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Grossi F, Lagasio M, Napoli A, Provenzale A, Tepsich P. Phytoplankton spring bloom in the NW Mediterranean Sea under climate change. Sci Total Environ 2024; 914:169884. [PMID: 38190897 DOI: 10.1016/j.scitotenv.2024.169884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 12/07/2023] [Accepted: 01/01/2024] [Indexed: 01/10/2024]
Abstract
The spring phytoplankton bloom is the main event influencing ecosystem richness in the pelagic realm of the Northwestern Mediterranean Sea (NW Med Sea). The Marine Strategy Framework Directive requires the achievement of a good ecological status for the pelagic habitat, and phytoplankton bloom phenology has been used as an indicator of the status of offshore waters. In this work we investigate interannual changes in the timing and magnitude of the phytoplankton bloom in the NW Med Sea, using phenological metrics. Daily maps of Chl-a concentration from 1998 to 2022 obtained by CMEMS were used to analyse bloom phenological metrics in 5 representative sites in the area. Chlorophyll-a data from 1998 to 2007 were used for determining the climatological behaviour, while 2008-2022 was identified as the study period. For this latter period, yearly spring bloom were identified and interannual variability and overall trends were analysed for each of the phenological metrics considered. Winter oceanographic and meteorological data were analysed to investigate possible correlations with the subsequent spring bloom. The frequency of anomalous years is increasing, both for bloom intensity and sea temperature. Bloom analysis revealed a negative trend only in some areas, but a steep decrease in the last 7 years was noticeable for all sites considered. Correlations of the Chl-a concentration during bloom with oceanographic variables revealed the importance of temperature, both marine and atmospheric, while Mixed Layer Depth played a lesser role. This work contributes to a better understanding of the dynamics of an area already under severe threat from human activities.
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Affiliation(s)
- F Grossi
- DIBRIS, Università di Genova, Via Balbi 5, 16126 Genova GE, Italy; CIMA Research Foundation, Via Armando Magliotto, 17100 Savona SV, Italy.
| | - M Lagasio
- CIMA Research Foundation, Via Armando Magliotto, 17100 Savona SV, Italy
| | - A Napoli
- Department of Civil, Environmental and Mechanical Engineering (DICAM), University of Trento, Trento, Italy; Center Agriculture Food Environment (C3A), Trento, Italy
| | - A Provenzale
- Institute of Geosciences and Earth Resources, CNR, Pisa, Italy
| | - P Tepsich
- CIMA Research Foundation, Via Armando Magliotto, 17100 Savona SV, Italy; NBFC, National Biodiversity Future Center, Palermo, Italy
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Novi L, von Hardenberg J, Hughes DW, Provenzale A, Spiegel EA. Rapidly rotating Rayleigh-Bénard convection with a tilted axis. Phys Rev E 2019; 99:053116. [PMID: 31212482 DOI: 10.1103/physreve.99.053116] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Indexed: 11/07/2022]
Abstract
We numerically explore the dynamics of an incompressible fluid heated from below, bounded by free-slip horizontal plates and periodic lateral boundary conditions, subject to rapid rotation about a distant axis that is tilted with respect to the gravity vector. The angle ϕ between the rotation axis and the horizontal plane measures the tilting of the rotation axis; it can be taken as a proxy for latitude if we think of a local Cartesian representation of the convective dynamics in a rotating fluid shell. The results of the simulations indicate the existence of three different convective regimes, depending on the value of ϕ: (1) sheared, intermittent large-scale winds in the direction perpendicular to the plane defined by the gravity and rotation vectors, when rotation is "horizontal" (ϕ=0^{∘}); (2) a large-scale cyclonic vortex tilted along the rotation axis, when the angle between the rotation axis and the gravity vector is relatively small (ϕ between about 45^{∘} and 90^{∘}); and (3) a new intermediate regime characterized by vertically sheared large-scale winds perpendicular to both gravity and rotation. In this regime, the winds are organized in bands that are tilted along the rotation axis, with unit horizontal wave number in the plane defined by gravity and rotation at values of ϕ less than about 60^{∘}. This intermediate solution, studied for the first time in this work, is characterized by weaker vertical heat transport than the cases with large-scale vortices. For intermediate values of ϕ (between about 45^{∘} and 60^{∘}), the banded, sheared solution coexists with the large-scale vortex solution, with different initial conditions leading to one or the other dynamical behavior. A discussion of the possible implications of these results for the dynamics of rapidly rotating planetary atmospheres is provided.
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Affiliation(s)
- L Novi
- Institute of Geosciences and Earth Resources (IGG), National Research Council (CNR), Pisa, 56124, Italy
| | - J von Hardenberg
- Institute of Atmospheric Sciences and Climate (ISAC), National Research Council (CNR), Torino, 10133, Italy
| | - D W Hughes
- Department of Applied Mathematics, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - A Provenzale
- Institute of Geosciences and Earth Resources (IGG), National Research Council (CNR), Pisa, 56124, Italy
| | - E A Spiegel
- Department of Astronomy, Columbia University, 550 W 120th St, New York, New York 10027, USA
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Guerra C, Pendleton L, Drakou E, Proença V, Appeltans W, Domingos T, Geller G, Giamberini S, Gill M, Hummel H, Imperio S, McGeoch M, Provenzale A, Serral I, Stritih A, Turak E, Vihervaara P, Ziemba A, Pereira H. Finding the essential: Improving conservation monitoring across scales. Glob Ecol Conserv 2019. [DOI: 10.1016/j.gecco.2019.e00601] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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von Hardenberg J, Goluskin D, Provenzale A, Spiegel EA. Generation of Large-Scale Winds in Horizontally Anisotropic Convection. Phys Rev Lett 2015; 115:134501. [PMID: 26451558 DOI: 10.1103/physrevlett.115.134501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Indexed: 06/05/2023]
Abstract
We simulate three-dimensional, horizontally periodic Rayleigh-Bénard convection, confined between free-slip horizontal plates and rotating about a distant horizontal axis. When both the temperature difference between the plates and the rotation rate are sufficiently large, a strong horizontal wind is generated that is perpendicular to both the rotation vector and the gravity vector. The wind is turbulent, large-scale, and vertically sheared. Horizontal anisotropy, engendered here by rotation, appears necessary for such wind generation. Most of the kinetic energy of the flow resides in the wind, and the vertical turbulent heat flux is much lower on average than when there is no wind.
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Affiliation(s)
- J von Hardenberg
- Institute of Atmospheric Sciences, National Research Council, Torino 10133, Italy
| | - D Goluskin
- Mathematics Department, University of Michigan, Ann Arbor, Michigan 48109, USA
- Center for the Study of Complex Systems, University of Michigan, Ann Arbor 48109, Michigan, USA
| | - A Provenzale
- Institute of Geosciences and Earth Resources, National Research Council, Pisa 56124, Italy
| | - E A Spiegel
- Astronomy Department, Columbia University, New York, New York 10027, USA
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Viterbi R, Cerrato C, Bassano B, Bionda R, Hardenberg A, Provenzale A, Bogliani G. Patterns of biodiversity in the northwestern Italian Alps: a multi-taxa approach. COMMUNITY ECOL 2013. [DOI: 10.1556/comec.14.2013.1.3] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Imperio S, Focardi S, Santini G, Provenzale A. Population dynamics in a guild of four Mediterranean ungulates: density-dependence, environmental effects and inter-specific interactions. OIKOS 2011. [DOI: 10.1111/j.1600-0706.2011.20085.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Zavala Sansón L, Provenzale A. The effects of abrupt topography on plankton dynamics. Theor Popul Biol 2009; 76:258-67. [DOI: 10.1016/j.tpb.2009.08.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2008] [Revised: 06/23/2009] [Accepted: 08/22/2009] [Indexed: 10/20/2022]
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Koszalka I, Bracco A, Pasquero C, Provenzale A. Plankton cycles disguised by turbulent advection. Theor Popul Biol 2007; 72:1-6. [PMID: 17481683 DOI: 10.1016/j.tpb.2007.03.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2006] [Revised: 01/26/2007] [Accepted: 03/16/2007] [Indexed: 11/25/2022]
Abstract
Mathematical models used to represent plankton dynamics often display limit-cycle behavior in a range of realistic parameter values. However, experimental data do not show evidence of plankton oscillations besides externally driven seasonal blooms, casting doubts on the validity of the models themselves. In this work we show that spatial-temporal variability, coupled with advection by mesoscale turbulence, can disguise limit-cycle behavior to the point that it cannot be detected in fixed-point measurements of plankton abundance. The results presented here have more general implications as they indicate that the behavior of ecosystem models in the presence of advection can be very different from that occurring for homogeneous conditions. Care should thus be exercised in drawing general conclusions from the analysis of homogeneous ecosystem models.
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Affiliation(s)
- I Koszalka
- Doctorate Program in Fluid Dynamics, Politecnico di Torino, Italy
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Gilad E, von Hardenberg J, Provenzale A, Shachak M, Meron E. A mathematical model of plants as ecosystem engineers. J Theor Biol 2006; 244:680-91. [PMID: 17007886 DOI: 10.1016/j.jtbi.2006.08.006] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2006] [Revised: 07/30/2006] [Accepted: 08/02/2006] [Indexed: 11/19/2022]
Abstract
Understanding the structure and dynamics of plant communities in water-limited systems often calls for the identification of ecosystem engineers--key species that modify the landscape, redistribute resources and facilitate the growth of other species. Shrubs are excellent examples; they self-organize to form patterns of mesic patches which provide habitats for herbaceous species. In this paper we present a mathematical model for studying ecosystem engineering by woody plant species in drylands. The model captures various feedbacks between biomass and water including water uptake by plants' roots and increased water infiltration at vegetation patches. Both the uptake and the infiltration feedbacks act as mechanisms for vegetation pattern formation, but have opposite effects on the water resource; the former depletes the soil-water content under a vegetation patch, whereas the latter acts to increase it. Varying the relative strength of the two feedbacks we find a trade-off between the engineering capacity of a plant species and its resilience to disturbances. We further identify two basic soil-water distributions associated with engineering at the single patch level, hump-shaped and ring-shaped, and discuss the niches they form for herbaceous species. Finally, we study how pattern transitions at the landscape level feedback to the single patch level by affecting engineering strength.
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Affiliation(s)
- E Gilad
- Department of Physics, Ben-Gurion University, Beer Sheva 84105, Israel.
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Gilad E, von Hardenberg J, Provenzale A, Shachak M, Meron E. Ecosystem engineers: from pattern formation to habitat creation. Phys Rev Lett 2004; 93:098105. [PMID: 15447146 DOI: 10.1103/physrevlett.93.098105] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2003] [Indexed: 05/24/2023]
Abstract
Habitat and species richness in drylands are affected by the dynamics of a few key species, termed "ecosystem engineers." These species modulate the landscape and redistribute the water resources so as to allow the introduction of other species. A mathematical model is developed for a pair of ecosystem engineers commonly found in drylands: plants forming vegetation patterns and cyanobacteria forming soil crusts. The model highlights conditions for habitat creation and for high habitat richness, and suggests a novel mechanism for species loss events as a result of environmental changes.
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Affiliation(s)
- E Gilad
- Department of Physics, Ben-Gurion University, Beer Sheva, 84105, Israel
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Abstract
We introduce a simple mathematical model for the description of 'dormancy', a survival strategy used by some bacterial populations that are intermittently exposed to external stress. We focus on the case of the cyanobacterial crust in drylands, exposed to severe water shortage, and compare the fate of ideal populations that are, respectively, capable or incapable of becoming dormant. The results of the simple model introduced here indicate that under a constant, even though low, supply of water the dormant strategy does not provide any benefit and it can, instead, decrease the chances of survival of the population. The situation is reversed for highly intermittent external stress, due to the presence of prolonged periods of dry conditions intermingled with short periods of intense precipitation. In this case, dormancy allows for the survival of the population during the dry periods. In contrast, bacteria that are incapable of turning into a dormant state cannot overcome the difficult times. The model also rationalizes why dormant bacteria, such as those composing the cyanobacterial crust in the desert, are extremely sensitive to other disturbances, such as trampling cattle.
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Affiliation(s)
- M Bär
- Max-Planck-Institut für Physik Komplexer Systeme, Nöthnitzer Strasse 38, D-01187 Dresden, Germany
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Abstract
Coexistence of competitive species is severely limited by the availability of resources and the characteristics of the environment. In particular, the so-called 'competitive exclusion principle' states that, at equilibrium, the number of coexisting species cannot be larger than the number of resources for which they compete. However, many in situ observations have revealed prolonged coexistence of a large number of competitive plankton species, a phenomenon known as 'the paradox of the plankton'. Here we investigate this problem and show that ocean mesoscale vortices generate transport barriers and incomplete horizontal mixing, allowing for a prolonged survival of the less-fit species, even for fully homogeneous resource distributions. In such a situation, the temporarily less-fit plankton species are protected from competition by the action of the vortices.
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Affiliation(s)
- A Bracco
- Istituto di Cosmogeofisica del Consiglio Nazionale delle Ricerche, Torino, Italy.
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13
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Babiano A, Cartwright JH, Piro O, Provenzale A. Dynamics of a small neutrally buoyant sphere in a fluid and targeting in Hamiltonian systems. Phys Rev Lett 2000; 84:5764-5767. [PMID: 10991049 DOI: 10.1103/physrevlett.84.5764] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/1999] [Indexed: 05/23/2023]
Abstract
We show that, even in the most favorable case, the motion of a small spherical tracer suspended in a fluid of the same density may differ from the corresponding motion of an ideal passive particle. We demonstrate furthermore how its dynamics may be applied to target trajectories in Hamiltonian systems.
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Affiliation(s)
- A Babiano
- Laboratoire de Meteorologie Dynamique, Ecole Normale Superieure, F-75231 Paris, France.
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14
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Abstract
We discuss how atmospheric eddies affect transport and mixing of tracers at midlatitudes. To this purpose, we study baroclinic life cycles in a simple dynamical model of the atmosphere. We consider the trapping properties of the developing eddies and the characteristics of meridional transport, and we identify regions of increased mixing. Although the flow is in principle three-dimensional, we illustrate how some of the concepts developed in the study of two-dimensional chaotic advection provide useful information on tracer dynamics in more complicated flows. (c) 2000 American Institute of Physics.
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Affiliation(s)
- J. Von Hardenberg
- Meteorologisches Institut der Universitat Hamburg, GermanyIstituto di Cosmogeofisica, Torino, Italy
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Abstract
The dynamics of a globally coupled, logistic map lattice is explored over a parameter plane consisting of the coupling strength, varepsilon, and the map parameter, a. By considering simple periodic orbits of relatively small lattices, and then an extensive set of initial-value calculations, the phenomenology of solutions over the parameter plane is broadly classified. The lattice possesses many stable solutions, except for sufficiently large coupling strengths, where the lattice elements always synchronize, and for small map parameter, where only simple fixed points are found. For smaller varepsilon and larger a, there is a portion of the parameter plane in which chaotic, asynchronous lattices are found. Over much of the parameter plane, lattices converge to states in which the maps are partitioned into a number of synchronized families. The dynamics and stability of two-family states (solutions partitioned into two families) are explored in detail. (c) 1999 American Institute of Physics.
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Affiliation(s)
- N. J. Balmforth
- Scripps Institution of Oceanography, University of California, La Jolla, California 92093Istituto di Cosmogeofisica, C. Fiume 4, 10133 Torino, Italy
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Abstract
The present distribution of galaxies in space is a remnant of their formation and interaction. On a large enough scale, we may represent the galaxies as a set of points and quantify the structures in this set by its generalized dimensions [Beck and Schlogl, Thermodynamics of Chaotic Systems (Cambridge University Press, Cambridge, 1986); Paladin and Vulpiani, Phys. Rep. 156, 147 (1987)]. The results of such evaluation are often taken to be evidence of a fractal (or multifractal) distribution of galaxies. However, those results, for some scales, may also reveal the presence of singularities formed in the gravitational processes that produce structure in the galaxy distribution. To try to make some decision about this issue, we look for the more subtle galactic lacunarity. We believe that this quantity is discernible in the currently available data and that it provides important evidence on the galaxy formation process. (c) 1997 American Institute of Physics.
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Affiliation(s)
- A. Provenzale
- Istituto di Cosmogeofisica, Corso Fiume 4, I-10133 Turin, Italy
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Borgani S, Murante G, Provenzale A, Valdarnini R. Multifractal analysis of the galaxy distribution: Reliability of results from finite data sets. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 1993; 47:3879-3888. [PMID: 9960460 DOI: 10.1103/physreve.47.3879] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Cini Castagnoli G, Bonino G, Provenzale A, Serio M, Callegari E. The CaCO3 profiles of deep and shallow Mediterranean sea cores as indicators of past solar-terrestrial relationships. ACTA ACUST UNITED AC 1992. [DOI: 10.1007/bf02507829] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Provenzale A, Osborne AR, Boffetta G, Serio M. Particle orbits from the Lagrangian and the Eulerian Korteweg–de Vries equations. ACTA ACUST UNITED AC 1990. [DOI: 10.1063/1.857635] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Bergamasco L, Provenzale A, Castagnoli GC, Serio M, Kudrjavtsev VA, Kuznetsov VA, Ryazhskaya OG. Effects of the solar cycle on the fractal and statistical properties of deep underground muons. ACTA ACUST UNITED AC 1990. [DOI: 10.1029/ja095ia03p02419] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Castagnoli GC, Bonino G, Provenzale A. The 206-year cycle in tree ring radiocarbon data and in the thermoluminescence profile of a recent sea sediment. ACTA ACUST UNITED AC 1989. [DOI: 10.1029/ja094ia09p11971] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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