8 research outputs found

    Escape strategy of the cockroach (Gromphadorhina portentosa) to heat and looming stimuli

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    Escape responses to aversive stimuli have been observed in insects, including species of cricket, fly, locust, and cockroach. The goal of this study was to investigate the escape strategy of the Madagascar cockroach, Gromphadorhina portentosa. In regard to this species, Erickson and colleagues (2015) showed that electrical stimulation of both cerci and antennae together could generate an escape response. However, in other reports (Olsen and Triblehorn, 2014), it was observed that wind could not elicit the escape response. In this study, G. portentosa was stimulated by looming and heat stimuli. A 2.5’’ black ball approaching at 1 m/s was used to mimic a predator and a laser was used to apply heat stimuli to the cockroach’s tarsi. The results showed that heat stimuli evoked robust turning and translation responses while the looming stimuli evoked small but significant translation but not turning. In conclusion, and in contrast to the literature, Madagascar cockroaches displayed robust escape responses to looming and especially heat stimuli

    MPXV DNA kinetics in bloodstream and other body fluids samples

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    Abstract Since spring 2022, the global epidemiology of the monkeypox virus (MPXV) has changed. The unprecedented increase of human clade II MPXV cases worldwide heightened concerns about this emerging zoonotic disease. We analysed the positivity rates, viral loads, infectiousness, and persistence of MPXV DNA for up to 4 months in several biological samples from 89 MPXV-confirmed cases. Our data showed that viral loads and positivity rates were higher during the first two weeks of symptoms for all sample types. Amongst no-skin-samples, respiratory specimens showed higher MPXV DNA levels and median time until viral clearance, suggesting their usefulness in supporting MPXV diagnosis, investigating asymptomatic patients, and monitoring viral shedding. Infectious virus was cultured from respiratory samples, semen, and stools, with high viral loads and collected within the first 10 days. Notably, only one saliva and one semen were found positive for viral DNA after 71 and 31 days from symptoms, respectively. The focus on bloodstream samples showed the best testing sensitivity in plasma, reporting the overall highest MPXV DNA detection rate and viral loads during the 3-week follow-up as compared to serum and whole-blood. The data here presented can be useful for MPXV diagnostics and a better understanding of the potential alternative routes of its onward transmission

    COVID-19 Convalescent Plasma Outpatient Therapy to Prevent Outpatient Hospitalization: A Meta-analysis of Individual Participant Data From Five Randomized Trials

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    BACKGROUND: Outpatient monoclonal antibodies are no longer effective and antiviral treatments for COVID-19 disease remain largely unavailable in many countries worldwide. Although treatment with COVID-19 convalescent plasma is promising, clinical trials among outpatients have shown mixed results. METHODS: We conducted an individual participant data meta-analysis from outpatient trials to assess the overall risk reduction for all-cause hospitalizations by day 28 in transfused participants. Relevant trials were identified by searching MEDLINE, Embase, MedRxiv, World Health Organization, Cochrane Library, and Web of Science from January 2020 to September 2022. RESULTS: Five included studies from four countries enrolled and transfused 2,620 adult patients. Comorbidities were present in 1,795 (69%). The virus neutralizing antibody dilutional titer levels ranged from 8 to 14,580 in diverse assays. 160 (12.2%) of 1315 control patients were hospitalized, versus 111 (8.5%) of 1305 COVID-19 convalescent plasma treated patients, yielding a 3.7% (95%CI: 1.3%-6.0%; p=.001) absolute risk reduction and 30.1% relative risk reduction for all-cause hospitalization. The hospitalization reduction was greatest in those with both early transfusion and high titer with a 7.6% absolute risk reduction (95%CI: 4.0%-11.1%; p=.0001) accompanied by at 51.4% relative risk reduction. No significant reduction in hospitalization was seen with treatment > 5 days after symptom onset or in those receiving COVID-19 convalescent plasma with antibody titers below the median titer. CONCLUSIONS: Among outpatients with COVID-19, treatment with COVID-19 convalescent plasma reduced the rate of all-cause hospitalization and may be most effective when given within 5 days of symptom onset and when antibody titer is higher
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