52 research outputs found
Melka Kunture (alto Awash, EtiopÃa) entre 2.000.000 y 5.000 años
Melka Kunture es un clúster de yacimientos prehistóricos situados en el altiplano etÃope, a 2.000-2.200 m sobre el nivel del mar, en la cuenca alta del rÃo Awash. El clima es más bien fresco (temperatura media anual de 17° C) y lluvioso. Los resultados palinológicos demuestran que la vegetación durante el Pleistoceno era de tipo afromontano y, por lo tanto, diferente a la de sabana que se desarrolla en cotas más bajas. Tras casi 60 años de excavaciones en 20 yacimientos y en unos 60 niveles arqueológicos distintos, la secuencia arqueológica identificada incluye el Olduvayense, Achelense, Middle Stone Age y Late Stone Age. También se han descubierto fósiles de homininos en asociación directa con industrias lÃticas de diferentes tecnocomplejos. Además, se conocen niveles icnológicos, que proporcionan información sobre la vida y el comportamiento de homininos y fauna. La investigación sobre la adaptación de los homininos al clima y al entorno de las tierras altas es relevante para entender cómo y cuándo se produjo el primer poblamiento de Europa
Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study
BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P < 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P < 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223
Understanding hunter-gatherers behaviour through the macro-fractures analysis of lithic backed points
La aplicació d'una metodologia sòlida és premissa fonamental per obtenir informació fiable en cada investigació cientÃfica, i particularment en arqueologia prehistòrica, on fà cilment es cometen errors en nivell interpretatiu.
L'objectiu principal d'aquest treball és comprendre la tasca dels caçadors-recol·lectors després l'Últim Mà xim Glacial i durant el Tardìoglacial en una à rea determinada a través de l'anà lisi funcional dels materials lÃtics arqueològics per tal d'aportar una primera presa de contacte a el paper que van desenvolupar els jaciments en un perÃode de canvis climà tics i mediambientals rà pids. Els jaciments de cultura Epigravettiana de Grotta di Pozzo al centre d'Ità lia i Riparo Villabruna al nord han investigat en profunditat des de la perspectiva lÃtica per identificar possibles puntes de projectil utilitzades durant activitats de caça. Això ofereix una informació detallada sobre tecnologies d'empunyadura i tècniques de caça, brindant un ampli marc dels coneixements i les habilitats prà ctiques de la població.
El projecte de recerca introdueix aspectes únics que mai abans havien estat investigats en els jaciments prèviament esmentats. L'adopció sistemà tica de l'arqueologia experimental és innovadora, i s'han provat aspectes especÃfics i majorità riament desconeguts sobre l'ús d'eines lÃtiques.
Les dades provinents de l'à mplia literatura i els resultats inesperats es creuen per comprendre les estratègies de caça, el comportament, els desplaçaments, els assentaments estacionals i la possible interrelació entre grups humans en aquesta gran à rea de centre-nord d'Ità lia a la fi de l'Plistocè.La aplicatión de una metodologÃa sólida es premisa fundamental para obtener información fiable en cada investigación cientÃfica, y particularmente en arqueologÃa prehistórica, donde fácilmente se cometen errores a nivel interpretativo.
El objetivo principal de este trabajo es comprender la labor de los cazadores-recolectores tras el Último Máximo Glacial y durante el Tardìoglacial en un área determinada a través del análisis funcional de los materiales lÃticos arqueológicos con el fin de aportar una primera mirada al papel que jugaron los yacimientos en un perÃodo de rápidos cambios climáticos y medioambientales. Los yacimientos de cultura Epigravettiana de Grotta di Pozzo en el centro de Italia y Riparo Villabruna al norte han investigado en profundidad desde la perspectiva lÃtica para identificar posibles puntas de proyectil utilizadas durante actividades de caza. Esto ofrece una detallada información sobre tecnologÃas de empuñadura y técnicas de caza, brindando un amplio marco de conocimientos y habilidades prácticas de la población.
El proyecto de investigación introduce aspectos únicos que nunca antes han sido investigados para los yacimientos mencionados. La adopción sistemática de la arqueologÃa experimental es innovadora, y se han probado aspectos especÃficos y en su mayorÃa desconocidos sobre el uso de herramientas lÃticas.
Los datos provenientes de la amplia literatura y los resultados inesperados se cruzan para comprender las estrategias de caza, el comportamiento, los desplazamientos, los asentamientos estacionales y la posible interrelación entre grupos humanos en esta gran área del centro-norte de Italia a finales del Pleistoceno.The application of a robust methodology is a fundamental precondition to get reliable information in every scientific investigation, in particular in prehistoric archaeology where it is easy to make mistakes on the interpretation level.
The main goal of this work is to understand the role of the hunter-gatherers after the Last Glacial Maximum and during the Late Glacial in a given area, through the functional analysis of the archaeological lithic materials, in order to give a glimpse of the function of the sites in a period of rapid climate and environmental changes. The Epigravettian sites of Grotta di Pozzo in the Central Italy and Riparo Villabruna in the North Italy have been investigated on the lithic point of view, as to individuate possible projectile points used during hunting activity. This contribution offers detailed information about hafting technologies and hunting techniques, giving a wide framework of knowledge and practical skills of the inhabitants.
The research project introduces unique aspects that have never been investigated before for the considered sites. The systematic adoption of the experimental archaeology is innovative, and there have been tested specific and mostly unknown aspects about the use of lithic tools.
The data coming from the large literature and the unexpected results are crossed together as to understand the hunting strategies, the behaviour, the movements, the seasonal settlements and the possible connection between human groups in this large area of North-Central Italy at the end of Pleistocene
Stone projectiles at Grotta di Pozzo (Italy). Results of a macro-fractures analysis
peer reviewedGrotta di Pozzo is a small cave at 720 m asl and 42â—¦ N in the Apennine range of Abruzzo (Central Italy), formerly opening on the edge of a now drained large lake, the Lake Fucino. The archaeological sequence starts on the top of a fluvial-lacustrine deposit at 23,000 cal. BP, with layers including lithic industry of the Early Epigravettian. Later on, from 15,500 cal. BP and up to 14,000 cal. BP, the lithics belong to the Final Epigravettian. Previous zooarchaeological analysis provided evidence of the seasonal hunting of chamois, followed by ibex and red deer, as well as marmot and black grouse, while trout eventually became another important food resource. Here we analyse the lithic industry in order to identify the projectile points using analysis under the microscope coupled with access to a reference collection and with experimental training. We conclude that microlithic backed tools were definitely projectile points, as widely assumed in the case of the Epigravettian but rarely confirmed by focused investigation. Furthermore, use-wears due to hafting suggest that after the Last Glacial Maximum the hunting gear possibly included complex weapons in the mountain environment of the Central Apennine
Finding a standard procedure in impact-fractures analysis: the case of Grotta di Pozzo (L’Aquila – Italy)
A hunter-gatherer in the North of Italy: impact fracture analysis of the lithic materials from Riparo Villabruna (Belluno, Italy)
Testing backed lithic points as perforators to create ornaments. Experimentation results and new possible use from Riparo Villabruna (Belluno -Italy)
editorial reviewe
Close the circle: backed lithic points used as perforators? New results and perspective of research from Riparo Villabruna (Belluno – Italy)
peer reviewe
Mid-Holocene Adaptation to the highland of Ethiopia: the case of Beefa Cave, Middle Awash
Projectile points vs tools for dental treatment? From the impact fracture analysis to a new perspective of research: the case of Riparo Villabruna (Belluno – Italy)
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