RESUMO
In the shift from the balance of nature to the flux of nature paradigm, the concept of resilience has gained great traction in ecology. While it has been suggested that the concept of resilience does not imply a genuine departure from the balance of nature paradigm, I shall argue against this stance. To do so, I first show that the balance of nature paradigm and the related conception of a single-state equilibrium relies on what Eliot Sober has named the "Natural State Model (NSM)", suggesting that the NSM has instead been dismissed in the flux of nature paradigm. I then focus on resilience as the main explanatory concept of the flux paradigm. After distinguishing between two main different understandings of "resilience", namely engineering resilience and ecological resilience, I argue that the former is close to the concept of balance or stability and still part of the NSM, while the latter is not. Finally, I claim that ecological resilience is inconsistent with the NSM, concluding that this concept-being incompatible with the NSM-is not part of the balance of nature paradigm but rather a genuinely new explanatory tool.
Assuntos
EcologiaRESUMO
Background: Convalescent plasma (CP), despite limited evidence on its efficacy, is being widely used as a compassionate therapy for hospitalized patients with COVID-19. We aimed to evaluate the efficacy and safety of early CP therapy in COVID-19 progression. Methods: Open-label, single-center, randomized clinical trial performed in an academic center in Santiago, Chile from May 10, 2020, to July 18, 2020, with final follow-up August 17, 2020. The trial included patients hospitalized within the first 7 days of COVID-19 symptoms onset, presenting risk factors for illness progression and not on mechanical ventilation. The intervention consisted in immediate CP (early plasma group) versus no CP unless developing pre-specified criteria of deterioration (deferred plasma group). Additional standard treatment was allowed in both arms. The primary outcome was a composite of mechanical ventilation, hospitalization for >14 days or death. Key secondary outcomes included: time to respiratory failure, days of mechanical ventilation, hospital length-of-stay, mortality at 30 days, and SARS-CoV-2 RT-PCR clearance rate. Results: Of 58 randomized patients (mean age, 65.8 years, 50% male), 57 (98.3%) completed the trial. A total of 13 (43.3%) participants from the deferred group received plasma based on clinical aggravation. We found no benefit in the primary outcome (32.1% vs 33.3%, OR 0.95, 95% CI 0.32-2.84, p>0.99) in the early versus deferred CP group. In-hospital mortality rate was 17.9% vs 6.7% (OR 3.04, 95% CI 0.54-17.2, p=0.25), mechanical ventilation 17.9% vs 6.7% (OR 3.04, 95% CI 0.54-17.2, p=0.25), and prolonged hospitalization 21.4% vs 30% (OR 0.64, 95%CI, 0.19-2.1, p=0.55) in early versus deferred CP group, respectively. Viral clearance rate on day 3 (26% vs 8%, p=0.20) and day 7 (38% vs 19%, p=0.37) did not differ between groups. Two patients experienced serious adverse events within 6 or less hours after plasma transfusion. Conclusion: Immediate addition of CP therapy in early stages of COVID-19 -compared to its use only in case of patient deterioration- did not confer benefits in mortality, length of hospitalization or mechanical ventilation requirement.
