258 research outputs found
κ -Poincaré comodules, braided tensor products, and noncommutative quantum field theory
We discuss the obstruction to the construction of a multiparticle field theory on a κ-Minkowski noncommutative spacetime: the existence of multilocal functions which respect the deformed symmetries of the problem. This construction is only possible for a lightlike version of the commutation relations, if one requires invariance of the tensor product algebra under the coaction of the κ-Poincaré group. This necessitates a braided tensor product. We study the representations of this product, and prove that κ-Poincaré-invariant N-point functions belong to an Abelian subalgebra, and are therefore commutative. We use this construction to define the 2-point Whightman and Pauli-Jordan functions, which turn out to be identical to the undeformed ones. We finally outline how to construct a free scalar κ-Poincaré-invariant quantum field theory, and identify some open problems
Relativistic kinematics beyond Special Relativity
In the context of departures from Special Relativity written as a momentum
power expansion in the inverse of an ultraviolet energy scale M, we derive the
constraints that the relativity principle imposes between coefficients of a
deformed composition law, dispersion relation, and transformation laws, at
first order in the power expansion. In particular, we find that, at that order,
the consistency of a modification of the energy-momentum composition law fixes
the modification in the dispersion relation. We therefore obtain the most
generic modification of Special Relativity that preserves the relativity
principle at leading order in 1/M.Comment: Version with minor corrections, to appear in Phys. Rev.
Metabolic profiling and post-harvest behavior of “dottato” fig (Ficus carica L.) fruit covered with an edible coating from O. ficus-indica
About Locality and the Relativity Principle Beyond Special Relativity
Locality of interactions is an essential ingredient of Special Relativity.
Recently, a new framework under the name of relative locality
\cite{AmelinoCamelia:2011bm} has been proposed as a way to consider Planckian
modifications of the relativistic dynamics of particles. We note in this paper
that the loss of absolute locality is a general feature of theories beyond
Special Relativity with an implementation of a relativity principle. We give an
explicit construction of such an implementation and compare it both with the
previously mentioned framework of relative locality and the so-called Doubly
Special Relativity theories.Comment: 10 pages, no figure
Glycoconjugates in Sheep Buccal Glands Investigated by Conventional and Lectin Histochemistry
Sheep buccal glands consist of mucous acini capped by demilunes. Information on the chemical structure of their secretory glycoconjugates were obtained by means of a battery of peroxidase conjugated lectins with affinity for specific terminal and / or internal sugars. Neuraminidase procedures followed by lectin staining were also used to visualize the carbohydrate sequence. Stored secretions in mucous acinar cells contained glycoconjugates with N-acetylglucosamine and sialic acid linked to αN-acetylgalactosamine and galactosyl (β1→3) N-acetylgalactosamine. Demilunar cells displayed fucose, mannose, N-acetylglucosamine and a, N- acetylgalactosamine residues. Cells lining duct system showed a very strong staining at the apical surface and in the cytoplasm with UEA I, LTA and Con
Expression of mesenchymal stem cell marker CD90 on dermal sheath cells of the anagen hair follicle in canine species
The dermal sheath (DS) of the hair follicle is comprised by fibroblast-like cells and extends along the follicular epithelium, from the bulb up to the infundibulum. From this structure, cells with stem characteristics were isolated: they have a mesenchymal origin and express CD90 protein, a typical marker of mesenchymal stem cells. It is not yet really clear in which region of hair follicle these cells are located but some experimental evidence suggests that dermal stem cells are localized prevalently in the lower part of the anagen hair follicle
Transcriptome changes induced by Arbuscular mycorrhizal symbiosis in leaves of durum wheat (Triticum durum Desf.) promote higher salt tolerance
The salinity of soil is a relevant environmental problem around the world, with climate change raising its relevance, particularly in arid and semiarid areas. Arbuscular Mycorrhizal Fungi (AMF) positively affect plant growth and health by mitigating biotic and abiotic stresses, including salt stress. The mechanisms through which these benefits manifest are, however, still unclear. This work aimed to identify key genes involved in the response to salt stress induced by AMF using RNA-Seq analysis on durum wheat (Triticum turgidum L. subsp. durum Desf. Husn.). Five hundred sixty-three differentially expressed genes (DEGs), many of which involved in pathways related to plant stress responses, were identified. The expression of genes involved in trehalose metabolism, RNA processing, vesicle trafficking, cell wall organization, and signal transduction was significantly enhanced by the AMF symbiosis. A downregulation of genes involved in both enzymatic and non-enzymatic oxidative stress responses as well as amino acids, lipids, and carbohydrates metabolisms was also detected, suggesting a lower oxidative stress condition in the AMF inoculated plants. Interestingly, many transcription factor families, including WRKY, NAC, and MYB, already known for their key role in plant abiotic stress response, were found differentially expressed between treatments. This study provides valuable insights on AMF-induced gene expression modulation and the beneficial effects of plant-AMF interaction in durum wheat under salt stress
Probing the quantum-gravity realm with slow atoms
For the study of Planck-scale modifications of the energy-momentum dispersion
relation, which had been previously focused on the implications for
ultrarelativistic (ultrafast) particles, we consider the possible role of
experiments involving nonrelativistic particles, and particularly atoms. We
extend a recent result establishing that measurements of "atom-recoil
frequency" can provide insight that is valuable for some theoretical models.
And from a broader perspective we analyze the complementarity of the
nonrelativistic and the ultrarelativistic regimes in this research area.Comment: LaTex, 13 page
Relation between biometric parameters and autumn-winter food availability in a roe deer (Capreolus capreolus) population in central Italy
The numerical increase of roe deer has resulted in a noticeable growth of hunting activities allowing to have a great availability of biometrical data from both the hunted samples and the population by describing trends and variations and, then, optimize the consequent wildlife management decisions. Specifically, we analyzed biometric data of a roe deer (Capreolus capreolus) population at the Macerata Province, in central Italy. We focused on two animal groups: fawns (<11 months old) and adults (>2 years old). We assessed the relationship between body parameters and trophic resources available during the autumn-winter period. In particular, we analyzed live weight, head–trunk length, height at shoulders, chest circumference, length of hock, total length of the cranium, condilo-basal length, mastoid width, zygomatic width, ectorbital width, entorbital width, teeth row length and mandible length. In the context of studying trophic resources, we identified three environmental categories based on their carrying capacity and then assigned a specific environmental category to each sample. Statistical analysis was performed. In fawn, only zygomatic width showed significant differences both between sexes and among the environmental categories. In adult, the analysis showed significant differences between sexes for live weight, head–trunk length, length of hock and zygomatic width, with the highest values for males. Among environmental categories, the analysis showed significant differences for live weight, head–trunk length, length of hock chest circumference, length of hock, ectorbital width and teeth row length. This approach, applied to a broader database could be useful to identify suitable parameters to be used in planning the optimum selective hunting of roe deer
Consumer Liking and Value Perception of Mountain Cheese from Different Pasture Periods: Evidence for Mountain Systems Supporting Policies
Every year, mountain pastures show a progressive impoverishment of forage. The loss in grassland feed value restricts the production period of local Pecorino cheeses, which strongly depend on the vegetative cycle of the pasture linked to climatic conditions. The Monte Fietone mountain area (Macerata, Italy) has emblematic pasture flora during spring and early summer. This unique environment is normally used for rearing sheep, allowing regular production of local Pecorino cheeses from their milk, which is rich in vitamins and intrinsic floral aromas. Biologists and agronomists are giving increasing importance to these mountain food products. We conducted sensorial tests and experimental auctions to investigate recognition of the quality of this rare artisanal product. The results indicate considerable potential for economic differentiation. Accordingly, we recommend useful and applicable marketing and policy actions to support the sustainability of mountain grazing systems
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