Oxidative status in feline pyometra

The oxidative status of the organism is dependent of the balance between oxidant reactants and antioxidant defenses. Oxidative stress develops when the oxidant reactants exceed the antioxidant defenses of the organism. The oxidative stress causes alterations in cellular metabolism and cellular damage. The antioxidant response of the organism can be assessed by determination of individual parameters such as total serum thiols (Thiol) and/or by determination of the total antioxidant capacity (TAC) of the organism. Parameters of oxidative status have proved to be useful biomarkers in several canine and feline diseases. Pyometra is considered one of the most important uterine diseases in cats. However, information about the oxidative status in queens with pyometra is lacking. Therefore, the main objectives of this study were to evaluate the oxidative status of feline pyometra through the determination of serum concentration of Thiol and TAC, and to evaluate the clinical evolution of these antioxidants in the post-ovariohysterectomy period. Serum concentrations of Thiol and TAC (determined by four different methodologies) were assessed in 17 queens with pyometra and in 13 healthy queens submitted to elective ovariohysterectomy (control group). Serum Thiol and TAC were also evaluated in six queens with pyometra at days two and 10 after surgery. Routine histopathology of the reproductive organs was performed in all animals, to confirm pyometra in the diseased queens, and to exclude uterine pathology in the control cats. At presentation, diseased queens presented significantly lower serum concentrations of Thiol and TAC than controls (P<0.001 in both cases). In the queens in which serial determinations of antioxidants were performed, serum Thiol and TAC were significantly higher at day 10 post-surgery than at presentation (P<0.05 in both cases). The results of the present study indicate that pyometra in queens is associated with presence of oxidative stress. Moreover, serum Thiol and TAC tended to evolve to physiologic values after surgery. Therefore, oxidative stress parameters could be useful in assessing the post-operative period in feline pyometra.O estado oxidativo do organismo depende do equilibrio entre os agentes oxidantes e os antioxidantes. O stresse oxidativo de senvolve-se quando os agentes oxidantes excedem a capacidade antioxidante do organismo. O stress oxidativo causa danos celulares, bem como alterações no seu metabolismo. A resposta antioxidante pode ser avaliada através da determinação de parâmetros individuais, tais como os tióis séricos, ou através da determinação da capacidade antioxidante total (TAC, do Inglês Total Antioxidant Capacity) do organismo. Diferentes parâmetros de avaliação do estado oxidativo do organismo provaram ser biomarcadores clinicamente úteis em diferentes doenças em cães e gatos. Contudo, existe falta de informação sobre o estado oxidativo em gatas com piómetra. Desta forma, os objetivos principais deste estudo foram avaliar o estado oxidativo em gatas diagnosticadas com piómetra, através da determinação dos níveis séricos de tióis e TAC (determinados através de quatro métodos diferentes: TEAC1, TEAC2, FRAP E CUPRAC), e avaliar a evolução clínica destes antioxidantes no período pós-ovariohisterectomia. As concentrações séricas de tióis e TAC foram determinadas em 17 gatas com piómetra (grupo em teste) e em 13 gatas saudáveis submetidas a ovariohisterectomia eletiva (grupo de controlo). Em seis gatas com piómetra foi possível efetuar o doseamento de tióis e TAC nos dias dois e 10 após a cirurgia. Foi realizada histopatologia dos órgãos reprodutores de todas as gatas incluídas no estudo, para comprovar a presença de piómetra nas gatas doentes, e para excluir doenças uterinas no grupo de controlo. No momento do diagnóstico, as gatas com piómetra apresentaram concentrações séricas de tióis e TAC significativamente inferiores às gatas do grupo de controlo (P<0,001 em ambos os casos). Nas gatas em que foi realizado um seguimento no período pós-cirurgia através de medições seriadas de antioxidantes, as concentrações de tióis e TAC apresentaram-se significativamente superiores no décimo dia pós-ovariohisterectomia que no dia do diagnóstico (P<0,05 em ambos os casos). Segundo os resultados obtidos neste estudo, em gatas a piómetra está associada ao desenvolvimento de stresse oxidativo. Para além disso, as concentrações séricas dos antioxidantes analisados tenderam a retomar os valores fisiológicos no período pós-ovariohisterectomia. Assim, estes parâmetros indicam utilidade clínica na monitorização do período pós cirúrgico em gatas com piómetra

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

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

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

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

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

Brazil in the face of new SARS-CoV-2 variantsemergencies and challenges in public health

Peer reviewedPublisher PD

Modelling the COVID-19 pandemic in context : An international participatory approach

Funding RA is funded by the Bill and Melinda Gates Foundation (OPP1193472). LW is funded by the Li Ka Shing Foundation. CF is funded by grant #2017/26770-8, São Paulo Research Foundation (FAPESP). The CoMo Consortium has support from the Oxford University COVID-19 Research Response Fund (ref: 0009280). Scientific writing assistance and editorial support was provided by Adam Bodley, according to Good Publication Practice guidelines.Peer reviewedPublisher PD

First-order perturbed Korteweg-de Vries solitons

We consider the Korteweg-de Vries equation with a perturbation arising naturally in many physical situations. Although being asymptotically integrable, we show that the corresponding perturbed solitons do not have the usual scattering properties. Specifically, we show that there is a solution, correct up to O(ε), where ε is the perturbative parameter, consisting, at t→ -∞ of two superposed deformed solitons characterized by wave numbers k1 and k2 that give rise, for t→ +∞, to the same but phase-shifted superposed solitons plus a coupling term depending on k1, and k2. We also find the condition on the original equation for which this coupling vanishes