Abstract This text proposes a reflection on the last books by Tamara Kamenszain and her gesture of rewriting some poems and essays from other previous books to replace the “I” or the autobiographical episode where it was erased or veiled “in a patina of artifice”. In it, there is speculation about the possible reasons for this rewriting, which unites poem and essay, as an exercise in addressing the question of the self to the “old literary criticism/ that despised private life/ in favor of a severe/ textualist purity”, as he writes in Chicas en tiempos supendidos. The reflection ends up leading to a reading hypothesis: could it be said that this rewriting would be his “terminal lyric”?

Resumen El presente texto investiga los últimos libros de Tamara Kamenszain y su gesto de reescritura de algunos poemas y ensayos de otros libros anteriores para reponer el “yo” o el episodio autobiográfico donde estaba borrado o velado “en una pátina de artificio”. En él se especula sobre las posibles intenciones de esta reescritura, que enlaza poema y ensayo, como un ejercicio de enderezamiento de la pregunta del yo hacia la “vieja crítica literaria/ que despreciaba la vida privada / en aras de una severa/ pureza textualista”, como ella dice en Chicas en tiempos suspendidos. La investigación acaba por llevar a una hipótesis de lectura: ¿se podría decir que esta reescritura sería su “lírica terminal”?

Resumo O presente texto propõe uma reflexão sobre os últimos livros de Tamara Kamenszain e seu gesto de reescrita de alguns poemas e ensaios de outros livros anteriores para repor o “eu” ou o episódio autobiográfico onde estava apagado ou velado “em uma pátina de artifício”. Nele, se especula sobre as razões possíveis desta reescrita, que une poema e ensaio, como um exercício de endereçamento da pergunta pelo eu à “velha crítica literária/ que desprezava a vida privada/ em prol de uma severa/ pureza textualista”, como escreve em Chicas en tiempos supendidos. A reflexão acaba por levar a uma hipótese de leitura: poderia-se dizer que esta reescrita seria sua “lírica terminal”?

ABSTRACT: This paper presents the results of a fieldwork conducted at La Flecha Canyon. These include the geolocation of different sectors with rock art, motif recording through digital photographic techniques and the excavation of a test pit next to the rock art concentration, which provides the first chronological information for the locality. Rock art results are compared with previous information generated through analogical techniques in order to monitor their preservation after more than three decades. Additionally, in order to start evaluating mobility circuits and interaction spheres on a regional scale, the similarities between motifs of La Flecha and those of other sectors of central-southern Patagonia are analyzed. The date obtained (1.653 to 1.802 AD) corresponds to one of the last occupations of this place by indigenous groups that maintained their hunter-gatherer way of life after contact with Europeans. The most recent petroglyphs with fresh patina are probably related to this date. However, most petroglyphs would probably be older, as suggested by the different patina and the presence of superimpositions. The comparative analysis of motifs points out to similarities between La Flecha and the canyons on the northern basin of the Santa Cruz River, the Strobel Lake Plateau, the Deseado Massif and the Pinturas River area, which suggest mobility between those spaces. Reasons for similarities at longer distances need to be analyzed more deeply.

RESUMEN: En este trabajo se presentan los resultados de los relevamientos realizados en el cañadón La Flecha, que incluyeron el geoposicionamiento de distintos sectores con arte rupestre, el registro de los motivos mediante técnicas fotográficas digitales y la ejecución de un sondeo al pie de la barda, a partir del cual se obtuvo la primera información cronológica para la localidad. Los resultados de la documentación del arte rupestre se comparan con la información previa generada mediante técnicas analógicas a fin de monitorear su estado de preservación después de más de tres décadas. De manera adicional y a los efectos de comenzar a evaluar circuitos de movilidad y esferas de interacción en una escala regional, se analizan las semejanzas entre los motivos rupestres de La Flecha y los de otros espacios de Patagonia centro- meridional. El fechado obtenido (1.653 a 1.802 AD) corresponde a una de las últimas ocupaciones de este espacio por parte de grupos cazadores-recolectores en un momento de contacto con los europeos, al cual probablemente puedan vincularse los petroglifos más recientes con pátina fresca. Sin embargo, la mayor parte de los motivos serían previos, tal como señalan las diferencias existentes en las pátinas y la presencia de superposiciones. El análisis comparativo de los motivos rupestres indica semejanzas entre La Flecha y los cañadones de la margen norte del río Santa Cruz, la Meseta del lago Strobel, el Macizo del Deseado y el área del río Pinturas, las cuales podrían vincularse con movilidad entre esos espacios. Las razones de las similitudes con lugares más distantes deben ser analizadas en mayor profundidad.

Resumen Esta investigación discute la categoría de Mapa Antiguo que encontramos de manera recurrente en la bibliografía referida a la historia de la cartografía. Para ello se analizan dos casos -uno chileno y otro argentino- que, si bien tienen singularidades y diferencias, comparten algunos aspectos que nos permite concluir que lo antiguo de los mapas no remite al paso del tiempo en sentido estricto sino que es el resultado de un entramado de cuestiones, en las que intervienen determinantes ideológicas, institucionales, coyunturales y materiales. En tal sentido, este artículo contribuye al campo de estudios de la historia de los mapas, de la historia del coleccionismo y los archivos y de sus fundamentos intelectuales en un periodo que abarca desde finales del siglo XIX a mediados del siglo XX. La primera mapoteca analizada corresponde a la colección reunida por el bibliófilo, editor e historiador José Toribio Medina (1852-1930), y que hoy forma parte de la Sala Medina de la Biblioteca Nacional de Chile. Esta colección se compuso desde el último decenio del siglo XIX y es actualmente -junto a la Mapoteca del Archivo Nacional y la Mapoteca de la Biblioteca Nacional- uno de los principales acervos cartográficos de Chile. La segunda mapoteca corresponde al Departamento de Investigaciones Históricas y Cartográficas de la Provincia de Buenos Aires (Archivo de Geodesia). En este caso, el acervo cartográfico corresponde a un archivo y es resultado del sedimento de materiales del trabajo de los técnicos agrimensores que, por obligación, debían entregar un ejemplar en la institución. Sobre este archivo, interviene José María Prado (1896-2002), funcionario a quien se le atribuye la revalorización de dichos materiales para nuevos usos de mapas técnicamente obsoletos. Se procedió analizando los textos producidos como correlato de la conformación de ambas mapotecas: notas, descripciones, catálogos y otros documentos de época. El análisis de estos materiales permitió observar que los procesos formativos de ambas mapotecas comparten al menos dos aspectos en común: la práctica no intencionada, no planificada, que les da origen, y la estrecha relación que se establece entre la valoración del acervo cartográfico y la pretensión de contar una historia de la cartografía y del territorio. Es en la conjunción de ambas características que se define lo antiguo del mapa. Al identificarse como antiguo, el material cartográfico quedaba habilitado para sustentar diversas operaciones historiográficas. Con estos mapas se podría construir genealogías del presente nacional o provincial al constituirse en huella material de verdades pasadas o testimonios antiguos de verdades duraderas, o bien, al explicitar su obsolescencia, introducir una distancia crítica respecto de lo ya acontecido. Como resultado, se les reconoció una pátina que, con cierta independencia de sus características materiales efectivas, les otorgaba renovada vigencia y legitimidad. Incluso, esta concepción justificaba que al lado de los mapas que ya habían adquirido la condición de antiguos, pudieran figurar otros que, siendo contemporáneos, estaban llamados a tornarse obsoletos con el paso del tiempo.

Abstract This study discusses the Ancient Map category that is recurrent in the literature on the history of cartography. To this end, we analyzed two cases — one in Chile and the other in Argentina — which, despite their unique characteristics and differences between them, share common features. These allow for concluding that the designation of maps as old does not strictly refer to the passage of time but results from a set of factors, including ideological, institutional, contextual, and material aspects. In this sense, this article contributes to the field of studies addressing the history of cartography, the history of collections and archives, and their intellectual foundations in a period spanning from the late 19th century to mid 20th century. The first map library analyzed corresponds to the collection gathered by the bibliophile, editor, and historian José Toribio Medina (1852-1930), which today is part of the Medina Room at the National Library of Chile. This collection was created in the last decade of the 19th century and is currently one of the main cartographic collections of Chile, along with the Map Library of the National Archive and the Map Library of the National Library. The second map library belongs to the Department of Historical and Cartographic Research of the Province of Buenos Aires (Geodesy Archive). In this case, the cartographic collection corresponds to an archive and is the result of the submission of materials derived from the work of the surveying technicians, who were requested to deliver a copy to the institution. José Maria Prado (1896-2002), a government officer credited with reevaluating these materials for new uses of technically obsolete maps, was involved in the review of this archive. We analyzed the texts related to the conformation of both map libraries: notes, descriptions, catalogs, and other documents of the time. The analysis of these materials revealed that the formative processes of both map libraries share at least two common aspects: the unintentional, unplanned practice that gave rise to them; and the close relationship between the valuation of the cartographic collection and the aim to recount a history of cartography and the territory; the combination of both characteristics defines the antiquity of the map. When identified as ancient, the cartographic material was available to undergo various historiographical processes. These maps would be used to build genealogies of the national or provincial present by becoming a material imprint of past truths or ancient testimonies of lasting truths; or, by evidencing their obsolescence, introducing a critical distance from past events. As a result, a patina was recognized that granted these maps renewed validity and legitimacy, regardless of their effective material characteristics. This conception even justified that besides the maps that had already been given the ancient status, others could be added, which, being contemporary, were bound to become obsolete through time.

Resumo Os materiais metálicos do século XX apresentam propriedades físicas e de resistência à corrosão com interesse para a arquitetura, tendo neste âmbito uma ampla gama de aplicações. Contudo, estão sujeitos a degradação, frequentemente associada às condições de utilização e ambiente de exposição, cujas consequências vão desde alterações estéticas à perda de funcionalidade dos componentes e estruturas em que se encontram aplicados. Neste artigo, descreve-se o comportamento típico de vários materiais metálicos correntemente usados nas edificações, quando usados em componentes de arquitetura exterior, correlacionando-o com a corrosividade ambiental e modos de utilização. O conjunto de informação reunida teve como objetivo contribuir para uma seleção adequada dos metais a aplicar numa determinada obra.

Abstract Metallic materials of the 20th century exhibit physical properties and corrosion resistance with interest for architecture, having in this scope a wide range of applications. However, they are subject to degradation, often associated with the conditions of use and environmental exposure. The consequences of which, range from aesthetic changes to the loss of functionality of the respective components. In this article, we describe the typical behavior of several metallic materials commonly used in buildings, when used in exterior architectural components, correlating it with atmospheric corrosivity and ways of use. The set of information gathered aimed to contribute for an adequate selection of the metals apply in future works.

The notion of thresholds and their potential to suggest liminality is usually associated with spatialities. However, I contend this notion can be extended to layered temporal thresholds and temporal liminalities. I present this argument, using postclassical narratological concepts as theoretical framework, with reference to the South African artist Jan van der Merwe's installation artwork Eclipse (2002). In this work, various spatial thresholds can be distinguished that relate to issues of conflict, mourning, exclusion, surveillance and the suggestion of death. This is achieved by means of a no man's land experienced when entering the artwork, where the viewer-participant finds him or herself compelled to follow a footpath surrounded by barbed wire on which clothes made of rusted metal are suspended. This journey culminates in a wall that presents three screens showing rose petals being dropped, as if into a grave. Various possible places suggest themselves: refugee camps, concentration camps, war zones and a cemetery. I argue that these spatialities are made possible by temporal thresholds that accompany them. Apart from the patina of the rusted material that suggest the passing of time, the moving flower petals in the screens repeat constantly to create not only liminal temporalities in terms of the artwork at large, but also an iterative sense of the ongoing culmination of these temporalities in death and mourning.

Die idee van drempels en hul potensiaal om die liminale te suggereer word tipies met ruimtelikhede geassosieer. Desnieteenstaande voer ek aan dat hierdie gedagte verbreed kan word na gelaagde tydmatige drempels en tydmatige liminaliteite. Ek bied hierdie argument vanuit die kader van postklassieke narratologie as teoretiese raamwerk en met verwysing na die Suid-Afrikaanse kunstenaar Jan van der Merwe se installasiekunswerk Eclipse (2002). In hierdie werk kan h aantal tydmatige drumpels onderskei word wat telkens kwessies van konflik, bewening, uitsluiting, dophou en die suggestie van dood aan die hand doen. Dit word bewerkstelling deur die ervaring van h niemandsland wanneer die kunswerk betree word, omdat die aanskouer-deelnemer noodgedwonge h voetpaadjie moet volg wat deur doringdraad omhul is en waarop klere wat uit geroeste metaal gesuspendeer is. Hierdie reis kulmineer in h muur waarop drie skerms gemonteer het wat roosblare toon, asof in h graf. Daar word gesinspee op verskeie moontlike plekke: vlugtelingkampe, konsentrasiekampe, oorloggebiede en h begraafplaas. Ek voer aan dat hierdie ruimtelikhede moontlik gemaak word deur tydmatige drumpels wat hand aan hand met die ruimtes gesuggereer word. Benewens die patina van die geroeste materiaal wat verband hou met die verloop van tyd, stel die herhalende beweging van die blomblare in die skerms ook liminale tydsfere aan die orde binne die kunswerk as geheel, en dryf ook - op iteratiewe wyse - hierdie tydsfere op die spits om h suggestie van die dood en rou aan die hand te doen.

Abstract This work is a theoretical and ethnographic approach about the city in ruins and the debris left by recent social protests in Plaza Dignidad in Santiago de Chile. In order to move towards an anthropological definition of the debris, we should ask ourselves, what is the debris after the protests and what place does it inhabit inside the city? What can it tell us and what accounts do these cracked and fissured remains contain, hide and destabilize? Why have they become a field of dispute, a field of forgetfulness, discomfort and fascination? Through the ethnographic and photographic records of post-revolt materialities, the analysis is organized into four dimensions: Skin and patina of the environmental memories; Ambivalence of form and destruction; Ghosts and fetish; Affections and topophilia in dystopia. It is concluded that whatever the ruined artifacts may be, they are always -like the residual materials they are- disorganizing and disconcerting the city, forcing it to reread and rewrite its significant forms. Herein may lie a secret fascination in the debris following the detonation of our city.

Resumen Este trabajo es un abordaje teórico y etnográfico sobre la ciudad derruida y los escombros dejados por el reciente estallido social en Plaza Dignidad de Santiago de Chile. Para avanzar hacia una definición antropológica de los escombros, queremos preguntarnos: ¿cuáles son los escombros del estallido y qué espacio ocupan al interior de la ciudad? ¿De qué nos hablan y qué historias contienen, esconden y desestabilizan esas pieles agrietadas y fisuradas? ¿Por qué razones ellas se transforman en campo de disputa, en campo de olvido, de incomodidad y de fascinación? A través del registro etnográfico y fotográfico de las materialidades de la revuelta, el análisis se organiza en torno a cuatro dimensiones: “Piel y pátina de las memorias envolventes”; “Ambivalencia de la forma y el destrozo”; “Fantasmas y fetiche”; “Afectos y topofilias en la distopía”. Se concluye que sean cuales sean los artefactos derruidos, ellos siempre -como las materialidades residuales que son- desordenan y desconciertan a nuestra ciudad, obligándola a releer y rescribir sus formas significadas. Allí reside posiblemente, la secreta fascinación de los escombros del estallido en Santiago.

Resumo: Testudinella é um táxon de Rotifera amplamente distribuído no Brasil. Em recentes coletas em lagos marginais conectados ao rio Paranapanema (São Paulo, Brasil), nós encontramos espécimes de Testudinella mucronata e T. patina com concavidades em suas lóricas. O objetivo do estudo foi descrever as concavidades observadas em indivíduos de ambas as espécies e discutir suas possíveis causas. Amostras de plâncton foram coletadas em duas estações de amostragem, na zona pelágica (PZ) e litorânea (LZ) dos lagos Panema e Coqueiral; ambos os lagos são ultra-oligotróficos e não poluídos. Para T. mucronata, 4% dos indivíduos com concavidades foram encontrados na PZ do lago Coqueiral e 50% na LZ do lago Panema. Em T. patina, a proporção de espécimes com concavidades correspondeu a 34% na LZ do lago Panema e 17% na PZ do lago Coqueiral. Nesse estudo, nós sugerimos que baixas temperaturas da água, eventos de predação e/ou recente eclosão são fatores que podem justificar as concavidades na lórica dos espécimes do nosso trabalho.

Abstract: Testudinella is a taxon of Rotifera broadly distributed in Brazil. In a recent collection in marginal lakes connected to the Paranapanema River (São Paulo, Brazil), we found specimens of Testudinella mucronata and T. patina with concavities on their lorica. The objective of this study was to describe the concavities observed in individuals of both species and discuss their possible causes. Plankton samples were collected at two sampling stations, in the pelagic (PZ) and littoral (LZ) zones of the Panema and Coqueiral lakes; both of these lakes are ultra-oligotrophic and not polluted. For T. mucronata, 4% of individuals with concavities were found in the PZ of Coqueiral lake and 50% in the LZ of Panema lake. In T. patina, the proportion of specimens with concavities corresponded to 34% in the LZ of Panema lake and 17% in PZ of Coqueiral lake. In this study, we discussed that low water temperatures, predation events and/or recent hatching are factors that may justify the concavities in the lorica of specimens of our work.

Abstract Las Papas ravine was silted by pyroclastic flows the last eruption of the Cerro Blanco Volcanic Complex (ca.4200 years BP), located in the Cordillera de San Buenaventura (4000 masl). Three sets of engraved rocks are located near the town of Las Papas at 2700 masl and about 20 km south of the focus of eruption. In 23 blocks were identified 184 images with broad domain of non-figurative motifs. Since they have both light and dark patinas, it was not possible to establish an exclusive partnership between one category of motif and a kind of patina. This work presents a first model of volumetric calculations to estimate the rate of incision depending on the erosion of pyroclastic material of Las Papas ravine over 4200 years. To do this, we articulate field work, analysis of satellite images, modeling and development of the contour lines of paleo-topography immediately after the eruption, and dating of a burial excavated in a terrace of Las Papas river. We evaluate when each block was available for visual intervention, depending on their spatial location and altitude to estimate a relative chronology for the engraved media. In this way it was possible to estimate a relative chronology for the engraved blocks and to establish that they were available for their visual intervention from 900-1000 B.C. In addition, the analysis of the differences of patina and the comparison with the regional register suggests that the production of the engravings was discontinuous in time and that a set of non-figurative images are the ancient ones.

Resumen La quebrada de Las Papas fue colmatada por flujos piroclásticos producto de la última erupción del Complejo Volcánico de Cerro Blanco (ca.4200 años AP) localizado en la Cordillera de San Buenaventura (4000 msnm). Cerca del pueblo de Las Papas se emplazan tres conjuntos de rocas grabadas a 2700 msnm y 20 km al sur del foco de la erupción. En los 23 bloques se identificaron 184 grabados fundamentalmente no-figurativos. Como presentan tanto pátinas claras como oscuras, no fue posible establecer una asociación exclusiva entre una categoría de motivo y un tipo de pátina. En este trabajo presentamos un primer modelo de cálculos volumétricos para estimar la tasa de incisión en función del desalojo del material piroclástico de la quebrada de Las Papas a lo largo de 4200 años, y estimar cuándo estuvieron los bloques disponibles para su intervención. Para ello, articulamos el registro de campo, el análisis de imágenes satelitales, el modelado y elaboración de una paleo-topografía de curvas de nivel del terreno inmediatamente después de la erupción y la datación de un entierro excavado en una terraza fluvial del río Las Papas. De esta manera, pudimos estimar una cronología relativa y establecer que las rocas soportes estuvieron disponibles para su intervención visual a partir del año 900-1000 a.C. Además, el análisis de las diferencias de pátina y la comparación con el registro rupestre regional sugiere que la producción de los grabados fue discontinua en el tiempo y que un conjunto de imágenes no figurativas son las más antiguas.

A aplicação de pátinas em objetos de prata, para produzir uma superfície de cor acinzentada a preta, é uma técnica de decoração frequentemente utilizada por ourives. A pátina é obtida por aplicação de uma solução, normalmente à base de compostos de enxofre, formando um revestimento constituído por compostos de prata e enxofre. Sendo estes compostos semelhantes aos produtos de corrosão atmosférica da prata, a conservação de objetos corroídos em prata com pátina levanta questões relacionadas com a incompatibilidade de tratamentos, resultantes da semelhança entre os compostos formados intencionalmente e os da corrosão atmosférica. Para definir tratamentos de conservação específicos, é fundamental caracterizar as superfícies com pátina e com pátina corroída. Neste estudo, amostras de prata sterling com pátina foram corroídas por imersão numa solução contendo sulfuretos. A caracterização das superfícies com pátina antes e após corrosão foi realizada por espectrofotometria de UV-Vis, difração de raios-X e por microscopia eletrónica de varrimento com espectrometria de raios-X dispersiva em energia. Os resultados revelaram que a corrosão das amostras de prata sterling com pátina compreende a dissolução da pátina seguida da formação de produtos de corrosão com composições e morfologias distintas contendo sulfuretos de prata e sulfuretos de cobre.

Patination has been frequently used by jewellers to modify the colour of silver alloys. By application of a solution of sulphur compounds, blackish or bluish surfaces can be obtained, but the intentionally produced silver-sulphur compounds are chemically similar to the atmospheric corrosion products that develop on silver alloys. The conservation of patinated silver objects, such as Art Nouveau jewellery, raises thus analytical challenges. In order to define accurate conservation treatments, the patina and corroded surfaces characterisation is mandatory. In this study, sterling silver samples were patinated and subjected to corrosion by immersion in a sulphide containing solution. The identification of the chemical compounds present on the patinated sterling silver before and after corrosion was carried out by UV-visible spectrophotometry, X-ray diffraction and scanning electron microscopy with energy dispersive X-ray spectrometry. Data obtained suggest a two-stage corrosion process: a decrease of the silver compounds patina thickness caused by its dissolution, followed by the formation of corrosion products with different compositions and morphologies containing silver and copper sulphur compounds.

In this paper we present new information on the paleoenvironmental context of southern Calchaquies Valleys, through the results of dating by varnish microlaminations over artifacts placed on the quarry-workshop of Ampajango (Catamarca province, Argentina). The obtained data points out two facts. Firstly, the existance of ten wet events, interspersed with arid events during the Holocene in the valley of Yocavil. Secondly, the difference of patina in one same device, which could be evidence of a reclamation process. This coupled with the existence of recycling and reuse in lithic artifacts, allows to consider the landscape as a mound, a natural and social construction at once.

En este artículo presentamos información novedosa sobre el marco paleoambiental del sur de los Valles Calchaquíes, a través de los resultados de las dataciones por microlaminaciones de barniz efectuadas sobre artefactos de la cantera-taller de Ampajango (provincia de Catamarca, Argentina). Los datos obtenidos señalan dos hechos. En primer lugar, la existencia de diez eventos húmedos, intercalados con eventos áridos durante el Holoceno en el valle de Yocavil. En segundo lugar, la diferencia de pátina en un mismo artefacto, lo cual podría ser evidencia de un proceso de reclamación. Esto sumado a la existencia de reciclaje y reutilización en artefactos líticos, permite considerar a este paisaje como un montículo, una construcción natural y social a la vez.

From a view of multiple types of knowledge for a blend in teacher education, the paper discusses the need for epistemological diversity in the types of knowledge for grade R teacher education. I claim in this article that for epistemological diversity, innovative mixes of knowledge are required and that they have to be explicated. The argument of the article is that the decisions made by teacher educators when constructing a curriculum for a new grade R qualification are especially challenging because of the narrow purpose of the qualification. The paper offers an analysis of various models of knowledge types and mixes, outlining each one's purpose. Finally, the paper provides an epistemological distillation in a conceptual framework which can guide the process of curriculum making, offering all participants a chance to contribute to the layers underneath the patina of the painting that offers life to the curriculum.

This contribution examines the seminal article titled The Idea of Patina and the Cleaning of Paintings, in which Paul Philippot both defined patina as a series of alterations affecting the work of art over time that produce irreversible, physicochemical changes, and, in turn, argued that cleaning, in any case, should not seek to restore the original state of the work of art, but rather to recognize this patina as evidence of its historical authenticity. After reviewing the text's background and its context of production, this paper discusses the concept of patina and its implications in the restoration process in order to conclude that the cleaning limits depend on a critical analysis: while science offers objective information about an artwork and its state of conservation, the restorer must interpret it at the time of the object's intervention, a process that cannot be fully objective since it greatly depends on the technical skill and experience of the specialist in charge of conservation-restoration decision-making.

Esta contribución analiza el texto seminal denominado La noción de pátina y la limpieza de las pinturas, en el cual Paul Philippot define la pátina como el conjunto de alteraciones que sufre la obra en el tiempo, cambios cuya naturaleza fisicoquímica los hace irreversibles; la limpieza, en todo caso, no debería procurar restituir su estado original, sino reconocer esta pátina como testimonio de la historicidad de la obra. Además de revisar sus antecedentes y contexto de producción, aquí se discute el propio concepto de la pátina y sus implicaciones en la práctica de la restauración. Con ello se concluye que los límites de la limpieza dependen de la visión crítica del restaurador; aunque la ciencia ofrece información objetiva de una obra y su estado de conservación, el restaurador debe interpretarla al momento de intervenir ésta, proceso que no puede ser por completo objetivo, pues depende en gran medida de la habilidad técnica y experiencia del especialista que toma la decisión.

Background: Urban surface stones in Mexico City are exposed to a temperate climate and a range of atmospheric conditions ranging from mildly impacted to heavily polluted areas. In this study, we focused on the characterization of the cultivable fungal component of selected biological patinas in the surrounding area of Chapultepec castle, a historic monument in Mexico City. Thirty four representative fungal isolates selected based on distinctive differential macroscopic characteristics out of a total of 300 fungi, were characterized using morphological and molecular approaches. Results: This identification strategy based on the combination of phenotypic- and molecular-based methodologies allowed us to discriminate the fungal community in some cases down to the species level. Conclusions: The characterization of this mycoflora revealed the presence of a complex fungal community mainly represented by filamentous fungi belonging to the genera Fusarium, Trichoderma, Aspergillus, Cladosporium, Alternaria, Mucor, Penicillium, Pestalotiopsis, and the dimorphic fungus Aureobasidium, along with the yeast Rhodotorula. A specific distribution of fungi could be observed based on the type of biological patina analyzed.

La Antigua Guatemala fue fundada como Santiago de Guatemala en 1524, después de que el conquistador Pedro de Alvarado entró en territorio guatemalteco y venció la resistencia de los quichés. Fue ubicada sobre la ciudad de Iximché y en 1527, luego de algunas sublevaciones, trasladada a las faldas del volcán Agua. Ese nuevo asentamiento fue destruido por una correntada que bajó del volcán en 1541 y su traslado al valle Panchoy se oficializó el 10 de marzo de 1543; ahí perduró hasta su destrucción en 1773. Permaneció en ruinas hasta cerca de 1860, cuando se introdujo el cultivo del café. Sus grandes monumentos transformados en ruinas se consolidaron, junto a la ciudad, como un conjunto enriquecido por la pátina del tiempo. Debido a esa unidad ha sido reconocida y hoy su valor radica en ser una ciudad viva, histórica y conservada. La ciudad ha sido motivo de estudios históricos, de su música, literatura, pintura y escultura, lo mismo que de su arquitectura. Sin embargo, su desarrollo edilicio y la tipología de su arquitectura no se han tratado de manera sistemática. Por interés personal y profesional he llegado a definir su evolución, del Renacimiento al Barroco, pasando por un breve período de transición.

La Antigua Guatemala was founded as "Santiago de Guatemala" in 1524 after the conqueror, Pedro de Alvarado, traveled to Guatemalan territory and overthrew the Quiché resistance. It was located at Iximché but, in 1527, after some uprisings, it was moved to the slopes of Volcano Agua. This new settlement was destroyed after a mudslide in 1541 and the city was moved to the Panchoy Valley officially on March 10, 1543 where it lasted until its destruction in 1773. It remained in ruins until around 1860, when coffee was introduced. The entire city and its monuments transformed into ruins over time and became a center enriched with the patina of time. Due to its historical importance that it is well known, today its importance also lies in that it is a city that is very much alive and preserved. The city has been a focal point of historical studies as well as studies in music, literature, paintings and sculpture and architecture. However, its architectural development and the architectural typology has not been studied systematically. For personal and professional interest, I have defined its evolution, from the Renaissance to Baroque, with a brief transitional period.

La Antigua Guatemala foi fundada com o nome de Santiago de Guatemala em 1524, depois que o conquistador Pedro de Alvarado entrou no território guatemalteco e superou a resistência dos indíginas Quiché. Foi sentada na cidade de Iximché e em 1527, depois de várias revoltas, foi transladada aos pés do vulcão de Agua. Este novo assentamento foi destruído por um grande deslizamento de agua e pedra que desceu desde a cratera do vulcão em 1541 e sua transferência para o Vale Panchoy, foi oficializada em 10 de março de 1543; permaneceu até sua destruição em 1773. Ela permaneceu em ruínas aproximadamente até 1860, quando se introduziu o cultivo do café. Seus grandes monumentos transformadas em ruínas se consolidaram, junto a cidade, como um conjunto enriquecido com a pátina do tempo. Devido a esta unidade ela foi reconhecida e hoje seu valor reside em ser uma cidade viva, histórica e preservada. A cidade tem sido motivo de estudos históricos, da sua música, literatura, pintura e escultura, bem como a sua arquitetura. No entanto, o seu desenvolvimento construtivo e a tipología da sua arquitetura não foi abordada de forma sistemática. Por interesse pessoal e profissional cheguei a definir a sua evolução, desde o Renascimento ao Barroco, passando por um breve período de transição.

A geoscientific study was accomplished to evaluate suitability for urban developments the in carboniferous basin of the Turbio River. This research included the characterization of natural resources: soil, water and landscape; the evaluation of natural and anthropic hazardous areas and the loss of farming and green lands. The implied area is located in the SW end of the Province of Santa Cruz. It is part of the carboniferous basin of the River Turbio. The towns of Rio Turbio and 28 de Noviembre hold the most numerous populations. These two locations developed from mining and cattle breeding activities. Taking into account geological, geomorphological, biotic, geotechnical, hydrological and soil features, eight (8) Landscape Units were identified and, resultant from the information produced, a Map of Aptitude for the urbanization of the area was produced as a basic input for the urban development plan. The landscape units found to have better possibilities for urban expansion are two: Moraine with herbaceous steppe and glacifluvial plains with mixed steppe. The erosive glacier with forests and fluvial terraces have acceptable conditions for urbanization, while the valley borders, canyons and alluvio-colluvial slopes, polygenetic Tertiary hills and mallines (humid meadows) and Lowlands are, for several reasons, units inappropriate for urbanization.

En el presente trabajo, se investiga el desarrollo de costras y pátinas encontradas en algunas obras provenientes de sectores urbanos y otras de áreas naturales. En el primer caso se seleccionaron monumentos funerarios del cementerio de la Recoleta y el palacio del Congreso Nacional, en tanto que en el segundo el sector de Los Pizarrones en el Parque Nacional Talampaya. Para los estudios, se emplearon técnicas de microscopia óptica, difracción de rayos X y microscopia electrónica con análisis por microsonda. Los monumentos pertenecientes al ámbito de la Recoleta seleccionados para este trabajo, corresponden a Nicolás Avellaneda, Olivera de Pignetto y Luis María Campos. Las diferencias encontradas entre los monumentos radica en las condiciones de exposición (intemperie o resguardada) a las que contribuyen acciones biológicas, antropogénicas y de polución ambiental. De manera similar, el palacio del Congreso Nacional ubicado en el sector céntrico de la ciudad también revela que la caliza de sus fachadas, desarrolla costras como en los monumentos de Recoleta aunque con alguna variación de su composición mineral. La acción biológica se manifiesta en los contenidos encontrados de P, S y Si. El ejemplo de Los Pizarrones como área natural muestra el desarrollo de una pátina con importante acción biológica, pero sin la detección de elementos metálicos propios de zonas urbanas. De lo expuesto, se concluye que las alteraciones superficiales de las rocas obedecen a factores que dependen de su ubicación urbana o natural, de la acción biológica y la actividad antrópica en diferentes manifestaciones.