3,234 research outputs found
Metaplex networks: influence of the exo-endo structure of complex systems on diffusion
In a complex system the interplay between the internal structure of its
entities and their interconnection may play a fundamental role in the global
functioning of the system. Here, we define the concept of metaplex, which
describes such trade-off between internal structure of entities and their
interconnections. We then define a dynamical system on a metaplex and study
diffusive processes on them. We provide analytical and computational evidences
about the role played by the size of the nodes, the location of the internal
coupling areas, and the strength and range of the coupling between the nodes on
the global dynamics of metaplexes. Finally, we extend our analysis to two
real-world metaplexes: a landscape and a brain metaplex. We corroborate that
the internal structure of the nodes in a metaplex may dominate the global
dynamics (brain metaplex) or play a regulatory role (landscape metaplex) to the
influence of the interconnection between nodes.Comment: 28 pages, 19 figure
Active Senior Community
This Active Senior Living Community Project intends to achieve a design that helps older adults continue building their lives by providing spaces that makes senior residents feel excited and eager to navigate new chapter in their lives. This design seeks to achieve and creates a variety of opportunity for residents to connect, interact, and stay active. Therefore, key concepts that drive this design are promoting physical activity, strong sense of community and maximizing comfort
Un siglo de cambios en los Social Studies
Desde su constitución como materia escolar en 1916, los “Social Studies” no han dejado de introducir cambios e innovaciones en su currículo. Mediante una revisión bibliográfica de manuales norteamericanos se analizan las fechas claves de sus transformaciones, subrayando las razones que los impulsaron y las direcciones y tendencias que adoptan los cambios curriculares introducidosUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Nombrando lo conocido: una nueva especie de Desmopsis (Annonaceae) endémica de México
Background and Aims: A frequently collected species of Desmopsis (Annonaceae) in Mexico has remained indeterminate for more than 30 years. Its floral characteristics are similar to those present in the Asian genus Guamia (now Meiogyne), and for many years it has been named “Guamia mexicana”, but not formally described. Recently, it was shown that “Guamia mexicana” is phylogenetically related to Desmopsis and Stenanona and not to Guamia. However, and despite being frequently collected, its taxonomic status has not been clarified. Here, the phylogenetic relationships and the morphological and ecological characteristics that distinguish “Guamia mexicana” from other species were studied. As a result, this new species is herein described.
Methods: The new species was recognized using the unique combination of features through comparisons with morphologically similar species and a literature review. Its pollen characteristics were analysed using scanning electron microscopy. Its phylogenetic relationships were determined based on previously published phylogenies. Lastly, its conservation status was tentatively assessed by calculating extent of occurrence (EOO) and area of occupancy (AOO) using the GeoCAT tool and applying the IUCN Red List categories and criteria.
Key results: A new species of Annonaceae endemic to Mexico, namely Desmopsis ibarrarum, is described and illustrated. It is distinguished from other Desmopsis species by the combination of long and cylindrical fruits with many seeds, with a hard and woody testa and densely covered by very small sericeous hairs (velvety), glabrous leaves with percurrent tertiary venation, the absence of leafy bracts on the pedicels, the morphological differentiation of internal and external petals, and the partial fusion of the sepals.
Conclusions: Desmopsis ibarrarum is only closely related to Desmopsis dubia and both species are here considered members of a particular lineage within the Desmopsis-Stenanona clade, the “Desmopsis dubia group”.Antecedentes y Objetivos: Una especie de Desmopsis (Annonaceae) colectada frecuentemente en México ha permanecido indeterminada durante más de 30 años. Sus características florales son similares a las del género asiático Guamia (actualmente Meiogyne), y desde hace muchos años se le ha nombrado como “Guamia mexicana”, pero no ha sido descrita formalmente. Recientemente se demostró que “Guamia mexicana” está filogenéticamente emparentada con Desmopsis y Stenanona y no con Guamia. Sin embargo, y a pesar de ser colectada con frecuencia, no se ha aclarado su estatus taxonómico. En este artículo se estudiaron las relaciones filogenéticas y las características morfológicas y ecológicas que distinguen a “Guamia mexicana” de otras especies. Como resultado, esta especie nueva es aquí descrita.
Métodos: El reconocimiento de la especie nueva se basó en la correlación de varios caracteres morfológicos, a través de comparaciones con especies morfológicamente similares y de la revisión de literatura. Las características de su polen se analizaron mediante microscopía electrónica de barrido. Sus relaciones filogenéticas se determinaron con base en filogenias publicadas previamente. Finalmente, a partir de sus localidades conocidas se calculó extensión de ocurrencia (EOO) y área de ocupación (AOO) en GeoCAT, y aplicando las categorías y criterios de la Lista Roja de la UICN se determinó su estado de conservación.
Resultados clave: Desmopsis ibarrarum, una nueva especie de Annonaceae endémica de México, es descrita e ilustrada. Se distingue de otras especies de Desmopsis por la combinación de frutos largos y cilíndricos con muchas semillas, con una testa dura y leñosa y densamente cubierta por pelos seríceos muy pequeños (aterciopelados), por sus hojas glabras con venación terciaria percurrente, la ausencia de brácteas foliosas en los pedicelos, la diferenciación morfológica de los pétalos internos y externos, y por la fusión parcial de los sépalos.
Conclusiones: Desmopsis ibarrarum esta únicamente relacionada a Desmopsis dubia y las dos especies se consideran aquí miembros de un linaje particular dentro del clado Desmopsis-Stenanona, el "grupo Desmopsis dubia"
Vibrational response functions for multidimensional electronic spectroscopy: a coherent-state approach
Multi-dimensional spectroscopy represents a particularly insightful tool for
investigating the interplay of nuclear and electronic dynamics, which plays an
important role in a number of photophysical processes and photochemical
reactions. Here we present a coherent state representation of the vibronic
dynamics and of the resulting response functions. Analytical expressions are
initially derived for the case of third-order response functions in an N-level
system, with ground state initialization of the oscillator (zero-temperature
limit). The results are then generalized to the case of M-th order response
functions, with arbitrary M. The formal derivation is translated into a simple
recipe, whereby the explicit analytical expressions of the response functions
can be derived directly from the Feynman diagrams. We further generalize to the
whole set of initial coherent states, which form an overcomplete basis. This
allows one in principle to derive the dependence of the response functions on
arbitrary initial states of the vibrational modes and is here applied to the
case of thermal states. Finally, a non-Hermitian Hamiltonian approach is used
to include in the above expressions the effect of vibrational relaxation.Comment: 21 pages, 3 figure
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