Studies of the production of light- and heavy-flavor baryons are of prominent importance to characterize the partonic phase created in ultrarelativistic heavy-ion collisions and to investigate ...hadronization mechanisms at the LHC. Studies performed in p-Pb and pp collisions have revealed unexpected features, qualitatively similar to what is observed in larger collision systems and, in the charm sector, not in line with the expectations from e+e− and e−p interactions. The ALICE experiment has exploited its excellent tracking and particle indentification capabilities down to low transverse momentum to perform an extensive study of protons, hyperons and charmed baryons. In this paper, a discussion of the most recent results on light (protons and hyperons) and heavy-flavor (Λc) baryon production is presented, together with a comparison to phenomenological models.
Studies of the production of light- and heavy-flavor baryons are of prominent importance to characterize the partonic phase created in ultrarelativistic heavy-ion collisions and to investigate ...hadronization mechanisms at the LHC. Studies performed in p-Pb and pp collisions have revealed unexpected features, qualitatively similar to what is observed in larger collision systems and, in the charm sector, not in line with the expectations from \({\rm e}^{+}{\rm e}^{-}\) and \({\rm e}^{-}{\rm p}\) interactions. The ALICE experiment has exploited its excellent tracking and particle identification capabilities down to low transverse momentum to perform an extensive study of protons, hyperons and charmed baryons. In this paper, a discussion of the most recent results on light (protons and hyperons) and heavy-flavor \((\Lambda_{\rm c})\) baryon production is presented, together with a comparison to phenomenological models.
The global polarization of the 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%.
Cross sections for the coherent photoproduction of ρ0 vector mesons in ultra-peripheral Pb-Pb collisions at sNN−−−√ = 5.02 TeV are reported. The measurements, which rely on the π+π− decay channel, ...are presented in three regions of rapidity covering the range |y| < 0.8. For each rapidity interval, cross sections are shown for different nuclear-breakup classes defined according to the presence of neutrons measured in the zero-degree calorimeters. The results are compared with predictions based on different models of nuclear shadowing. Finally, the observation of a coherently produced resonance-like structure with a mass around 1.7 GeV/c2 and a width of about 140 MeV/c2 is reported and compared with similar observations from other experiments.
Event classifiers based either on the charged-particle multiplicity or the
event shape have been extensively used in proton-proton (pp) collisions by the
ALICE collaboration at the LHC. The use of ...these tools became very instrumental
since the observation of fluid-like behavior in high-multiplicity pp
collisions. In particular, the study as a function of the charged-particle
multiplicity registered in the forward V0 ALICE detector allowed for the
discovery of strangeness enhancement in high-multiplicity pp collisions.
However, one drawback of the multiplicity-based event classifiers is that
requiring a high charged-particle multiplicity biases the sample towards hard
processes like multi-jet final states. These biases make it difficult to
perform jet-quenching searches in high-multiplicity pp collisions. In this
context, the present paper explores the use of the new event classifier,
flattenicity; which uses the multiplicity calculated in the forward
pseudorapidity region. To illustrate how this tool works, pp collisions at
$\sqrt{s}=13.6$ TeV simulated with PYTHIA~8 are explored. The sensitivity of
flattencity to multi-partonic interactions as well as to the ``hardness'' of
the collision are discussed. PYTHIA 8 predictions for the transverse momentum
spectra of light- and heavy-flavored hadrons as a function of flattenicity are
presented.
Event classifiers based either on the charged-particle multiplicity or the event shape have been extensively used in proton-proton (pp) collisions by the ALICE collaboration at the LHC. The use of ...these tools became very instrumental since the observation of fluid-like behavior in high-multiplicity pp collisions. In particular, the study as a function of the charged-particle multiplicity registered in the forward V0 ALICE detector allowed for the discovery of strangeness enhancement in high-multiplicity pp collisions. However, one drawback of the multiplicity-based event classifiers is that requiring a high charged-particle multiplicity biases the sample towards hard processes like multi-jet final states. These biases make it difficult to perform jet-quenching searches in high-multiplicity pp collisions. In this context, the present paper explores the use of the new event classifier, flattenicity; which uses the multiplicity calculated in the forward pseudorapidity region. To illustrate how this tool works, pp collisions at \(\sqrt{s}=13.6\) TeV simulated with PYTHIA~8 are explored. The sensitivity of flattencity to multi-partonic interactions as well as to the ``hardness'' of the collision are discussed. PYTHIA 8 predictions for the transverse momentum spectra of light- and heavy-flavored hadrons as a function of flattenicity are presented.
The tomato is a widely cultivated and consumed vegetable globally. Comarca Lagunera is an important tomato-exporting region of Mexico. Salinity is an abiotic factor that reduces productivity and ...increases production costs. To advance growing period, there is high demand for the sustainable production of seedlings. Plant-growth-promoting rhizobacteria (PGPR) are characterized by improving plant growth through different mechanisms and can be an option for reducing the misuse of chemical fertilizers. The importance of the application of strains, evaluating various inoculation methods (in seed, soil, foliar spraying, and root immersion), should be evaluated to propose biofertilization packages in a specific crop. Thus, the study aimed to determine the effect of PGPR (Bacillus paralicheniformis, Acinetobacter guillouiae, Aeromonas caviae, and Pseudomonas lini) vs. nutrient solution and distilled water in the seedlings stage of saladette-type tomato on morphophysiological variables, nitrate reductase (NR) enzyme activity, and plant minerals via tissue analysis under greenhouse conditions. The four PGPR were inoculated by different methods (inoculation in seed, sprinkling, and both) in saladette-type tomato seedlings under greenhouse conditions and evaluated in vivo 40 days after sowing for morphophysiological variables, such as seedling height; stem diameter; root displaced volume; fresh and dry weight matter of the leaves, stems, and roots; leaf area; and nitrate reductase enzyme activity. The effect of the inoculation of PGPR showed significant results for Pseudomonas lini vs. the control, with 40% higher values, on average, for plant height, stem diameter, displaced root volume, and fresh weight of root, leaf, and stem. The response of enzymatic and mineral content in seedlings was variable with nutrient solution and significant with distilled water. Studies related to the promotion of plants in the subsequent phenological stages of a tomato, considering the selected PGPR, should be considered in future research.
There is growing evidence that exposure to titanium dioxide nanoparticles (TiO2 NPs) could be harmful. Previously, we have shown that TiO2 NPs induces endothelial cell dysfunction and damage in glial ...cells. Considering that inhaled particles can induce systemic effects and the evidence that nanoparticles may translocate out of the lungs, we evaluated whether different types of TiO2 NPs can induce the expression of receptors for adhesion molecules on monocytes (U937 cell line). We evaluated the role of reactive oxygen spices (ROS) on these effects.
The expression of receptors for early (sLe(x) and PSGL-1) and late (LFA-1, VLA-4 and αVβ3) adhesion molecules was evaluated in U937 cells on a time course (3-24 h) using a wide range of concentrations (0.001-100 μg/mL) of three types of TiO2 NPs (<25 nm anatase, 50 nm anatase-rutile or < 100 nm anatase). Cells exposed to TNFα were considered positive controls, and unexposed cells, negative controls. In some experiments we added 10 μmolar of N-acetylcysteine (NAC) to evaluate the role of ROS.
All tested particles, starting at a concentration of 0.03 μg/mL, induced the expression of receptors for early and late adhesion molecules. The largest increases were induced by the different molecules after 3 h of exposure for sLe(x) and PSGL-1 (up to 3-fold of the positive controls) and after 18 h of exposure for LFA-1, VLA-4 and αVβ3 (up to 2.5-fold of the positive controls). Oxidative stress was observed as early as 10 min after exposure, but the maximum peak was found after 4 h of exposure. Adhesion of exposed or unexposed monocytes to unexposed or exposed endothelial cells was tested, and we observed that monocytes cells adhere in similar amounts to endothelial cells if one of the two cell types, or both were exposed. When NAC was added, the expression of the receptors was inhibited.
These results show that small concentrations of particles may activate monocytes that attach to endothelial cells. These results suggest that distal effects can be induced by small amounts of particles that may translocate from the lungs. ROS play a central role in the induction of the expression of these receptors.
Certified-organic farming systems in Baja California Peninsula and Northwest Mexico are nationally and globally recognized, especially due to the production of vegetables and aromatic herbs under ...protected agriculture systems. Based on the background of some species of the flora of Baja California Sur (BCS) to inhibit a diversity of microorganisms, the effect of 22 medicinal plants of the region was explored to know the in vitro activity against the fungus Fusarium oxysporum f. sp. basilici isolated from basil (Ocimum basilicum L.). The plants processed as crude ethanolic and aqueous extracts were analyzed in duplicate (three replicates) evaluating the inhibition of mycelial growth and spore germination. In mycelial inhibition test, all plants extracts (1000 mg L-1) showed an effectiveness of 11 to 40% to inhibit F. oxysporum. The most effective plant extracts according to 50% effective inhibition dose (ED50), were Larrea tridentata, Hymenoclea monogyra and Lippia palmeri with an ED50 of 220, 303 and 3000 mg L-1, respectively. Tukey’s PostHoc tests indicated that H. monogyra and L. tridentata are ten times (ED50 <300 mg L-1) more effective than L. palmeri (ED50 3000 mg L-1). In addition, the dose-response trend analyzes according to the logarithmic-logistic model (drc packages), showed the maximum slope values between 100 and 1000 mg L-1. In the spore germination inhibition tests, most ethanolic extracts (5000 mg L-1) showed an effectiveness between 21 and 80%. The results of this study demonstrated that the inhibitory potential of these plants used in BCS traditional medicine are a viable alternative for the control of F. oxysporum f. sp. basilici in organic basil production systems.
Highlights
22 medicinal native plants from the Baja California peninsula can effectively inhibit (in vitro) oxysporum f. sp. basilica.
The most effective species were Larrea tridentata, Hymenoclea monogyra and Lippia palmeri with a mycelial growth inhibition (ED50) of 220, 300 and 3000 mg L-1, respectively.
In vitro effectiveness of Fusarium-growth inhibition of medicinal plants of BCS were in ED50 ranges from 220 to 3000 mg L-1.
Creosote bush (L. tridentata) extract at a dose of 5000 mg L-1 can inhibit the fungal sporulation by up 80%.
The ethanol-aqueous extract of the medicinal plants of BCS have the potential to be used for long-term control of the fusariosis disease in basil.
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