Supersymmetric Barotropic FRW Model and Dark Energy

Using the superfield approach we construct the $n=2$ supersymmetric lagrangian for the FRW Universe with barotropic perfect fluid as matter field. The obtained supersymmetric algebra allowed us to take the square root of the Wheeler-DeWitt equation and solve the corresponding quantum constraint. This model leads to the relation between the vacuum energy density and the energy density of the dust matter.Comment: 11 pages, minor corrections, published versio

Supersymmetric FRW model and the ground state of supergravity

In this work we construct the vacuum configuration of supergravity interacting with homogeneous complex scalar matter fields. The corresponding configuration is of the FRW model invariant under the $n=2$ local conformal time supersymmetry, which is a subgroup of the four dimensional space-time supersymmetry. We show, that the potential of the scalar matter fields is a function of the K\"ahler potential and of the arbitrary parameter $\alpha$. This parameter enumerates the vacuum states. The scalar matter potential induces the spontaneous breaking of supersymmetry in supergravity. On the quantum level our model is a specific supersymmetric quantum mechanics, which admits quantum states in supergravity, and the states with zero energy are described by the wave function of the FRW universe.Comment: 18 pages, Revtex, submitted to PR

A Reliable Method for the Isolation and Characterization of Microplastics in Fish Gastrointestinal Tracts Using an Infrared Tunable Quantum Cascade Laser System

[Abstract] Societal and environmental concern due to frequent reports of microplastics in fish stomachs raised as they may accumulate along the trophic chain. The request for analysing microplastics in fish stresses two major analytical issues: sample treatment and final characterization. The, so far, workhorse for chemical characterization is infrared spectroscopy which is time-consuming. Here, a quantum cascade laser-based device is used to accelerate the characterization stage. Its novelty poses new challenges for sample processing and particle handling because the unknown particles must be transferred to a reflective slide. In this study, three sample digestion protocols (alkaline-oxidative with H2O2, and alkaline-oxidative with NaClO and enzymatic-oxidative) and three different procedures to transfer the filter cake to reflective slides are compared. A simplified enzymatic-oxidative digestion (validated through an interlaboratory exercise) combined with a Syncore® automatic evaporation system and a Laser Direct Infrared Imaging (LDIR) device is proposed first time as a reliable and relatively fast method to treat gastrointestinal tracts of fish. Analytical recoveries were studied using samples of Scomber scombrus and they were ca. 100% for big –i.e., >500 μm- and ca. 90% for medium –i.e., 200–300 μm- particles and ca. 75% for 10 μm thick fibres.This research was supported by the LAnd-Based Solutions for PLAstics in the Sea Project (LABPLAS Project), Grant Agreement No. 101003954, under the European Union's Horizon 2020 research and innovation programme, and the Integrated approach on the fate of MicroPlastics (MPs) towards healthy marine ecosystems Project (MicroplastiX project), Grant PCI2020-112145, supported by the JPI_Oceans Program and by MCIN/AEI/10.13039/501100011033 and the European Union “Next Generation EU/PRTR”. The Program ‘Consolidación e Estructuración de Unidades de Investigación Competitivas” of the Galician Government (Xunta de Galicia) is also acknowledged (Grant ED431C 2021/56)Xunta de Galicia; ED431C 2021/5

Quantum state correction of relic gravitons from quantum gravity

The semiclassical approach to quantum gravity would yield the Schroedinger formalism for the wave function of metric perturbations or gravitons plus quantum gravity correcting terms in pure gravity; thus, in the inflationary scenario, we should expect correcting effects to the relic graviton (Zel'dovich) spectrum of the order (H/mPl)^2

Quantum Fields on Star Graphs

We construct canonical quantum fields which propagate on a star graph modeling a quantum wire. The construction uses a deformation of the algebra of canonical commutation relations, encoding the interaction in the vertex of the graph. We discuss in this framework the Casimir effect and derive the correction to the Stefan-Boltzmann law induced by the vertex interaction. We also generalize the algebraic setting for covering systems with integrable bulk interactions and solve the quantum non-linear Schroedinger model on a star graph.Comment: LaTex 23+1 pages, 4 figure

Magnetic-field effects on transport in carbon nanotube junctions

Here we address a theoretical study on the behaviour of electronic states of heterojunctions and quantum dots based on carbon nanotubes under magnetic fields. Emphasis is put on the analysis of the local density of states, the conductance, and on the characteristic curves of current versus voltage. The heterostructures are modeled by joining zigzag tubes through single pentagon-heptagon pair defects, and described within a simple tight binding calculation. The conductance is calculated using the Landauer formula in the Green functions formalism. The used theoretical approach incorporates the atomic details of the topological defects by performing an energy relaxation via Monte Carlo calculation. The effect of a magnetic field on the conductance gap of the system is investigated and compared to those of isolated constituent tubes. It is found that the conductance gap of the studied CNHs exhibits oscillations as a function of the magnetic flux. However, unlike the pristine tubes case, they are not Aharonov-Bohm periodic oscillations

Measuring primality in numerical semigroups with embedding dimension three

Electronic version of an article published as Journal of Algebra and Its Applications, 15, 1, 2016, 1650007. DOI:10.1142/S0219498816500079 © World Scientific Publishing Company https://www.worldscientific.com/doi/abs/10.1142/S0219498816500079In this paper, we find the ω-value of the generators of any numerical semigroup with embedding dimension three. This allows us to determine all possible orderings of the ω-values of the generators. In addition, we relate the ω-value of the numerical semigroup to its catenary degree.The first and third authors received National Science Foundation support under DMS-1262897. The second author is supported by the projects MTM2010-15595, FQM-343, FQM-5849, NSF-1061366 and FEDER funds

Tuberculosis in pregnancy and adverse neonatal outcomes in two peruvian hospitals

Background: According to the World Health Organization, tuberculosis (TB) ranks among the top 10 causes of death worldwide. The significance of TB during pregnancy lies in its symptoms, which can be mistaken for physiological changes associated with pregnancy. This confusion can lead to maternal-perinatal complications. Objective: To evaluate the association between pulmonary TB in pregnancy and adverse neonatal outcomes in two Peruvian hospitals. Methods: This is a retrospective cohort study. The target population consisted of pregnant women with and without pulmonary TB whose deliveries were attended at two public hospitals, located in Lima, Peru. The adverse neonatal outcomes were prematurity, low birth weight (LBW), and being small for gestational age (SGA). Crude and adjusted relative risks (RRa) were calculated with their respective 95% confidence intervals (95%CI). Results: Information from 212 patients was analyzed; 48.1% had TB during pregnancy, and 23.1% had adverse neonatal outcomes (8%, 11.3%, and 12.3% for LBW, prematurity, and SGA, respectively). In the adjusted model, pregnant women with pulmonary TB had a 3.52 times higher risk of having a newborn with at least one of the adverse outcomes than those who were not exposed (aRR, 3.52; 95%CI: 1.93–6.68). Conclusion: Pulmonary TB in pregnancy was jointly and independently associated with adverse neonatal outcomes, including LBW, prematurity, and being SGA

Development of a Fast and Efficient Method to Analyze Microplastics in Planktonic Samples

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract] Microplastics (MPs) affect plankton (a basis of the trophic chain) and planktivorous fish can ingest them through food confusion or by trophic transmission. Consensus to determine MPs in plankton is lacking and, so, three digestion treatments were evaluated: Alkaline (potassium hydroxide) and enzymatic (protease plus lipase) digestions, both combined with a hydrogen peroxide stage; and an oxidative method using a surfactant (sodium dodecyl sulfate) plus hydrogen peroxide. The alkaline method using potassium hydroxide was found to damage polystyrene. MPs were identified with a stereomicroscope and characterized by reflectance infrared microscopy in semi-automatic mode (using dedicated multi-well aluminium plates). Analytical recoveries for polypropylene, polystyrene, polyethylene, polyamide, polyvinyl chloride and polyethylene terephthalate were higher than 75%, 82% and 83% for the alkaline, enzymatic and oxidative treatments, respectively. The enzymatic method was successfully validated in a European interlaboratory exercise and the oxidative method was demonstrated to be a reliable, fast and cheaper alternative.The Spanish Government (Ministerio de Economía y Competitividad and Ministerio de Ciencia e Innovación-Agencia Estatal de Investigación) and the JPI-Oceans European Program are acknowledged by the BASEMAN (PCIN-2015-170-C02-01, with FEDER/ERDF funds) and the MicroplastiX (PCIN-PCI2020-112145) projects. Thanks are given also to the Spanish Government by the CTM2016-77945-C3-3-R (ARPA-ACUA) Grant. The Galician Government (“Xunta de Galicia”) is acknowledged for its support to the QANAP group (Programa de Consolidación y Estructuración de Unidades de Investigación Competitiva. Ref. ED431C 2017/28) partially financed by FEDER/ERDF fundsXunta de Galicia; ED431C 2017/2