Dynamics and coexistence in a system with intraguild mutualism

It is a tenet of ecological theory that two competing consumers cannot stably coexist on a single limiting resource in a homogeneous environment. Many mechanisms and processes have since been evoked and studied, empirically and theoretically, to explain species coexistence and the observed biological diversity. Facilitative interactions clearly have the potential to enhance coexistence. Yet, even though mutual facilitation between species of the same guild is widely documented empirically, the subject has received very little theoretical attention. Here, we study one form of intraguild mutualism in the simplest possibly community module of one resource and two consumers. We incorporate mutualism as enhanced consumption in the presence of the other consumers. We find that intraguild mutualism can (a) significantly enhance coexistence of consumers, (b) induce cyclic dynamics, and (c) give rise to a bi-stability (a 'joint' Allee effect) and potentially catastrophic collapse of both consumer species.Fil: Assaneo, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física. Laboratorio de Sistemas Dinámicos; ArgentinaFil: Coutinho, Renato Mendes. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Lin, Yangchen. University of Cambridge; Estados UnidosFil: Mantilla, Carlos. Universidad de Carabobo.; VenezuelaFil: Lutscher, Frithjof. University of Ottawa; Canad

Climate drivers of malaria at its southern fringe in the Americas

In this work we analyze potential environmental drivers of malaria cases in Northwestern Argentina. We inspect causal links between malaria and climatic variables by means of the convergent cross mapping technique, which provides a causality criterion from the theory of dynamic systems. Analysis is based on 12 years of weekly malaria P. vivax cases in Tartagal, Salta, Argentina—at the southern fringe of malaria incidence in the Americas—together with humidity and temperature time-series spanning the same period. Our results show that there are causal links between malaria cases and both maximum temperature, with a delay of five weeks, and minimum temperature, with delays of zero and twenty two weeks. Humidity is also a driver of malaria cases, with thirteen weeks delay between cause and effect. Furthermore we also determined the sign and strength of the effects. Temperature has always a positive non-linear effect on cases, with maximum temperature effects more pronounced above 25C and minimum above 17C, while effects of humidity are more intricate: maximum humidity above 85% has a negative effect, whereas minimum humidity has a positive effect on cases. These results might be signaling processes operating at short (below 5 weeks) and long (over 12 weeks) time delays, corresponding to effects related to parasite cycle and mosquito population dynamics respectively. The non-linearities found for the strength of the effect of temperature on malaria cases make warmer areas more prone to higher increases in the disease incidence. Moreover, our results indicate that an increase of extreme weather events could enhance the risks of malaria spreading and re-emergence beyond the current distribution. Both situations, warmer climate and increase of extreme events, will be remarkably increased by the end of the century in this hot spot of climate change.Fil: Laneri, Karina Fabiana. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigaciones y Aplicaciones No Nucleares. Gerencia de Física (cab). División Física Estadística; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Cabella, Brenno. Universidade Estadual Paulista Julio de Mesquita Filho. Faculdade de Engenharia; BrasilFil: Prado, Paulo Inácio. Universidade de Sao Paulo; BrasilFil: Coutinho, Renato Mendes. Universidad Federal Do Abc; BrasilFil: Kraenkel, Roberto André. Universidade Estadual Paulista Julio de Mesquita Filho. Faculdade de Engenharia; Brasi

Evaluation of slag and calcareous rocks as corrective of the acidity of the ground in the culture of lettuce

O presente trabalho objetivou avaliar os efeitos da escória de siderurgia e dos calcários magnesiano e dolomítico, na produção de matéria seca da alface (Lactuca sativa L.) e as alterações na sua nutrição e em alguns atributos químicos do solo. Os tratamentos consistiram dos corretivos calcário magnesiano e dolomítico e escória de siderurgia, em três doses: 2,36, 4,72 e 7,08 g por vaso. Utilizou-se o delineamento experimental inteiramente casualizado, com quatro repetições, em esquema fatorial 3x3+1 (três corretivos x três doses + testemunha). Todos os materiais corretivos aumentaram a produção de matéria seca da alface, porém destacaram-se os calcários, sendo que para a escória, a alta concentração do Mn na parte aérea limitou a produção. Na parte aérea da alface, os teores e quantidade acumulada de Ca, Mg e Cu aumentaram, e os teores de Mn e Zn não foram alterados com a aplicação dos corretivos. Todos os materiais corretivos foram eficientes na correção da acidez do solo, especialmente quando se utilizou calcário magnesiano. A escória de siderurgia não é o corretivo mais apropriado para a cultura da alface.The present work was carried out to evaluate the effect of the slag and of magnesian and dolomitic calcareous rocks on the production of dry matter of lettuce (Lactuca sativa L.) on its nutrition alteration and on some chemical attributes of the soil. The treatments consisted of the three corrective agent: magnesian lime and dolomitic and slag in three doses: 2.36, 4.72 and 7.08 g/pot. A completely randomized design in a factorial scheme 3x3+1 (three corrective agents x three doses + control) with four replications was used. The corrective agents increased production of dry matter (lettuce), especially lime. In the treatment with slag, the production was limited by high concentration of the Mn in plants. In the aerial part of lettuce correctives increased the concentration and content of Ca, Mg, and Cu, but did not alter concentration of Mn and Zn. The application of the corrective agents promoted efficient neutralization of acidity in soil, especially utilized when magnesian lime was used. The slag does not fit for lettuce culture purposes

Evaluation of slag and calcareous rocks as corrective of the acidity of the ground in the culture of lettuce

O presente trabalho objetivou avaliar os efeitos da escória de siderurgia e dos calcários magnesiano e dolomítico, na produção de matéria seca da alface (Lactuca sativa L.) e as alterações na sua nutrição e em alguns atributos químicos do solo. Os tratamentos consistiram dos corretivos calcário magnesiano e dolomítico e escória de siderurgia, em três doses: 2,36, 4,72 e 7,08 g por vaso. Utilizou-se o delineamento experimental inteiramente casualizado, com quatro repetições, em esquema fatorial 3x3+1 (três corretivos x três doses + testemunha). Todos os materiais corretivos aumentaram a produção de matéria seca da alface, porém destacaram-se os calcários, sendo que para a escória, a alta concentração do Mn na parte aérea limitou a produção. Na parte aérea da alface, os teores e quantidade acumulada de Ca, Mg e Cu aumentaram, e os teores de Mn e Zn não foram alterados com a aplicação dos corretivos. Todos os materiais corretivos foram eficientes na correção da acidez do solo, especialmente quando se utilizou calcário magnesiano. A escória de siderurgia não é o corretivo mais apropriado para a cultura da alface.The present work was carried out to evaluate the effect of the slag and of magnesian and dolomitic calcareous rocks on the production of dry matter of lettuce (Lactuca sativa L.) on its nutrition alteration and on some chemical attributes of the soil. The treatments consisted of the three corrective agent: magnesian lime and dolomitic and slag in three doses: 2.36, 4.72 and 7.08 g/pot. A completely randomized design in a factorial scheme 3x3+1 (three corrective agents x three doses + control) with four replications was used. The corrective agents increased production of dry matter (lettuce), especially lime. In the treatment with slag, the production was limited by high concentration of the Mn in plants. In the aerial part of lettuce correctives increased the concentration and content of Ca, Mg, and Cu, but did not alter concentration of Mn and Zn. The application of the corrective agents promoted efficient neutralization of acidity in soil, especially utilized when magnesian lime was used. The slag does not fit for lettuce culture purposes

Percolation across households in mechanistic models of non-pharmaceutical interventions in SARS-CoV-2 disease dynamics

We thank all members of Observatório COVID-19 BR and the CoMo Consortium for the collaborative work. The authors also thank the research funding agencies: São Paulo Research Foundation (FAPESP) – Brazil (grant number: 2019/26310-2 and 2017/26770-8 to CF, 2018/24037-4 to SP, 2018/23984-0 to VS and contract number: 2016/01343-7 to RAK), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) – Brazil (Finance Code 001 to LSF) and the Brazilian National Council for Scientific and Technological Development (CNPq) (grant number: 315854/2020-0 to MEB, 313055/2020-3 to PIP and 311832/2017-2 to RAK). RA is funded by the Bill and Melinda Gates Foundation (OPP1193472). LW is funded by the Li Ka Shing Foundation, Hong Kong. The CoMo Consortium has support from the Oxford University COVID-19 Research Response Fund (ref: 0009280).Peer reviewedPublisher PD

Modeling the impact of school reopening and contact tracing strategies on COVID-19 dynamics in different epidemiologic settings in Brazil

This study was funded by the Brazilian National Council for Scientific and Technological Development (CNPq) - Process # 402834/2020-8 (request for proposals MCTIC/CNPq/FNDCT/MS/SCTIE/Decit Number 07/2020). The funding sources played no role in the study design; collection, analysis, or interpretation of the data; writing the report, or decision to submit the paper for publication. MEB received a technological and industrial scholarship from CNPq (grant number 315854/2020-0). LSF received a masters scholarship from Coordination of Superior Level Staff Improvement (CAPES) (finance code 001). SP was supported by Sao Paulo State Research Support Foundation (FAPESP) (grant number: 2018/24037-4). CF was supported by FAPESP (grant number: 2019/26310-2 and 2017/26770-8). RAK has been supported by CNPq (grant number: 311832/2017-2) and FAPESP (contract number: 2016/01343-7). PIP has been supported by CNPq (grant number: 313055/2020-3). RSK has been supported by CNPq (proc. 312378/2019-0). MQMR received a postdoctoral scholarship from CAPES (grant number 305269/2020-8). CMT has been supported by CNPq productivity fellowship and the National Institute of Science and Technology for Health Technology Assessment (IATS) (proc: 465518/2014-1). AMB received a technological and industrial scholarship from CNPq (grant number 402834/2020-8). LMS received a technological and industrial scholarship from CNPq (grant number 315866/2020-9). JAFD-F has been supported by CNPq productivity fellowship and the National Institutes for Science and Technology in Ecology, Evolution and Biodiversity Conservation (INCT-EEC), supported by MCTIC/CNPq (proc. 465610/2014-5) and FAPEG (proc. 201810267000023).Preprin

Modelling the impact of school reopening and contact tracing strategies on Covid-19 dynamics in different epidemiologic settings in Brazil

We simulate the impact of school reopening during the COVID-19 pandemic in three major urban centers in Brazil to identify the epidemiological indicators and the best timing for the return of in-school activities and the effect of contact tracing as a mitigation measure. Our goal is to offer guidelines for evidence-based policymaking. We implement an extended SEIR model stratified by age and considering contact networks in different settings – school, home, work, and community, in which the infection transmission rate is affected by various intervention measures. After fitting epidemiological and demographic data, we simulate scenarios with increasing school transmission due to school reopening, and also estimate the number of hospitalization and deaths averted by the implementation of contact tracing. Reopening schools results in a non-linear increase in reported COVID-19 cases and deaths, which is highly dependent on infection and disease incidence at the time of reopening. When contact tracing and quarantining are restricted to school and home settings, a large number of daily tests is required to produce significant effects in reducing the total number of hospitalizations and deaths. Policymakers should carefully consider the epidemiological context and timing regarding the implementation of school closure and return of in-person school activities. While contact tracing strategies prevent new infections within school en- vironments, they alone are not sufficient to avoid significant impacts on community transmission

Modeling the impact of child vaccination (5–11 y) on overall COVID-19 related hospitalizations and mortality in a context of omicron variant predominance and different vaccination coverage paces in Brazil

Background Developing countries have experienced significant COVID-19 disease burden. With the emergence of new variants, particularly omicron, the disease burden in children has increased. When the first COVID-19 vaccine was approved for use in children aged 5–11 years of age, very few countries recommended vaccination due to limited risk-benefit evidence for vaccination of this population. In Brazil, ranking second in the global COVID-19 death toll, the childhood COVID-19 disease burden increased significantly in early 2022. This prompted a risk-benefit assessment of the introduction and scaling-up of COVID-19 vaccination of children. Methods To estimate the potential impact of vaccinating children aged 5–11 years with mRNA-based COVID-19 vaccine in the context of omicron dominance, we developed a discrete-time SEIR-like model stratified in age groups, considering a three-month time horizon. We considered three scenarios: No vaccination, slow, and maximum vaccination paces. In each scenario, we estimated the potential reduction in total COVID-19 cases, hospitalizations, deaths, hospitalization costs, and potential years of life lost, considering the absence of vaccination as the base-case scenario. Findings We estimated that vaccinating at a maximum pace could prevent, between mid-January and April 2022, about 26,000 COVID-19 hospitalizations, and 4200 deaths in all age groups; of which 5400 hospitalizations and 410 deaths in children aged 5–11 years. Continuing vaccination at a slow/current pace would prevent 1450 deaths and 9700 COVID-19 hospitalizations in all age groups in this same time period; of which 180 deaths and 2390 hospitalizations in children only. Interpretation Maximum vaccination of children results in a significant reduction of COVID-19 hospitalizations and deaths and should be enforced in developing countries with significant disease incidence in children

Assessing the best time interval between doses in a two-dose vaccination regimen to reduce the number of deaths in an ongoing epidemic of SARS-CoV-2

Funding: This work was supported by the Coordination of Superior Level Staff Improvement (CAPES), Brazil (Finance Code 001 to LSF and FMDM), National Council for Scientific and Technological Development (CNPq), Brazil (grant number: 315854/2020-0 to MEB, 141698/2018-7 to RLPS, 312559/2020-8 to MASMV and 311832/2017-2 to RAK), São Paulo Research Foundation (FAPESP), Brazil (grant #2019/26310-2 and #2017/26770-8 to CF, #2018/26512-1 to OC, #2018/24037-4 to SP, #2018/23984-0 to VS and contract #2016/01343-7 to RAK) and Swiss National Science Foundation (grant PCEFP3_181243 to VS). The Sound Foundation (Massachusetts, USA) provided financial support for the open-source publication of this work via a grant to The University of Oxford (UK) to support the work of members of the COVID-19 International Modeling (CoMo) Consortium. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Towards an applied metaecology

The complexity of ecological systems is a major challenge for practitioners and decision-makers who work to avoid, mitigate and manage environmental change. Here, we illustrate how metaecology – the study of spatial interdependencies among ecological systems through fluxes of organisms, energy, and matter – can enhance understanding and improve managing environmental change at multiple spatial scales. We present several case studies illustrating how the framework has leveraged decision-making in conservation, restoration and risk management. Nevertheless, an explicit incorporation of metaecology is still uncommon in the applied ecology literature, and in action guidelines addressing environmental change. This is unfortunate because the many facets of environmental change can be framed as modifying spatial context, connectedness and dominant regulating processes - the defining features of metaecological systems. Narrowing the gap between theory and practice will require incorporating system-specific realism in otherwise predominantly conceptual studies, as well as deliberately studying scenarios of environmental change.We thank FAPESP (grants 2014/10470-7 to AM, 2013/04585-3 to DL, 2013/50424-1 to TS and 2015/18790-3to LS), CNPq (Productivity Fellowships 301656/2011-8 to JAFDF,308205/2014-6 to RP, 306183/2014-5 to PIP and 307689/2014-0 to VDP), the National Science Foundation (DEB 1645137 toJGH), the Natural Sciences and Engineering Council of Canada (SJL,PPN), and the Academy of Finland (grants 257686 and 292765 toMC) for support. This work contributes to the Labex OT-Med (no.ANR-11-LABX-0061), funded by the French government throughthe A*MIDEX project (no. ANR-11-IDEX-0001-02)