2,250 research outputs found

    Instal·lacions per a la recollida de neu a Mallorca

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    Es presenta una revisió de la bibliografia publicada sobre les instal·lacions per a la recollida de neu a Mallorca. A partir d’aquesta revisió es prepara un catàleg integral de cases de neu a Mallorca i es caracteritzen tots els components i tipologies d’aquestes instal·lacions

    Tracking relations among bacterial and protozoan communities in wastewater treatment plants

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    Background: Understanding the interactions between prokaryotic and eukaryotic populations in complex environments can be challenging. Particularly, there is a recognized difficulty in establishing how the interactions between the bacterial and the protozoan populations can affect the performance of wastewater treatment plants (WWTP). Objectives: In order to determine the relationships between microbial communities (protozoa, metazoa and filamentous bacteria) and abiotic parameters (physical-chemical and operational), thirty seven WWTP with activated sludge process were studied in Portugal, during two years, in a trimestral sampling strategy. Methods: Samples were collected to enable a molecular characterization of the microbiota. In order to ensure the diversity of microorganisms, 100 samples were selected based on their geographic localization and time-spaced to track relationships within bacteria and protozoa. A 16S rRNA gene PCR-DGGE approach was carried out for bacterial community fingerprinting. The resulting profiles were analysed together with the results obtained from the survey of the protozoa populations. Finally, the study of the correlations between the physical-chemical and operational parameters and the microbial communities was also investigated. Conclusions: The study of these interactions constitutes a strategy for the understanding of how the different metabolic groups of prokaryotic and protozoa are affected by the relations between this populations, allowing a better prediction of the overall community dynamics. This will allow setting the conditions that better contribute to improve the wastewater treatment while increasing the knowledge of overall communities networking in complex environments

    Cultural continuities and discontinuities at the Neolithic transition in Eastern Iberia: an analysis of the morphometry of geometric microliths

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    The main goal of this paper is to explore possible cultural continuities and discontinuities at the Neolithic transition in Eastern Iberia. To address this issue, we introduce a twofold methodology, consisting of Geometric Morphometrics and the use of the self-developed Geomeasure system, to examine evolutionary patterns in geometric microliths. These are a specific type of arrowhead shared by both the last hunter-gatherers and the first farmers from two reference sites in the region: Cueva de la Cocina and Cova de l’Or (Eastern Iberia). Although advances in research have contributed to a better comprehension of this process, there are still unanswered questions, especially when the study is approached from a regional perspective. Such is the case for the Neolithisation of the Eastern Iberian Peninsula, and the way in which the previous Mesolithic population interacted—if they interacted at all—with the first farmers. In this case, some sites present archaeological contexts that have been catalogued as acculturation contexts. This has traditionally been the case for phase C of Cueva de la Cocina (Spain), although recent research points to the possibility that the content of this specific deposit is the result of post-depositional processes. Here we try first to understand the cultural evolutionary patterns and relations between the different geometric microlith technocomplexes and, second, to address the specific problem of the interpretation of taphonomic disturbances in the archaeological record. We use the Cueva de l’Or and the Cueva de la Cocina for comparison, and our conclusions raise serious doubts about the existence of an acculturation phase at the latter
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