Marketing y hábitos alimentarios en la población infanto-juvenil española

La progresiva instauración de estilos de vida poco saludables entre la población, ha provocado que la prevalencia de sobrepeso y obesidad se haya disparado a lo largo de las últimas décadas en nuestro país. La infancia es un momento esencial para la adquisición de hábitos adecuados que perduren durante la etapa adulta, en especial los relacionados con la alimentación. Son numerosos los factores que pueden afectar a la forma de comer de los más pequeños. Entre ellos, cabe destacar el efecto del marketing promovido por la industria alimentaria, especialmente a nivel televisivo. Así, el presente trabajo buscó analizar la publicidad de tipo alimentaria emitida en televisión en horario infantil en los canales de mayor cuota televisiva España. Se ha realizado un estudio transversal, observacional y descriptivo. La muestra estuvo formada por 156 horas de emisión en 6 canales de televisión durante los meses de enero y febrero de 2018. Se analizó la representatividad de los diferentes grupos de alimentos en los spots de tipo alimentario, la presión publicitaria ejercida por las diferentes marcas y empresas, el patrón alimentario descrito por la publicidad y la calidad nutricional de los productos anunciados. Se propone, además, una unidad didáctica sobre alimentación saludable y equilibrada con la intención de que sea puesta en marcha desde las aulas. El 22% del tiempo de emisión se dedicó a fines publicitarios. De ellos, el 18% correspondía a productos alimentarios. De los canales estudiados, “Boing” fue el que presentó una mayor proporción de anuncios de alimentos. El 80% de los spots publicitarios se dedicaron a promocionar el consumo de alimentos tipo: “Harinas y derivados”, “Conservas, platos precocinados y productos especiales”, “Lácteos y derivados” y “Edulcorantes naturales y derivados”. Estos productos, considerados de tipo ocasional por las guías alimentarias, se correspondieron con aquellos que, según el estudio ALADINO (1–3), más han incrementado su consumo entre la población infantil a lo largo de los últimos años. Entre el 70 y el 80% de los productos anunciados fueron catalogados como “insanos”. “Boing” y “Disney Channel” fueron los canales que dedicaron mayor tiempo de emisión a la promoción de alimentos con peores perfiles nutricionales. Los niños de nuestro país son bombardeados a diario con anuncios televisivos que mayoritariamente promueven el consumo de alimentos insanos. Así, productos considerados por las guías alimentarias de tipo ocasional, son los que mayor representación tuvieron a nivel publicitario, mientras que los más saludables prácticamente se encontraron ausentes. Este patrón alimenticio se corresponde además con los hábitos cada vez menos adecuados de los más pequeños en España. Se evidencia por tanto la necesidad de poner en marcha acciones formativas que contrarresten el posible efecto negativo de la publicidad en sus hábitos dietéticos.Grado en Nutrición Humana y Dietétic

Low temperature Terahertz Spectroscopy of LaFeO3_3, PrFeO3_3, ErFeO3_3, and LuFeO3_3: Quasimagnon resonances and ground multiplet transitions

We report on zone center THz excitations of non-Jahn Teller LaFeO$_3$, PrFeO$_3$, ErFeO$_3$, and LuFeO$_3$ distorted perovskites under external magnetic fields up 7 T. Low temperature-low energy absorptions of LaFeO$_3$ show antiferromagnetic and ferromagnetic quasimagnons at $\omega$AFM ~31.4 and $\omega$FM ~26.7 cm$^{-1}$ in the $\Gamma$4 (Gx, Ay, Fz) representation. LuFeO$_3$ is characterized by zero field magnetic resonances at $\omega$AFM ~26.3 cm$^{-1}$ and $\omega$FM ~22.4 cm$^{-1}$ in addition to Fe$^{3+}$ Zeeman-split crystal field (CF) 6A$_1$ ground transitions at ~10.4 cm$^{-1}$ triggered by structural deviations induced by smaller Lu 4f$^{14}$. This local non-centrosymmetric departure is also found in ErFeO$_3$ (Kramers 4f$^{11}$ Er$^{3+}$ (4I15/2); {\Gamma}2 (Fx, Cy, Gz) <TSR ~93 K), but with the ~4 cm$^{-1}$ Fe$^{3+}$ Zeeman branching strongly biased toward higher energies. Quasimagnons at $\omega$AFM ~31.5 cm$^{-1}$ and $\omega$FM ~21.5 cm$^{-1}$ in ErFeO$_3$ do not undergo field induced band splits but a 13-fold increase in the antiferro ($\omega$AMF) /ferro($\omega$AFM) intensity ratio. There is a remarkable field-dependent CF matching population balance between Fe$^{3+}$ higher and Er$^{3+}$ lower Zeeman branches. Antiferro- and ferro- resonances in PrFeO$_3$ turn much broader as non-Kramers Pr$^3$ introduces ligand changes at the A site leading into near degeneracy the antiferromagnetic mode and the lowest Pr$^{3+}$ CF transition. We conclude that low energy excitations in RFeO$_3$ (R=rare earth) strongly depend on the lanthanide ionic size. Minute lattice displacements also underlie considering non-centrosymmetric the most distorted RFeO$_3$ (R=rare earth). Changes triggered by the smaller rare earth and the nonlinear intrinsic oxygen ion polarizability provide grounds for interplay of ionic and electronic interactions yielding ferroelectric spontaneous polarization.Comment: Full Manuscript and Supplemental Material, 73 pages, 27 figure

Phonons and Hybrid Modes in the High and Low Temperature Far Infrared Dynamics of Hexagonal TmMnO3

We report on TmMnO3 far infrared emissivity and reflectivity spectra from 1910 K to 4 K. At the highest temperature the number of infrared bands is lower than that predicted for centrosymmetric P63/mmc (D6h4) (Z=2) space group due high temperature anharmonicity and possible defect induced bitetrahedra misalignments. On cooling, at ~1600 K TmMnO3 goes from non-polar to an antiferroelectric-ferroelectric polar phase reaching the ferroelectric onset at the ~700 K. The 300 K reflectivity is fitted using 19 oscillators and this number of phonons is maintained down to 4 K. A weak phonon anomaly in the band profile at 217 cm-1 (4 K) suggests subtle Rare Earth magnetoelectric couplings at ~TN and below. A low energy collective excitation is identified as a THz instability associated with room temperature eg electrons in a d-orbital fluctuating environment. It condenses into two modes that emerge pinned to the E-type antiferromagmetic order hardening simultaneously down to 4 K. They obey power laws with TN as the critical temperature and match known zone center magnons. The one peaking at 26 cm-1, with critical exponent \b{eta}=0.42 as for antiferromagnetic order in a hexagonal lattice, is dependent on the Rare Earth. The band at ~50 cm-1, with \b{eta}=0.25, splits at ~TN into two peaks. The weaker band of the two is assimilated to the upper branch of gap opening in the transverse acoustical (TA) phonon branch crossing the magnetic dispersion found in YMnO3. (Petit et al, 2007 PRL 99, 266604). The stronger second at ~36 cm-1 corresponds to the lower branch of the TA gap. We assign both excitations as zone center magnetoelectric hybrid quasiparticles concluding that in NdMnO3 perovskite the equivalent picture corresponds to an instability which may be driven by an external field to transform NdMnO3 into a multiferroic compound by perturbation enhancing the TA phonon-magnetic correlation.Comment: 39 pages, 9 Figure

High Temperature Far Infrared Dynamics of Orthorhombic NdMnO3: Emissivity and Reflectivity

We report on near normal far- and mid-infrared emission and reflectivity of NdMnO3 perovskite from room temperature to sample decomposition above 1800 K. At 300 K the number infrared active phonons is in close agreement with the 25 calculated for the orthorhombic D2h16-Pbnm (Z=4) space group. Their number gradually decreases as we approach the temperature of orbital disorder at ~1023 K where the orthorhombic O' lower temperature cooperative phase coexists with the cubic orthorhombic O. At above ~1200 K, the three infrared active phonons coincide with the expected for cubic Pm-3m (Z=1) in the high temperature insulating regime. Heating samples in dry air triggers double exchange conductivity by Mn3+ and Mn4+ ions and a small polaron mid-infrared band. Fits to the optical conductivity single out the octahedral antisymmetric and symmetric vibrational modes as main phonons in the electron-phonon interactions at 875 K. For 1745 K, it is enough to consider the symmetric stretching internal mode. An overdamped defect induced Drude component is clearly outlined at the highest temperatures. We conclude that Rare Earth manganites eg electrons are prone to spin, charge, orbital, and lattice couplings in an intrinsic orbital distorted perovskite lattice favoring embryonic low energy collective excitations.Comment: 32 pages with 5 figure

Paramagnetic Collective Electronic Mode and Low Temperature Hybrid Modes in the Far Infrared Dynamics of Orthorhombic NdMnO3

We report on far- and mid-infrared reflectivity of NdMnO3 from 4 K to 300K. Two main features are distinguished in the infrared spectra: active phonons in agreement with the expected for orthorhombic D2h 16-Pbnm (Z=4) space group remaining constant down to 4 K and a well-defined collective excitation in the THz region due to eg electrons in a d-orbital fluctuating environment. We trace its origin to the NdMnO3 high temperature orbital disordered intermediate phase not being totally dynamically quenched at lower temperatures. This results in minute orbital misalignments that translate in randomize non-static eg electrons within orbitals yielding a room temperature collective excitation. Below TN~78 K, electrons gradually localize inducing long-range magnetic order as the THz band condenses into two modes that emerge pinned to the A-type antiferromagmetic order. They harden simultaneously down to 4 K obeying power laws with TN as the critical temperature and exponents {\beta}~0.25 and {\beta}~0.53, as for a tri-critical point and Landau magnetic ordering, respectively. At 4K they match known zone center spin wave modes. The power law dependence is concomitant with a second order transition in which spin modes modulate orbital instabilities in a magnetoelectric hybridized orbital/charge/spin/lattice scenario. We also found that phonon profiles also undergo strong changes at TN~78 K due to magnetoelasticity.Comment: 40 pages with 8 figure

Mid-infrared optical properties of pyrolytic boron nitride in the 390 to 1050 ∘^{\circ}C temperature range using spectral emissivity measurements

This paper shows a systematic experimental and theoretical study on the temperature dependence of the infrared optical properties of pyrolytic boron nitride (pBN), from 390 to 1050 $^{\circ}$CC for wavelengths between 4 and 16 {\mu}m. The temperature dependence of these properties has never been analyzed before. The measured emissivity spectra were fitted to a dielectric function model and an effective medium approximation. The phonon frequencies and dielectric constants agreed well with room temperature experimental values from the literature, as well as with ab initio and first principles calculations. In addition, the phonon frequencies of the perpendicular mode and the dielectric constants of the parallel mode showed an appreciable parabolic temperature dependence, which justifies the interest of more theoretical efforts in order to explain this behavior. Finally, the results of this work demonstrate that thermal emission spectroscopy allows obtaining the values of the optical and dielectric parameters of impure ceramic materials in a simple manner as a function of temperature.Comment: 6 pages, 6 figure

Laser-induced highly oriented pyrolytic graphite for high-performance screen-printed electrodes

Screen-printed carbon electrodes (SPCEs) are enjoying increasing popularity in different electrochemistry areas, from electroanalysis to energy storage and power generation. Highly oriented pyrolytic graphite (HOPG), an ordered form of graphite, displays excellent electrochemical properties. However, its application in screen-printed electrodes has remained elusive. In this work, we present a straightforward laser-based process to selectively transform, in ambient conditions, the surface of conventional SPCEs into highly homogeneous HOPG. Energy densities between 6.8 and 7.7 mJ cm(-2) result in a binder-free, high-purity HOPG surface with very fast electron transfer rates. The electrode transformation to HOPG has been followed by SEM, Raman spectroscopy and XPS. Cyclic voltammetry of model systems ferrocyanide, ferrocenecarboxylic acid, dopamine and hydroquinone has been used to determine variations in electrode kinetics (from 50% increase for ferrocenecarboxylic acid, up to ca. 2 orders of magnitude for ferrocyanide and dopamine) and interfacial capacitance (from 40 up to 220 mu F cm(-2)). Finally, differential pulse voltammetry (DPV) has been used to demonstrate the ability of these electrodes to detect dopamine in the presence of an excess amount of ascorbic acid.The authors are grateful for the technical and human support provided by SGIker of UPV/EHU and European funding (ERDF and ESF). We acknowledge funding from the European Union's Horizon 2020 Programme for Research, ICT-02-2018 - Flexible and Wearable Electronics, Grant agreement no. 825339 - WEARPLEX. Lia Campos-Arias thanks the University of Basque Country (UPV/EHU) for doctoral grant PIFI20/04. Project number PID2020-113154RB-C22 from the Spanish Ministry of Science and Innovation is also gratefully acknowledged

Far- and mid-infrared emission and reflectivity of orthorhombic and cubic ErMn O 3: Polarons and bipolarons

We report on the high-temperature evolution of far- and mid-infrared reflectivity and emissivity spectra of ambient orthorhombic ErMnO3 from 12 K to sample decomposition above 1800 K. At low temperatures the number of phonons agrees with the predictions for orthorhombic space group D2h16-Pbnm (Z=4) and coexists with a paramagnon spin resonance and rare-earth crystal-field transitions. Increasing the temperature, a number of vibrational bands undergo profile broadening and softening approaching the orbital disordered phase where the orthorhombic Ó lower-temperature cooperative phase coexists with cubic-orthorhombic O. O-ErMnO3 undergoes a first-order order-disorder transition into the perovskite cubic phase at Tcubic∼1329K±20K where the three triple degenerate phonons allowed by the space group Pm-3m (Z=1) are identified. At about 800 K, a quantitative small polaron analysis of the orthorhombic midinfrared real part optical conductivity shows that antisymmetric and symmetric breathing modes sustain the strongest electron-phonon interactions. Above Tcubic the bipolaron fingerprint profile is the midinfrared dominant and only feature. Its appearance correlates with the localized screening of the highest vibrational mode reststrahlen band. We propose that the longitudinal optical mode macroscopic field screening is a consequence of dynamically sharing δ disproportioned eg electrons hovering over the Jahn-Teller distorted octahedral dimer {Mn(QJT)3+δ[Mn(QJT)[3]-δ]O6/2}2. A thermal driven insulator-metal transition is detected with onset ∼1600 K. We also address the occurrence of an inhomogeneity induced terahertz band result of heating the samples in dry air, triggering Mn3+-Mn4+ double exchange, under the presence of Mn4+ smaller ions stabilizing the orthorhombic lattice.Centro de Química Inorgánic

High temperature far-infrared dynamics of orthorhombic NdMnO₃: emissivity and reflectivity

We report on near normal far- and mid-infrared emission and reflectivity of NdMnO₃ perovskite from room temperature to sample decomposition above 1800 K. At 300 K the number infrared active phonons is in close agreement with the 25 calculated for the orthorhombic D¹⁶2h-Pbnm (Z=4) space group. Their number gradually decreases as we approach the temperature of orbital disorder at ~1023 K where the orthorhombic O' lower temperature cooperative phase coexists with the cubic orthorhombic O. At above ~1200 K, the three infrared active phonons coincide with the expected for cubic Pm-3m (Z=1) in the high temperature insulating regime. Heating samples in dry air triggers double exchange conductivity by Mn³⁺ and Mn⁴⁺ ions and a small polaron mid-infrared band. Fits to the optical conductivity single out the octahedral antisymmetric and symmetric vibrational modes as main phonons in the electron-phonon interactions at 875 K. For 1745 K, it is enough to consider the symmetric stretching internal mode. An overdamped defect induced Drude component is clearly outlined at the highest temperatures. We conclude that Rare Earth manganites eg electrons are prone to spin, charge, orbital, and lattice couplings in an intrinsic orbital distorted perovskite lattice favoring embryonic low energy collective excitations.Facultad de Ciencias ExactasCentro de Química Inorgánic

Paramagnetic collective electronic mode and low temperature hybrid modes in the far infrared dynamics of orthorhombic NdMnO₃

We report on the far- and mid-infrared reflectivity of NdMnO₃ from 4 to 300 K. Two main features are distinguished in the infrared spectra: active phonons in agreement with expectations for the orthorhombic D¹⁶2h-Pbnm (Z = 4) space group remaining constant down to 4 K and a well defined collective excitation in the THz region due to eg electrons in a d-orbital fluctuating environment. We trace its origin to the NdMnO₃ high-temperature orbital disordered intermediate phase not being totally dynamically quenched at lower temperatures. This results in minute orbital misalignments that translate into randomized non-static eg electrons within orbitals yielding a room-temperature collective excitation. Below TN ∼ 78 K, electrons gradually localize, inducing long-range magnetic order as the THz band condenses into two modes that emerge pinned to the A-type antiferromagnetic order. They harden simultaneously down to 4 K, obeying power laws with TN as the critical temperature and exponents β ∼ 0.25 and β ∼ 0.53, as for a tri-critical point and Landau magnetic ordering, respectively. At 4 K they match known zone center spin wave modes. The power law dependence is concomitant with a second order transition in which spin modes modulate orbital instabilities in a magnetoelectric hybridized orbital-charge-spin-lattice scenario. We also found that phonon profiles also undergo strong changes at TN ∼ 78 K due to magnetoelasticity.Facultad de Ciencias ExactasCentro de Química Inorgánic