269 research outputs found
Non-isothermal model for the direct isotropic/smectic-A liquid crystalline transition
An extension to a high-order model for the direct isotropic/smectic-A liquid
crystalline phase transition was derived to take into account thermal effects
including anisotropic thermal diffusion and latent heat of phase-ordering.
Multi-scale multi-transport simulations of the non-isothermal model were
compared to isothermal simulation, showing that the presented model extension
corrects the standard Landau-de Gennes prediction from constant growth to
diffusion-limited growth, under shallow quench/undercooling conditions.
Non-isothermal simulations, where meta-stable nematic pre-ordering precedes
smectic-A growth, were also conducted and novel non-monotonic
phase-transformation kinetics observed.Comment: First revision: 20 pages, 7 figure
The Landscape Archaeology of Knettishall Heath, Suffolk and its Implications
This paper briefly describes the results of archaeological fieldwork carried out in an area of heathland, currently managed as a nature reserve, in East Anglia. Although the earthworks recorded are for the most part unremarkable, they demonstrate the variety and intensity of human exploitation which shaped this ‘traditionally managed’ habitat. They also serve to emphasise the extent to which modern conservation management can radically change the long-term character of individual places
In silico evolution of signaling networks using rule-based models: bistable response dynamics
One of the ultimate goals in biology is to understand the design principles
of biological systems. Such principles, if they exist, can help us better
understand complex, natural biological systems and guide the engineering of de
novo ones. Towards deciphering design principles, in silico evolution of
biological systems with proper abstraction is a promising approach. Here, we
demonstrate the application of in silico evolution combined with rule-based
modelling for exploring design principles of cellular signaling networks. This
application is based on a computational platform, called BioJazz, which allows
in silico evolution of signaling networks with unbounded complexity. We provide
a detailed introduction to BioJazz architecture and implementation and describe
how it can be used to evolve and/or design signaling networks with defined
dynamics. For the latter, we evolve signaling networks with switch-like
response dynamics and demonstrate how BioJazz can result in new biological
insights on network structures that can endow bistable response dynamics. This
example also demonstrated both the power of BioJazz in evolving and designing
signaling networks and its limitations at the current stage of development.Comment: 24 pages, 7 figure
Being Attractive Brings Advantages: The Case of Parrot Species in Captivity
Background: Parrots are one of the most frequently kept and bred bird orders in captivity. This increases poaching and thus the potential importance of captive populations for rescue programmes managed by zoos and related institutions. Both captive breeding and poaching are selective and may be influenced by the attractiveness of particular species to humans. In this paper, we tested the hypothesis that the size of zoo populations is not only determined by conservation needs, but also by the perceived beauty of individual parrot species assessed by human observers. Methodology/Principal Findings: For the purpose of data collection, we defined four sets of species (40 parrots, 367 parrots, 34 amazons, 17 macaws). Then, we asked 776 human respondents to evaluate parrot pictures of the selected species according to perceived beauty and we analyzed its association with color and morphological characters. Irrespective of the species set, we found a good agreement among the respondents. The preferred species tended to be large, colorful, and long-tailed. Conclusions/Significance: We repeatedly confirmed significant, positive association between the perceived beauty and the size of worldwide zoo population. Moreover, the range size and body size appeared to be significant predictors of zoo population size. In contrast, the effects of other explanatory variables, including the IUCN (International Union for Conservation of Nature) listing, appeared insignificant. Our results may suggest that zoos preferentially keep beautifu
Prácticas docentes para creatividad en la universidad: estudio en Portugal y Brasil
Creativity is nowadays seen as an essential feature in higher education. Nevertheless, there is a discrepancy between the need for creativity and what higher education classrooms provide. This study assessed the perceptions of 1599 higher education students from two countries (1059 Brazilian and 540 Portuguese students), from two academic domains (Sciences and Technologies – Sc&T; Social Sciences, Arts, and Humanities – SScA&H), about the presence of creativity in their teachers’ instruction and evaluation practices. The study’s findings evidence interactive effects between the variables country and academic domain for most of the assessed factors: encouragement of new ideas, climate for the expression of ideas, and interest in students’ learning. Brazilian Sc&T students presented more negative perceptions of their classroom environments when compared to SScA&H students; Portuguese students showed opposite patterns
of results. Some hypothetical explanations are discussed and future directions for research are presented.Criatividade é atualmente tomada como aspecto essencial na Educação Superior. Há, contudo, discrepância entre a necessidade
de criatividade e o que a universidade proporciona. Este estudo avaliou percepções de 1599 alunos universitários de dois paÃses (1059
brasileiros e 540 portugueses), de duas áreas curriculares (Ciências e Tecnologias – Sc&T; Ciências Sociais, Artes e Humanidades – SscA&H)
sobre a presença de criatividade nas práticas docentes, instrucionais e avaliativas, de que são alvo. Os resultados mostraram efeitos
interativos significativos entre as variáveis paÃs e área curricular para a maioria dos fatores avaliados: encorajamento de novas ideias,
clima para expressão de ideias e interesse pela aprendizagem dos alunos. Os estudantes brasileiros de Sc&T mostraram percepções mais
negativas da sala de aula, comparados com os de SScA&H; os alunos portugueses obtiveram padrões opostos nos resultados. Algumas
hipóteses explicativas são discutidas e são apresentadas orientações para pesquisa futura.La creatividad está actualmente considerada como aspecto esencial en la Educación Superior. Sin embargo, existe discrepancia
entre la necesidad de creatividad y lo que la universidad ofrece. Este estudio evaluó percepciones de 1.599 estudiantes universitarios
(1.059 de Brasil y 540 de Portugal) de dos áreas curriculares (Ciencia y TecnologÃa – Sc&T; Ciencias Sociales, Artes y Humanidades
– SscA&T) acerca de la presencia de creatividad en las prácticas docentes, instructivas y evaluativas dirigidas a ellos. Los resultados mostraron
efectos de interacción significativos entre las variables paÃs y área curricular para la mayorÃa de los factores evaluados: fomento de
nuevas ideas, entorno para la expresión de ideas e interés en el aprendizaje del estudiante. Los estudiantes brasileños de Sc&T mostraron
percepciones más negativas de la clase en comparación con los de SSCA&H; los estudiantes portugueses obtuvieron patrones opuestos en
los resultados. Algunas hipótesis explicativas se discuten y se presentan directrices para investigación futura.Thermo Scientificinfo:eu-repo/semantics/publishedVersio
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