Continuous spectra in high-harmonic generation driven by multicycle laser pulses

We present observations of the emission of XUV continua in the 20-37 eV region by high harmonic generation (HHG) with $4$-$7\ \mathrm{fs}$ pulses focused onto a Kr gas jet. The underlying mechanism relies on coherent control of the relative delays and phases between individually generated attosecond pulse, achievable by adjusting the chirp of the driving pulses and the interaction geometry. Under adequate negative chirp and phase matching conditions, the resulting interpulse interference yields a continuum XUV spectrum, which is due to both microscopic and macroscopic (propagation) contributions. This technique opens the route for modifying the phase of individual attosecond pulses and for the coherent synthesis of XUV continua from multicycle driving laser pulses without the need of an isolated attosecond burst.Comment: 14 pages, 5 figures. Submitted to Physical Review

Characterization of wash-off from urban impervious surfaces and SuDS design criteria for source control under semi-arid conditions

[EN] Knowledge about pollutant wash-off from urban impervious surfaces is a key feature for developing effective management strategies. Accordingly, further information is required about urban areas under semi-arid climate conditions at the sub-catchment scale. This is important for designing source control systems for pollution. In this study, a characterization of pollutant wash-off has been performed over sixteen months, at the sub-catchment scale for urban roads as impervious surfaces. The study was conducted in Valencia, Spain, a city with a Mediterranean climate. The results show high event mean concentrations for suspended solids (98 mg/l), organic matter (142 mgCOD/l, 25 mg BOD5/l), nutrients (3.7mgTN/l, 0.4 mg TP/l), and metals (0.23, 0.32, 0.62 and 0.17 mg/l for Cu, Ni, Pb, and Zn, respectively). The results of the runoff characterization highlight the need to control this pollution at its source, separately from wastewater because of their different characteristics. The wash-off, defined in terms of mobilized mass (g/m(2)) fits well with both process-based and statistical models, with the runoff volume and rainfall depth being the main explanatory variables. Based on these results and using information collected from hydrographs and pollutographs, an approach for sizing sustainable urban drainage systems (SuDS), focusing on water quality and quantity variables, has been proposed. By setting a concentration-based target (TSS discharged to receiving waters < 35 mg/l), the results indicate that for a SuDS type detention basin (DB), an off-line configuration performs better than an on-line configuration. The resulting design criterion, expressed as SuDS volume per unit catchment area, assuming a DB type SuDS, varies between 7 and 10 l/m(2).This research was funded through the SUPRIS-SUReS projects (Ref. BIA2015-65240-C2-1-R MINECO/ERDF, UE) and SUPRIS-SUPeI (Ref. BIA2015-65240-C2-2-R MINECO/ERDF, UE), financed by the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund (ERDF) and by the project IMBORNAL (Ref. SP20120732), financed by Universitat Politecnica de Valencia.Andrés Doménech, I.; Hernández Crespo, C.; Martín Monerris, M.; Andrés-Valeri, VC. (2018). Characterization of wash-off from urban impervious surfaces and SuDS design criteria for source control under semi-arid conditions. The Science of The Total Environment. 612:1320-1328. https://doi.org/10.1016/j.scitotenv.2017.09.011S1320132861

FORMACIÓN DEL DIREGENTE ESTUDIANTIL UNIVERSITARIO PARA EL LIDERAZGO

Los dirigentes estudiantiles universitarios se distinguen del resto del estudiantado por sus manifestaciones de liderazgo dentro del grupo escolar, sin embargo, no es lo mismo ser líder en el grupo, que ejercer el liderazgo en su desempeño directivo. Para diagnosticar la influencia de los dirigentes estudiantiles en los procesos institucionales de la Universidad de Ciego de Ávila, se determinaron dimensiones e indicadores que evidenciaron como contradicción las necesidades formativas para el ejercicio de la dirección estudiantil y su desempeño directivo. Este trabajo tiene el objetivo de contribuir a la formación del liderazgo en los dirigentes estudiantiles, y para atender esta carencia en el proceso de formación profesional, se elaboró  un sistema de actividades extracurriculares, sustentado en elementos de psicología de la dirección, con métodos y técnicas encaminadas a la formación del liderazgo de estos dirigentes, supliendo  con  ello  las  necesidades  cognitivas, procedimentales y actitudinales detectadas desde la caracterización de su desempeño directivo

Large-eddy simulation of spectral coherence in a wind turbine wake

This work is mainly dedicated to the study of the characteristics of spectral coherence of turbulence fluctuations in wind turbine wakes. A computational fluid dynamics (CFD) code has been implemented using a large-eddy simulation (LES) approach, which is thought to be conceptually more suitable for studying the turbulence evolution in a wind turbine wake. Comparisons with experimental data from the Nørrekær Enge II Windfarm, in Denmark, and with an analytical model proposed by Panofsky and Dutton have been performed, and the results are found to be in reasonable agreement with both

Intermediate band solar energy conversion in ZnTeO

Energy conversion in solar cells incorporating ZnTeO base layers is presented. The ZnTeO base layers incorporate intermediate electronic states located approximately 0.4eV below the conduction band edge as a result of the substitution of O in Te sites in the ZnTe lattice. Cells with ZnTeO base layers demonstrate optical response at energies lower than the ZnTe bandedge, a feature that is absent in reference cells with ZnTe base layers. Quantum efficiency is significantly improved with the incorporation of ZnSe emitter/window layers and transition from growth on GaAs substrates to GaSb substrates with a near lattice match to ZnTe

Mutations on a conserved distal enhancer in the porcine C-reactive protein gene impair its expression in liver

C-reactive protein (CRP) is an evolutionary highly conserved protein. Like humans, CRP acts as a major acute phase protein in pigs. While CRP regulatory mechanisms have been extensively studied in humans, little is known about the molecular mechanisms that control pig CRP gene expression. The main goal of the present work was to study the regulatory mechanisms and identify functional genetic variants regulating CRP gene expression and CRP blood levels in pigs. The characterization of the porcine CRP proximal promoter region revealed a high level of conservation with both cow and human promoters, sharing binding sites for transcription factors required for CRP expression. Through genome-wide association studies and fine mapping, the most associated variants with both mRNA and protein CRP levels were localized in a genomic region 39.3 kb upstream of CRP. Further study of the region revealed a highly conserved putative enhancer that contains binding sites for several transcriptional regulators such as STAT3, NF-kB or C/EBP-β. Luciferase reporter assays showed the necessity of this enhancer-promoter interaction for the acute phase induction of CRP expression in liver, where differences in the enhancer sequences significantly modified CRP activity. The associated polymorphisms disrupted the putative binding sites for HNF4α and FOXA2 transcription factors. The high correlation between HNF4α and CRP expression levels suggest the participation of HNF4α in the regulatory mechanism of porcine CRP expression through the modification of its binding site in liver. Our findings determine, for the first time, the relevance of a distal regulatory element essential for the acute phase induction of porcine CRP in liver and identify functional polymorphisms that can be included in pig breeding programs to improve immunocompetence.The authors declare financial support was received for the research, authorship, and/or publication of this article. The study was funded by grants AGL2016-75432-R and PID2020-112677RB-C21 awarded by MCIN/AEI/10.13039/501100011033 and GENE-SWitCH project (https://www.gene-switch.eu), which is funded by the European Union’s Horizon 2020 Research and Innovation Programme under the grant agreement n°817998. T. Jové-Juncà was funded with an IRTA fellowship (CPI1221) and C. Hernández-Banqué was supported by a FPI grant (PRE2021-097825) granted by the Spanish Ministry of Science and Innovation. YR-C was financially supported by a Ramon y Cajal contract (RYC2019-027244-I) from the Spanish Ministry of Science and Innovation. The authors are part to a Consolidated Research Group AGAUR, with the reference 2021-SGR-01552.info:eu-repo/semantics/publishedVersio

Spitzer observations of NGC2264: The nature of the disk population

NGC2264 is a young cluster with a rich circumstellar disk population which makes it an ideal target for studying the evolution of stellar clusters. Our goal is to study its star formation history and to analyse the primordial disk evolution of its members. The study presented is based on data obtained with Spitzer IRAC and MIPS, combined with deep NIR ground-based FLAMINGOS imaging and previously published optical data. We build NIR dust extinction maps of the molecular cloud associated with the cluster, and determine it to have a mass of 2.1x10^3Msun above an Av of 7mag. Using a differential K_s-band luminosity function of the cluster, we estimate the size of its population to be 1436$\pm$242 members. The star formation efficiency is ~25%. We identify the disk population: (i) optically thick inner disks, (ii) anaemic inner disks, and (iii) disks with inner holes, or transition disks. We analyse the spatial distribution of these sources and find that sources with thick disks segregate into sub-clusterings, whereas sources with anaemic disks do not. Furthermore, sources with anaemic disks are found to be unembedded (Av<3mag), whereas the clustered sources with thick disks are still embedded within the parental cloud. NGC2264 has undergone more than one star-forming event, where the anaemic and extincted thick disk population appear to have formed in separate episodes. We also find tentative evidence of triggered star-formation in the Fox Fur Nebula. In terms of disk evolution, our findings support the emerging disk evolution paradigm of two distinct evolutionary paths for primordial optically thick disks: a homologous one where the disk emission decreases uniformly at NIR and MIR wavelengths, and a radially differential one where the emission from the inner region of the disk decreases more rapidly than from the outer region (forming transition disks).Comment: accepted for publishing in A&

Levels of Participants Satisfaction with Initial Contact and Examination Visit: The Hispanic Community Health Study/ Study of Latinos (HCHS /SOL)

Objective: This study examined perceived satisfaction among Hispanic/Latino individuals who participated in a baseline examination for the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), a large cohort study of 16,415 adults living in four selected communities. Method: An estimated 22% (n= 3,584) of participants completed a questionnaire regarding satisfaction with staff attention, the overall experience during the study examination, and the influence of the informed consent digital video disc (DVD). Results: The majority of participants who completed the questionnaire expressed overall satisfaction with the study. Most participants reported that staff were friendly, courteous and respectful and study test procedures were clearly explained. Participants who preferred to complete the interview in Spanish felt that the informed consent DVD positively influenced their ability to make an informed decision to enroll in the study. Participants who preferred to complete the interview in English tended to report that the baseline examination was longer than expected compared with participants who completed the interview in Spanish. Conclusion: Results demonstrate that culturally and linguistically trained staff and the use of the study’s informed consent DVD were effective in explaining study procedures and positively influenced decisions to participate in the HCHS/SOL study. These results can inform recruitment and enrollment strategies for future participation of minority groups into longitudinal cohort studies. Ethn Dis. 2016;26(3):435-442; doi:10.18865/ed.26.3.435 </p

Intermediate band to conduction band optical absorption in ZnTeO

ZnTe doped with high concentrations of oxygen has been proposed in previous works as an intermediate band (IB) material for photovoltaic applications. The existence of extra optical transitions related to the presence of an IB has already been demonstrated in this material and it has been possible to measure the absorption coefficient of the transitions from the valence band (VB) to the IB. In this study, we present the first measurement of the absorption coefficient associated with transitions from the IB to the conduction band (CB) in ZnTeO. The samples used are 4-mum-thick ZnTe layers with or without O in a concentration ~10 19 cm -3, which have been grown on semiinsulating GaAs substrates by molecular beam epitaxy (MBE). The IB-CB absorption coefficient peaks for photon energies ~0.4 eV. It is extracted from reflectance and transmittance spectra measured using Fourier transform infrared (FTIR) spectroscopy. Under typical FTIR measurement conditions (low light intensity, broadband spectrum), the absorption coefficient in IB-to-CB transitions reaches 700 cm -1. This is much weaker than the one observed for VB-IB absorption. This result is consistent with the fact that the IB is expected to be nearly empty of electrons under equilibrium conditions in ZnTe(O)

Intermediate Band to Conduction Band optical absorption in ZnTe:O

ZnTe doped with high concentrations of oxygen has been proposed in previous works as intermediate band (IB) material for photovoltaic applications. The existence of extra optical transitions related to the presence of an IB has already been demonstrated in this material and it has been possible to measure the absorption coefficient of the transitions from the valence band (VB) to the IB. In this work we present the first measurement of the absorption coefficient associated to transitions from the IB to the conduction band (CB) in ZnTe:O. The samples used are 4 ?m thick ZnTe layers with or without O in a concentration ~ 1019 cm-3, which have been grown on semi-insulating GaAs substrates by molecular beam epitaxy (MBE). The IB-CB absorption coefficient peaks for photon energies ~ 0.4 eV. It is extracted from reflectance and transmittance spectra measured using Fourier Transform Infrared (FTIR) spectroscopy. Under typical FTIR measurement conditions (low light intensity, broadband spectrum) the absorption coefficient in IB-to-CB transitions reaches 700 cm-1. This is much weaker than the one observed for VB-IB absorption. This result is consistent with the fact that the IB is expected to be nearly empty of electrons under equilibrium conditions in ZnTe(:O). The absorption for VB to IB transitions is also observed in the same samples through reflectance measurements performed in the visible range using a monochromator. These measurements are compared with the quantum efficiency (QE) from solar cells fabricated under similar conditions