90 research outputs found

    Acció climàtica. El repte d'una dècada

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    L’estiu passat ens va mostrar que el canvi climàtic és una realitat incontestable, però el seu abast i impacte dependrà de les polítiques públiques que apliquem i dels canvis socials i culturals siguem capaços de promoure. No actuar ara ens sortirà molt més car

    Global patterns of phosphatase activity in natural soils

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    imbalance-P paper contact with Olga Margalef: [email protected] phosphatase levels strongly control the biotic pathways of phosphorus (P), an essential element for life, which is often limiting in terrestrial ecosystems. We investigated the influence of climatic and soil traits on phosphatase activity in terrestrial systems using metadata analysis from published studies. This is the first analysis of global measurements of phosphatase in natural soils. Our results suggest that organic P (Porg), rather than available P, is the most important P fraction in predicting phosphatase activity. Structural equation modeling using soil total nitrogen (TN), mean annual precipitation, mean annual temperature, thermal amplitude and total soil carbon as most available predictor variables explained up to 50% of the spatial variance in phosphatase activity. In this analysis, Porg could not be tested and among the rest of available variables, TN was the most important factor explaining the observed spatial gradients in phosphatase activity. On the other hand, phosphatase activity was also found to be associated with climatic conditions and soil type across different biomes worldwide. The close association among different predictors like Porg, TN and precipitation suggest that P recycling is driven by a broad scale pattern of ecosystem productivity capacity

    Three Millennia of Climatic, Ecological, and Cultural Change on Easter Island: An Integrative Overview

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    Eastern Island (Rapa Nui) is famous for the legacy of an extinct civilization symbolized by the megalithic statues called moai. Several enigmas regarding the colonization of the island its deforestation and a presumed cultural collapse of the ancient civilization still remain elusive. According to the prevailing view, the first settlers arrived between AD 800 and AD 1200 from east Polynesia and overexploited the island's natural resources causing an ecological catastrophe leading to a cultural collapse (Flenley and Bahn, 2003 ). The main evidence for this theory was the abrupt replacement of palm pollen by grass pollen in the sediments of the island's lakes and mires (Raraku, Kao, and Aroi), which was interpreted in terms of a thorough deforestation between approximately AD 1200 and AD 1400/1600 (Flenley and King, 1984; Flenley et al., 1991; Mann et al., 2008). This ecocidal view is widely accepted not only by the scientific community but also by society, thanks to its popularization by the mass media

    Late Holocene vegetation dynamics and deforestation in Rano Aroi: implications for Easter Island's ecological and cultural history

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    Easter Island (Rapa Nui) has been considered an example of how societies can cause their own destruction through the overexploitation of natural resources. The flagship of this ecocidal paradigm is the supposed abrupt, island-wide deforestation that occurred about one millennium ago, a few centuries after the arrival of Polynesian settlers to the island. Other hypotheses attribute the forest demise to different causes such as fruit consumption by rats or aridity but the occurrence of an abrupt, island-wide deforestation during the last millennium has become paradigmatic in Rapa Nui. We argue that such a view can be questioned, as it is based on the palynological study of incomplete records, owing to the existence of major sedimentary gaps. Here, we present a multiproxy (pollen, charcoal and geochemistry) study of the Aroi core, the first gap-free sedimentary sequence of the last millennia obtained to date in the island. Our results show changing vegetation patterns under the action of either climatic or anthropogenic drivers, or both, depending on the time interval considered. Palm forests were present in Aroi until the 16th century, when deforestation started, coinciding with fire exacerbation elikely of human origine and a dry climate. This is the latest deforestation event recorded so far in the island and took place roughly a century before European contact. In comparison to other Easter Island records, this record shows that deforestation was neither simultaneous nor proceeded at the same pace over the whole island. These findings suggest that Easter Island's deforestation was a heterogeneous process in space and time, and highlights the relevance of local catchment traits in the island's environmental and land management history

    Climate changes and cultural shifts on Easter Island during the last three millennia

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    Easter Island's cultural shifts have been explained mostly by anthropogenic forcing and climate changes have been dismissed as relevant drivers of societal change. Recent findings demand a more complex scenario in which climatic, ecological and cultural factors interact

    Macrofossils in Raraku Lake (Easter Island) integrated with sedimentary and geochemical records: Towards a palaeoecological synthesis for the last 34,000 years

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    Macrofossil analysis of a composite 19m long sediment core from Rano Raraku Lake (Easter Island) wasrelated to litho-sedimentary and geochemical features of the sediment. Strong stratigraphical patterns are shown by indirect gradient analyses of the data. The good correspondence between the stratigraphical patterns derived from macrofossil (Correspondence Analysis) and sedimentary and geochemical data (Principal Component Analysis) shows that macrofossil associations provide sound palaeolimnological information in conjunction with sedimentary data. The main taphonomic factors influencing the macrofossil assemblages are run-off from the catchment, the littoral plant belt, and the depositional environment within the basin. Five main stages during the last 34,000 calibrated years BP (calyrBP) are characterised from the lithological, geochemical, and macrofossil data. From 34 to 14.6calkyrBP (last glacial period) the sediments were largely derived from the catchment, indicating a high energy lake environment with much erosion and run-off bringing abundant plant trichomes, lichens, and mosses into the centre of Raraku Lake. During the early Holocene the infilling of the lake basin and warmer conditions favoured the growth of a littoral plant belt that obstructed terrigenous input. Cladoceran remains and Solanaceae seeds are indicative of reduced run-off and higher values of N and organic C indicate increased aquatic and catchment productivity. From 8.7 to 4.5calkyrBP a swamp occupied the entire basin. The increase of Cyperaceae seeds reflects this swamp development and, with oribatid mites and coleopteran remains, indicates a peaty environment and more anoxic conditions in Raraku. At around 4.5calkyrBP dry conditions prevented peat growth and there is a sedimentary hiatus. About 800calyrBP, peat deposition resumed. Finally, in the last few centuries, a small lake formed within the surrounding swamp. Evidence of human activity is recorded in these uppermost sediments. © 2011 Elsevier Ltd.This research was funded by the Spanish Ministry of Science and Education through the projects LAVOLTER (CGL2004-00683/BTE), GEOBILA (CGL2007-60932/BTE) and CONSOLIDER GRACCIE (CSD2007-00067) and an undergraduate grant (BES-2008-002938 to N. Cañellas-Boltà).Peer Reviewe

    CLAFS, a Holistic Climatic-Ecological-Anthropogenic Hypothesis on Easter Island's Deforestation and Cultural Change: Proposals and Testing Prospects

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    This paper reviews the existing hypotheses concerning the cultural shift from the Ancient Cult (AC) to the Birdman Cult (BC) that occurred on Easter Island (Rapa Nui) during the last millennium and introduces a holistic new hypothesis called CLAFS (Climate-Landscape-Anthropogenic Feedbacks and Synergies), which considers a variety of potential drivers of cultural change and their interactions. The CLAFS hypothesis can be tested with future paleoecological studies on new sedimentary sequences such as the new continuous and coherent record encompassing the last millennium from Rano Kao (KAO08-03) using a combination of pollen, non-pollen palynomorphs (NPP), charcoal, and fecal lipid analyses, at decadal to multidecadal resolution. The Kao record should be compared with other continuous records of the last millennium available for the two other freshwater bodies of the island, Rano Aroi and Rano Raraku, to obtain an island-wide perspective of spatio-temporal deforestation patterns in relation to climatic shifts and human activities. The CLAFS hypothesis predicts that the shift from the AC to the BC was associated with the drying out and deforestation of Rano Raraku (the center of the AC) by ∼1,570 CE, followed by human migration to Rano Kao (the social center of the BC), where freshwater and forests were still available. Under the CLAFS scenario, this migration would have occurred by ∼1,600 CE. Findings to the contrary would require modification and refinement, or outright rejection, of the CLAFS hypothesis and the consideration of alternate hypotheses compatible with new paleoecological evidence. Regardless the final results, archeological evidence will be required to link climatic and ecological events with cultural developments

    Gaining insight into the implementation of an e-learning smoking cessation course in Latin American countries

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    Continuous medical education focused on health problems emerging in low- and middle-income countries (LMICs) is scarce. Although tobacco consumption is increasing in LMICs, there is a lack of tobacco cessation training programs in these countries. To promote smoking cessation interventions in Bolivia, Guatemala and Paraguay, we adapted an e-learning program developed in Catalonia (Spain). This process evaluation study reports on reach, dose and satisfaction of participants with the course, as well as the contextual factors of its application. We conducted a multiple method evaluation, which included a survey and several focus groups, each one specific to the same type of healthcare professional (nurses, doctors, other professionals). Two hundred and ninety-two participants registered into the online course. The motivation for undertaking the course was different between doctors and nurses. The main sources of difficulty in enrolling and finishing the course were the technical problems experienced when accessing the platform, and lack of acquaintance with computers and the Internet in general. Our results show that implementing e-learning education in hospitals from LMICs is feasible, especially when there are similarities between participating countries and the country in which the original program was developed. However, several elements such as strong organizational commitment, technical support and resources and adequate communication channels should be provided to facilitate enrollment and training completion. Efforts to improve Internet access should be made to avoid jeopardizing students' motivation to enroll and complete online training

    Terra Negra: a soil over shales in Montnegre

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    Montnegre’s mountain range boasts a large variety of landscapes because of the spatial variability of its geological materials. Its parent materials are comprised of igneous and metamorphic rocks, mainly granites, shales and phyllites with small incursions of calcareous and basaltic rocks. As a result, Montnegre also presents a certain diversity of soil types. Very close to Sant Martí de Montnegre we can find one of the most geologically interesting sites in Montnegre, the so called Terra Negra, surely named this way because of the colour of its rocks and soils. Terra Negra is located on a doughnut-like incursion of black shale, dating from the Carboniferous Period, rounded mainly by phyllites and hornfels and by granite at the north side. On the 11th of April 2015 we carried out a field exploration of the location to collect soil data and samples for further analyses in the laboratory. Therefore, the main aim of this paper is to present the data we have collected from the soil of Terra Negra. Finally, with the available data, we discuss some of the properties of the soil and their effects on the local plant community

    BRCA1 mutations in high-grade serous ovarian cancer are associated with proteomic changes in DNA repair, splicing, transcription regulation and signaling

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    Ovarian cancer; ProteomicsCáncer de ovarios: ProteómicaCàncer d'ovaris; ProteòmicaDespite recent advances in the management of BRCA1 mutated high-grade serous ovarian cancer (HGSC), the physiology of these tumors remains poorly understood. Here we provide a comprehensive molecular understanding of the signaling processes that drive HGSC pathogenesis with the addition of valuable ubiquitination profiling, and their dependency on BRCA1 mutation-state directly in patient-derived tissues. Using a multilayered proteomic approach, we show the tight coordination between the ubiquitination and phosphorylation regulatory layers and their role in key cellular processes related to BRCA1-dependent HGSC pathogenesis. In addition, we identify key bridging proteins, kinase activity, and post-translational modifications responsible for molding distinct cancer phenotypes, thus providing new opportunities for therapeutic intervention, and ultimately advance towards a more personalized patient care.This work was supported by the PhD4MD collaborative research program between the Vall d’Hebron Research Institute (VHIR) and the Centre for Genomic Regulation (CRG). The CRG/UPF Proteomics Unit is part of the Spanish Infrastructure for Omics Technologies (ICTS OmicsTech) and it is a member of the ProteoRed PRB3 consortium which is supported by grant PT17/0019 of the PE I+D+i 2013-2016 from the Instituto de Salud Carlos III (ISCIII) and ERDF. We acknowledge support from the Spanish Ministry of Science, Innovation and Universities, (CTQ2016-80364-P and “Centro de Excelencia Severo Ochoa 2013-2017”, SEV-2012-0208), and “Secretaria d’Universitats i Recerca del Departament d’Economia i Coneixement de la Generalitat de Catalunya” (2017SGR595 and 2017SGR1661). This project has also received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 823839 (EPIC-XS). It has also been supported by grants from the Instituto Carlos III (PI15/00238, PI18/01017, PI21/00977), the Miguel Servet Program (CP13/00158 and CPII18/00027) and the Ministerio de Economía y Competitividad y Fondos FEDER (RTC-2015-3821-1). The authors are grateful to the team members of the Proteomics Unit at the Centre for Genomic Regulation, the Biomedical Research Group in Gynecology at the Vall d’Hebron Institute, the Gynecological Oncology Unit at the Vall d’Hebron Hospital and the Biomedical Research Group in Urology at the Vall d’Hebron Institute for their assistance
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