A Path-integral for the Master Constraint of Loop Quantum Gravity

In the present paper, we start from the canonical theory of loop quantum gravity and the master constraint programme. The physical inner product is expressed by using the group averaging technique for a single self-adjoint master constraint operator. By the standard technique of skeletonization and the coherent state path-integral, we derive a path-integral formula from the group averaging for the master constraint operator. Our derivation in the present paper suggests there exists a direct link connecting the canonical Loop quantum gravity with a path-integral quantization or a spin-foam model of General Relativity.Comment: 19 page

The volume operator in covariant quantum gravity

A covariant spin-foam formulation of quantum gravity has been recently developed, characterized by a kinematics which appears to match well the one of canonical loop quantum gravity. In particular, the geometrical observable giving the area of a surface has been shown to be the same as the one in loop quantum gravity. Here we discuss the volume observable. We derive the volume operator in the covariant theory, and show that it matches the one of loop quantum gravity, as does the area. We also reconsider the implementation of the constraints that defines the model: we derive in a simple way the boundary Hilbert space of the theory from a suitable form of the classical constraints, and show directly that all constraints vanish weakly on this space.Comment: 10 pages. Version 2: proof extended to gamma > 1

Shape in an Atom of Space: Exploring quantum geometry phenomenology

A phenomenology for the deep spatial geometry of loop quantum gravity is introduced. In the context of a simple model, an atom of space, it is shown how purely combinatorial structures can affect observations. The angle operator is used to develop a model of angular corrections to local, continuum flat-space 3-geometries. The physical effects involve neither breaking of local Lorentz invariance nor Planck scale suppression, but rather reply on only the combinatorics of SU(2) recoupling. Bhabha scattering is discussed as an example of how the effects might be observationally accessible.Comment: 14 pages, 7 figures; v2 references adde

Contribution of irisin pathway in protective effects of mandarin juice (Citrus reticulata Blanco) on metabolic syndrome in rats fed with high fat diet

The beneficial effects of Citrus fruits and their secondary metabolites on the cardio- vascular system are well established. Moreover, growing evidence suggests beneficial role for prevention of obesity and related dysfunctions. Citrus reticulata Blanco (Rutaceae) is one of the most consumed Citrus fruits, but it is poorly investigated. Mandarin juice obtained from C. reticulata fruits, collected in the Horti Simplicium of Pisa Charterhouse, presents a high amount of flavanone glycosides, including hesper- idin and a number of polymethoxyflavonoids, in particular nobiletin and tangeretin. On Wistar rats fed with a high fat diet for 21 days, mandarin juice significantly con- tained the percentage weight gain, reduced visceral adipose tissue and the inflamma- tory markers TNF and IL-6. Furthermore, mandarin juice influenced irisin pathway, increasing its plasma levels. Finally, supplementation with mandarin juice contributed to improve mitochondrial membrane potential, partially compromised with high fat diet, making mitochondria less susceptible to harmful events, such as ischemia. Taken together, these results suggest that C. reticulata, through its main metabolites, is able to produce beneficial effects in metabolic syndrome and to promote browning pro- cess, through involvement of the novel interesting irisin pathway

Alternating block copolymer-based nanoparticles as tools to modulate the loading of multiple chemotherapeutics and imaging probes

Abstract Cancer therapy often relies on the combined action of different molecules to overcome drug resistance and enhance patient outcome. Combined strategies relying on molecules with different pharmacokinetics often fail due to the lack of concomitant tumor accumulation and, thus, to the loss of synergistic effect. Due to their ability to enhance treatment efficiency, improve drug pharmacokinetics, and reduce adverse effects, polymer nanoparticles (PNPs) have been widely investigated as co-delivery vehicles for cancer therapies. However, co-encapsulation of different drugs and probes in PNPs requires a flexible polymer platform and a tailored particle design, in which both the bulk and surface properties of the carriers are carefully controlled. In this work, we propose a core-shell PNP design based on a polyurethane (PUR) core and a phospholipid external surface. The modulation of the hydrophilic/hydrophobic balance of the PUR core enhanced the encapsulation of two chemotherapeutics with dramatically different water solubility (Doxorubicin hydrochloride, DOXO and Docetaxel, DCTXL) and of Iron Oxide Nanoparticles for MRI imaging. The outer shell remained unchanged among the platforms, resulting in un-modified cellular uptake and in vivo biodistribution. We demonstrate that the choice of PUR core allowed a high entrapment efficiency of all drugs, superior or comparable to previously reported results, and that higher core hydrophilicity enhances the loading efficiency of the hydrophilic DOXO and the MRI contrast effect. Moreover, we show that changing the PUR core did not alter the surface properties of the carriers, since all particles showed a similar behavior in terms of cell internalization and in vivo biodistribution. We also show that PUR PNPs have high passive tumor accumulation and that they can efficient co-deliver the two drugs to the tumor, reaching an 11-fold higher DOXO/DCTXL ratio in tumor as compared to free drugs. Statement of Significance Exploiting the synergistic action of multiple chemotherapeutics is a promising strategy to improve the outcome of cancer patients, as different agents can simultaneously engage different features of tumor cells and/or their microenvironment. Unfortunately, the choice is limited to drugs with similar pharmacokinetics that can concomitantly accumulate in tumors. To expand the spectrum of agents that can be delivered in combination, we propose a multi-compartmental core-shell nanoparticles approach, in which the core is made of biomaterials with high affinity for drugs of different physical properties. We successfully co-encapsulated Doxorubicin Hydrochloride, Docetaxel, and contrast agents and achieved a significantly higher concomitant accumulation in tumor versus free drugs, demonstrating that nanoparticles can improve synergistic cancer chemotherapy

Deciphering the genetic control of innate and adaptive immune responses in pig: a combined genetic and genomic study

Improving animal robustness and resistance to pathogens by adding health criteria in selection schemes is one of the challenging objectives of the next decade. In order to better understand the genetic control of immunity in French Large White pigs, we have launched a program combining genetic and genomic studies not focussing on any particular pathogen. Animals recorded for production traits were scored for a wide range of immunity parameters three weeks after vaccination against Mycoplasma hyopneumoniae: i) total white blood cells and lymphocyte counts and proportions of various leucocyte subsets including cells harbouring IgM, γδTCR, CD4/CD8, CD16/CD2 and CD16/CD172a/MHCII, ii) innate immune response parameters (phagocytosis and in vitro production of IL1B, IL6, IL8, TNF, IL12 and IFNαafter blood stimulation), iii) adaptive immune response parameters (lymphocyte proliferation, in vitro production of IL2, IL4, IL10 and IFNγ after blood stimulation, total IgG, IgA, IgM and specific IgG levels) and iv) two acute phase proteins (C-reactive protein and haploglobin). Across traits, heritability estimates reached 0.4 on average (se=0.1) and 42 of the 54 measured parameters showed moderate to high heritabilities (≥0.2), confirming that many parameters are under genetic control and could be included in selection protocols. Functional analyses revealed that the blood transcriptome is informative for part of the immunity traits and should provide relevant phenotypic information to better characterize some immunity traits

Physical boundary Hilbert space and volume operator in the Lorentzian new spin-foam theory

A covariant spin-foam formulation of quantum gravity has been recently developed, characterized by a kinematics which appears to match well the one of canonical loop quantum gravity. In this paper we reconsider the implementation of the constraints that defines the model. We define in a simple way the boundary Hilbert space of the theory, introducing a slight modification of the embedding of the SU(2) representations into the SL(2,C) ones. We then show directly that all constraints vanish on this space in a weak sense. The vanishing is exact (and not just in the large quantum number limit.) We also generalize the definition of the volume operator in the spinfoam model to the Lorentzian signature, and show that it matches the one of loop quantum gravity, as does in the Euclidean case.Comment: 11 page

Feynman diagrammatic approach to spin foams

"The Spin Foams for People Without the 3d/4d Imagination" could be an alternative title of our work. We derive spin foams from operator spin network diagrams} we introduce. Our diagrams are the spin network analogy of the Feynman diagrams. Their framework is compatible with the framework of Loop Quantum Gravity. For every operator spin network diagram we construct a corresponding operator spin foam. Admitting all the spin networks of LQG and all possible diagrams leads to a clearly defined large class of operator spin foams. In this way our framework provides a proposal for a class of 2-cell complexes that should be used in the spin foam theories of LQG. Within this class, our diagrams are just equivalent to the spin foams. The advantage, however, in the diagram framework is, that it is self contained, all the amplitudes can be calculated directly from the diagrams without explicit visualization of the corresponding spin foams. The spin network diagram operators and amplitudes are consistently defined on their own. Each diagram encodes all the combinatorial information. We illustrate applications of our diagrams: we introduce a diagram definition of Rovelli's surface amplitudes as well as of the canonical transition amplitudes. Importantly, our operator spin network diagrams are defined in a sufficiently general way to accommodate all the versions of the EPRL or the FK model, as well as other possible models. The diagrams are also compatible with the structure of the LQG Hamiltonian operators, what is an additional advantage. Finally, a scheme for a complete definition of a spin foam theory by declaring a set of interaction vertices emerges from the examples presented at the end of the paper.Comment: 36 pages, 23 figure