Landau parameters for isospin asymmetric nuclear matter based on a relativistic model of composite and finite extension nucleons

We study the properties of cold asymmetric nuclear matter at high density, applying the quark meson coupling model with excluded volume corrections in the framework of the Landau theory of relativistic Fermi liquids. We discuss the role of the finite spatial extension of composite baryons on dynamical and statistical properties such as the Landau parameters, the compressibility, and the symmetry energy. We have also calculated the low lying collective eigenfrequencies arising from the collisionless quasiparticle transport equation, considering both unstable and stable modes. An overall analysis of the excluded volume correlations on the collective properties is performed.Comment: 24 pages, 6 figure

η1-Allylpalladium complexes with a tridentate PNP ligand with different phosphino groups

The iminodiphosphine 2-(PPh2)C6H4-1-CHvNC6H4-2-(PPh2) (P–N–P′) is used for the preparation of the complexes [Pd(η1-CHR1–CHvCR2R3)(P–N–P′)]BF4 [R1 = R2 = R3 = H: (1); R1 = R2 = Ph, R3 = H: (2); R1 = R3 = H, R2 = Ph: (3); R1 = H, R2 = R3 = Me: (4)]. The P–N–P′ tridentate coordination and the η1-allyl bonding mode in the solid are confirmed by the X-ray structural analysis of 1. In solution, the complexes 1 and 2 undergo an η1–η3–η1 rearrangement at 298 K interconverting the bonding site of the allyl group. A five-coordinate structure with the phosphine ligands in the axial position is proposed for the η3-allyl intermediate. For the dynamic process, a ΔG≠ value of 53.8 kJ mol−1 is obtained from 1H NMR data of 2. In 3 and 4, the allyl ligand is rigidly bound to the metal through the less substituted terminus, in line with the higher free energy content of the corresponding isomers: [Pd(η1-CHPh– CHvCH2)(P–N–P′)]+ +48.78 kJ mol−1; [Pd(η1-CMe2–CHvCH2)(P–N–P′)]+ +69.35 kJ mol−1. The complexes react with secondary amines in the presence of fumaronitrile at different rates yielding allylamines and the palladium(0) derivative [Pd(η2-fn)(P–N–P′)] (5). On the basis of charge distribution on the allylic carbon atoms and of steric factors, the difference in rate and the regioselectivity in the amination of 1–3 are better rationalized by a mechanism with nucleophilic attack at the η3-intermediate rather than by an SN2 mechanism with nucleophilic attack at the Pd–CHR1 carbon atom. The high regioselectivity in the reaction of 4 with piperidine implies an SN2′ mechanism with nucleophilic attack at the CMe2 allyl carbon. A dynamic process occurs also for the 18-electron complex 5 consisting in a dissociation–association equilibrium of the olefin

The Rarita-Schwinger Particles Under de Influence of Strong Magnetic Fields

In this work, we calculate the solutions of the Rarita-Schwinger equation with the inclusion of the eletromagnetic interaction. Our gauge and coupling prescription choices lead to Dirac-type solutions. One of the consequences of our results are the Landau level occupation of particles, quite different from the usual spin 1/2 particle system occupation numbers.Comment: 12 page

Effects of defoliation at fruit set on vine physiology and berry composition in cabernet sauvignon grapevines

Grapevine canopy defoliation is a fundamentally important technique for the productivity and quality of grapes. Leaf removal is a pivotal operation on high-density vines which aims to improve air circulation, light exposure, and leaf gas exchange. The effects of leaf removal (LR) on vine physiology and berry composition in Cabernet Sauvignon grapevines were studied during the 2018–2019 growing season in the Bolgheri area, Tuscany, Italy. The basal leaves were removed at fruit set at two severity levels (removal of four basal leaves of each shoot (LR4) and removal of eight basal leaves (LR8)). The two treatments were compared with the not defoliated control (CTRL). The following physiological parameters of vines were measured: leaf gas exchange, leaf water potential, chlorophyll fluorescence and indirect chlorophyll content. The results showed that defoliation increased single leaf photosynthesis. In addition, qualitative grape parameters (phenolic and technological analyses) and daytime and night-time berry temperature were studied. The results showed that leaf removal had an impact on total soluble solids (°Brix), titratable acidity, and pH. The LR8-treated grapes had higher titratable acidity, while those in the LR4 treatment had higher °Brix and extractable anthocyanin and polyphenol content. Berry weight was not significantly influenced by the timing and severity of basal defoliation. Therefore, this research aims to investigate the effects of defoliation at the fruit set on vines performance

First record of the Borneo Earless Monitor Lanthanotus borneensis (Steindachner, 1877) (Reptilia: Lanthanotidae) in West Kalimantan (Indonesian Borneo)

The following paper presents the first published record of the cryptic Borneo Earless Monitor (Lanthanotus borneensis Steindachner, 1877) from West Kalimantan (Indonesian Borneo). This sole member of the family Lanthanotidae is endemic to Borneo. Since its description in 1877, all locality records of specimens refer to Sarawak (Malaysian Borneo). The recent discovery of this "living fossil" in an oil palm estate under development in Landak District expands its known distribution southward to Kalimantan. This paper (i) describes the circumstances of the discovery, characteristics of the individual and microhabitat structure in which it was found, (ii) provides results from local community interviews about the local distribution of the species, suggesting it is found more broadly in the Landak District and possibly elsewhere, and (iii) places this information in a broader context of current knowledge and high conservation value of L. borneensis