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1.
Dev Cogn Neurosci ; 54: 101102, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35398645

RESUMEN

An individual's early interactions with their environment are thought to be largely passive; through the early years, the capacity for volitional control develops. Here, we consider: how is the emergence of volitional control characterised by changes in the entrainment observed between internal activity (behaviour, physiology and brain activity) and the sights and sounds in our everyday environment (physical and social)? We differentiate between contingent responsiveness (entrainment driven by evoked responses to external events) and oscillatory entrainment (driven by internal oscillators becoming temporally aligned with external oscillators). We conclude that ample evidence suggests that children show behavioural, physiological and neural entrainment to their physical and social environment, irrespective of volitional attention control; however, evidence for oscillatory entrainment beyond contingent responsiveness is currently lacking. Evidence for how oscillatory entrainment changes over developmental time is also lacking. Finally, we suggest a mechanism through which periodic environmental rhythms might facilitate both sensory processing and the development of volitional control even in the absence of oscillatory entrainment.


Asunto(s)
Atención , Periodicidad , Atención/fisiología , Niño , Humanos
2.
Appl Opt ; 61(1): 135-140, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-35200812

RESUMEN

The transmission properties of a photonic crystal immersed in several different oils have been characterized using terahertz time domain spectroscopy in the spectral range of 0.3-1.5 THz. As in previous works, oil samples can be distinguished using terahertz transmission measurements. When the same oils are introduced into a photonic crystal, we find that the effective refractive index of the photonic crystal is sensitive to the properties of the oils and shows differences not seen in bulk measurements. These effects are described in detail and have potential applications in both the sensing of very small volumes of oils and in the fine control of the refractive indices of photonic crystals.

5.
Opt Lett ; 45(21): 6030-6033, 2020 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-33137061

RESUMEN

We demonstrate tunable microring resonators (TMRs) based on light-activated functional polymer coatings deposited on glass optical fibers. TMRs were fabricated using two layers of polydimethylsiloxane-based compounds: one incorporating an azobenzene dye and one using a fluorescent ytterbium and erbium-doped sodium yttrium fluoride powder. The latter yields a photoluminescent composite producing green up-conversion emission under infrared pumping. This visible emission triggers photoinduced birefringence effects in the azobenzene layer, thereby modifying the spectral features of the TMR devices. The shift in the resonance peaks as a function of pump power is linear, yielding a tuning range of 1.3 nm. Aside from the observed photoinduced effects, we also discuss the photothermal effects involved in the tuning mechanism.

6.
Front Psychol ; 11: 2176, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33013561

RESUMEN

The present study is the first to empirically test a hierarchical, positive-oriented model of the self and its relationship to second language (L2) achievement motivation, and compare it in three different cultural contexts of Japan, the United States, and Taiwan. Based on the L2 self-model (Lake, 2016), three levels of constructs were developed: Global Self (i.e., Flourishing, Curiosity, and Hope); Positive L2 domain self (i.e., interested-in-L2 self, harmonious passion for L2 learning, and mastery L2 goal orientation); and L2 Motivational Variables (i.e., reading, speaking and listening self-efficacy). A total of 667 students participated in this study, including 181 first-year college students in Japan, 159 high school students in Taiwan, and 327 community college students in the United States. All the participants were learning L2 in school. Results showed that the measures of positive global self, L2 domain self, and L2 motivational self all had a stronger relationship within their respective levels, and progressively weaker relationships as level of generality/specificity became more distal. Furthermore, the relationships among measures varied in the differing cultural contexts with the Japan-based student participants relatively lower on all measures. Implications for teacher educators in the L2 context have been discussed.

7.
Schweiz Arch Tierheilkd ; 162(6): 365-376, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32489181

RESUMEN

INTRODUCTION: Wild boar (i.e., Sus scrofa) are susceptible to a range of diseases that can be transmitted to domestic pigs. Assessing the potential risk of transmission-related events involves identifying where wild boar occur in Switzerland and where they still can colonize. It also involves identifying zones where piggeries are dense. In the work presented here, the distribution of wild boar in Switzerland was projected from grid data as probabilities of presence using an approach based on statistical modeling, separately for closed and open season for hunting. The predicted probabilities of wild boar presence were related to the density of piggeries in the six agricultural zones. The resulting maps show how the potential risk of transmission-related events, as a proxy for disease transmission, is distributed in Switzerland. Wild boar presence data consisted of hunting data and casual observations recorded from September 2011 to February 2018 at the coordinate level. They were obtained from all 16 Swiss cantons maintaining a license hunting system plus Solothurn (for 2017) and Zurich, as well as from info fauna. The probability of wild boar occurrence was high (> 0.7) in Jura, the valleys of the Southern Alps, the Rhone Valley down the river from Martigny, and the Rhine Valley down the river from Bündner Herrschaft; it was fair (0.5-0.7) in the Swiss Plateau. These regions broadly overlap agricultural zones with a high density of piggeries. Patches of perennially suitable, but currently not colonized habitat were found in the cantons of Berne, Obwalden, Uri, Schwyz, Glarus, and Grisons. The probability of wild boar occurrence across the entire study area, including the Alps, increased by 12% during closed season for hunting. The results were discussed with reference to similar studies.


INTRODUCTION: Le sanglier (Sus scrofa) est sensible à plusieurs maladies qui peuvent être transmises au cochon domestique. Afin d'estimer le risque potentiel de transmission, il est important d'identifier les zones occupées par le sanglier en Suisse ainsi que celles qu'il pourrait encore coloniser. De plus, cela implique également de pouvoir situer les secteurs où les élevages de cochons sont les plus abondant. Dans le présent travail, la distribution du sanglier a été projetée selon une grille à l'échelle de la Suisse à partir des présences confirmées en utilisant des méthodes statistiques, ceci en considérant la période d'ouverture de chasse d'une part et la période de fermeture d'autre part. Les probabilités de présence calculées ont été misent en relation avec la densité des porcheries dans les différentes zones agricoles. Les cartes résultant de cet exercice montrent comment le risque potentiel de transmission de maladies est distribué en Suisse. La base de données utilisée contenait des informations sur les sangliers tirés lors de la chasse, ainsi que des observations occasionnelles, rapportées à l'échelle de la coordonnée entre Septembre 2011 et Février 2018. Ces données ont étés obtenues de l'ensemble des 16 cantons maintenant un système de chasse à patente, plus Soleure (2017) et Zurich, et des données disponibles sur info fauna. La probabilité de trouver des sanglier est élevée (> 0.7) dans le Jura, les vallées du sud des Alpes, la vallée du Rhône en aval de Martigny et la vallée du Rhin en aval de Bündner Herrschaft. Elle est modérée (0.5­0.7) pour le Plateau Suisse. Ces régions correspondent à peu près aux zones agricoles possédant les plus grandes densités de porcheries. Des secteurs offrant des conditions favorables toute l'année, mais encore inoccupés par le sanglier ont été trouvés dans les cantons de Berne, Obwald, Uri, Schwyz, Glaris et les Grisons. Sur l'ensemble de la zone d'étude, la probabilité de présence des sangliers était supérieur de 12% en dehors de la période de chasse. Les résultats ont été discutés en les comparant à des études similaires.


Asunto(s)
Animales Salvajes , Modelos Biológicos , Enfermedades de los Porcinos/transmisión , Animales , Animales Domésticos , Sus scrofa , Porcinos , Enfermedades de los Porcinos/epidemiología , Suiza/epidemiología
8.
Front Psychol ; 10: 2122, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31681057

RESUMEN

Are bilingualism and/or biculturalism good for a person's positive well being? A growing number of studies have shown different positive outcomes of being exposed to two cultures or speaking two languages respectively, but the benefits of being both bilingual and bicultural have rarely been investigated theoretically or empirically. The purpose of this paper is to summarize the main beneficial outcomes of bilingualism and biculturalism, and to integrate these benefits into a new conceptual framework: Positive Bilingualism and Biculturalism GEAR model. The GEAR model suggests that the beneficial outcomes of bilingualism and biculturalism can be systematically classified into four positive dimensions (psychological Growth; cognitive Exploration; linguistic Awareness; and social Reinforcement), in which there are dynamic interactions among these four dimensions. The hypothetical GEAR model provides an intricate theoretical approach to understand the potential benefits to an individual of experiencing more than one language and one culture in their life. The proposed model in this research offers a systematic framework for conducting future research to examine whether bilingualism and biculturalism accrue benefits to the individual.

9.
Front Psychol ; 10: 2128, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31607981

RESUMEN

The present contribution offers an overview of a new area of research in the field of foreign language acquisition, which was triggered by the introduction of Positive Psychology (PP) (MacIntyre and Gregersen, 2012). For many years, a cognitive perspective had dominated research in applied linguistics. Around the turn of the millennium researchers became increasingly interested in the role of emotions in foreign language learning and teaching, beyond established concepts like foreign language anxiety and constructs like motivation and attitudes toward the foreign language. As a result, a more nuanced understanding of the role of positive and negative learner and teacher emotions emerged, underpinned by solid empirical research using a wide range of epistemological and methodological approaches. PP interventions have been carried out in schools and universities to strengthen learners and teachers' experiences of flow, hope, courage, well-being, optimism, creativity, happiness, grit, resilience, strengths, and laughter with the aim of enhancing learners' linguistic progress. This paper distinguishes the early period in the field that started with MacIntyre and Gregersen (2012), like a snowdrop after winter, and that was followed by a number of early studies in relatively peripheral journals. We argue that 2016 is the starting point of the current period, characterized by gradual recognition in applied linguistics, growing popularity of PP, and an exponential increase in publications in more mainstream journals. This second period could be compared to a luxuriant English garden in full bloom.

10.
Sci Rep ; 9(1): 13572, 2019 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-31537889

RESUMEN

We report on a novel implementation of the cryo-etching method, which enabled us to fabricate low-roughness hBN-encapsulated graphene nanoconstrictions with unprecedented control of the structure edges; the typical edge roughness is on the order of a few nanometers. We characterized the system by atomic force microscopy and used the measured parameters of the edge geometry in numerical simulations of the system conductance, which agree quantitatively with our low temperature transport measurements. The quality of our devices is confirmed by the observation of well defined quantized 2e2/h conductance steps at zero magnetic field. To the best of our knowledge, such an observation reports the clearest conductance quantization in physically etched graphene nanoconstrictions. The fabrication of such high quality systems and the scalability of the cryo-etching method opens a novel promising possibility of producing more complex truly-ballistic devices based on graphene.

11.
PeerJ ; 7: e6361, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30740273

RESUMEN

The Hoatzin (Opisthocomus hoazin) is the only extant member of the order Opisthocomiformes. This unique South American bird lives in the riparian lowland vegetation characteristic of the Amazon and Orinoco basins. Hoatzins nest in communal social units close to water bodies; they are strictly folivores being the only bird with pregastric fermentation in the crop. Because of the complex logistics involved in capturing this bird, there is a knowledge gap on its parasites. This study documents two distant lineages of haemosporidian parasites (Plasmodium spp.) in a juvenile and two adults sampled in the Cojedes state, Venezuela. Although negative by microscopy, the parasite identification was possible by using molecular methods. We estimated the phylogenetic relationships on the parasite cytochrome b (cytb, 480 bp) gene and the mitochondrial DNA. We found one of the parasites lineages in two individuals (nestling and adult), and the corresponding fragment of cytb was identical to a one found in Wood Stork (Mycteria americana) from Brazil. The other lineage, found in an adult, has an identity of 469 out of 478 bp (98%) with Plasmodium sp. GAL-2012 (isolate THAMB08) from Brazil. Although a morphological description of these parasites was not possible, this is the first molecular study focusing on Hoatzin haemosporidian parasites and the first documentation of Plasmodium infections in the Hoatzin from Venezuela. Furthermore, we reported microfilaria in two adults as well as hematological parameters for six individuals. Information on hematological parameters could contribute to establishing the necessary baseline to detect underlying conditions, such as infections, in this bird species.

12.
Sci Rep ; 8(1): 8897, 2018 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-29891993

RESUMEN

We present a new technique allowing the fabrication of large modal count photonic lanterns for space-division multiplexing applications. We demonstrate mode-selective photonic lanterns supporting 10 and 15 spatial channels by using graded-index fibres and microstructured templates. These templates are a versatile approach to position the graded-index fibres in the required geometry for efficient mode sampling and conversion. Thus, providing an effective scalable method for large number of spatial modes in a repeatable manner. Further, we demonstrate the efficiency and functionality of our photonic lanterns for optical communications. Our results show low insertion and mode dependent losses, as well as enhanced mode selectivity when spliced to few mode transmission fibres. These photonic lantern mode multiplexers are an enabling technology for future ultra-high capacity optical transmission systems.

13.
PLoS One ; 13(3): e0194857, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29579092

RESUMEN

Gut bacterial communities have been shown to be influenced by diet, host phylogeny and anatomy, but most of these studies have been done in captive animals. Here we compare the bacterial communities in the digestive tract of wild birds. We characterized the gizzard and intestinal microbiota among 8 wild Neotropical bird species, granivorous or frugivorous species of the orders Columbiformes and Passeriformes. We sequenced the V4 region of the 16S rRNA gene in 94 collected samples from 32 wild birds from 5 localities, and compared bacterial communities by foraging guild, organ, locality and bird taxonomy. 16S rRNA gene-based sequencing data were examined using QIIME with linear discriminant analysis effect size (LEfSe) and metabolic pathways were predicted using PICRUSt algorism. We identified 8 bacterial phyla, dominated by Firmicutes, Actinobacteria and Proteobacteria. Beta diversity analyses indicated significant separation of gut communities by bird orders (Columbiformes vs. Passerifomes) and between bird species (p<0.01). In lower intestine, PICRUSt shows a predominance of carbohydrate metabolism in granivorous birds and xenobiotics biodegradation pathways in frugivorous birds. Gizzard microbiota was significantly richer in granivorous, in relation to frugivorous birds (Chao 1; non-parametric t-test, p<0.05), suggesting a microbial gizzard function, beyond grinding food. The results suggest that the most important factor separating the bacterial community structure was bird taxonomy, followed by foraging guild. However, variation between localities is also likely to be important, but this could not been assessed with our study design.


Asunto(s)
Animales Salvajes/microbiología , Columbiformes/microbiología , Microbioma Gastrointestinal , Molleja de las Aves/patología , Passeriformes/microbiología , Gastropatías/patología , Algoritmos , Animales , Bacterias/genética , Bacterias/aislamiento & purificación , Biodiversidad , ADN Bacteriano/química , ADN Bacteriano/aislamiento & purificación , ADN Bacteriano/metabolismo , Análisis Discriminante , Molleja de las Aves/microbiología , Intestinos/microbiología , Análisis de Componente Principal , ARN Ribosómico 16S/genética , ARN Ribosómico 16S/metabolismo , Análisis de Secuencia de ADN , Gastropatías/microbiología , Gastropatías/veterinaria
14.
Opt Lett ; 43(6): 1303-1306, 2018 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-29543277

RESUMEN

We demonstrate a simple approach based on a photonic lantern spatial-mode multiplexer and a few-mode fiber for optical and manipulation of multiple microspheres. Selective generation of linearly polarized (LP) fiber modes provides light patterns useful for trapping one or multiple microparticles. Furthermore, rotation of the particles can be achieved by switching between degenerate LP modes, as well as through polarization rotation of the input light. Our results show that emerging fiber optic devices such as photonic lanterns can provide a versatile and compact means for developing optical fiber traps.

15.
Sci Rep ; 7(1): 12061, 2017 09 21.
Artículo en Inglés | MEDLINE | ID: mdl-28935891

RESUMEN

We present a comprehensive study of the crystal structure of the thin-film, ferromagnetic topological insulator (Bi, Sb)2-x V x Te3. The dissipationless quantum anomalous Hall edge states it manifests are of particular interest for spintronics, as a natural spin filter or pure spin source, and as qubits for topological quantum computing. For ranges typically used in experiments, we investigate the effect of doping, substrate choice and film thickness on the (Bi, Sb)2Te3 unit cell using high-resolution X-ray diffractometry. Scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy measurements provide local structural and interfacial information. We find that the unit cell is unaffected in-plane by vanadium doping changes, and remains unchanged over a thickness range of 4-10 quintuple layers (1 QL ≈ 1 nm). The in-plane lattice parameter (a) also remains the same in films grown on different substrate materials. However, out-of-plane the c-axis increases with the doping level and thicknesses >10 QL, and is potentially reduced in films grown on Si (1 1 1).

16.
J Chromatogr A ; 1520: 35-47, 2017 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-28918855

RESUMEN

An in-tube solid phase microextraction, coupled with high-performance liquid chromatography with diode array detection (IT-SPME-HPLC-DAD) method, has been developed for the simultaneous determination of 13 diesters (from dimethyl to dioctylphthalate plus diisobutyl, benzylbutyl, di-2-ethylhexyl, diisononyl and diisodecylphthalate) and 2 monoesters of phthalic acid (mono-butyl and mono-(2-ethylhexyl) phthalate) in particulate matter (PM10). Triethylamine at pH=3 was used as an ion-pair reagent with a double function, of regulating the chromatographic retention of the monoesters and the most hydrophilic diesters on a monolithic silica column, and of improving their extraction on a porous polymer with divinylbenzene-4-vinylpyridine capillary. The chromatographic separation was achieved in 13min. A previous ultrasound-assisted extraction from PM10filters was also optimized using methanol as solvent. The method detection limits were 0.09-0.52ngm-3, the inter-day precision at concentration of 20ngmL-1 was between 4.2% and 12.7% (n=15), and the average recovery was 87.3%. The average absolute IT-SPME recovery was 26.2% and the linear range reached up to 109ngm-3 for most analytes. The method was applied to PM10 samples from different environments collected in Galicia (Spain). DiBP was the major phthalate, followed by its isomer DnBP in urban sites and by DEP in the suburban area. In all samples, DEHP quantified correlates with the isomers of dibutylphthalate. Total PAE concentration was between 14.5 and 245.5ngm-3. To the best of our knowledge, this is the first time that a method allows the simultaneous determination of 13 phthalates and their degradation products in particulate matter.


Asunto(s)
Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente/métodos , Material Particulado/química , Ácidos Ftálicos/análisis , Microextracción en Fase Sólida , Cromatografía Líquida de Alta Presión , Límite de Detección , España
17.
Nat Commun ; 8: 14984, 2017 04 12.
Artículo en Inglés | MEDLINE | ID: mdl-28401951

RESUMEN

The Josephson effect is a fundamental quantum phenomenon where a dissipationless supercurrent is introduced in a weak link between two superconducting electrodes by Andreev reflections. The physical details and topology of the junction drastically modify the properties of the supercurrent and a strong enhancement of the critical supercurrent is expected to occur when the topology of the junction allows an emergence of Majorana bound states. Here we report charge transport measurements in mesoscopic Josephson junctions formed by InAs nanowires and Ti/Al superconducting leads. Our main observation is a colossal enhancement of the critical supercurrent induced by an external magnetic field applied perpendicular to the substrate. This striking and anomalous supercurrent enhancement cannot be described by any known conventional phenomenon of Josephson junctions. We consider these results in the context of topological superconductivity, and show that the observed critical supercurrent enhancement is compatible with a magnetic field-induced topological transition.

18.
Antonie Van Leeuwenhoek ; 110(6): 833-841, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28324231

RESUMEN

The Vibrionaceae are Gram-negative bacteria present in marine and estuarine environments worldwide, including several species known as important pathogens to humans and aquatic organisms. The aim of this research was to investigate the occurrence and virulence properties of Vibrio and Salinivibrio isolated from lagoons at Cuare Wildlife Refuge and Margarita Island in the southern Caribbean Sea. Water, plankton and oyster samples were collected during October 2011 and March 2012 and examined by specific PCR and culture methods. Vibrio genus DNA was detected in 95% of samples, while the intergenic spacer region (ISR) of Vibrio cholerae and the genes that code for the thermolabile direct haemolysin (tl) of Vibrio parahaemolyticus and the haemolysin/cytolysin (vvhA) of Vibrio vulnificus were absent or amplified in low proportions (23, 5, and 0%, respectively). Nine isolates from water and plankton were confirmed as Vibrio or Salinivibrio by phenotypic tests, 16S rRNA gene sequencing and phylogenetic analysis. All the isolates presented similar patterns of virulence factors, in which the genes ctxA (encoding for cholera toxin), tl and vvhA were lacking, whereas seven isolates displayed antibiotic resistance against ampicillin and cephalosporins. The 16S rRNA phylogenetic analysis showed the clustering of Vibrio isolates in three main clades: the plankton isolate from Cuare Wildlife Refuge formed a group with V. cholerae and Vibrio mimicus while the Margarita isolates clustered with sequences from the harveyi clade and Salinivibrio. This is the first time that Salinivibrio species are reported in tropical lagoons of the Caribbean Sea with antibiotic resistance.


Asunto(s)
Vibrio/patogenicidad , Microbiología del Agua , Animales , Región del Caribe , Humanos , Filogenia , ARN Ribosómico 16S , Agua de Mar , Clima Tropical , Vibrio/genética , Vibrio/aislamiento & purificación , Virulencia
20.
Chemosphere ; 175: 52-65, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28211335

RESUMEN

Six phthalic acid esters were determined in rainwater samples, from which a very low sample volume was collected. This method combines on-line in-tube solid-phase microextraction coupled to high-performance liquid chromatography with a diode-array detector. In order to obtain a short analysis time and to reduce the consumption of organic solvents, two chromatographic phases (C18 monolithic and cyanopropyl silica) are compared. Although three critical pairs are found, faster separation, good resolution and lower pressures are achieved using C18 monolithic column. In order to achieve a simple and sensitive method, two commercial capillaries (a porous polymer with divinylbenzene-4-vinylpyridine and a liquid-phase capillary with 95% poly(dimethylsiloxane)-5% poly(diphenylsiloxane)) are tested for the extraction process. Due to great differences of hydrophobicity among the six phthalates, the selection of a modifier is necessary for a good extraction. The best conditions are achieved using 5 mL of sample containing 40% methanol in a 70 cm-long porous polymer capillary. The procedural blanks are controlled and taken into account in the calculation of the detection limits. Except for dimethylphthalate, the method detection limits are in the range from 0.2 to 0.9 ng mL-1 and the inter-day precision is between 5.3% and 12.5%. The recoveries were within the range of 71%-101%. Rainwater samples are analyzed in order to examine the dilution effect and washout of phthalates in the atmosphere. Dibutyl phthalate is the predominant phthalate found and di-(2-ethylhexyl) phthalate is detected in all analyzed samples.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Ácidos Ftálicos/análisis , Lluvia/química , Microextracción en Fase Sólida/métodos , Dibutil Ftalato/análisis , Ésteres/análisis , Límite de Detección
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