Travel Directions

Travel Directions. In telling the story of their own trips, vacations and excursions through film, amateur movie makers use opening and closing credits, as well as footage of sign posts and road signs, to articulate the narration of their experience “into stages”. While opening and closing credits – like captions for intermissions and transitions between sequences – belong to the paratextual dimension of thresholds, footage of sign posts and road signs enters into the diegesis and is thus internal to the film text or “intra-textual”. However, Roger Odin claim that a key feature of family film is the absence of text. Given this assertion, we may ask what is the function of textual insertions within amateur movie makers’ narrations of their journeys, especially since textual additions are extremely common in amateur travel films. As was already mentioned, Odin identifies the deliberate absence of textual elements as a key feature of family films a feature that indeed determines their significance as a sign. One of the multiple readings that Odin offers of this absence is that the stories involved in family films cannot be constrained within narrative limits. The compulsiveness to shoot every event imprinted in the film would constrain one to participate in a larger film extending throughout the entire family history, the end of which would only come with the family’s own extinction. We may ask how textual inserts relate to the narrative structure of the story. On the one hand, textual inserts usually serve to indicate the places and year of a particular experience (and to mark the end of the story with the word “end”). On the other hand, textual inserts serve not only to delimit the spatio-temporal dimension of events, but also to constrain them within a finite space that is delimited as “other”— the space of traveling within which the amateur filmmaker’s journey unfolds next to their loved ones as an extra-ordinary occasion external to the domestic context

Travel Directions

Travel Directions. In telling the story of their own trips, vacations and excursions through film, amateur movie makers use opening and closing credits, as well as footage of sign posts and road signs, to articulate the narration of their experience “into stages”. While opening and closing credits – like captions for intermissions and transitions between sequences – belong to the paratextual dimension of thresholds, footage of sign posts and road signs enters into the diegesis and is thus internal to the film text or “intra-textual”. However, Roger Odin claim that a key feature of family film is the absence of text. Given this assertion, we may ask what is the function of textual insertions within amateur movie makers’ narrations of their journeys, especially since textual additions are extremely common in amateur travel films. As was already mentioned, Odin identifies the deliberate absence of textual elements as a key feature of family films a feature that indeed determines their significance as a sign. One of the multiple readings that Odin offers of this absence is that the stories involved in family films cannot be constrained within narrative limits. The compulsiveness to shoot every event imprinted in the film would constrain one to participate in a larger film extending throughout the entire family history, the end of which would only come with the family’s own extinction. We may ask how textual inserts relate to the narrative structure of the story. On the one hand, textual inserts usually serve to indicate the places and year of a particular experience (and to mark the end of the story with the word “end”). On the other hand, textual inserts serve not only to delimit the spatio-temporal dimension of events, but also to constrain them within a finite space that is delimited as “other”— the space of traveling within which the amateur filmmaker’s journey unfolds next to their loved ones as an extra-ordinary occasion external to the domestic context

Studi epidemiologici su popolazioni umane esposte a basse e moderate concentrazioni di arsenico nelle acque potabili

Arsenic and its inorganic compounds are classified as human carcinogens. Several epidemiological studies conducted in areas of the world characterized by high arsenic concentration in drinking water, even up to 3,000 μg/l, report associations between arsenic exposure and skin, bladder, lung, liver and kidney cancer as well as cardiovascular diseases, diabetes and reproductive and developmental effects. Since general population is not exposed to these high arsenic concentrations in the last years attention focused on adverse health effects that low-to-moderate arsenic concentrations (0-150 μg/l) in drinking water could induce. The World Health Organization recommends a maximum limit of 10 μg/l for arsenic in drinking water. Almost all epidemiological studies conducted on populations exposed to low-to-moderate arsenic concentrations in drinking water are limited due to problems arising from both individual exposure assessment and low subjects number. The aim of the present review is to collect literature-based evidences regarding adverse health effects associated with exposure to low-to-moderate arsenic concentrations in drinking water (10-150 μg/l) in order to obtain a comprehensive picture of the health outcomes that such exposure can have on general population.L\u27arsenico e i suoi composti inorganici sono classificati come cancerogeni certi per l\u27uomo. Molti studi epidemiologici condotti in aree del mondo caratterizzate da elevate concentrazioni di arsenico nelle acque potabili, anche fino a 3.000 μg/l, riportano associazioni tra l\u27esposizione ad arsenico e cancro della pelle, della vescica, del polmone, del fegato e dei reni, cos? come malattie cardiovascolari, diabete ed effetti sia sulla riproduzione sia sullo sviluppo. La popolazione generale non ? solitamente esposta a queste concentrazioni di arsenico e negli ultimi anni sta crescendo sempre pi? la preoccupazione che anche moderate o basse concentrazioni di arsenico nelle acque potabili (10-150 μg/l) possano indurre esiti dannosi sulla salute umana. L\u27Organizzazione mondiale della sanit? raccomanda per l\u27arsenico nelle acque potabili il valore massimo di 10 μg/l. Quasi tutti gli studi epidemiologici condotti su popolazioni esposte a concentrazioni di arsenico nelle acque potabili, da basse a moderate, sono limitati a causa dei problemi derivanti sia dalla valutazione dell\u27esposizione individuale sia dalla bassa numerosit? delle popolazioni in studio. Lo scopo di questa rassegna ? raccogliere ci? che ? presente in letteratura per quanto riguarda gli effetti sulla salute associati all\u27esposizione a concentrazioni di arsenico, da basse a moderate, nelle acque destinate al consumo umano (10-150 μg/l) in modo da cercare di ottenere un quadro globale degli esiti che tale esposizione pu? avere sulla popolazione generale

Pyruvate kinase deficiency

Over the past few years the inherited disorders of erythrocyte metabolism have been the object of intensive research which has resulted in a better understanding of their molecular basis. However, curative therapy for red blood cell (RBC) enzyme defects still remains undeveloped. Among glycolyti

Baby 8mm e Super8. L'immagine del bambino al mare nelle pellicole del passo ridotto tra gli anni Cinquanta e gli anni Settanta

During the second half of the 20th century, and especially in the 1960s, there was a veritable competition among Italians to achieve “symbols of well-being”, which included beach holidays and the practice of amateur film-making.Home movies from the mid-fifties and seventies give rise to a totalizing image of the child, in the absence of whom the family seems to lose interest in recording the holidays at all, to the extent that fathers, mothers and grandparents appear almost exclusively in order to accompany and showcase the little ones

Adaptaciones de metodologías de enseñanza presencial a la modalidad virtual

Todos los docentes de la universidad Nacional de la Plata hemos tenido que aprender en tiempo récord como abordar la educación a distancia, debido a la pandemia del covid 19. Si bien, en la década del ´90 se comenzó a discutir cómo abordar este tipo de educación, no se la adoptó masivamente. Otto Peters, en 1993, subrayaba el hecho de que el estudio a distancia debe planificarse, prepararse y organizarse cuidadosamente; hoy se cuenta con diseños pedagógicos rigurosos existiendo en la literatura material respecto a los fundamentos, posibilidades y perspectivas. La mayoría de los profesores no conocíamos estas herramientas por lo cual tuvimos un doble desafío, trasmitir los conocimientos propios de la asignatura y crear, sistematizar el material necesario para compartir con los alumnos en las plataformas. Este tipo de educación requiere de una buena conexión a internet requisito que no siempre se cumplía. Sin embargo, esta dificultad fue sorteada por el trabajo de los docentes que grabaron sus clases dándole la oportunidad a los alumnos de escuchar estas clases de manera asincrónica. Uno de los aspectos más difíciles de sortear fue la interacción docente – alumno, alumno-alumno. Los resultados porcentuales de los alumnos aprobados fueron similares a los de la modalidad presencial, sin embargo, el número de alumnos en clase fue notablemente inferior en el año 2021.Investigación en Metodologías Alternativas para la Enseñanza de las Ciencia

Modelado de la estructura de hidroxiapatitas de calcio dopadas con zinc

Entre los principales materiales desarrollados como sustitutos del tejido óseo se destacan los fosfatos de calcio. El estudio de estos compuestos, y en particular de la hidroxiapatita de calcio (CaHap), ha recibido especial atención debido a sus propiedades de bioactividad y biocompatibilidad tisular. No obstante, la aplicación presenta algunas dificultades; entre ellas, su baja reabsorción en la zona de implante, hecho que limita su uso en ortopedia. Con el objetivo de mejorar las propiedades osteointegradoras de las hidroxiapatitas de calcio (CaHap) hemos sintetizado y caracterizado diversas apatitas sustituyendo Ca(II) por Zn(II). Dicho reemplazo resulta particularmente relevante dado que ambos cationes son muy abundantes en los sistemas biológicos y permite una más eficiente osteointegración. Es conocido que la CaHap puede cristalizar en dos fases: hexagonal (grupo espacial P63/m) y monoclínica (grupo espacial P21/b). La fase más frecuente es la hexagonal, aunque la monoclínica es más estable termodinámicamente. En trabajos previos, se estudiaron, a partir de datos de difracción de rayos X de polvos (DRX) empleando el análisis de Rietveld, las estructuras de apatitas puras y sustituidas con Zn(II), sintetizadas por el método de Hayek y Newesely. Los sólidos analizados mostraron una transformación de la fase monoclínica a hexagonal al incorporar una pequeña proporción de Zn a la estructura, cambio atribuible a la incorporación de un elevado porcentaje de agua a su estructura, lo cual traía como resultado una baja estabilidad térmica. Hemos encontrado que, sinterizando las muestras a 700 °C con un método similar al desarrollado por I. R. Gibson and W. Bonfield, es posible estabilizar la fase apatítica de CaHap dopados con pequeñas cantidades de Zn [(Zn,Ca)Hap]. Esta síntesis permite que la incorporación de agua sea inferior a lo reportado hasta el momento en la literatura. Sin embargo, se desconoce el efecto del Zn sobre la estructura cristalina, el tamaño de grano y porqué por encima de cierto porcentaje de Zn la fase apatítica se desestabiliza. En el presente trabajo proponemos estudiar las propiedades microestructurales de (Zn,Ca)Hap empleando el análisis Rietveld a partir de datos de difracción de Rayos X en polvo. En particular nos interesa explorar la posible influencia del tamaño de grano y microesfuerzos (isotrópico o anisotrópico) en los patrones de difracción de rayos X de CaHap sustituidas con distintos porcentajes de Zn.Facultad de Ingenierí

Óxidos binarios antiferromagnéticos de metales de transición: relación estructura propiedad en nanoestructuras

El advenimiento de la nanociencia, cuyas herramientas básicas son el confinamiento geométrico, la proximidad física y la auto-organización ha hecho posible fabricar sistemas artificiales con dimensiones nanométricas donde se ven los efectos del confinamiento cuántico en dos, una y cero dimensiones (2D, 1D, 0D). En 1986 se descubrieron experimentalmente los puntos cuánticos (0D), en 1991 se fabricaron los primeros nanotubos de carbono (1D), en 1993 Eigler armó el primer corral cuántico (2D). En esta tesis vamos a restringirnos al comportamiento de los sistemas 3D de tamaño finito (dimensiones del orden de pocos nanómetros, 1nm = 10Å), en los que a diferencia de los sistemas cristalinos con ordenamientos de largo alcance, aparece una interesante variedad de fenómenos físicos no convencionales. Esto en parte es debido a que en los materiales granulares una alta fracción de átomos está localizada en los bordes de grano, por lo cual, las propiedades físicas estarán determinadas por la competencia entre los efectos del grano y del borde de grano. Es usual describir a las nanoestructuras como la superposición de estas dos fases: grano y borde de grano, cada una con sus propiedades particulares. Para tener una idea de los números que se manejan, un simple cálculo nos permite determinar el número de celdas en el borde de grano. Supongamos un material con una red cúbica cristalina y con un parámetro de celda de 5Å, constituidos por cristalitos cúbicos de 37,5 nm de lado con un borde de grano 1nm de espesor, en este caso un 15% de las celdas estarán en la superficie, mientras que en un cristalito de 5,7 nm de lado poseerá el 75% de celdas en superficie. Por lo tanto, es de esperar que las propiedades de las nanoestructuras, estén dominadas por la fase borde de grano. Existen diferentes modelos teóricos para simular y estimar el espesor del borde de grano. La comprensión y el rol que juega el borde de grano es un tema abierto, actualmente no existe una teoría global para esta fase, sin embargo, existe una extensa bibliografía para aspectos particulares de la misma.Facultad de Ciencias Exacta

Genotoxic and epigenetic mechanisms in arsenic carcinogenicity

Arsenic is a human carcinogen with weak mutagenic properties that induces tumors through mechanisms not yet completely understood. People worldwide are exposed to arsenic-contaminated drinking water, and epidemiological studies showed a high percentage of lung, bladder, liver, and kidney cancer in these populations. Several mechanisms by which arsenical compounds induce tumorigenesis were proposed including genotoxic damage and chromosomal abnormalities. Over the past decade, a growing body of evidence indicated that epigenetic modifications have a role in arsenic-inducing adverse effects on human health. The main epigenetic mechanisms are DNA methylation in gene promoter regions that regulate gene expression, histone tail modifications that regulate the accessibility of transcriptional machinery to genes, and microRNA activity (noncoding RNA able to modulate mRNA translation). The "double capacity" of arsenic to induce mutations and epimutations could be the main cause of arsenic-induced carcinogenesis. The aim of this review is to better clarify the mechanisms of the initiation and/or the promotion of arsenic-induced carcinogenesis in order to understand the best way to perform an early diagnosis and a prompt prevention that is the key point for protecting arsenic-exposed population. Studies on arsenic-exposed population should be designed in order to examine more comprehensively the presence and consequences of these genetic/epigenetic alterations

Quantitation of cellular deoxynucleoside triphosphates

Eukaryotic cells contain a delicate balance of minute amounts of the four deoxyribonucleoside triphosphates (dNTPs), sufficient only for a few minutes of DNA replication. Both a deficiency and a surplus of a single dNTP may result in increased mutation rates, faulty DNA repair or mitochondrial DNA depletion. dNTPs are usually quantified by an enzymatic assay in which incorporation of radioactive dATP (or radioactive dTTP in the assay for dATP) into specific synthetic oligonucleotides by a DNA polymerase is proportional to the concentration of the unknown dNTP. We find that the commonly used Klenow DNA polymerase may substitute the corresponding ribonucleotide for the unknown dNTP leading in some instances to a large overestimation of dNTPs. We now describe assay conditions for each dNTP that avoid ribonucleotide incorporation. For the dTTP and dATP assays it suffices to minimize the concentrations of the Klenow enzyme and of labeled dATP (or dTTP); for dCTP and dGTP we had to replace the Klenow enzyme with either the Taq DNA polymerase or Thermo Sequenase. We suggest that in some earlier reports ribonucleotide incorporation may have caused too high values for dGTP and dCTP