36 research outputs found

    The evolution of forecasting for decision-making in dynamic environments

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    Climate change and technological advances are reshaping ecosystems and societies. Strategic choices that were best yesterday may be sub-optimal tomorrow; and environmental conditions that were once taken for granted may soon cease to exist. In dynamic settings, how people choose behavioral strategies has important consequences for environmental dynamics. Economic and evolutionary theories make similar predictions for strategic behavior in a static environment, even though one approach assumes perfect rationality and the other assumes no cognition whatsoever; but predictions differ in a dynamic environment. Here we explore a middle ground between economic rationality and evolutionary myopia. Starting from a population of myopic agents, we study the evolutionary viability of a new type that forms environmental forecasts when making strategic decisions. We show that forecasting types can have an advantage in changing environments, even when the act of forecasting is costly. Forecasting types can invade but rarely overtake the population, producing a stable coexistence with myopic types. Moreover, forecasting fosters collective intelligence by providing a public good which reduces the amplitude of environmental oscillations and often increases mean payoffs to forecasting and myopic types alike. We interpret our results for understanding the evolution of different modes of decision-making such as forecasting. And we discuss implications for the management of environmental systems of societal importance

    Etnobotñnica e medicina popular no tratamento de malária e males associados na comunidade ribeirinha Julião – baixo Rio Negro (Amazînia Central)

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    RESUMO A utilização de plantas medicinais para o tratamento de doenças tropicais como a malĂĄria na AmazĂŽnia Central Ă© de suma importĂąncia, principalmente em locais onde o sistema Ășnico de saĂșde nĂŁo se encontra presente como na maioria das comunidades ribeirinhas desta regiĂŁo. Sendo assim, investigar e resgatar o conhecimento popular a respeito de plantas medicinais utilizadas no tratamento de malĂĄria e males associados pelos moradores da comunidade JuliĂŁo situada na Reserva de Desenvolvimento SustentĂĄvel do TupĂ©, Manaus-AM, torna-se importante no registro de como as populaçÔes locais se previnem e tratam essa doença tĂŁo prevalente e perigosa na regiĂŁo. O trabalho foi conduzido na forma de oficinas participativas, segregadas por gĂȘnero e complementadas com entrevistas semiestruturadas aliadas Ă  tĂ©cnica da turnĂȘ-guiada nos quintais e floresta adjacente Ă  comunidade. Foram calculados os Ă­ndices de diversidade de Shannon-Wiener, equitabilidade e concordĂąncia quanto ao uso principal (CUP). A partir da colaboração efetiva de 13 comunitĂĄrios foram registradas 62 espĂ©cies vegetais pertencentes a 53 gĂȘneros e 34 famĂ­lias botĂąnicas que resultaram em Ă­ndice de diversidade (H’) de 1,62 decits e equitabilidade de 0,9. As famĂ­lias mais representativas foram: Fabaceae (7 espĂ©cies), Asteraceae e Lamiaceae (4 espĂ©cies cada) e Solanaceae e Rutaceae (3 espĂ©cies cada). Vale destacar que 16 espĂ©cies (25,8%) foram citadas para tratamento de malĂĄria e males associados pela primeira vez em estudos etnobotĂąnicos realizados na AmĂ©rica Latina

    Para-infectious brain injury in COVID-19 persists at follow-up despite attenuated cytokine and autoantibody responses

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    To understand neurological complications of COVID-19 better both acutely and for recovery, we measured markers of brain injury, inflammatory mediators, and autoantibodies in 203 hospitalised participants; 111 with acute sera (1–11 days post-admission) and 92 convalescent sera (56 with COVID-19-associated neurological diagnoses). Here we show that compared to 60 uninfected controls, tTau, GFAP, NfL, and UCH-L1 are increased with COVID-19 infection at acute timepoints and NfL and GFAP are significantly higher in participants with neurological complications. Inflammatory mediators (IL-6, IL-12p40, HGF, M-CSF, CCL2, and IL-1RA) are associated with both altered consciousness and markers of brain injury. Autoantibodies are more common in COVID-19 than controls and some (including against MYL7, UCH-L1, and GRIN3B) are more frequent with altered consciousness. Additionally, convalescent participants with neurological complications show elevated GFAP and NfL, unrelated to attenuated systemic inflammatory mediators and to autoantibody responses. Overall, neurological complications of COVID-19 are associated with evidence of neuroglial injury in both acute and late disease and these correlate with dysregulated innate and adaptive immune responses acutely

    Immune history shapes specificity of pandemic H1N1 influenza antibody responses

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    Human antibody responses against the 2009 pandemic H1N1 (pH1N1) virus are predominantly directed against conserved epitopes in the stalk and receptor-binding domain of the hemagglutinin (HA) protein. This is in stark contrast to pH1N1 antibody responses generated in ferrets, which are focused on the variable Sa antigenic site of HA. Here, we show that most humans born between 1983 and 1996 elicited pH1N1 antibody responses that are directed against an epitope near the HA receptor-binding domain. Importantly, most individuals born before 1983 or after 1996 did not elicit pH1N1 antibodies to this HA epitope. The HAs of most seasonal H1N1 (sH1N1) viruses that circulated between 1983 and 1996 possess acritical K133 amino acid in this HA epitope, whereas this amino acid is either mutated ordeleted in most sH1N1 viruses circulating before 1983 or after 1996. We sequentially infected ferrets with a 1991 sH1N1 virus and then a pH1N1 virus. Sera isolated from these animals were directed against the HA epitope involving amino acid K133. These data suggest that the specificity of pH1N1 antibody responses can be shifted to epitopes near the HA receptor-binding domain after sequential infections with sH1N1 and pH1N1 viruses that share homology in this region

    A Phenomenological Spatial Model for Macro-Ecological Patterns in Species-Rich Ecosystems

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    Over the last few decades, ecologists have come to appreciate that key ecological patterns, which describe ecological communities at relatively large spatial scales, are not only scale dependent, but also intimately intertwined. The relative abundance of species—which informs us about the commonness and rarity of species—changes its shape from small to large spatial scales. The average number of species as a function of area has a steep initial increase, followed by decreasing slopes at large scales. Finally, if we find a species in a given location, it is more likely we find an individual of the same species close-by, rather than farther apart. Such spatial turnover depends on the geographical distribution of species, which often are spatially aggregated. This reverberates on the abundances as well as the richness of species within a region, but so far it has been difficult to quantify such relationships. Within a neutral framework—which considers all individuals competitively equivalent—we introduce a spatial stochastic model, which phenomenologically accounts for birth, death, immigration and local dispersal of individuals. We calculate the pair correlation function—which encapsulates spatial turnover—and the conditional probability to find a species with a certain population within a given circular area. Also, we calculate the macro-ecological patterns, which we have referred to above, and compare the analytical formulé with the numerical integration of the model. Finally, we contrast the model predictions with the empirical data for two lowland tropical forest inventories, showing always a good agreement
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