Prehistoric Exploitation of Marine Resources in Southern Africa with Particular Reference to Shellfish Gathering: Opportunities and Continuities.

Este artículo se centra en la discusión de tres casos de estudio en los cuales los recursos marinos desempeñaron un rol importante en el desarrollo humano del sur de África desde hace 164 ka. La capacidad de los humanos modernos de emigrar fuera de África se ve, en parte, como una expansión en la capacidad de forrajeo inicialmente expresada en el litoral rocoso para incluir más tarde las costas de playas de arena. La selección de un hábitat cercano a la costa, donde se congregaban grupos diversos dentro de un marco de bajas densidades poblacionales inmediatamente después de la última glaciación, permitió que esos grupos pudieran cumplir con sus necesidades sociales básicas y así asegurar la supervivencia de la población. Del mismo modo, durante el Holoceno observamos un consumo significativamente alto de recursos marinos como consecuencia del considerable incremento demográfico de los grupos humanos. Otros temas relacionados y un poco más generales son igualmente discutidos.This paper discusses three case studies in which marine resources played an important role in human development in southern Africa over the last 164 ka: the ability of modern humans to exit successfully from Africa is seen partly as the result of a foraging expansion from rocky shores to sandy beaches; the location of an aggregation site close to the coast in the context of low human densities during post-glacial times allowed people to meet social needs and ensure population survival; and a heavy reliance on marine resources supported highest populations levels during the late Holocene. Broader and related issues are also discussed.Este artículo se centra en la discusión de tres casos de estudio en los cuales los recursos marinos desempeñaron un rol importante en el desarrollo humano del sur de África desde hace 164 ka. La capacidad de los humanos modernos de emigrar fuera de África se ve, en parte, como una expansión en la capacidad de forrajeo inicialmente expresada en el litoral rocoso para incluir más tarde las costas de playas de arena. La selección de un hábitat cercano a la costa, donde se congregaban grupos diversos dentro de un marco de bajas densidades poblacionales inmediatamente después de la última glaciación, permitió que esos grupos pudieran cumplir con sus necesidades sociales básicas y así asegurar la supervivencia de la población. Del mismo modo, durante el Holoceno observamos un consumo significativamente alto de recursos marinos como consecuencia del considerable incremento demográfico de los grupos humanos. Otros temas relacionados y un poco más generales son igualmente discutidos

Datos ecológicos de las arañas epigeas en dos bosques de la región mediterránea

A study on the epigean spiders from two managed forests of pine (Pinus pinea L.) and black poplar (Populus nigra L.) was made, differentiating the areas within each forest and during an annual period and analysing space and temporal perspectives. Each forest is characterised by a number of spider species, grounded on their activity. It is cloncluded that each of these areas possesses special characteristics and is defined as a particular microambient, that the spiders hold a differential temporal distribution and that the spider composition of pine and black poplar forests is clearly different, being poorer in the latter. These results are discussed as to their possible origin from the different human intewentions in the forests.Se estudia la composición araneonológica epigea de dos ecosistemas de la región mediterránea, intewenidos por el hombre: un pinar (Pinus pinea L.) y una chopera (Populus nigra L.), con diferenciación de áreas dentro de cada bosque y durante un periodo anual, analizándose bajo las perspectivas espacial y temporal. Los bosques y áreas estudiados se caracterizan por un número de especies teniendo en cuenta su actividad. Se concluye que cada Brea posee caracteristicas especificas que las definen como microambientes particulares; que las arañas presentan una distribución temporal diferencial; y que la composición araneológica de pinares y choperas es claramente distinta, siendo mas pobre en estos últimos bosques. Se discuten estos resultados como posible reflejo de la diferente intevención antrópica a la que se ven sometidos

A bridge for two views: Checkland’s soft systems methodology and Maturana’s ontology of the observer

© 2019, © Operational Research Society 2019. Checkland and Maturana’s work aim to understand and to improve problematic situations in organisations and in our everyday life. Maturana’s phenomenological onto-epistemology (we are immersed in the praxis of living in an ontological multi-universe) seems to resonate with Soft Systems Methodology (SSM) interpretivist epistemology. We argue that this concurrence makes it possible to reflect and explore some of Maturana’s ideas (structural determinism/structural coupling/organisational closure) when they are grafted into the phases of the Checkland’s SSM seven-step process. This article aims to complement SSM by proposing a framework in which some key concepts from Maturana’s Ontology of the Observer (OoO) might enhance and expand the understanding of the SSM application process. An enriched and enhanced SSM process could have significant consequences in the Management Science/Operational Research (MS/OR) and Systems community practice. The framework proposed can have major social repercussions since it will incorporate the well-known influential OoO ideas into MS/OR practice

Incidencia de la práctica del piragüismo en el desarrollo del Cáncer de mamas

Tesis (Profesor de Educación Física para la Enseñanza Básica, Licenciado en Educación)Esta investigación tiene como objetivo determinar la incidencia de la práctica del piragüismo en el desarrollo del cáncer de mama, es por esto, que se establecieron dos variables claves, por un lado, el cáncer de mama como variable dependiente y el piragüismo como variable independiente, considerando de antemano que esta práctica puede tener una relación positiva ya sea para prevenir la enfermedad como también positiva para quien la padece. La pregunta de investigación es la siguiente: ¿es el piragüismo una disciplina que previene el desarrollo de cáncer de mama? Se recopiló información del piragüismo y del cáncer a través de un estado del arte considerando bibliografía de estudios científicos, libros y sitio de internet que abordaran estas temáticas de investigación. También se mencionaron y describieron factores de riesgo implicados que puedan causar esta enfermedad, al igual como se observa en el ámbito fisiológico. Para poder llevar a cabo esta investigación de carácter cuantitativa y descriptiva, se realizó una encuesta cerrada dirigida a deportistas de todas partes del mundo que practican diferentes tipos de piragüismo, con el fin de determinar cuántos individuos que acostumbran esta disciplina tienen cáncer de mama, e identificar los diferentes factores de riesgo frente a los que desarrollan esta enfermedad. Los resultados arrojados más importantes que se obtuvieron indican una relación en los beneficios de la práctica deportiva en relación a la incidencia con el cáncer de mama. El realizar deporte para el ser humano favorece el metabolismo, por lo que también se generan más procesos de apoptosis, dejando menos opciones de ambiente propicio para la formación de cáncer

A drowned Mesolithic shell midden complex at Hjarnø Vesterhoved,Denmark and its wider significance

Anthropogenic shell accumulations (shell middens), often of great size, occur in their tens of thousands around the world’s coastlines. They mostly date from the Mid-Holocene onwards and are frequently taken as symptomatic of a Postglacial ‘revolution’ involving world-wide population growth and intensification in exploitation of marine resources. However, the comparative rarity of earlier deposits may have as much to do with Postglacial sea-level rise and the loss of evidence from earlier palaeoshorelines as with genuine socio-economic trends. Here we investigate the underwater Mesolithic (Ertebølle) shellmidden of Hjarnø Vesterhoved in Denmark, one of the first underwater shell middens to be systematically verified as an anthropogenic shell deposit in a region world-famous for its many hundreds of Ertebølle shell mounds on the present shoreline. We show how a combination of geophysical survey, coring, excavation, stratigraphic interpretation and macroscopic analysis of midden contents can be used to identify underwater deposits, to unravel their taphonomic and post-depositional history in relation to surrounding sediments, and to distinguish between cultural and natural agencies of shell accumulation and deformation. We demonstrate the presence of an intact underwater shell-midden deposit dated at 5400–5100 cal BC, one of the earliest in Denmark. We demonstrate the usefulness of such material in giving new information about early coastal subsistence economies and greater precision to the measurement of palaeosea levels. We discuss the implications of our results for an improved understanding of the Mesolithic record in Denmark and of biases in the archaeological record of Late Pleistocene and Early-to-Mid-Holocene coastal contexts. We emphasise the importance of researching more fully the geomorphological and taphonomic processes that affect the accumulation, destruction, burial, preservation and visibility of underwater archaeological deposits, the need to extend underwater investigations more widely and to more deeply submerged palaeoshorelines, and the combination of methods required to advance such investigations

Temporal variability in shell mound formation at Albatross Bay, northern Australia

We report the results of 212 radiocarbon determinations from the archaeological excavation of 70 shell mound deposits in the Wathayn region of Albatross Bay, Australia. This is an intensive study of a closely co-located group of mounds within a geographically restricted area in a wider region where many more shell mounds have been reported. Valves from the bivalve Tegillarcca granosa were dated. The dates obtained are used to calculate rates of accumulation for the shell mound deposits. These demonstrate highly variable rates of accumulation both within and between mounds. We assess these results in relation to likely mechanisms of shell deposition and show that rates of deposition are affected by time-dependent processes both during the accumulation of shell deposits and during their subsequent deformation. This complicates the interpretation of the rates at which shell mound deposits appear to have accumulated. At Wathayn, there is little temporal or spatial consistency in the rates at which mounds accumulated. Comparisons between the Wathayn results and those obtained from shell deposits elsewhere, both in the wider Albatross Bay region and worldwide, suggest the need for caution when deriving behavioural inferences from shell mound deposition rates, and the need for more comprehensive sampling of individual mounds and groups of mounds

Limpet Shells from the Aterian Level 8 of El Harhoura 2 Cave (Témara, Morocco): Preservation State of Crossed-Foliated Layers

International audienceThe exploitation of mollusks by the first anatomically modern humans is a central question for archaeologists. This paper focuses on level 8 (dated around * 100 ka BP) of El Har-houra 2 Cave, located along the coastline in the Rabat-Témara region (Morocco). The large quantity of Patella sp. shells found in this level highlights questions regarding their origin and preservation. This study presents an estimation of the preservation status of these shells. We focus here on the diagenetic evolution of both the microstructural patterns and organic components of crossed-foliated shell layers, in order to assess the viability of further investigations based on shell layer minor elements, isotopic or biochemical compositions. The results show that the shells seem to be well conserved, with microstructural patterns preserved down to sub-micrometric scales, and that some organic components are still present in situ. But faint taphonomic degradations affecting both mineral and organic components are nonetheless evidenced, such as the disappearance of organic envelopes surrounding crossed-foliated lamellae, combined with a partial recrystallization of the lamellae. Our results provide a solid case-study of the early stages of the diagenetic evolution of crossed-foliated shell layers. Moreover, they highlight the fact that extreme caution must be taken before using fossil shells for palaeoenvironmental or geochronological reconstructions. Without thorough investigation, the alteration patterns illustrated here would easily have gone unnoticed. However, these degradations are liable to bias any proxy based on the elemental, isotopic or biochemical composition of the shells. This study also provides significant data concerning human subsistence behavior: the presence of notches and the good preservation state of limpet shells (no dissolution/recrystallization, no bioerosion and no abrasion/fragmentation aspects) would attest that limpets were gathered alive with tools by Middle Palaeolithic (Aterian) populations in North Africa for consumption

A Conceptual Framework Based on Maturana’s Ontology of the Observer to Explore the Checkland’s Soft Systems Methodology

© 2019, Springer Science+Business Media, LLC, part of Springer Nature. This paper explores Checkland’s Soft Systems Methodology (SSM) through the lenses of a theoretical framework that incorporates key concepts from Maturana’s Ontology of the Observer (OoO) with the view of complementing Checkland’s SSM application process. We outline and examine paradigmatic compatibility between: Checkland’s ontological position (reality is problematic/chaotic) together with his interpretivist epistemology (multiple perceptions enrich the ever-changing reality); and Maturana’s OoO (we are immersed in the praxis of living in an ontological multi-universe). We argue that OoO resonates with key SSM theoretical underpinnings. After establishing compatibility between these two influential systems thinkers, we advance a conceptual framework in which Checkland’s SSM learning process is re-visited through a the framework grounded on Maturana’s OoO. The proposed framework illustrates how key ideas drawn from Maturana’s OoO can shed light into the way in which some of the main SSM devices (i.e.: Root definitions, Conceptual model) are used in the SSM process. By doing that, SSM is enriched and becomes more flexible as the stakeholders involved are placed within the domain of constitutive ontologies from which, a deeper dialogue can be promoted in a domain of coexistence in mutual acceptance. We argue that this is a suitable way to have more flexible and holistic views for a SSM intervention in particular to promote the learning process and debating proposed changes amongst the stakeholders involved. The proposed framework, when applied, may enhance the power of SSM learning process and when adopted can have substantial implications to complement the SSM process

Nutritional values of tortoises relative to ungulates from the Middle Stone Age levels at Blombos Cave, South Africa: Implications for foraging and social behaviour

The site of Blombos Cave (BBC), Western Cape, South Africa has been a strong contributor to establishing the antiquity of important aspects of modern human behaviour, such as early symbolism and technological complexity. However, many linkages between Middle Stone Age (MSA) behaviour and the subsistence record remain to be investigated. Understanding the contribution of small fauna such as tortoises to the human diet is necessary for identifying shifts in overall foraging strategies as well as the collecting and processing behaviour of individuals unable to participate in large-game hunting. This study uses published data to estimate the number of calories present in tortoises as well as ungulates of different body size classes common at South African sites. A single tortoise (Chersina angulata) provides approximately 3332 kJ (796 kcal) of calories in its edible tissues, which is between 20 and 30% of the daily energetic requirements for an active adult (estimated between 9360 kJ [3327 kcal] and 14,580 kJ [3485 kcal] per day). Because they are easy to process, this would have made tortoises a highly-ranked resource, but their slow growth and reproduction makes them susceptible to over-exploitation. Zooarchaeological abundance data show that during the ca. 75 ka (thousands of years) upper Still Bay M1 phase at BBC, tortoises contributed twice as many calories to the diet relative to ungulates than they did during the ca. 100 ka lower M3 phase. However, in spite of the abundance of their fossils, their absolute caloric contribution relative to ungulates remained modest in both phases. At the end of the site's MSA occupation history, human subsistence strategies shifted to emphasise high-return large hunted mammals, which likely precipitated changes in the social roles of hunters and gatherers during the Still Bay