14 research outputs found
Using shell tools in Mesolithic and early Neolithic coastal sites from Northern Spain: experimental program for use wear analysis in malacological materials.
RESUMEN: Uno de los debates más extendidos en la historiografía sobre el Mesolítico y el Neolítico inicial en la región cantábrica es el de la escasez de tecnologías “tradicionales” en la mayor parte de los contextos existentes, especialmente en aquellos con grandes acumulaciones de conchas. Actualmente, varias de las hipótesis propuestas atribuyen este fenómeno a diferencias en la organización espacial de los asentamientos, al aumento en la utilización de materiales perecederos o a cambios en las estrategias de subsistencia. A partir del hallazgo de siete instrumentos de concha en el yacimiento de Santimamiñe (Kortezubi, Bizkaia), que a su vez constituyen la primera evidencia de su categoría en la región cantábrica, se propone como hipótesis el empleo de tecnologías de concha en algunas de las actividades productivas desarrolladas por los grupos de cazadores recolectores de los períodos indicados. Con el objetivo de confirmar/refutar los resultados obtenidos mediante el análisis funcional de estos instrumentos se ha llevado a cabo un programa experimental con diferentes especies de moluscos para procesar madera, piel fresca/seca y planta no leñosa. Los resultados del programa experimental confirman la utilización de estos instrumentos en diversas actividades productivas orientadas al procesado de algunas de estas materias.ABSTRACT: One of the most common debates surrounding the Mesolithic and early Neolithic periods in northern Spain focuses on the scarcity of lithic and osseous technologies identified in large shell midden contexts. Currently, several hypotheses have been proposed that attribute this phenomenon to differences in site spatial organization, increases in perishable material use, or changes in subsistence strategies. However, recently shell tools have been identified in the early Neolithic levels at Santimamiñe cave located in the Basque Country of northern Spain. These artifacts are the first evidence of shell tools to be identified in Northern Spain in an early Neolithic shell midden context. This paper proposes the hypothesis that shell tools were being used in subsistence activities. To test this hypothesis, the authors developed an experimental programme using different types of mollusc shells to examine evidence of functional use on wood, dry/fresh animal skin and non-woody plants. The experimental results were then used to examine the patterns of use on the seven shell tools from Santimamiñe. The results of the comparisons indicate that the seven shell tools have similar use patterns as the experimental shells. This evidence supports the proposed hypothesis that shell tools may have been used frequently in shell midden contexts during the Mesolithic and early Neolithic for the working of wood, plants or animal skin.La Universidad de Cantabria financió esta investigación a través de una beca y un contrato predoctorales concedidos a dos de los autores (D.C.S. e I.G.Z.). Manuel R. González Morales, Alejandro García Moreno y Juan Carlos López Quintana nos ayudaron en diversas cuestiones relacionadas con este trabajo
Modeling species invasions using thermal and trophic niche dynamics under climate change
Changing marine temperatures modify the distributional ranges of natural populations, but the success of invasion of new areas depends on local physical and ecological conditions. We explore the invasion by thermophilic species and their ecosystem effects by simulating a sea surface temperature increase using a trophodynamic model for the northern Adriatic Sea (NAS), in which thermal and trophic niches are explicitly represented for each thermophilic non-indigenous species and native species. The NAS acts as a cul-de-sac for local species, preventing a further poleward migration as a response to temperature rise. In this situation, model results showed that effects of warming and invasion produced complex, non-linear changes on biomasses but never resulted in a complete overturn of a group of native species and/or a bloom of invasive ones. Despite this, the diversity index stabilizes at increased values after simulating invasion, possibly indicating that in such enclosed systems the establishment of invasive species could represent enrichment in ecosystem structure. In addition, the absence of complete species substitution clearly showed the contribution of resident species towards increasing the resilience, i.e. the capability of the system to cope with invasion without changing substantially. Contrasting scenarios highlighted that changes in ecosystem primary production and species adaptation had secondary effects in ecosystem structure, while results for scenarios with different exploitation levels indicated that fishing can destabilize community structure in these change contexts, e.g. reducing community resilience. The results confirmed the importance of an ecological niche approach to analyze possible effects of invasion and highlighted the complexity of dynamics linked to temperature-driven species invasion’, in terms of both the predicted strength of impacts and the direction of biomass change
The histology of ovarian cancer: worldwide distribution and implications for international survival comparisons (CONCORD-2)
Objective Ovarian cancers comprise several histologically distinct tumour groups with widely different prognosis. We aimed to describe the worldwide distribution of ovarian cancer histology and to understand what role this may play in international variation in survival. Methods The CONCORD programme is the largest population-based study of global trends in cancer survival. Data on 681,759 women diagnosed during 1995â\u80\u932009 with cancer of the ovary, fallopian tube, peritoneum and retroperitonum in 51 countries were included. We categorised ovarian tumours into six histological groups, and explored the worldwide distribution of histology. Results During 2005â\u80\u932009, type II epithelial tumours were the most common. The proportion was much higher in Oceania (73.1%), North America (73.0%) and Europe (72.6%) than in Central and South America (65.7%) and Asia (56.1%). By contrast, type I epithelial tumours were more common in Asia (32.5%), compared with only 19.4% in North America. From 1995 to 2009, the proportion of type II epithelial tumours increased from 68.6% to 71.1%, while the proportion of type I epithelial tumours fell from 23.8% to 21.2%. The proportions of germ cell tumours, sex cord-stromal tumours, other specific non-epithelial tumours and tumours of non-specific morphology all remained stable over time. Conclusions The distribution of ovarian cancer histology varies widely worldwide. Type I epithelial, germ cell and sex cord-stromal tumours are generally associated with higher survival than type II tumours, so the proportion of these tumours may influence survival estimates for all ovarian cancers combined. The distribution of histological groups should be considered when comparing survival between countries and regions
Effects of depth and bottom communities on the distribution of highly territorial reef fish in the northwestern region of Cuba
Correction: Post-Control Surveillance of Triatoma infestans and Triatoma sordida with Chemically-Baited Sticky Traps
Correction: Post-Control Surveillance of Triatoma infestans and Triatoma sordida with Chemically-Baited Sticky Traps
Therapeutic management of a new case of LCAT deficiency with a multifactorial long-term approach based on high doses of angiotensin II receptor blockers (ARBs).
Familial lecithin cholesterol acyltransferase (LCAT) deficiency (FLD) is characterized by the appearance of corneal opacity, anemia, proteinuria progressing to chronic renal failure and abnormalities in the composition of plasma lipoproteins. No established therapy currently exists for this condition. We report here a new case of FLD caused by two novel mutations in the LCAT gene in which, for the first time, aggressive therapy with angiotensin II receptor blockers and lipid-lowering drugs showed benefit in blood pressure, lipid abnormalities, proteinuria and also kidney function, probably delaying progression to renal failur