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Träfflista för sökning "(WFRF:(Farkas J)) srt2:(2015-2019)"

Sökning: (WFRF:(Farkas J)) > (2015-2019)

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  • Gambadauro, Pietro, et al. (författare)
  • Correlates of sexual initiation among European adolescents
  • 2018
  • Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 13:2
  • Tidskriftsartikel (refereegranskat)abstract
    • BackgroundSexuality is a physiological component of adolescent development, though early initiation is associated with reproductive health risk. This study aimed at identifying correlates and predictors of sexual initiation in a large multinational cohort of European adolescents.MethodsA questionnaire addressing socio-demographics, behaviours, mental health and sexual activity, was delivered to 11,110 adolescents recruited from 168 randomly selected schools in 10 European countries between 2009 and 2011. A follow-up questionnaire was delivered after 12 months. The longitudinal association of baseline risk behaviors, psychological attributes and contextual vulnerabilities, with sexual initiation during follow-up was evaluated through simple and multivariable age/sex stratified logistic regression. Multinomial logistic regression measured the association between predictors and sexual initiation with or without coexisting reproductive risk factors, such as multiple partners or infrequent condom use.ResultsBaseline sexual experience was reported by 19.2% of 10,757 respondents (median age 15; IQR 14–15; females 59.6%). This was significantly more frequent among pupils older than 15 (41%) and males (20.8%). Of 7,111 pupils without previous experience who were available at follow-up (response rate 81.8%), 17% reported sexual initiation, without differences between females and males. Baseline smoking (age/sex adjusted odds ratio [aOR] 3.63), alcohol use (aOR 2.95), illegal drugs use (aOR 2.72), and poor sleep (aOR 1.71) predicted sexual initiation. Stratified analyses showed a particularly strong association in case of younger and female pupils, and, among girls, when initiation was reported together with multiple partners and/or infrequent condom use. Externalizing (i.e. conduct and hyperactivity) symptoms independently predicted sexual initiation. Internalizing difficulties (i.e. emotional and peer problems) were negatively associated with early and risky sexual initiation among boys. Significant predictors included also being bullied, fighting, truancy, and low parental involvement.ConclusionsAdolescent sexual behaviours are related to non-sexual risk behaviours, psychological difficulties and contextual vulnerabilities. While gateway effects explain some associations, a comprehensive model is needed to understand adolescent sexual behaviours, their physical, mental, and social health outcomes, and their potential positive effects on wellbeing. Tailored interventions may need to consider younger girls as a particularly vulnerable group in view of a strong association between non-sexual and sexual behaviors.
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  • Kondratyuk, Sergey, et al. (författare)
  • New and noteworthy lichen-forming and lichenicolous fungi 7
  • 2018
  • Ingår i: Acta Botanica Hungarica. - : Akademiai Kiado Zrt.. - 1588-2578 .- 0236-6495. ; 60:1-2, s. 115-115
  • Tidskriftsartikel (refereegranskat)abstract
    • Nineteen new to science species of lichen forming fungi, i.e.: Agonimia ascendens S. Y. Kondr., L. Lőkös et J.-S. Hur, A. sunchonensis S. Y. Kondr. et J.-S. Hur, A. yongsangensis S. Y. Kondr. et J.-S. Hur, Biatora loekoesiana S. Y. Kondr. et J.-S. Hur, Caloplaca ivanpisutii S. Y. Kond., L. Lőkös et J.-S. Hur, Candelariella makarevichiae S. Y. Kondr., L. Lőkös et J.-S. Hur, Huriella pohangensis S. Y. Kondr., L. Lőkös et J.-S. Hur, H. salyangiana S. Y. Kondr. et J.-S. Hur, Hyperphyscia oxneri S. Y. Kondr. et J.-S. Hur, Nectriopsis gangwondoensis S. Y. Kondr., L. Lőkös et J.-S. Hur, Porina ulleungdoensis S. Y. Kondr., L. Lőkös, J. Halda et J.-S. Hur, Psoroglaena gangwondoensis S. Y. Kondr., L. Lőkös, J.-J. Woo et J.-S. Hur, Pyrenopsis cavernicola S. Y. Kondr., L. Lőkös et J.-S. Hur, Rhizocarpon sunchonense S. Y. Kondr. et J.-S. Hur, Rufoplaca ulleungensis S. Y. Kondr., L. Lőkös et J.-S. Hur, Sarcogyne ulleungdoensis S. Y. Kondr., L. Lőkös et J.-S. Hur, Skyttea bumyoungsungii S. Y. Kondr. et J.-S. Hur, Thelopsis gangwondoensis S. Y. Kondr., L. Lőkös, J.-J. Woo et J.-S. Hur, Topelia loekoesiana S. Y. Kondr., J.-J. Woo et J.-S. Hur, all from South Korea, as well as Gallowayella awasthiana S. Y. Kondr. et D. K. Upreti from India and Franwilsia skottsbergii S. Y. Kondr., A. Thell, S.-O. Oh et J.-S. Hur from Chile are described,illustrated and compared with closely related taxa. A key to Agonimia species known from Eastern Asia is also included. Lecanora helicopis is recorded for Korea for the first time, as well as a number of new to Jeju-do Island species (i.e.: Agonimia loekoesii, Biatora pseudosambuci, Buellia extremoorientalis, and Ivanpisutia oxneri) are recorded. Additional data on conidiomata and morphological characters of thallus and apothecia and illustrations as well as data on newly located isotype specimens recently described from Canary Islands, Spain Fominiella tenerifensis are provided. Two new combinations, i.e.: Phaeophyscia saxatilis (for Physcia saxatilis Kashiw.), and Xanthoparmelia umezuana (for Karoowia umezuana Moon K. H. et Kashiw.) are also proposed.
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  • Zamora, Juan Carlos, et al. (författare)
  • Considerations and consequences of allowing DNA sequence data as types of fungal taxa
  • 2018
  • Ingår i: IMA Fungus. - : INT MYCOLOGICAL ASSOC. - 2210-6340 .- 2210-6359. ; 9:1, s. 167-185
  • Tidskriftsartikel (refereegranskat)abstract
    • Nomenclatural type definitions are one of the most important concepts in biological nomenclature. Being physical objects that can be re-studied by other researchers, types permanently link taxonomy (an artificial agreement to classify biological diversity) with nomenclature (an artificial agreement to name biological diversity). Two proposals to amend the International Code of Nomenclature for algae, fungi, and plants (ICN), allowing DNA sequences alone (of any region and extent) to serve as types of taxon names for voucherless fungi (mainly putative taxa from environmental DNA sequences), have been submitted to be voted on at the 11th International Mycological Congress (Puerto Rico, July 2018). We consider various genetic processes affecting the distribution of alleles among taxa and find that alleles may not consistently and uniquely represent the species within which they are contained. Should the proposals be accepted, the meaning of nomenclatural types would change in a fundamental way from physical objects as sources of data to the data themselves. Such changes are conducive to irreproducible science, the potential typification on artefactual data, and massive creation of names with low information content, ultimately causing nomenclatural instability and unnecessary work for future researchers that would stall future explorations of fungal diversity. We conclude that the acceptance of DNA sequences alone as types of names of taxa, under the terms used in the current proposals, is unnecessary and would not solve the problem of naming putative taxa known only from DNA sequences in a scientifically defensible way. As an alternative, we highlight the use of formulas for naming putative taxa (candidate taxa) that do not require any modification of the ICN.
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  • Bathen, M. E., et al. (författare)
  • Anisotropic and plane-selective migration of the carbon vacancy in SiC : Theory and experiment
  • 2019
  • Ingår i: Physical Review B. - : American Physical Society. - 2469-9950 .- 2469-9969. ; 100:1
  • Tidskriftsartikel (refereegranskat)abstract
    • We investigate the migration mechanism of the carbon vacancy (VC) in silicon carbide (SiC) using a combination of theoretical and experimental methodologies. The VC, commonly present even in state-of-the-art epitaxial SiC material, is known to be a carrier lifetime killer and therefore strongly detrimental to device performance. The desire for VC removal has prompted extensive investigations involving its stability and reactivity. Despite suggestions from theory that VC migrates exclusively on the C sublattice via vacancy-atom exchange, experimental support for such a picture is still unavailable. Moreover, the existence of two inequivalent locations for the vacancy in 4H-SiC [hexagonal, VC(h), and pseudocubic, VC(k)] and their consequences for VC migration have not been considered so far. The first part of the paper presents a theoretical study of VC migration in 3C- and 4H-SiC. We employ a combination of nudged elastic band (NEB) and dimer methods to identify the migration mechanisms, transition state geometries, and respective energy barriers for VC migration. In 3C-SiC, VC is found to migrate with an activation energy of EA=4.0 eV. In 4H-SiC, on the other hand, we anticipate that VC migration is both anisotropic and basal-plane selective. The consequence of these effects is a slower diffusivity along the axial direction, with a predicted activation energy of EA=4.2 eV, and a striking preference for basal migration within the h plane with a barrier of EA=3.7 eV, to the detriment of the k-basal plane. Both effects are rationalized in terms of coordination and bond angle changes near the transition state. In the second part, we provide experimental data that corroborates the above theoretical picture. Anisotropic migration of VC in 4H-SiC is demonstrated by deep level transient spectroscopy (DLTS) depth profiling of the Z1/2 electron trap in annealed samples that were subject to ion implantation. Activation energies of EA=(4.4±0.3) eV and EA=(3.6±0.3) eV were found for VC migration along the c and a directions, respectively, in excellent agreement with the analogous theoretical values. The corresponding prefactors of D0=0.54cm2/s and 0.017cm2/s are in line with a simple jump process, as expected for a primary vacancy point defect.
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  • Farkas, B., et al. (författare)
  • Optical, compositional and structural properties of pulsed laser deposited nitrogen-doped Titanium-dioxide
  • 2018
  • Ingår i: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 433, s. 149-154
  • Tidskriftsartikel (refereegranskat)abstract
    • N-doped TiO2 thin films were prepared using pulsed laser deposition by ablating metallic Ti target with pulses of 248 nm wavelength, at 330 °C substrate temperature in reactive atmospheres of N2/O2 gas mixtures. These films were characterized by spectroscopic ellipsometry, X-ray photoelectron spectroscopy and X-ray diffraction. Optical properties are presented as a function of the N2 content in the processing gas mixture and correlated to nitrogen incorporation into the deposited layers. The optical band gap values decreased with increasing N concentration in the films, while a monotonically increasing tendency and a maximum can be observed in case of extinction coefficient and refractive index, respectively. It is also shown that the amount of substitutional N can be increased up to 7.7 at.%, but the higher dopant concentration inhibits the crystallization of the samples.
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