1,721,345 research outputs found
Microcanonical solution of the mean-field phi(4) model: Comparison with time averages at finite size
No full textWe study the mean-field phi(4) model in an external magnetic field in the microcanonical ensemble using two different methods
Experimental tests of the Peyrard-Bishop model applied to the melting of very short DNA chains
No full textThe melting curves of short heterogeneous DNA chains in solution are calculated on the basis of statistical thermodynamics, and compared to experiments. The computation of the partition function is based on the Peyrard-Bishop Hamiltonian, which has already been adopted in a theoretical description of the melting of long DNA chains. In the case of short chains it is necessary to consider not only the breaking of the hydrogen bonds between single base pairs, but also the complete dissociation of the two strands forming the double helix
Melting of DNA oligomers: dynamical models and comparison with experimental data
No full textWe compare experimental melting curves of short heterogeneous DNA oligomers with theoretical curves derived from statistical mechanics. Partition functions are computed with the one-dimensional Peyrard-Bishop (PB) Hamiltonian, already used in the study of the melting of long DNA chains. Working with short chains we take into account, in the computations, not only the breaking of the interstrand hydrogen bonds, but also the complete dissociation of the double helix into separate single strands. Since this dissociation equilibrium is of general relevance, independent of the particular microscopic model, we give some details of its treatment. We discuss how the non bonded three-dimensional interactions, not explicitly considered in the one-dimensional PB model, are taken into account through the treatment of the dissociation equilibrium. We also evaluate the relevance of the dissociation as a function of the chain length
Cr?nica de una campa?a de desprestigio Fracasada.
No full textEl Poder Ejecutivo comenz? en 2007la campa?a de agravios contra el Poder Legislativo, luego le toc? el turna-a la Corte Suprema, el Ministerio P?blico, Procuradur?a y ahora .contra las FF A
Overdamped dynamics of long-range systems on a one-dimensional lattice: Dominance of the mean-field mode and phase transition
No full textWe prove that the mean-field mode always dominates in the dynamics of the alpha-HMF model in the canonical ensemble
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Campa?a de Bien P?blico para la prevenci?n del Condiloma Acuminado en los adolescentes del municipio Las Tunas
No full textEl Condiloma Acuminado constituye una verdadera epidemia de esta ?poca; sin
embargo existen evidencias que revelan entre los adoptantes objetivo un incipiente
conocimiento en torno a la infecci?n lo que deviene en una primaria percepci?n del
riesgo. La presente investigaci?n responde a la necesidad de darle tratamiento desde
una nueva perspectiva a esta Infecci?n de Transmisi?n Sexual mediante la propuesta
de una campa?a de bien p?blico que contribuya a la prevenci?n del Condiloma
Acuminado en los adolescentes del municipio Las Tunas. Por esa raz?n la autora
defiende la idea de que una campa?a de bien p?blico para prevenir esta ITS debe
disminuir los ?ndices de infecci?n en los adolescentes del municipio. La campa?a
est? estructura en una parte te?rica y una operativa. Se fundamenta en elementos
te?ricos generales para lo cual la autora tuvo presente los factores que pueden
hacer fracasar la campa?a de bien p?blico, los factores que pueden atentar contra
el impacto positivo de los medios de comunicaci?n utilizados, los factores que
pueden garantizar el ?xito de la campa?a y finalmente los factores favorables desde
la perspectiva de los adoptantes objetivo. La parte operativa incluye los componentes
espec?ficos de la campa?a tales como nombre gen?rico y comercial, objetivos de
esta campa?a, la plataforma promocional, las estrategias de los medios de
comunicaci?n y mensajes, las acciones espec?ficas y otros elementos que
consideramos de vital inter?s para el desarrollo y puesta en pr?ctica de la propuesta.
En la parte conclusiva de la investigaci?n respondemos de manera sucinta cada uno
de los objetivos propuestos luego de que se alineara con el problema detectado y la
idea que se defiende. De igual manera en las recomendaciones se enfatiza en el
cumplimiento de las acciones propuestas en consonancia con el control y evaluaci?n
de las mismas
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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