416 research outputs found
A brief overview on the evolution of drawing machines
Through the pictorial narratives engraved on the walls of the caves during prehistory, we are sure that Humans used drawing to express feelings and communicate, long before inventing writing. In the same way that utensils were used to help him, he also used several utensils to draw.
In the middle of the twentieth century, with all the technological evolution, we saw machines that helped artists in drawing and others that are extensions of the artist.
In a project seeking the development of a robotic system capable of drawing autonomously we were faced with the question for how long artists have used drawing machines for their aid or even their extension? In this work, we present a collection of artworks that demonstrates the use of drawing machines throughout history in the last 500 years and how they are being adapted and reinvented according to the most current and also developing technology. At present there is a vast field of experimentation of these machines with Interfaces and Sensors and Intelligent Human-Computer Interaction.(undefined
Statistically robust representation and comparison of mortality profiles in archaeozoology
Archaeozoological mortality profiles have been used to infer site-specific subsistence strategies. There is however no common agreement on the best way to present these profiles and confidence intervals around age class proportions. In order to deal with these issues, we propose the use of the Dirichlet distribution and present a new approach to perform age-at-death multivariate graphical comparisons. We demonstrate the efficiency of this approach using domestic sheep/goat dental remains from 10 Cardial sites (Early Neolithic) located in South France and the Iberian Peninsula. We show that the Dirichlet distribution in age-at-death analysis can be used: (i) to generate Bayesian credible intervals around each age class of a mortality profile, even when not all age classes are observed; and (ii) to create 95% kernel density contours around each age-at-death frequency distribution when multiple sites are compared using correspondence analysis. The statistical procedure we present is applicable to the analysis of any categorical count data and particularly well-suited to archaeological data (e.g. potsherds, arrow heads) where sample sizes are typically small
Cell patterning using a dielectrophoreticâhydrodynamic trap
The paper presents a dielectrophoretic method for cell patterning using dielectrophoreticâhydrodynamic trap. A distinctive characteristic of the device is that the dielectrophoretic (DEP) force is generated using a structure that combines conventional electrode-based DEP (eDEP) with insulator-based DEP method (iDEP). The conventional eDEP force is generated across the microfluidic channel between a top plate indium tin oxide electrode and a thin CrAu electrode. Meantime, an isolating cage built from SU8 photoresist around the thin electrode modifies the electric field generating an iDEP force. The cells that are flowing through a microfluidic channel are trapped in the SU8 cage by the total DEP force. As a result, according to the cell dimension and the thickness of the SU8 layer, different cell patterns can be achieved. If the cellâs size is sensitively smaller than the dimensions of the hydrodynamic trap, due to the dipoleâdipole interaction, the cell can be organized in 3D structures. The trapping method can be used for conducting genetic, biochemical or physiological studies on cells
Statistically robust representation and comparison of mortality profiles in archaeozoology
Archaeozoological mortality profiles have been used to infer site-specific subsistence strategies. There is however no common agreement on the best way to present these profiles and confidence intervals around age class proportions. In order to deal with these issues, we propose the use of the Dirichlet distribution and present a new approach to perform age-at-death multivariate graphical comparisons. We demonstrate the efficiency of this approach using domestic sheep/goat dental remains from 10 Cardial sites (Early Neolithic) located in South France and the Iberian Peninsula. We show that the Dirichlet distribution in age-at-death analysis can be used: (i) to generate Bayesian credible intervals around each age class of a mortality profile, even when not all age classes are observed; and (ii) to create 95% kernel density contours around each age-at-death frequency distribution when multiple sites are compared using correspondence analysis. The statistical procedure we present is applicable to the analysis of any categorical count data and particularly well-suited to archaeological data (e.g. potsherds, arrow heads) where sample sizes are typically small
Animal Board Invited Review: Sheep birth distribution in past herds: a review for prehistoric Europe (6th to 3rd millennia BC)
In temperate latitudes sheep have a seasonal reproductive behaviour, which imposes strong constraints on husbandry in terms of work organization and availability of animal products. During the last 50 years, researchers have focused on understanding the mechanisms driving small ruminantsâ reproduction cycles and finding ways to control them. This characteristic is inherited from their wild ancestor. However, the history of its evolution over the 10 millennia that separates present day European sheep from their Near Eastern ancestorsâ remains to be written. This perspective echoes archaeologistsâ current attempts at reconstructing ancient pastoral societiesâ socio-economical organization. Information related to birth seasonality may be retrieved directly from archaeological sheep teeth. The methodology consists of reconstructing the seasonal cycle record in sheep molars, through sequential analysis of the stable oxygen isotope composition (δ 18O) of enamel. Because the timing of tooth development is fixed within a species, inter-individual variability in this parameter reflects birth seasonality. A review of the data obtained from 10 European archaeological sites dated from the 6th to the 3rd millennia BC is provided. The results demonstrate a restricted breeding season for sheep: births occurred over a period of 3 to 4 months, from late winter to early summer at latitudes 43°N to 48°N, while a later onset was observed at a higher latitude (59°N). All conclusions concurred with currently held expectations based on present day sheep physiology, which, aside from the historical significance, contributes to the reinforcing of the methodological basis of the approach. Further study in this area will permit regional variability attributable to technical choices, within global schemes, to be fully reported
Protocol for recording enamel hypoplasia in modern and archaeological caprine populations
This paper outlines the first methodology for recording dental enamel hypoplasia in the high-crowned dentition of modern and archaeological caprine teeth. The method has been developed and trialed on five caprine populations from Orkney (UK); two modern populations (Shetland and North Ronaldsay breeds) and three Neolithic assemblages from the archaeological sites of Knap of Howar, Skara Brae and Holm of Papa Westray. Problems associated with differential tooth wear, as well as the presence of coronal cementum, are discussed, and recommendations are given on the identification and recording of hypoplastic dental defects in caprines
Durrington Walls to West Amesbury by way of Stonehenge: a major transformation of the Holocene landscape
A new sequence of Holocene landscape change has been discovered through an investigation of sediment sequences, palaeosols, pollen and molluscan data discovered during the Stonehenge Riverside Project. The early post-glacial vegetational succession in the Avon valley at Durrington Walls was apparently slow and partial, with intermittent woodland modification and the opening-up of this landscape in the later Mesolithic and earlier Neolithic, though a strong element of pine lingered into the third millennium BC. There appears to have been a major hiatus around 2900 cal BC, coincident with the beginnings of demonstrable human activities at Durrington Walls, but slightly after activity started at Stonehenge. This was reflected in episodic increases in channel sedimentation and tree and shrub clearance, leading to a more open downland, with greater indications of anthropogenic activity, and an increasingly wet floodplain with sedges and alder along the riverâs edge. Nonetheless, a localized woodland cover remained in the vicinity of DurringtonWalls throughout the third and second millennia BC, perhaps on the higher parts of the downs, while stable grassland, with rendzina soils, predominated on the downland slopes, and alderâhazel carr woodland and sedges continued to fringe the wet floodplain. This evidence is strongly indicative of a stable and managed landscape in Neolithic and Bronze Age times. It is not until c 800â500 cal BC that this landscape was completely cleared, except for the marshy-sedge fringe of the floodplain, and that colluvial sedimentation began in earnest associated with increased arable agriculture, a situation that continued through Roman and historic times
Sedimentary DNA from a submerged site reveals wheat in the British Isles 8000 years ago
YesThe Mesolithic-to-Neolithic transition marked the time when a hunter-gatherer economy gave way to agriculture, coinciding with rising sea levels. Bouldnor Cliff, is a submarine archaeological site off the Isle of Wight in the United Kingdom that has a well-preserved Mesolithic paleosol dated to 8000 years before the present. We analyzed a core obtained from sealed sediments, combining evidence from microgeomorphology and microfossils with sedimentary ancient DNA (sedaDNA) analyses to reconstruct floral and faunal changes during the occupation of this site, before it was submerged. In agreement with palynological analyses, the sedaDNA sequences suggest a mixed habitat of oak forest and herbaceous plants. However, they also provide evidence of wheat 2000 years earlier than mainland Britain and 400 years earlier than proximate European sites. These results suggest that sophisticated social networks linked the Neolithic front in southern Europe to the Mesolithic peoples of northern Europe
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