Linearized gravity as a gauge theory

We discuss linearized gravity from the point of view of a gauge theory. In (3+1)-dimensions our analysis allows to consider linearized gravity in the context of the MacDowell-Mansouri formalism. Our observations may be of particular interest in the strong-weak coupling duality for linearized gravity, in Randall-Sundrum brane world scenario and in Ashtekar formalism.Comment: Latex, 13 page

Hamiltonian Noether theorem for gauge systems and two time physics

The Noether theorem for Hamiltonian constrained systems is revisited. In particular, our review presents a novel method to show that the gauge transformations are generated by the conserved quantities associated with the first class constraints. We apply our results to the relativistic point particle, to the Friedberg et al. model and, with special emphasis, to two time physics.Comment: 20 pages, Latex, references added, the "massless" sense of (87) is clarifie

Are Antiprotons Forever?

Up to one million antiprotons from a single LEAR spill have been captured in a large Penning trap. Surprisingly, when the antiprotons are cooled to energies significantly below 1 eV, the annihilation rate falls below background. Thus, very long storage times for antiprotons have been demonstrated in the trap, even at the compromised vacuum conditions imposed by the experimental set up. The significance for future ultra-low energy experiments, including portable antiproton traps, is discussed.Comment: 12 pages, latex; 4 figures, uufiled. Slightly expanded discussion of expected energy dependence of annihilation cross section and rate, and of estimates of trap pressure, plus minor text improvement

ON HIGHER ORDER NONLINEAR IMPULSIVE BOUNDARY VALUE PROBLEMS

This work studies some two point impulsive boundary value problems composed by a fully differential equation, which higher order contains an increasing homeomorphism, by two point boundary conditions and impulsive e ects. We point out that the impulsive conditions are given via multivariate generalized functions, including impulses on the referred homeomorphism. The method used apply lower and upper solutions technique together with xed point theory. Therefore we have not only the existence of solutions but also the localization and qualitative data on their behavior. Moreover a Nagumo condition will play a key role in the arguments

SIZE-REACTIVITY OF DISSOLVED ORGANIC MATTER IN THE CAPE VERDE FRONTAL ZONE

Oral communicationDissolved organic matter (DOM) plays a major role in the recycling, export and sequestration of biogenic organic carbon, being a key component of ocean biogeochemical cycles and of the biological and microbial carbon pumps. Microbial degradation of DOM not only produces CO 2 but also generates dissolved molecules of decreasing bioavailability that can accumulate in the oceans for hundreds to thousands of years. The size-reactivity continuum (SRC) model is the conceptual framework to explain the DOM reactivity on a size basis, although field tests are still scarce and some of the pieces of this puzzle remain unclear. Taking advantage of the FLUXES-I cruise in the Cape Verde Frontal Zone (CVFZ), we have studied the size fractionated reactivity of the high (HMW; >1 KDa) and low (LMW; <1 KDa) molecular weight fractions of the DOM from surface down to 4000 m, using a high-efficiency and low-concentration-factor ultrafiltration cell. The wide ageing range covered by the water masses of the CVFZ makes it an excellent site to test the SRC model. Regarding the bulk C and N pools, the water masses with higher oxygen utilization were more depleted in HMW molecules, with a significant preference for the degradation of large N-containing compounds. Accordingly, preferential degradation of HMW fluorescent protein-like compounds was observed. In parallel, fluorescent humic-like compounds of both HMW and LMW were generated as by-product of the degradation of HMW organic compounds, and the remineralization of the DOM increases the aromaticy of both fractions, but especially the LMW one.ASL

Dynamics of Weyl Scale Invariant non-BPS p=3 Branes

In this paper a Weyl scale invariant $p=3$ brane scenario is introduced, with the brane embedded in a higher dimensional bulk space with $N=1, 5D$ Super--Weyl symmetry. Its action, which describes its long wave oscillation modes into the ambient superspace and breaks the target symmetry down to the lower dimensional Weyl W(1,3) symmetry, is constructed by the approach of coset method.Comment: 12 pages, modified versio

Role of geometric shape in chiral optics

The distinction of chiral and mirror symmetric objects is straightforward from a geometrical point of view. Since the biological as well as the optical activity of molecules strongly depend on their handedness, chirality has recently attracted high interest in the field of nano-optics. Various aspects of associated phenomena including the influences of internal and external degrees of freedom on the optical response have been discussed. Here, we propose a constructive method to evaluate the possibility of observing any chiral response from an optical scatterer. Based on solely the T-matrix of one enantiomer, planes of minimal chiral response are located and compared to geometric mirror planes. This provides insights into the relation of geometric and optical properties and enables identifying the potential of chiral scatterers for nano-optical experiments

Social value framing of physical activity in European Member State policies: a content analysis

BackgroundEngagement in physical activity (PA) benefits physical and mental health as well as many other areas of society. In Europe however, 1/3 adults do not meet minimum PA recommendations. Social value, and its quantification through social return on investment (SROI) evidence, may be a useful framing to enhance PA promotion. This study aimed to assess the current use of social value framing of PA in European Union (EU) policies.MethodsContent analysis of 45 EU member state policies which contain reference to PA was conducted to evaluate the presence of five social value domains and SROI evidence. Data was analysed using manual inductive coding, supported by DeepL translation and NVivo tools.ResultsSocial value framing was present to a certain extent in existing policies, with improved health being the most commonly referenced benefit of PA, followed by reference to social and community and then environmental benefits. Acknowledgement of the positive impacts of PA on wellbeing and education was the least present. Reference to SROI evidence was also limited. Generally, policies lacked holistic recognition of the social value of PA. Policies from the health sector were particularly limited in recognising the wider benefits of PA, whilst those from the environmental sector acknowledged the widest range of co-benefits.ConclusionAdopting social value framing could be a useful approach for enhancing PA promotion. Whilst it is present to a certain extent in existing policy, this could be increased in terms of comprehensiveness to increase issue salience and multisectoral policy action

NEW DESCRIPTORS TO CHARACTERIZE POROUS MATERIALS

5

A One-Step, Versatile Synthesis of Dibenzo [n.2.2] Macrobicyclic Compounds via a Conformation-Directed Macrocyclization Reaction

A series of dibenzo [n.2.2] bicyclic compounds (n = 2–20) were prepared in one step and good yields starting from dimethyl anthracene-9,10-dicarboxylate. Reduction of the aromatic diester using lithium/naphthalene led to a bis-enolate that was cyclized with a variety of bis-electrophiles. The ease of the cyclization is probably due to the puckered conformation of the intermediate formed after the first alkylation step, in which the newly introduced chain that will become the bridge portion occupies a pseudoaxial position, positioning the leaving group close to the enolate nucleophile in the macrocyclization stepThis work was supported by the Ministerio de Economía y Competitividad of Spain (CTQ2011-22436) and Xunta de Galicia (PGIDIT10-PXIB209113PR, 10PXIB209155PR, and 2007/085)S