Taking measures using digital photographs: An experimental review of existing procedures, possible error sources, replicability of the method and potential uses

El uso de medios digitales para el análisis arqueológico está a la orden del día. Un ejemplo es el uso de fotografías digitales para la obtención de medidas en diferentes objetos. Se presenta aquí un repaso al procedimiento de medida de filos en lascas publicado por Eren et al., (2008), una experiencia de reproductividad del método, y una ampliación experimental de sus potenciales usos para el análisis de industria lítica. Los resultados muestran que se trata de un procedimiento relativamente rápido, accesible con una mínima inversión en software y hardware, y con una alta fiabilidad en la obtención de datosThe use of digital resources for archaeological analysis is at the order of the day. Digital photographs constitute a good example of haw precise measures can be obtained. A review of Eren’s et al., (2008) procedure for measuring edge length is provided along with an experience of data replicability, and an experimental extension of possible applications for the analysis of lithic industry. Results show that the procedure provides reliable and precise data with a low investment of hardware, software and tim

Multiple approaches to predicting flake mass

Predicting original flake mass is a major goal of lithic analysis. Predicting original flake mass allows for researchers to make estimations of remaining mass, lost mass, and other features. All these measures relate to the organization of lithic technology by past societies. The present work tests three different models to predict log of flake mass: multiple linear regression, random forest regression, and artificial neural networks (ANN). Estimations of flake mass were performed using the remaining features of flakes from an experimental assemblage. This assemblage was obtained by the expansion of a previous dataset through the inclusion of bigger flakes, allowing the analysis to account for the effects of sample size and value distribution. Correlation results show a large/ strong relation between predictions and real outcome (r 2 = 0.78 in the best case). Comparison of the models affords insights into variable importance for predicting flake mass. Results show that (for the present dataset) multiple linear regression still stands as the best method for predicting log of flake weight. Additionally, transformation of predicted values from the multiple linear regression and true values to the linear scale reinforces the linear correlation above the 0.8 threshold. This article is the result of the research projects “Como, Quien Y Donde?: Variabilidad De Comportamientos En La Captacion ´ Y Transformacion ´ De Los Recursos Liticos Dentro De Grupos Neandertales 2” (HAR2016-76760-C3-2-P) financed by Agencia Estatal de Investigacion ´ (AEI), Fondo Europeo de Desarrollo Regional (FEDER); and “En Los Limites De La Diversidad: Comportamiento Neandertal En El Centro Y Sur De La Penisula Iberica” (ID2019- 103987 GB-C33) financed by the Programa Estatal de Generacion ´ de Conocimiento y Fortalecimiento Científico y Tecnologico ´ del Sistema de I + D + i y de I + D + i Orientada a los Retos de la Sociedad, del Plan Estatal de Investigacion ´ Científica y T´ecnica y de Innovacion ´ (2017–2020). Development of the experimentation and analysis of the materials were undertaken at the Laboratory of Experimental Archaeology (Universidad Autonoma ´ de Madrid). This work has been carried out with the financial support of the Generalitat de Catalunya, AGAUR agency (2017SGR1040 Research Group), the Universitat Rovira i Virgili (2021PFR-URV-126), and the Spanish Ministry of Science and Innovation (MICINN/FEDER project PID2021-122355NB-C32).The Institut Catala ` de Paleoecologia Humana i Evolucio ´ Social (IPHES-CERCA) has received financial support from the Spanish Ministry of Science and Innovation through the “María de Maeztu” program for Units of Excellence (CEX2019-000945-M

Combining quantitative approaches to differentiate between backed products from discoidal and Levallois reduction sequences

Backed flakes (core edge flakes and pseudo-Levallois points) represent special products of Middle Paleolithic centripetal flaking strategies. Their peculiarities are due to their roles as both a technological objective and in the management of core convexities to retain its geometric properties during reduction. In Middle Paleolithic contexts, these backed implements are commonly produced during Levallois and discoidal reduction sequences. Backed products from Levallois and discoidal reduction sequences often show common geometric and morphological features that complicate their attribution to one of these methods. This study examines the identification of experimentally produced discoidal and recurrent centripetal Levallois backed products (including all stages of reduction) based on their morphological features. 3D geometric morphometrics are employed to quantify morphological variability among the experimental sample. Dimensionality reduction though principal component analysis is combined with 11 machine learning models for the identification of knapping methods. A supported vector machine with polynomial kernel has been identified as the best model (with a general accuracy of 0.76 and an area under the curve [AUC] of 0.8). This indicates that combining geometric morphometrics, principal component analysis, and machine learning models succeeds in capturing the morphological differences of backed products according to the knapping methodThis research has been supported by the project SI1/PJI/2019-00488 funded by Comunidad Autonoma de Madrid and Universidad Autonoma de Madrid. FR research studies are also supported by the project ID2019-103987GBC33 funded by the Spanish Ministry of Science and Innovatio

Agarrar o no agarrar: Una aproximación experimental para comprender el uso de áreas prensiles en útiles Musterienses

The existence of a more or less complex handling technology with the lithic tools during the Lower and Middle Paleolithic is an interesting topic for understanding aspects of the human behavior during these periods. In this work we present a preliminary experimental evaluation of the possible functionality of prehensile area in some of the most representative lithic types of the Mousterian assemblages (dorsal elements and levallois chapeau de gendarme proximal area), in which the morphological comparative analysis of imprints and prehensile tool areas, is compared by 3D analysis procedures. Preliminary results indicate that there is a close relationship between the digital grasp morphologie and the prehensile area of some Mousterian techno-types. We also discussed the relevance and significance of these provisional conclusions in the context of hunter gather communitiesLa existencia de una tecnología más o menos compleja en el manejo de los útiles líticos durante el Paleolítico Inferior y Medio es una clave interesante para conocer, en todas sus facetas, a los grupos humanos de estos periodos. En este trabajos presentamos una evaluación experimental de carácter preliminar sobre el posible funcionamiento de las áreas prensiles de algunos de los tipos líticos más representativos de los conjuntos musterienses (elementos de dorso y talones Levallois de chapeau de gendarme) en la que el análisis morfológico de improntas en masillas y en útiles líticos se compara mediante procedimientos de análisis 3D. Los resultados preliminares indican que existe una estrecha relación entre las morfologías de prensión digital y las áreas prensiles de algunos tecno-tipos musterienses. Igualmente discutimos qué significado pueden tener estas conclusiones provisionale

Preliminary experimental insights into differential heat impact among lithic artifacts

The presence of thermally altered and broken flint artifacts is common at archaeological sites. Most studies focus their attention on the effects of heat treatment on flint to improve knapping qualities, disregarding the effects of fire over flint under uncontrolled conditions. This paper aims to show how under uncontrolled heating processes flint artifacts develop different heat alterations (such as levels of breakage, presence of scales, etc.) as a result of vertical distribution, volume or raw material and to establish a gradient of rock changes and behavior. Artifacts where macroscopically analyzed and a series of uncontrolled heating experiments through the distribution of flint blanks under two hearths were carried out, allowing a comparison of the before and after of the blanks. Preliminary results show how levels of breakage, surface alteration or development of heat alteration features can be differentiated according to artifact volume, vertical distribution and level of surface alteration. Results also show how two different raw materials react differently to similar thermal impact, and how surface alteration reacts at different rhythm in the case of recycled artifacts. We conclude that levels of thermal alteration can be differentiated through macroscopic analysis of flint surface

What lies in between: Levallois, discoid and intermediate methods

Lithic artefacts are usually associated with the different knapping methods used in their production. Flakes exhibit metric and technological features representative of the flaking method used to detach them. However, lithic production is a dynamic process in which discrete methods can be blurred, and in which features can vary throughout the process. An intermediate knapping method between the discoid and Levallois is commonly referred to under an umbrella of terms (the present research uses the term hierarchical discoid), and is associated with a broad geographical and chronological distribution throughout the Early and Middle Palaeolithic. This intermediate knapping strategy exhibits features of both the discoid and Levallois knapping methods, raising the question of the extent to which flakes from the three knapping methods can be differentiated and, when one is mistaken for another, the direction of confusion. An experimental assemblage of flakes detached by means of the three methods was used along with an attribute analysis and machine learning models in an effort to identify the knapping methods employed. In general, our results were able to very effectively differentiate between the three knapping methods when a support vector machine with polynomial kernel was used. Our results also underscored the singularity of flakes detached by means of Levallois reduction sequences, which yielded outstanding identification values, and were rarely erroneously attributed to either of the other two knapping methods studied. Mistaking the products of the discoid and hierarchical discoid methods was the most common direction of confusion, although a good identification value was achieved for discoid flakes and an acceptable value for hierarchical discoid flakes. This shows the potential applicability of machine learning models in combination with attribute analysis for the identification of these knapping methods among flakes

Experimental study on flint hammerstone use in Discoid-Levallois technologies: A comparison with the workshop assemblages of the central Iberian Peninsula

The basins of the Manzanares and Jarama rivers have been connected to human activity since the early Palaeolithic. At the boundary between these rivers the abundance of flint has given place to exploitation and mining activities even in historical times. In recent years, projects related to urban expansion in the southeast of Madrid have brought to light various Palaeolithic deposits associated with workshops and tool production. These sites do not have evidence of river pebbles of quartzite, quartz or sandstone in the immediate environment that could have been used as hammerstones, meaning that hammerstones in these raw materials had to be transported and introduced into the sites from large distances. Given this situation, attention was paid to flint elements that show clear signs of being used as hammerstones. The aim of this study is to test the effectiveness of flint as hammerstone, testing whether the use of this raw material is indifferent to other rock types or if you have limitations or advantages in this regard. An experimental protocol was developed, allowing to observe specific knapping behaviours and justifying them in the archaeological and technological context in which they are located.Las cuencas del Manzanares y el Jarama, se han relacionado con actividad humana desde los inicios del Paleolítico. Nuestra área de estudio se encuentra situada en la Plataforma divisoria entre dichos ríos. El sílex, muy abundante en dicha área fue empleado por los distintos grupos humanos recurrentemente, incluso en tiempos históricos. En los últimos años, los distintos proyectos de ampliación urbana del sureste de la ciudad de Madrid han sacado a la luz diversos yacimientos asociados a talleres de producción de herramientas. El sílex juega un papel fundamental en esta área. En estos yacimientos no tenemos evidencias de cantos de río en cuarcita, cuarzo o arenisca en el entorno inmediato que sean susceptibles de ser empleados como percutores. No obstante, sí aparecen percutores en estas materias primas que son claramente aportados a los yacimientos desde mayores distancias. Dada esta situación, llaman especialmente la atención los elementos en sílex que presentan claras huellas de haber sido empleados en la percusión.La existencia de éste tipo de percutores nos puede mostrar dos concepciones distintas: por un lado, un uso inmediato de la materia prima más cercana y por otro el reciclaje de elementos previamente desechados o agotados. También es probable un doble uso de una misma herramienta, como es el caso de los bifaces y percutores.El planteamiento principal, en este caso de estudio, era comprobar la eficacia del sílex como percutor. Por medio de la experimentación, podemos comprobar si el empleo de esta materia prima resulta indiferente con respecto a otros tipos de rocas o si presenta dificultades o ventajas en este sentido. Para alcanzar dicho objetivo se ha planteado un programa experimental específico. Con esta experimentación tratamos de observar comportamientos concretos de los talladores y justificarlos enmarcándolos dentro del contexto en el que se encuentran

La ciudad de La Plata en el contexto del COVID-19: desafíos y oportunidades a un modelo de ordenamiento territorial y gestión sustentable

Se trata de una reflexion realizada en el marco del proyecto de investigacion titulado“Problemas y conflictos ambientales. Aportes para su mitigación desde la Planificación y Gestión ambiental en el partido de La Plata. (2000-2020)”, radicado en el Centro de Investigaciones Geograficas, donde se expresan los desafios y las oportunidades a un modelo de Ordenamiento territorial y gestion sustentable en laciudad de La Plata en el contexto del COVID-19

Aurora A drives early signalling and vesicle dynamics during T-cell activation

Aurora A is a serine/threonine kinase that contributes to the progression of mitosis by inducing microtubule nucleation. Here we have identified an unexpected role for Aurora A kinase in antigen-driven T-cell activation. We find that Aurora A is phosphorylated at the immunological synapse (IS) during TCR-driven cell contact. Inhibition of Aurora A with pharmacological agents or genetic deletion in human or mouse T cells severely disrupts the dynamics of microtubules and CD3z-bearing vesicles at the IS. The absence of Aurora A activity also impairs the activation of early signalling molecules downstream of the TCR and the expression of IL-2, CD25 and CD69. Aurora A inhibition causes delocalized clustering of Lck at the IS and decreases phosphorylation levels of tyrosine kinase Lck, thus indicating Aurora A is required for maintaining Lck active. These findings implicate Aurora A in the propagation of the TCR activation signal.We thank S. Bartlett for English editing and critical reading of the manuscript, Dr A. Akhmanova for providing reagents, Maria Navarro for the her critical reading of the manuscript and scientific recommendations, Miguel Vicente-Manzanares for his critical reading of the manuscript, and Aitana Sanguino and Maria Jose Lopez for the technical support. We also thank the Confocal Microscopy \& Dynamic Imaging Unit (CNIC), Madrid, Spain. This study was supported by grants SAF2011-25834, SAF2014-55579-R and BIO2012-37926 from the Spanish Ministry of Economy and Competitiveness, INDISNET-S2011/BMD-2332 from the Comunidad de Madrid ERC-2011-AdG 294340-GENTRIS and ERC-2013-AdG 334763-NOVARIPP. Red Cardiovascular RD 12-0042-0056 from Instituto Salud Carlos III (ISCIII). The Centro Nacional de Investigaciones Cardiovasculares (CNIC, Spain) is supported by the Spanish Ministry of Science and Innovation, and the Pro-CNIC Foundation.S

Crónicas de Jurisprudencia. Derechos Fundamentales y Libertades Púlbicas

Crónica de la jurisprudencia sobre derechos y libertades de los siguientes tribunales: Tribunal Europeo de Derechos Humanos, Tribunal de Justicia de la Unión Europea, Tribunal Constitucional, Tribunal SupremoFUNDACIÓ BOSCH I GIMPERA y Editorial Aranzadi (Thomson Reuters)2020-2