1,650 research outputs found

    Dynamics of ecosystem services along ecological network seascapes

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    Human societies depend on services provided by ecosystems, from local needs as clean water and pest control to global services like ozone layer and the ocean biological pump. Ecosystem services are intrinsically linked to the states of the ecosystem, which are, in turn, governed by a complex web of ecological interactions. These interactions and, consequently, the services they support, are increasingly under threat from environmental changes driven by human activities. Therefore, safeguarding these vital services require an understanding of how the structure and dynamics of ecological interactions are affected by environmental change. A critical step towards this goal is the development of an integrative theoretical framework that can elucidate how ecosystem services are sustained or impaired by interactions within these complex ecosystems in fluctuating environments. Recent years have seen significant progress in quantitatively characterizing the organization and the dynamics of ecological interactions through the study of ecological networks. However, linking temporally varying network structure in fluctuating environments, the seascapes of ecological networks, and their impact on ecosystem services remains a challenge. We propose an approach based upon merging empirical ecological network analysis with Boolean functions and modeling techniques accounting for fluctuating environments to tackle how ecosystem services are affected by the changing structure and dynamics of ecological networks. The approach aims to contribute to the study of how the organization of ecological interactions affects the persistence of ecosystem services. Specifically, we discuss how this approach can be used provide new insights into how environmental change affect the relationship between ecological networks and ecosystem services. The combination of information on ecosystem services, Boolean networks and fluctuating environments might allow to enhance the research around conservation strategies for preserving biodiversity and ecosystem services in the face of ongoing environmental change

    Vulnerabilidade das microrregiões do Estado de São Paulo à pandemia do novo coronavírus (SARS-CoV-2)

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    Neste relatório, associamos dados da rede de fluxos rodoviários e da demografia das microrregiões paulistas com os casos confirmados de COVID-19 atualizados em 04/04/2020 para gerar i nformações estratégicas sobre a propagação geográfica da pandemia de SARS-CoV-2 no Estado de São Paulo. Identificamos microrregiões que podem atuar como núcleos propagadores da epidemia ou que têm alta vulnerabilidade a receber pessoas i nfectadas. Desta forma, atualizamos a i dentificação das microrregiões mais vulneráveis à propagação geográfica da pandemia do novo coronavírus ( SARS-CoV-2) no estado

    Collapse of an ecological network in Ancient Egypt

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    The dynamics of ecosystem collapse are fundamental to determining how and why biological communities change through time, as well as the potential effects of extinctions on ecosystems. Here we integrate depictions of mammals from Egyptian antiquity with direct lines of paleontological and archeological evidence to infer local extinctions and community dynamics over a 6000-year span. The unprecedented temporal resolution of this data set enables examination of how the tandem effects of human population growth and climate change can disrupt mammalian communities. We show that the extinctions of mammals in Egypt were nonrandom, and that destabilizing changes in community composition coincided with abrupt aridification events and the attendant collapses of some complex societies. We also show that the roles of species in a community can change over time, and that persistence is predicted by measures of species sensitivity, a function of local dynamic stability. Our study is the first high-resolution analysis of the ecological impacts of environmental change on predator-prey networks over millennial timescales, and sheds light on the historical events that have shaped modern animal communities

    Interaction paths promote module integration and network-level robustness of spliceosome to cascading effects

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    CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPThe functionality of distinct types of protein networks depends on the patterns of protein-protein interactions. A problem to solve is understanding the fragility of protein networks to predict system malfunctioning due to mutations and other errors. Spec8111CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informação2017/08406-7, 2017/06994-9We thank Ana Paula Assis, Pâmela C. Santana and Leandro Giacobelli for helpful comments. PRG was supported by CNPq and FAPESP (2017/08406-7). PPC was supported by FAPESP (2017/06994-9). MC was supported by a PMP/BS postdoctoral fellowship (UFPR/UNIVALI 4

    Thermal fluctuations of a quantized massive scalar field in Rindler background

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    Thermal fluctuations for a massive scalar field in the Rindler wedge are obtained by applying the point-splitting procedure to the zero temperature Feynman propagator in a conical spacetime. Renormalization is implemented by removing the zero temperature contribution. It is shown that for a field of non vanishing mass the thermal fluctuations, when expressed in terms of the local temperature, do not have Minkowski form. As a by product, Minkowski vacuum fluctuations seen by an uniformly accelerated observer are determined and confronted with the literature.Comment: 10 pages; Latex fil

    Coevolution creates complex mosaics across large landscapes

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    The spatial distribution of populations can influence the evolutionary outcome of species interactions. The variation in direction and strength of selection across local communities creates geographic selection mosaics that, when combined with gene flow and genomic processes such as genome duplication or hybridization, can fuel ongoing coevolution. A fundamental problem to solve is how coevolution proceeds when many populations that vary in their ecological outcomes are connected across large landscapes. Here we use a lattice model to explore this problem. Our results show that the complex interrelationships among the elements of the geographic mosaic of coevolution can lead to the formation of clusters of populations with similar phenotypes that are larger than expected by local selection. Our results indicate that neither the spatial distribution of phenotypes nor the spatial differences in magnitude and direction of selection alone dictate coevolutionary dynamics: the geographic mosaic of coevolution affects formation of phenotypic clusters, which in turn affect the spatial and temporal dynamics of coevolution. Because the formation of large phenotypic clusters depends on gene flow, we predict that current habitat fragmentation will change the outcomes of geographic mosaics, coupling spatial patterns in selection and phenotypes1942217229We acknowledge the funding provided by the European Union Seventh Framework Programme (FP7/2007–2013; grant agreement 289384 [L.D.F.]), the São Paulo Research Foundation (grants 2009/54422-8 [P.R.G.], 2016/06054-3 [M.A.M.A.], and 2015/26989-4 [L.D.F.]), the National Council of Scientific and Technological Development (M.A.M.A. and P.L.-C.), and the National Science Foundation (DEB0839853 [J.N.T.]

    Elastic scattering and total reaction cross sections for the 8Li + 12C system

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    The elastic-scattering angular distribution for 8Li on 12C has been measured at ELAB=23.9 MeV with 8Li radioactive nuclear beam produced by the Radioactive Ion Beams in Brazil facility. This angular distribution was analyzed in terms of optical-model with Woods-Saxon and double-folding São Paulo potential. The roles of the breakup and inelastic channels were also investigated with cluster folding and deformed potentials, respectively, through coupled-channels calculations. The angular distribution for the proton-transfer 12C(8Li,9Be)11B reaction was also measured at the same energy. The spectroscopic factor for the 9Be|8Li+p bound system was obtained and compared with shell-model calculations and with other experimental values. Total reaction cross sections for the present system were also extracted from the elastic-scattering analysis. A systematic of the reduced reaction cross sections obtained from the present and published data on 6,7,8Li isotopes on 12C was performed as a function of energy

    A case of equine multicentric lymphoma: Clinical, microscopical, and molecular findings

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    Background: Although relatively uncommon, lymphoma is the most prevalent haematopoietic neoplasia in horses, and multicentric lymphoma remains the most common presentation of the disease. The pathogenesis of equine lymphoma is still poorly understood and the diagnosis is usually confirmed at an advanced stage of the disease, compromising the prognosis. This study investigated the clinical, pathological, and molecular features of a case of equine multicentric lymphoma. Case description: An apparently healthy 5-year-old crossbreed mare hospitalized at the Centre of Animal Reproduction of Vairão, Portugal, suddenly presented clinical signs of supraorbital oedema and mandibular lymph node enlargement, developing fever, facial oedema, and generalized lymphadenopathy. The mare ended up dying twenty-four days after the first clinical signs due to multisystem organ failure. Haematological and biochemical analyses, necropsy, and microscopic and molecular evaluation of affected tissues were performed. At necropsy, the main findings were multiple multinodular lesions, distributed along the serous surface of oropharynx, trachea, pericardium, gastrointestinal tract, and mesentery. Microscopically, these consisted of solid proliferations of neoplastic round cells that exhibited immunopositivity for CD3 (T cells). Based on these findings, a medium-grade multicentric T-cell lymphoma was diagnosed. Conclusion: There is still very little research regarding the molecular characterization of lymphoma in horses. As an entity itself is quite heterogeneous, it is important to describe the interspecies particularities to understand its development and behaviour.GFS (2022.14765.BD) acknowledges the Portuguese Foundation for Science and Technology (FCT), for financial support. IPATIMUP integrates the i3S Research Unit, which is partially supported by FCT
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