previous measurements in p–Pb collisions at sNN=5.02 TeV, and with AMPT and CGC-based theoretical calculations are discussed. The findings impose new constraints on the theoretical interpretations of the origin of the collective behaviour in small collision systems

    Performance of the ALICE Electromagnetic Calorimeter

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    International audienceThe performance of the electromagnetic calorimeter of theALICE experiment during operation in 2010–2018 at the Large HadronCollider is presented. After a short introduction into the design,readout, and trigger capabilities of the detector, the proceduresfor data taking, reconstruction, and validation are explained. Themethods used for the calibration and various derived corrections arepresented in detail. Subsequently, the capabilities of thecalorimeter to reconstruct and measure photons, light mesons,electrons and jets are discussed. The performance of thecalorimeter is illustrated mainly with data obtained with test beamsat the Proton Synchrotron and Super Proton Synchrotron or inproton-proton collisions at √s = 13 TeV, and compared tosimulations

    Two-particle transverse momentum correlations in pp and p-Pb collisions at LHC energies

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    Two-particle transverse momentum differential correlators, recently measured in Pb-Pb collisions at LHC energies, provide an additional tool to gain insights into particle production mechanisms and infer transport properties, such as the ratio of shear viscosity to entropy density, of the medium created in Pb--Pb collisions. The longitudinal long-range correlations and the large azimuthal anisotropy measured at low transverse momenta in small collision systems, namely pp and p-Pb, at LHC energies resemble manifestations of collective behaviour. This suggests that locally equilibrated matter may be produced in these small collision systems, similar to what is observed in Pb-Pb collisions. In this work, the same two-particle transverse momentum differential correlators are exploited in pp and p-Pb collisions at s=7\sqrt{s} = 7 TeV and sNN=5.02\sqrt{s_{\rm NN}} = 5.02 TeV, respectively, to seek evidence for viscous effects. Specifically, the strength and shape of the correlators are studied as a function of the produced particle multiplicity to identify evidence for longitudinal broadening that might reveal the presence of viscous effects in these smaller systems. The measured correlators and their evolution from pp and p-Pb to Pb-Pb collisions are additionally compared to predictions from Monte Carlo event generators, and the potential presence of viscous effects is discussed.Two-particle transverse momentum differential correlators, recently measured in Pb--Pb collisions at energies available at the CERN Large Hadron Collider (LHC), provide an additional tool to gain insights into particle production mechanisms and infer transport properties, such as the ratio of shear viscosity to entropy density, of the medium created in Pb-Pb collisions. The longitudinal long-range correlations and the large azimuthal anisotropy measured at low transverse momenta in small collision systems, namely pp and p-Pb, at LHC energies resemble manifestations of collective behaviour. This suggests that locally equilibrated matter may be produced in these small collision systems, similar to what is observed in Pb-Pb collisions. In this work, the same two-particle transverse momentum differential correlators are exploited in pp and p-Pb collisions at s=7\sqrt{s} = 7 TeV and sNN=5.02\sqrt{s_{\rm NN}} = 5.02 TeV, respectively, to seek evidence for viscous effects. Specifically, the strength and shape of the correlators are studied as a function of the produced particle multiplicity to identify evidence for longitudinal broadening that might reveal the presence of viscous effects in these smaller systems. The measured correlators and their evolution from pp and p--Pb to Pb--Pb collisions are additionally compared to predictions from Monte Carlo event generators, and the potential presence of viscous effects is discussed.Two-particle transverse momentum differential correlators, recently measured in Pb-Pb collisions at energies available at the CERN Large Hadron Collider (LHC), provide an additional tool to gain insights into particle production mechanisms and infer transport properties, such as the ratio of shear viscosity to entropy density, of the medium created in Pb-Pb collisions. The longitudinal long-range correlations and the large azimuthal anisotropy measured at low transverse momenta in small collision systems, namely pp and p-Pb, at LHC energies resemble manifestations of collective behavior. This suggests that locally equilibrated matter may be produced in these small collision systems, similar to what is observed in Pb-Pb collisions. In this work, the same two-particle transverse momentum differential correlators are exploited in pp and p-Pb collisions at s=7TeV and sNN=5.02TeV, respectively, to seek evidence for viscous effects. Specifically, the strength and shape of the correlators are studied as a function of the produced particle multiplicity to identify evidence for longitudinal broadening that might reveal the presence of viscous effects in these smaller systems. The measured correlators and their evolution from pp and p-Pb to Pb-Pb collisions are additionally compared to predictions from Monte Carlo event generators, and the potential presence of viscous effects is discussed

    First measurement of Λc+\Lambda_\mathrm{c}^{+} production down to pT=0p_\mathrm{T} = 0 in pp and p-Pb collisions at sNN=5.02\sqrt{s_\mathrm{NN}} = 5.02 TeV

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    The production of prompt Λc+{\mathrm {\Lambda_{c}^{+}}} baryons has been measured at midrapidity in the transverse momentum interval 0 Λc+ baryons has been measured at midrapidity in the transverse momentum interval 0<pT<1 GeV/c for the first time, in pp and p–Pb collisions at a center-of-mass energy per nucleon-nucleon collision sNN=5.02TeV. The measurement was performed in the decay channel Λc+→pKS0 by applying new decay reconstruction techniques using a Kalman-Filter vertexing algorithm and adopting a machine-learning approach for the candidate selection. The pT-integrated Λc+ production cross sections in both collision systems were determined and used along with the measured yields in Pb–Pb collisions to compute the pT-integrated nuclear modification factors RpPb and RAA of Λc+ baryons, which are compared to model calculations that consider nuclear modification of the parton distribution functions. The Λc+/D0 baryon-to-meson yield ratio is reported for pp and p–Pb collisions. Comparisons with models that include modified hadronization processes are presented, and the implications of the results on the understanding of charm hadronization in hadronic collisions are discussed. A significant (3.7σ) modification of the mean transverse momentum of Λc+ baryons is seen in p–Pb collisions with respect to pp collisions, while the pT-integrated Λc+/D0 yield ratio was found to be consistent between the two collision systems within the uncertainties.The production of prompt \mathrm {\Lambda_{c}^{+}}baryonshasbeenmeasuredatmidrapidityinthetransversemomentuminterval baryons has been measured at midrapidity in the transverse momentum interval 0<p_{\rm T}<1GeV/ GeV/cforthefirsttime,inppandp−Pbcollisionsatacentre−of−massenergypernucleon−nucleoncollision for the first time, in pp and p-Pb collisions at a centre-of-mass energy per nucleon-nucleon collision \sqrt{s_\mathrm{NN}} = 5.02TeV.Themeasurementwasperformedinthedecaychannel TeV. The measurement was performed in the decay channel {\rm \Lambda_{c}^{+}\to p K^{0}_{S}}byapplyingnewdecayreconstructiontechniquesusingaKalman−Filtervertexingalgorithmandadoptingamachine−learningapproachforthecandidateselection.The by applying new decay reconstruction techniques using a Kalman-Filter vertexing algorithm and adopting a machine-learning approach for the candidate selection. The p_{\rm T}−integrated-integrated \mathrm {\Lambda_{c}^{+}}productioncrosssectionsinbothcollisionsystemsweredeterminedandusedalongwiththemeasuredyieldsinPb−Pbcollisionstocomputethe production cross sections in both collision systems were determined and used along with the measured yields in Pb-Pb collisions to compute the p_{\rm T}−integratednuclearmodificationfactors-integrated nuclear modification factors R_{\rm pPb}and and R_\mathrm{AA}of of \mathrm{\Lambda_{c}^{+}}baryons,whicharecomparedtomodelcalculationsthatconsidernuclearmodificationofthepartondistributionfunctions.The baryons, which are compared to model calculations that consider nuclear modification of the parton distribution functions. The \mathrm{\Lambda_{c}^{+}/D^0}baryon−to−mesonyieldratioisreportedforppandp−Pbcollisions.Comparisonswithmodelsthatincludemodifiedhadronisationprocessesarepresented,andtheimplicationsoftheresultsontheunderstandingofcharmhadronisationinhadroniccollisionsarediscussed.Asignificant( baryon-to-meson yield ratio is reported for pp and p-Pb collisions. Comparisons with models that include modified hadronisation processes are presented, and the implications of the results on the understanding of charm hadronisation in hadronic collisions are discussed. A significant (3.7\sigma)modificationofthemeantransversemomentumof) modification of the mean transverse momentum of \mathrm {\Lambda_{c}^{+}}baryonsisseeninp−Pbcollisionswithrespecttoppcollisions,whilethe baryons is seen in p-Pb collisions with respect to pp collisions, while the p_{\rm T}−integrated-integrated \mathrm{\Lambda_{c}^{+}/D^0}$ yield ratio was found to be consistent between the two collision systems within the uncertainties
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