12,700 research outputs found
Non-stochastic behavior of atomic surface diffusion on Cu(111) at all temperatures
Atomic diffusion is usually understood as a succession of random, independent
displacements of an adatom over the surface's potential energy landscape.
Nevertheless, an analysis of Molecular Dynamics simulations of self-diffusion
on Cu(111) demonstrates the existence of different types of correlations in the
atomic jumps at all temperatures. Thus, the atomic displacements cannot be
correctly described in terms of a random walk model. This fact has a profound
impact on the determination and interpretation of diffusion coefficients.Comment: 5 figure
Europe in a global context: Eurogeo and the role of geography and european geographers
EUROGEO is the European Association of Geographers created in 1979, so in 2019 we have celebrated its 40th anniversary. In 2020 geographers celebrate the bicentennial of the foundation of the first Chair of Geography at the University of Berlin. In 2021, the bicentennial creation of the first geographical society in Paris, and in 2022 the centennial of the establishment of the International Geographical Union. Geography is a relative young scientific discipline. For a long a time, there has been a discussion about its scientific status, the diversity of paradigms or national research schools. Despite several voices arguing the end of geography or burring the lines of the discipline, among other reasons because of the revolution of geospatial information, this paper claims that geography is more important today than ever and geography is fashionable. Geography is essential for education and for environment, but also for society, economics and politics: globalization, sustainable development, climate change and technology are at the forefront of the world and European challenges. So, geographer''s international contributions -like EUROGEO does-are also essential to have the better understanding of the present context and to help problem solving and decision-making
Transcriptome of the deep-sea black scabbardfish, Aphanopus carbo (Perciformes: Trichiuridae) : tissue-specific expression patterns and candidate genes associated to depth adaptation
Deep-sea fishes provide a unique opportunity to study the physiology and evolutionary adaptation to extreme environments. We carried out a high throughput sequencing analysis on a 454 GS-FLX titanium plate using unnormalized cDNA libraries from six tissues of A. carbo. Assemblage and annotations were performed by Newbler and InterPro/Pfam analyses, respectively. The assembly of 544,491 high quality reads provided 8,319 contigs, 55.6% of which retrieved blast hits against the NCBI nonredundant database or were annotated with ESTscan. Comparison of functional genes at both the protein sequences and protein stability levels, associated with adaptations to depth, revealed similarities between A. carbo and other bathypelagic fishes. A selection of putative genes was standardized to evaluate the correlation between number of contigs and their normalized expression, as determined by qPCR amplification. The screening of the libraries contributed to the identification of new EST simple-sequence repeats (SSRs) and to the design of primer pairs suitable for population genetic studies as well as for tagging and mapping of genes. The characterization of the deep-sea fish A. carbo first transcriptome is expected to provide abundant resources for genetic, evolutionary, and ecological studies of this species and the basis for further investigation of depth-related adaptation processes in fishes.Publisher PDFPeer reviewe
HT Cas - eclipsing dwarf nova during its superoutburst in 2010
We present results of a world-wide observing campaign of the eclipsing dwarf
nova - HT Cas during its superoutburst in November 2010. Using collected data
we were able to conduct analysis of the light curves and we calculated
diagrams.
The CCD photometric observations enabled us to derive the superhump period
and with the timings of eclipses the orbital period was calculated. Based on
superhump and orbital period estimations the period excess and mass ratio of
the system were obtained
IX Draconis - a curious ER UMa-type dwarf nova
We report results of an extensive world-wide observing campaign devoted to a
very active dwarf nova star - IX Draconis. We investigated photometric
behaviour of the system to derive its basic outburst properties and understand
peculiarities of IX Dra as well as other active cataclysmic variables, in
particular dwarf novae of the ER Uma-type. In order to measure fundamental
parameters of the system, we carried out analyses of the light curve, O-C
diagram, and power spectra. During over two months of observations we detected
two superoutbursts and several normal outbursts. The V magnitude of the star
varied in the range 14.6 - 18.2 mag. Superoutbursts occur regularly with the
supercycle length of 58.5+/-0.5 d. When analysing data over the past 20 years,
we found that the supercycle length is increasing at a rate of P_dot = 1.8 *
10^{-3}. Normal outbursts appear to be irregular, with typical occurrence times
in the range 3.1 - 4.1 d. We detected a double-peaked structure of superhumps
during superoutburst, with the secondary maximum becoming dominant near the end
of the superoutburst. The mean superhump period observed during superoutbursts
equals 0.066982(36) d, which is constant over the last two decades of
observations. Based on the power spectrum analysis, the evaluation of the
orbital period was problematic. We found two possible values: the first one,
0.06641(3) d, which is in agreement with previous studies and our O-C analysis
(0.06646(2) d), and the second one, 0.06482(3) d, which is less likely. The
evolutionary status of the object depends dramatically on the choice between
these two values. A spectroscopic determination of the orbital period is
needed. We updated available information on ER UMa-type stars and present a new
set of their basic statistics. Thereby, we provide evidence that this class of
stars is not uniform.Comment: Accepted for publication in MNRAS; 15 pages, 15 figures, 6 tables;
typo correcte
Novel Microscopic Mechanism of Intermixing during Growth on Soft Metallic Substrates
Generic computer simulations using empiric interatomic potentials suggest a new, collective mechanism that could be responsible for mixing at heteroepitaxial interfaces. Even if single adsorbate atoms diffuse by hopping on the substrate surface and do not mix at the terraces, two-dimensional islands formed by nucleation may become unstable above a certain critical size and explode upwards forming clusters of several atomic layers. This process is accompanied by strong distortions of the underlying atomic layers, and on soft materials it can result in surface etching and incorporation of substrate atoms into the islands.Fil: Gomez, Liliana Maria. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; ArgentinaFil: Slutzky, Claudia Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Ferron, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: de la Figuera, J.. Sandia National Laboratories; Estados UnidosFil: Camarero, J.. Universidad Autónoma de Madrid; EspañaFil: Vazquez de Parga, A.. Universidad Autónoma de Madrid; EspañaFil: de Miguel, J.J.. Universidad Autónoma de Madrid; EspañaFil: Miranda, R.. Universidad Autónoma de Madrid; Españ
The Nova SBE University merchandising venture
A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and EconomicsThe objective of this Work Project is twofold: to create a research project on the opportunities for launching a Nova School of Business and Economics (Nova SBE) merchandise project; and the description of the planned strategy for this project. The objective of the research is to identify, validate and measure what opportunities lie within offering NOVA SBE merchandise. The objective of the strategy’s plan is to provide a guideline for the project, so it can start being implemented as soon as possible. This guideline will include recommendations regarding the product line, pricing and marketing in the short and long-term
Education on Sustainable Development Goals: Geographical Perspectives for Gender Equality in Sustainable Cities and Communities
Because of its interdisciplinary approach as a social science directly related to the natural sciences, geography is the academic discipline and school subject that equips students well with knowledge, skills, and values related to education on sustainable development goals. This study is part of the results of MyGEO, a project funded by the European Commission, and it is based on a collaborative mapping of streets named after women in a medium-sized city (Zaragoza, Spain), in connection with the international initiative GeoChicas (GeoGirls) on OpenStreetMap. Its main objective is to obtain evidence to emphasize, through public and digital space, gender equality and the empowerment of women in teacher education by means of their achievements. The learning methodology consists of (i) standardization and correction of alphanumeric information referring to street names contained in the OpenStreetMap spatial database that identify gender and (ii) linking and creating thematic information through Wikipedia editing. The results show that Zaragoza is at the top of the ranking of Spanish and Latin American cities mapped to date in the “Women’s Streets” viewer, with 18% of the streets named after women, compared to the average 15% in the rest of the 30 cities involved in GeoChicas. The direct participation of trainee primary and secondary schoolteachers in this project makes it possible to consolidate a narrative as well as a specific instructional design on education for sustainable development, particularly on SDG number 5 (gender balance) and SDG number 11 (sustainable cities and communities). © 2022 by the authors. Licensee MDPI, Basel, Switzerland
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