Measuring Propagation Speed of Coulomb Fields

The problem of gravity propagation has been subject of discussion for quite a long time: Newton, Laplace and, in relatively more modern times, Eddington pointed out that, if gravity propagated with finite velocity, planets motion around the sun would become unstable due to a torque originating from time lag of the gravitational interactions. Such an odd behavior can be found also in electromagnetism, when one computes the propagation of the electric fields generated by a set of uniformly moving charges. As a matter of fact the Li\'enard-Weichert retarded potential leads to a formula indistinguishable from the one obtained assuming that the electric field propagates with infinite velocity. Feyman explanation for this apparent paradox was based on the fact that uniform motions last indefinitely. To verify such an explanation, we performed an experiment to measure the time/space evolution of the electric field generated by an uniformely moving electron beam. The results we obtain on such a finite lifetime kinematical state seem compatible with an electric field rigidly carried by the beam itself.Comment: 23 pages, 15 figure

Rememoración histórica en el documental de entrevista de la Transición española

The majority of the filmography composed by the full-length documentaries released during the Spanish Transition to democracy (1976-1982) focuses its attention on exhaustively revisiting recent History, especially the Civil War and the Francoist dictatorship. It also recurrently uses interviews as the epicentre of its discourse –its protagonists speak up as witnesses or narrators– with an aim to allow alternative voices to the official version of past events imposed during the decades of dictatorship. This body of films aims at, rather than recalling what happened, making a remembrance of it; building an account of it selectively and with an awareness of the present it tries to serve: the ongoing political, social, and cultural change. Using film textual analysis as a methodology, this paper aims at determining the contribution of documentary interviews in laying the foundation of the historical memory of the Spanish society that was experiencing a transition from dictatorship to democracy. In the report of results, three categories of documentaries, which can be distinguished depending the intentions behind the remembrance, are established: the “memory of the losers”, praising the victims of the war and openly questioning Franco’s figure and ideology; the “activist memories”, which propose vindications, allegations and complaints in the highly spirited debate on the fight for freedom during the Spanish Transition to democracy; or the “biographical memories”, which disclose the repression that had been piling up during years of dictatorship in contexts of intimacy, and which leads to extrapolate those experiences to the society of that time.El grueso de la filmografía que ocupan los largometrajes documentales estrenados durante el periodo de la Transición española caracteriza su discurso por una profusa revisión del pasado histórico –sobre todo la Guerra Civil y el periodo franquista– y un empleo recurrente de la entrevista como epicentro de su enunciación –sus protagonistas toman la palabra en calidad de testigo o narrador–, con la intención de dar cabida a voces alternativas a la de la versión de los hechos pretéritos impuesta por décadas de dictadura. Ese corpus de filmes se propone no tanto recordar lo sucedido como rememorarlo: construir un relato del mismo de forma selectiva y con conciencia del presente al que sirve: el cambio político, social y cultural en tránsito. Empleando como metodología el análisis textual fílmico, el presente artículo persigue determinar la contribución de los documentales de entrevista en la cimentación de la memoria histórica de la sociedad española que experimentó el paso de la dictadura a la democracia. En su exposición de resultados, establece tres categorías de películas documentales diferenciadas por sus intenciones en la rememoración planteada: la “memoria de los perdedores” que ensalza a las víctimas de la guerra y cuestiona frontalmente la figura de Franco y su ideario, las “memorias militantes” que plantean reivindicaciones, alegatos y denuncias desde la efervescencia del debate de la lucha por las libertades de la Transición, o las “memorias biográficas”, que hacen pública la represión acumulada durante años de dictadura en contextos de intimidad, permitiendo extrapolar su experiencia a la sociedad de entonces

The artistic avant-gardes of the 20th century and its theoretical contribution in the exhibitionist definition of Film’s nature

A pesar de que las vanguardias artísticas de principios de siglo constituyen un grupo de movimientos heterogéneo coinciden en un ideal común: la ruptura del estatus del arte en la sociedad burguesa. El desplazamiento del sujeto del centro del proceso creador y la aparición de un nuevo sistema de representación basado en la perspectiva múltiple harán que el cine se sitúe en el punto de mira de distintas propuestas rupturistas como el cubismo, el futurismo o el dadaísmo. El objetivo del presente texto es destacar las aportaciones de los movimientos de vanguardia emergentes durante las primeras décadas del siglo XX en la fragua de conceptos teóricos capaces de dotar al cine de un estatus discursivo basado en la forma y la construcción al que denominaremos exhibicionista, que se opone al de su consideración como cine clásico supeditado a suceder a la literatura decimonónica en su misión narrativaAlthough the artistic avant-gardes of the beginning of the 20th century are a heterogeneous group, they all coincide in a common ideal: contravening the status of art of the bourgeois society. Displacing the individual from the centre of the creative process and the appearance of a new system of representation based in a multiple perspective will attract different groundbreaking approaches such as Cubism, Futurism or Dadaism to Film. This paper aims at highlighting the contributions of the emerging avant-garde movements during the first decades of the 20th century to the forge of theoretical concepts that provided films with a discursive status based on forms and structures that we call exhibitionist, as opposed to classic film, which was meant to follow the steps of 19th-Century literature in its narrative missio

Respeitosa e simpática solidariedade para com od doentes

La representación artística de la persona en su enfermedad, durante el siglo XIX, no es muy frecuente si se compara con el total de la producción de los pintores españoles. Esta premisa, junto con la sorpresa del descubrimiento de la obra, fueron los determinantes que nos movieron a su estudio. Se trata de una obra de José Roldán que realizó ca. 1864 y le puso como nombre Su Majestad la reina Isabel II en el acto de besar la mano al pobre mas antiguo del hospital de la Caridad de Sevilla. La justificación del trabajo gira en torno a la descripción de actitudes y comportamiento hacia el enfermo y su cuidador en la España isabelina. Se trata de un estudio descriptivo e interpretativo donde se irán conectando los personajes que aparecen en la escena con objeto de entender el acontecimiento que los concita. Quiénes son, porqué están y que papel representan. La obra fue presentada por Roldan en Exposición Nacional 1864. Se encuadra en el género costumbrista sevillano, reflejo de una sociedad de marcada religiosidad con gusto por las procesiones y las obras de caridad, de las festividades y celebraciones ciudadanas. En la pintura analizada la representación no es casual, están todos los que son y son todos los que están. La enfermería, aún sin voces propias que la expresen públicamente, justifica su presencia en tanto en cuanto hay una persona, enferma en este caso, que necesita de sus cuidados. La satisfacción de sus necesidades vitales es la argumentación.Portraits of sick people showing their illnesses were not really frequent along XIX century, compared to the full production of Spanish painters. This premise together with my own surprise at the discovering of the piece of art I herewith consider, were determinant on my decision to develop the present study. The piece of art, is a portrait by José Roldán painted around 1864, Her Majesty Queen Elizabeth II in the act of kissing the hand of the poorest and eldest man in the Charity Hospital of Seville. The reason for this study goes around the description of attitudes and behaviour towards the ill patient and his/her care taker in the Elizabethan Spanish period. It is a descriptive and interpreting study where characters appearing on the stage would be considered according to the events they are suppose to take part in. Who they are, why they are where they are and what sort of role they do perform. The piece of work was exhibited by Roldán in the National Exhibition 1864. It could be regarded within a Seville genre presenting a society of extreme Christian habits and their interest in religious processions, charity and festivity and civil celebrations. In the analyzed portrait nothing is merely accidental, those characters present must be present. Nursing, still voiceless at that time justifies punctually and clearly its presence there as there is an ill person who needs 'care'. The argument is the satisfaction of his vital needs be fulfilled.A representação artística da pessoa em sua enfermidade, durante o século XIX, não é muito freqüente, se se comparada com o total da produção dos pintores espanhóis. Esta premissa, junto com a surpresa do descobrimento da obra, foram os determinantes que nos moveram a este estudo. Trata-se de uma obra de José Roldán que realizou em 1864 e o pôs como nome sua majestade a Rainha Isabel II no ato de beijar a mãe ao pobre mais antigo do hospital da caridade de Sevilha. A justificativa do trabalho gira em torno à descrição de atitudes e comportamento em direção ao enfermo e seu cuidador na Espanha isabelina. Trata-se de um estudo descritivo e interpretativo, no qual serão conectados os personagens que aparecem na cena com o objeto de entender o acontecimento que os cerca. Quem são, por que estão e que pael representam? A obra foi apresentada por Roldán em exposição nacional em 1864. Enquadra-se no gênero dos costumes de Sevilha, o reflexo de uma sociedade demarcada pela religiosidade com gosto pelas procissões e as obras de caridade, das festividades e celebrações cidadãs. Na pintura analisada, a representação não é casual; estão todos os que são e são todos os que estão. A enfermagem, ainda sem vocês próprias que a expresem publicamente, justifica sua presença no fato de que há uma pessoa enferma e, neste caso, que necessita de seus cuidados. A satisfação de suas necessidades vitais é a argumentação

Murillo's miracle of Saint John of God

Con motivo de su restauración y posterior exposición en el Museo del Prado, de la interesante obra de Murillo (1617–1682) La caída de San Juan de Dios procedente del Hospital de la Santa Caridad de Sevilla, durante el primer trimestre del 2006, nos proponemos realizar su análisis icnográfico. Entendemos que el estudio nos permitirá: 5. Conocer el contexto histórico-social que propició la representación de un personaje, que se distinguió por su especial dedicación al cuidado de sus semejantes. 6. Evidenciar el arte como historia, no solamente técnica, sino como lenguaje de toda una época, ni siquiera de un hombre. 7. Descifrar la encrucijada “concepción de la salud, conocimientos sobre su cuidado y los cuidadores” durante el periodo de ejecución de la obra en el entorno sevillano de la época. 8. Analizar el discurso y su contenido. Análisis iconográfico del San Juan de Dios de Murillo, y descubrir lo que está detrás de lo que se ve, yendo mas allá de la representación, llegando a conocer el porqué de la elección de la caída de San Juan de Dios. Hemos tratado de releer nuestra historia, siendo conscientes de que cada uno de los fenómenos humanos puede ser leído desde otros puntos de vista. Aún siendo difícil y arriesgado asumir una conclusión o cierre al estudio, si creemos descubrir aspectos humanistas de la enfermería, en un momento histórico marcado por el humanismo renacentista, expresados en los nexos de unión entre el enfermero y el paciente.An iconographic analysis will be made of the interesting painting by Murillo (1617–1682), San Juan de Dios (Saint John of God), from the Holy Charity Hospital in Seville. This painting has been restored and was exhibited at the Prado Museum between January and March 2006. The analysis will make it possible to: 1. Become acquainted with the social and historical context leading to the portrayal of a person who became famous for his special devotion towards looking after other people. 2. Show art as a historical source; rather than a mere technique, it should be considered as the language of a whole age, and not even of one person. 3. Explore the issues of “views on health, knowledge on healthcare and healthcare providers” at the time the painting was made in the Seville of its time. 4. Analyze the discourse and its contents. An iconographic analysis of Murillo’s San Juan de Dios will make it possible to discover what lies hidden beyond the representation, and will explain the choice of Saint John of God’s fall. An attempt has been made to re-read our history, in the awareness that all human events can be seen from a different point of view. In spite of the difficulty to reach a conclusion to our study, it is our belief that some humanist issues on nursing can be detected, in an age heavily influenced by Renaissance humanism, as expressed in the bonds between the nurse and the patient

Hollywood y la representación de la Otredad. Análisis histórico del papel desempeñado por el cine estadounidense en la forja de enemigos nacionales

Hollywood has played a decisive role in shaping the recent and short history of its founding country, the United States. This paper aims at exploring the representation of peoples outside the Western standard in Hollywood movies to spot recurrences in portraying Others, especially in vilifying terms. The analysis of plots and characters in American movies in different historical stages reveal not only consistent patterns in the depiction of Otherness, but also an even more interesting need to define and reaffirm the Self through the opposition to changing Others that mainly depend on the historical and political period occurring.Hollywood ha desempeñado un papel decisivo en la configuración de la corta historia del país bajo cuyo abrigo nació, los Estados Unidos de América. En este artículo se examinan la representación de los pueblos no occidentales en las películas hollywoodienses desde finales de la década de los años sesenta hasta finales de la década de los años noventa; con el fin de detectar recurrencias en los retratos de esos Otros, especialmente cuando se tiende a describirlos en términos peyorativos, lo que demuestra que la tendencia era recurrente y estaba bien asentada en Hollywood mucho antes incluso de los ataques del 11 de septiembre. El análisis de argumentos y personajes de las películas americanas a través de las diferentes etapas históricas observadas ratifica no solo los conocidos lazos entre Hollywood y la Casa Blanca, sino que revela una serie de patrones recurrentes en la caracterización de esta Otredad y también una necesidad aún más interesante de definir y reafirmar la propia identidad a través de la oposición a un Otro cuya fisonomía cambia de manera pareja al momento político e histórico que coincida con el lanzamiento de la película

Terapia génica: ¿Qué es y para qué sirve?

Gene therapy has developed as a method of approach to the treatment of human diseases based on the transfer of genetic material to the cells of an individual. Normally, the aim of this transfer of genetic material is to re-establish a cellular function that has been abolished or is defective, to introduce a new function or to interfere with an existing function. Thus, the different gene therapy strategies are based on the combination of three key elements: the genetic material to be transferred, the method of transfer and the cellular type that will incorporate this genetic material. Attention was initially centred on the treatment of monogenic hereditary diseases, but subsequently the majority of clinical trials (over four hundred) have concerned the treatment of cancer. In China a genetic product has been approved for commercialisation: an adenovirus that transfers the correct version of the tumour suppressor gene p53. And, in the late 1990s, a group of children with severe combined immunodeficiency were successfully treated through the ex vivo transfer of the correct version of the altered gene to their bone marrow, although some of these children later developed lymphoproliferative syndromes due to the activation of an oncogen in the corrected cells. Human gene therapy is feasible and can be useful, but the tools need improving for it to become part of the therapeutic arsenal

Targets for immunotherapy of liver cancer

Drug development in hepatocellular carcinoma (HCC) has been characterised by many failures in the past. Despite good rationales and promising phase II data, many phase III trials failed. Immunotherapy represents an alternative treatment approach that has been successful in many different cancer types. As an inflammation induced cancer, HCC represents a very interesting target for immune based approaches. Indeed, early results from clinical trials testing immune checkpoint inhibitors are not only promising, but have already led to evaluation in a phase III setting. Herein, we summarise our current knowledge on the rationale, mechanism of action and clinical data for immune checkpoint blockade in HCC. In addition, we provide an overview of other novel immune based approaches currently under development for the treatment of HCC, such as adoptive cell based and antibody-based approaches