Evidences of evanescent Bloch waves in Phononic Crystals

We show both experimentally and theoretically the evanescent behaviour of modes in the Band Gap (BG) of finite Phononic Crystal (PC). Based on experimental and numerical data we obtain the imaginary part of the wave vector in good agreement with the complex band structures obtained by the Extended Plane Wave Expansion (EPWE). The calculated and measured acoustic field of a localized mode out of the point defect inside the PC presents also evanescent behaviour. The correct understanding of evanescent modes is fundamental for designing narrow filters and wave guides based on Phononic Crystals with defects.Comment: 8 pages, 3 figure

Be creative, my friend! Engaging users on Instagram by promoting positive emotions

Instagram is emerging as the most influential social network; this phenomenon is especially apparent in the fashion industry. Fashion brands are launching creative campaigns on Instagram to engage their followers. The present study aims to increase the understanding of followers’ engagement by analyzing the consequences of brand publications on Instagram. Taking as a basis the S-O-R framework, brand publications (stimulus) may generate perceptions of creativity and positive emotions in their followers (organism) which, in turn, may influence their affective commitment and interaction intentions (response). Our results, based on data collected from 808 followers of an Instagram fashion brand account, analyzed using structural equation modeling, confirmed that perceived creativity is a crucial aspect of Instagram. In addition, positive emotions and affective commitment act as partial mediators in the relationship between perceived creativity and interaction intentions. These results have interesting implications for both the fashion industry and content generation on Instagram

Influencers and brands successful collaborations: A mutual reinforcement to promote products and services on social media

Brands and influencers are increasingly collaborating in the development of marketing campaigns. This work analyses to what extent the collaboration of influencers with renowned brands affects the effectiveness of the message and the influencer’s own reputation. The results of an experiment with more than four hundred Spanish consumers indicated that renowned brand-influencer collaborations, in comparison to non-renowned brand-influencer collaborations, enhanced consumers’ attitude towards the message, their purchase intentions and the perceived credibility of the influencer. Furthermore, positive attitude towards the message and intention to search for information are greater for services offered by renowned brands than for their products. This study contributes by bridging a gap in the literature and raises interesting implications for brand managers and their decisions to collaborate with influencers on social media

Analytical model to predict the effect of a finite impedance surface on the propagation properties of a 2D Sonic Crystal

The use of Sonic Crystals as environmental noise barriers has certain advantages from the acoustical and the constructive point of view with regard to conventional ones. One aspect do not studied yet is the acoustic interaction between the Sonic Crystals and the ground due to, up to now, this latter is not included in the analytical models used to characterize these Sonic Crystals. We present here an analytical model, based on multiple scattering theory, to study this interaction considering the ground as a finite impedance surface. Using this model we have obtained interesting conclusions that allow to design more effectively noise screens based on Sonic Crystals. The obtained results have been compared with experimental and numerical, finding a good agreement between them

Analytical methodologies based on LC–MS/MS for monitoring selected emerging compounds in liquid and solid phases of the sewage sludge

In this work, two analytical methodologies based on liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS) were developed for quantification of emerging pollutants identified in sewage sludge after a previous wide-scope screening. The target list included 13 emerging contaminants (EC): thiabendazole, acesulfame, fenofibric acid, valsartan, irbesartan, salicylic acid, diclofenac, carbamazepine, 4-aminoantipyrine (4- AA), 4-acetyl aminoantipyrine (4-AAA), 4-formyl aminoantipyrine (4-FAA), venlafaxine and benzoylecgonine. The aqueous and solid phases of the sewage sludge were analyzed making use of Solid-Phase Extraction (SPE) and UltraSonic Extraction (USE) for sample treatment, respectively. The methods were validated at three concentration levels: 0.2, 2 and 20mg L 1 for the aqueous phase, and 50, 500 and 2000mg kg 1 for the solid phase of the sludge. In general, the method was satisfactorily validated, showing good recoveries (70–120%) and precision (RSD < 20%). Regarding the limit of quantification (LOQ), it was below 0.1mg L 1 in the aqueous phase and below 50mg kg 1 in the solid phase for the majority of the analytes. The method applicability was tested by analysis of samples from a wider study on degradation of emerging pollutants in sewage sludge under anaerobic digestion. The key benefits of these methodologies are: SPE and USE are appropriate sample procedures to extract selected emerging contaminants from the aqueous phase of the sewage sludge and the solid residue. LC–MS/MS is highly suitable for determining emerging contaminants in both sludge phases. Up to our knowledge, the main metabolites of dipyrone had not been studied before in sewage sludge. ãFinancial support of Generalitat Valenciana (Prometeo II/2014/023,ISIC/2014/016

Behaviour of emerging contaminants in sewage sludge after anaerobic digestion

Nowadays, there is an increasing concern over the presence of contaminants in the aquatic environment, where they can be introduced from wastewater after their incomplete removal in the treatment plants. In this work, degradation of selected emerging pollutants in the aqueous and solid phases of sewage sludge has been investigated after anaerobic digestion using two different digesters: mesophilic and thermophilic. Initially, sludge samples were screened by ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UHPLC-QTOF MS) for identification of emerging contaminants in the samples. In a second step, a target quantitative method based on LC coupled to tandem MS was applied for selected pollutants identified in the previous screening. The behaviour of the compounds under anaerobic conditions was studied estimating the degradation efficiency and distribution of compounds between both sludge phases. Irbesartan and benzoylecgonine seemed to be notably degraded in both phases of the sludge. Venlafaxine showed a significant concentration decrease in the aqueous phase in parallel to an increase in the solid phase. The majority of the compounds showed an increase of their concentrations in both phases after the digestion. Concentrations in the solid phase were commonly higher than in the aqueous for most contaminants, indicating that they were preferentially adsorbed onto the solid particles.The authors are very grateful to the Ecophysiology and Biotechnology group (University Jaume I) and to The Institute of Aquaculture “Torre de la Sal” (IATS) (Consejo Superior de Investigaciones Científicas, CSIC) for using their lyophilizer systems. The financial support of Generalitat Valenciana (Prometeo II/2014/023, ISIC/2014/016) is also acknowledged

Overlapping of acoustic bandgaps using fractal geometries

The transmission of acoustic waves in a fractal distribution of rigid scatterers embedded in air is reported in this work. The Sierpinsky fractal is used to produce a compact small device containing several periodicities, therefore the fractal distribution contains several finite sonic crystals. The attenuation band produced by the fractal distribution results from the sum of the Bragg peaks of each periodicity. On the other hand, bandgaps of sonic crystal depend on the well-known filling fraction, thus the radii of the scatterers in the fractal distribution has been optimized using genetic algorithm in order to overlap the bandgaps of each periodicity obtaining a wide and full attenuation band.This work was supported by MCI (Spanish Government) and FEDER funds, under Grant Nos. MAT2009-09438 and MTM2009-14483-C02-02. The authors would like to thank Prof. K. ATTENBOROUGH and Dr. E. A. SANCHEZ-PEREZ for their suggestions and for the revision of the manuscript.Castiñeira Ibáñez, S.; Romero García, V.; Sánchez Pérez, JV.; García-Raffi, LM. (2010). Overlapping of acoustic bandgaps using fractal geometries. EPL. 92(2):240071-240073. doi:10.1209/0295-5075/92/24007S24007124007392

Oxidized low-density lipoprotein receptor in lymphocytes prevents atherosclerosis and predicts subclinical disease

Background: Although the role of Th17 and regulatory T cells in the progression of atherosclerosis has been highlighted in recent years, their molecular mediators remain elusive. We aimed to evaluate the association between the CD69 receptor, a regulator of Th17/regulatory T cell immunity, and atherosclerosis development in animal models and in patients with subclinical disease. Methods: Low-density lipoprotein receptor-deficient chimeric mice expressing or not expressing CD69 on either myeloid or lymphoid cells were subjected to a high fat diet. In vitro functional assays with human T cells were performed to decipher the mechanism of the observed phenotypes. Expression of CD69 and NR4A nuclear receptors was evaluated by reverse transcription-polymerase chain reaction in 305 male participants of the PESA study (Progression of Early Subclinical Atherosclerosis) with extensive (n=128) or focal (n=55) subclinical atherosclerosis and without disease (n=122). Results: After a high fat diet, mice lacking CD69 on lymphoid cells developed large atheroma plaque along with an increased Th17/regulatory T cell ratio in blood. Oxidized low-density lipoprotein was shown to bind specifically and functionally to CD69 on human T lymphocytes, inhibiting the development of Th17 cells through the activation of NR4A nuclear receptors. Participants of the PESA study with evidence of subclinical atherosclerosis displayed a significant CD69 and NR4A1 mRNA downregulation in peripheral blood leukocytes compared with participants without disease. The expression of CD69 remained associated with the risk of subclinical atherosclerosis in an adjusted multivariable logistic regression model (odds ratio, 0.62; 95% CI, 0.40-0.94; P=0.006) after adjustment for traditional risk factors, the expression of NR4A1, the level of oxidized low-density lipoprotein, and the counts of different leucocyte subsets. Conclusions: CD69 depletion from the lymphoid compartment promotes a Th17/regulatory T cell imbalance and exacerbates the development of atherosclerosis. CD69 binding to oxidized low-density lipoprotein on T cells induces the expression of anti-inflammatory transcription factors. Data from a cohort of the PESA study with subclinical atherosclerosis indicate that CD69 expression in PBLs inversely correlates with the presence of disease. The expression of CD69 remained an independent predictor of subclinical atherosclerosis after adjustment for traditional risk factors.Funding was provided by the Spanish Ministry of Economy and Competitiveness: Plan Nacional de Salud SAF2017-82886-R to Dr Sánchez-Madrid, SAF2015-64767-R to Dr Martínez-González; Instituto de Salud Carlos III (AES 2016): PI16/01956 to Dr Martin, Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares; European Research Council, ERC- 2011-AdG294340-GENTRIS to Dr Sánchez-Madrid; Proyecto Integrado de Excelencia PIE13/041 and Fundació La Marató TV3 (20152330 31); and Comunidad Autónoma de Madrid CAM (S2017/BMD-3671) to Drs Martin and Sánchez-Madrid. Dr Tsilingiri is cofunded by the European Union Marie Curie Program. M. Relaño is supported by a Contratos Predoctorales Severo Ochoa para la formación de doctores (BES-2015–072625) from the Spanish Ministry of Economy and Competitiveness. This research has been cofinanced by Fondo Europeo de Desarrollo Regional. Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain, is supported by the Ministerio de Ciencia, Innovación y Universidades, and the Pro CNIC Foundation and is a Severo Ochoa Center of Excellence (SEV-2015-0505). The PESA study is cofunded equally by the Pro CNIC Foundation and Banco Santander, Madrid, Spai

Non-supersymmetric heterotic model building

We investigate orbifold and smooth Calabi-Yau compactifications of the non-supersymmetric heterotic SO(16)xSO(16) string. We focus on such Calabi-Yau backgrounds in order to recycle commonly employed techniques, like index theorems and cohomology theory, to determine both the fermionic and bosonic 4D spectra. We argue that the N=0 theory never leads to tachyons on smooth Calabi-Yaus in the large volume approximation. As twisted tachyons may arise on certain singular orbifolds, we conjecture that such tachyonic states are lifted in the full blow-up. We perform model searches on selected orbifold geometries. In particular, we construct an explicit example of a Standard Model-like theory with three generations and a single Higgs field.Comment: 1+30 pages latex, 11 tables; v2: references and minor revisions added, matches version published in JHE

Growth of Au-Pd2Sn Nanorods via Galvanic Replacement and Their Catalytic Performance on Hydrogenation and Sonogashira Coupling Reactions

Altres ajuts: Beatriu de Pinós postdoctoral grant (2013 BP-A00344)Colloidal PdSn and Au-PdSn nanorods (NRs) with tuned size were produced by the reduction of Pd and Sn salts in the presence of size- and shape-controlling agents and the posterior growth of Au tips through a galvanic replacement reaction. PdSn and Au-PdSn NRs exhibited high catalytic activity toward quasi-homogeneous hydrogenation of alkenes (styrene and 1-octene) and alkynes (phenylacetylene and 1-octyne) in dichloromethane. Au-PdSn NRs showed higher activity than PdSn for 1-octene, 1-octyne, and phenylacetylene. In Au-PdSn heterostructures, X-ray photoelectron spectroscopy evidenced an electron donation from the PdSn NR to the Au tips. Such heterostructures showed distinct catalytic behavior in the hydrogenation of compounds containing a triple bond such as tolan. This can be explained by the aurophilicity of triple bonds. To further study this effect, PdSn and Au-PdSn NRs were also tested in the Sonogashira coupling reaction between iodobenzene and phenylacetylene in N,N-dimethylformamide. At low concentration, this reaction provided the expected product, tolan. However, at high concentration, more reduced products such as stilbene and 1,2-diphenylethane were also obtained, even without the addition of H. A mechanism for this unexpected reduction is proposed