172 research outputs found

    Synergy between biology and systems resilience

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    Resilient systems have the ability to endure and successfully recover from disturbances by identifying problems and mobilizing the available resources to cope with the disturbance. Resiliency lets a system recover from disruptions, variations, and a degradation of expected working conditions. Biological systems are resilient. Immune systems are highly adaptive and scalable, with the ability to cope with multiple data sources, fuse information together, makes decisions, have multiple interacting agents, operate in a distributed manner over a multiple scales, and have a memory structure to facilitate learning. Ecosystems are resilient since they have the capacity to absorb disturbance and are able to tolerate the disturbances. Ants build colonies that are dispersed, modular, fine grained, and standardized in design, yet they manage to forage intelligently for food and also organize collective defenses by the property of resilience. Are there any rules that we can identify to explain the resilience in these systems? The answer is yes. In insect colonies, rules determine the division of labor and how individual insects act towards each other and respond to different environmental possibilities. It is possible to group these rules based on attributes. These attributes are distributability, redundancy, adaptability, flexibility, interoperability, and diversity. It is also possible to incorporate these rules into engineering systems in their design to make them resilient. It is also possible to develop a qualitative model to generate resilience heuristics for engineering system based on a given attribute. The rules seen in nature and those of an engineering system are integrated to incorporate the desired characteristics for system resilience. The qualitative model for systems resilience will be able to generate system resilience heuristics. This model is simple and it can be applied to any system by using attribute based heuristics that are domain dependent. It also provides basic foundation for building computational models for designing resilient system architectures. This model was tested on recent catastrophes like the Mumbai terror attack and hurricane Katrina. With the disturbances surrounding the current world this resilience model based on heuristics will help a system to deal with crisis and still function in the best way possible by depending mainly on internal variables within the system --Abstract, page iii

    Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

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    Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

    Knowledge, attitudes and biosecurity practices among the small‐scale dairy farmers in Sylhet district, Bangladesh

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    Abstract Background In the context of zoonosis, Bangladesh's small‐scale dairying is yet to frame satisfactory levels due to poor biosecurity practices. Objectives This study intended to reveal the degree of knowledge, attitudes and biosecurity practices among Sylhet district, Bangladesh's small‐scale dairy farmers. We also focused on the association between biosecurity practices and the incidence of non‐specific enteritis in humans. Methods A questionnaire‐based survey was conducted on the farmers’ KAP via personal interviews of 15 farmers from the randomly selected fifteen small‐scale dairy farms. The questionnaire was developed with 6 questions for knowledge, 6 questions for attitude and 12 questions for the practice of biosecurity measures. Alongside that, data on the number of non‐specific enteritis cases experienced by the farmers or their family members were also recorded. Spearman correlation was used to find out the correlation among KAP variables and between practice scores and non‐specific enteritis incidences. Results We found an insignificant (p > 0.05) influence of demographic characteristics over knowledge, attitude and biosecurity practices. Significant (p < 0.05) and strong correlations were found in knowledge–attitude (r = 0.65), knowledge–practice (r = 0.71) and attitude–practice (r = 0.64). Incidences of non‐specific enteritis and biosecurity measures’ practice were also strongly correlated (r = −0.9232) and statistically significant (p < 0.05). Conclusions Our study suggests that increasing knowledge and developing a good attitude are necessary to increase the adaptation of biosecurity measures as three of these factors are correlated. Moreover, farm biosecurity measures are closely related to human health

    Multiplicity dependence of light (anti-)nuclei production in p–Pb collisions at sNN=5.02 TeV

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    The measurement of the deuteron and anti-deuteron production in the rapidity range −1 < y < 0 as a function of transverse momentum and event multiplicity in p–Pb collisions at √sNN = 5.02 TeV is presented. (Anti-)deuterons are identified via their specific energy loss dE/dx and via their time-of- flight. Their production in p–Pb collisions is compared to pp and Pb–Pb collisions and is discussed within the context of thermal and coalescence models. The ratio of integrated yields of deuterons to protons (d/p) shows a significant increase as a function of the charged-particle multiplicity of the event starting from values similar to those observed in pp collisions at low multiplicities and approaching those observed in Pb–Pb collisions at high multiplicities. The mean transverse particle momenta are extracted from the deuteron spectra and the values are similar to those obtained for p and particles. Thus, deuteron spectra do not follow mass ordering. This behaviour is in contrast to the trend observed for non-composite particles in p–Pb collisions. In addition, the production of the rare 3He and 3He nuclei has been studied. The spectrum corresponding to all non-single diffractive p-Pb collisions is obtained in the rapidity window −1 < y < 0 and the pT-integrated yield dN/dy is extracted. It is found that the yields of protons, deuterons, and 3He, normalised by the spin degeneracy factor, follow an exponential decrease with mass number

    Measuring KS0^0_{\rm S}K±^{\rm \pm} interactions using Pb-Pb collisions at sNN=2.76{\sqrt{s_{\rm NN}}=2.76} TeV

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    We present the first ever measurements of femtoscopic correlations between the KS0 and K ± particles. The analysis was performed on the data from Pb–Pb collisions at sNN=2.76 TeV measured by the ALICE experiment. The observed femtoscopic correlations are consistent with final-state interactions proceeding via the a0(980) resonance. The extracted kaon source radius and correlation strength parameters for KS0K− are found to be equal within the experimental uncertainties to those for KS0K+ . Comparing the results of the present study with those from published identical-kaon femtoscopic studies by ALICE, mass and coupling parameters for the a0 resonance are tested. Our results are also compatible with the interpretation of the a0 having a tetraquark structure instead of that of a diquark

    Study of the Λ\Lambda-Λ\Lambda interaction with femtoscopy correlations in pp and p-Pb collisions at the LHCC

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    This work presents new constraints on the existence and the binding energy of a possible Λ\Lambda-Λ\Lambda bound state, the H-dibaryon, derived from Λ\Lambda-Λ\Lambda femtoscopic measurements by the ALICE collaboration. The results are obtained from a new measurement using the femtoscopy technique in pp collisions at s=13\sqrt{s}=13 TeV and p-Pb collisions at sNN=5.02\sqrt{s_{\mathrm{NN}}}=5.02 TeV, combined with previously published results from pp collisions at s=7\sqrt{s}=7 TeV. The Λ\Lambda-Λ\Lambda scattering parameter space, spanned by the inverse scattering length f0−1f_0^{-1} and the effective range d0d_0, is constrained by comparing the measured Λ\Lambda-Λ\Lambda correlation function with calculations obtained within the Lednicky model. The data are compatible with hypernuclei results and lattice computations, both predicting a shallow attractive interaction, and permit to test different theoretical approaches describing the Λ\Lambda-Λ\Lambda interaction. The region in the (f0−1,d0)(f_0^{-1},d_0) plane which would accommodate a Λ\Lambda-Λ\Lambda bound state is substantially restricted compared to previous studies. The binding energy of the possible Λ\Lambda-Λ\Lambda bound state is estimated within an effective-range expansion approach and is found to be BΛΛ=3.2−2.4+1.6(stat)−1.0+1.8(syst)B_{\Lambda\Lambda}=3.2^{+1.6}_{-2.4}\rm{(stat)}^{+1.8}_{-1.0}\rm{(syst)} MeV.This work presents new constraints on the existence and the binding energy of a possible Λ–Λ bound state, the H-dibaryon, derived from Λ–Λ femtoscopic measurements by the ALICE collaboration. The results are obtained from a new measurement using the femtoscopy technique in Image 1 collisions at s=13 TeV and p–Pb collisions at sNN=5.02 TeV, combined with previously published results from Image 1 collisions at s=7 TeV. The Λ–Λ scattering parameter space, spanned by the inverse scattering length f0−1 and the effective range d0 , is constrained by comparing the measured Λ–Λ correlation function with calculations obtained within the LednickĂœ model. The data are compatible with hypernuclei results and lattice computations, both predicting a shallow attractive interaction, and permit to test different theoretical approaches describing the Λ–Λ interaction. The region in the (f0−1,d0) plane which would accommodate a Λ–Λ bound state is substantially restricted compared to previous studies. The binding energy of the possible Λ–Λ bound state is estimated within an effective-range expansion approach and is found to be BΛΛ=3.2−2.4+1.6(stat)−1.0+1.8(syst) MeV.This work presents new constraints on the existence and the binding energy of a possible Λ\Lambda-Λ\Lambda bound state, the H-dibaryon, derived from Λ\Lambda-Λ\Lambda femtoscopic measurements by the ALICE collaboration. The results are obtained from a new measurement using the femtoscopy technique in pp collisions at s=13\sqrt{s}=13 TeV and p-Pb collisions at sNN=5.02\sqrt{s_{\mathrm{NN}}}=5.02 TeV, combined with previously published results from p-Pb collisions at s=7\sqrt{s}=7 TeV. The Λ\Lambda-Λ\Lambda scattering parameter space, spanned by the inverse scattering length f0−1f_0^{-1} and the effective range d0d_0, is constrained by comparing the measured Λ\Lambda-Λ\Lambda correlation function with calculations obtained within the Lednicky model. The data are compatible with hypernuclei results and lattice computations, both predicting a shallow attractive interaction, and permit to test different theoretical approaches describing the Λ\Lambda-Λ\Lambda interaction. The region in the (f0−1,d0)(f_0^{-1},d_0) plane which would accommodate a Λ\Lambda-Λ\Lambda bound state is substantially restricted compared to previous studies. The binding energy of the possible Λ\Lambda-Λ\Lambda bound state is estimated within an effective-range expansion approach and is found to be BΛΛ=3.2−2.4+1.6(stat)−1.0+1.8(syst)B_{\Lambda\Lambda}=3.2^{+1.6}_{-2.4}\mathrm{(stat)}^{+1.8}_{-1.0}\mathrm{(syst)} MeV

    Investigations of Anisotropic Flow Using Multiparticle Azimuthal Correlations in pppp, p−Pbp-Pb, Xe-Xe, and Pb-Pb Collisions at the LHC

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    International audienceMeasurements of anisotropic flow coefficients (vn) and their cross-correlations using two- and multiparticle cumulant methods are reported in collisions of pp at s=13  TeV, p-Pb at a center-of-mass energy per nucleon pair sNN=5.02  TeV, Xe-Xe at sNN=5.44  TeV, and Pb-Pb at sNN=5.02  TeV recorded with the ALICE detector. The multiplicity dependence of vn is studied in a very wide range from 20 to 3000 particles produced in the midrapidity region |η|v3>v4 is found in pp and p-Pb collisions, similar to that seen in large collision systems, while a weak v2 multiplicity dependence is observed relative to nucleus-nucleus collisions in the same multiplicity range. Using a novel subevent method, v2 measured with four-particle cumulants is found to be compatible with that from six-particle cumulants in pp and p-Pb collisions. The magnitude of the correlation between vn2 and vm2, evaluated with the symmetric cumulants SC(m,n) is observed to be positive at all multiplicities for v2 and v4, while for v2 and v3 it is negative and changes sign for multiplicities below 100, which may indicate a different vn fluctuation pattern in this multiplicity range. The observed long-range multiparticle azimuthal correlations in high multiplicity pp and p-Pb collisions can neither be described by pythia 8 nor by impact-parameter-Glasma, music, and ultrarelativistic quantum molecular dynamics model calculations, and hence, provide new insights into the understanding of collective effects in small collision systems

    Global polarization of Λ and Λ hyperons in Pb-Pb collisions at √ s N N = 2.76 and 5.02 TeV

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    The global polarization of Λ and Λ hyperons is measured for Pb-Pb collisions at √sNN = 2.76 and 5.02 TeV recorded with the ALICE at the Large Hadron Collider (LHC). The results are reported differentially as a function of collision centrality and hyperon’s transverse momentum (pT ) for the range of centrality 5–50%, 0.5 < pT < 5 GeV/c, and rapidity |y| < 0.5. The hyperon global polarization averaged for Pb-Pb collisions at √sNN = 2.76 and 5.02 TeV is found to be consistent with zero, ⟹PH⟩(%)≈0.01±0.06(stat.)±0.03(syst.) in the collision centrality range 15–50%, where the largest signal is expected. The results are compatible with expectations based on an extrapolation from measurements at lower collision energies at the Relativistic Heavy Ion Collider, hydrodynamical model calculations, and empirical estimates based on collision energy dependence of directed flow, all of which predict the global polarization values at LHC energies of the order of 0.01%
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