41 research outputs found

    Global impacts of projected climate changes on the extent and aboveground biomass of mangrove forests

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    Aim: Over the past 50 years, anthropogenic activities have led to the disappearance of approximately one-third of the world's mangrove forests and their associated ecosystem services. The synergetic combined effect of projected climate change is likely to further impact mangroves in the years to come, whether by range expansions associated with warming at higher latitudes or large-scale diebacks linked to severe droughts. We provide an estimate of future changes in the extent and aboveground biomass (AGB) of mangrove forests at global scales by considering contrasting Representative Concentration Pathway scenarios (decade 2090-2100 under RCP 2.6 in line with the Paris Agreement expectations, and RCP 8.5 of higher emissions). Location: Global. Methods: Boosted regression trees fitted occurrence and AGB of mangroves against high-resolution biologically meaningful data on air temperature, precipitation, wave energy, slope and distance to river Deltas. Results: On the global scale, models produced for present-day conditions retrieved high accuracy scores and estimated a total area of 12,780,356 ha and overall biomass of 2.29 Pg, in line with previous estimates. Model projections showed poleward shifts along temperate regions, which translated into comparable gains in total area, regardless of the RCP scenario (area change RCP 2.6: 17.29%; RCP 8.5: 15.77%). However, biomass changes were dependent on the emission scenario considered, remaining stable or even increasing under RCP 2.6, or undergoing severe losses across tropical regions under RCP 8.5 (overall biomass change RCP 2.6: 12.97%; RCP 8.5: -11.51%). Such losses were particularly aggravated in countries located in the Tropical Atlantic and Eastern Pacific, and the Western and Eastern Indo-Pacific regions (regions with losses above similar to 20% in overall biomass). Conclusions: Our global estimates highlight the potential effect of future climate changes on mangrove forests and how broad compliance with the Paris Agreement may counteract severe trajectories of loss. The projections made, also provided at the country level, serve as new baselines to evaluate changes in mangrove carbon sequestration and ecosystem services, strongly supporting policy-making and management directives, as well as to guide restoration actions considering potential future changes in niche availability.info:eu-repo/semantics/publishedVersio

    Phenotypic plasticity in sargassum forests may not counteract projected biomass losses along a broad latitudinal gradient

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    Phenotypic plasticity and local adaptation can adjust individual responses to environmental changes across species' ranges. Studies addressing the implications of such traits have been underrepresented in the marine environment. Sargassum cymosum represents an ideal model to test phenotypic plasticity, as populations along the southwestern Atlantic Ocean display a sharp decrease in abundance toward distributional range limits. We (1) characterized the macroecological environment of S. cymosum across a latitudinal gradient, (2) evaluated potential differences in ecophysiological adjustments (biomass, photosynthetic pigments, phenolic compounds, total soluble sugars and proteins, and carbon-nitrogen-CN-content), and (3) tested for differences in thermal tolerance based on time series analyses produced from the present to contrasting representative concentration pathways scenarios (RCP) of future climate changes. Our results showed distinct macroecological environments, corresponding to tropical and warm temperate conditions, driving biomass and ecophysiological adjustments of S. cymosum. Populations from the two environments displayed contrasting thermal tolerances, with tropical individuals better coping with thermal stress when compared to more temperate ones (lethal temperatures of 33 degrees C vs. 30 degrees C); yet both populations lose biomass in response to increasing thermal stress while increasing secondary metabolites (for example, carotenoids and phenolic compounds) and decrease chlorophyll's content, Fv/Fm, total soluble sugars concentration and CN ratio, owing to oxidative stress. Despite evidence for phenotypic plasticity, significant future losses might occur in both tropical and warm temperate populations, particularly under the no mitigation RCP scenario, also known as the business as usual (that is, 8.5). In this context, broad compliance with the Paris Agreement might counteract projected impacts of climate change, safeguarding Sargassum forests in the years to come.This study was supported by grants from Boticario Foundation, FAPESC-Foundation Support Research and Innovation in the State of Santa Catarina, Capes Higher Education Personnel Improvement Coordination, CNPq-National Council for Scientific and Technological Development, Petrobras Ambiental, REBENTOS-Habitat monitoring network coastal Benthic and ProspecMar-Islands Sustainable Prospecting in Ocean Islands: Biodiversity, Chemistry, Ecology and Biotechnology, Rede Coral Vivo, REDEALGAS, a Pew Marine Fellowship, the Foundation for Science and Technology (FCT) of Portugal via SFRH/BSAB/150485/2019, SFRH/BD/144878/2019, UID/Multi/04326/2019, PTDC/BIA-CBI/6515/2020 and the transitional norm DL57/2016/CP1361/CT0035. LPG received a doctorate scholarship (88882.438723/2019-01) from Capes. CFDG thanks CNPq grants PQ-309658/2016-0and306304/2019-8. PAH thanks CAPES-Senior Visitor, CAPESPrInt 310793/2018-01, CNPq-PVE 407365/2013-3, CNPq-Universal 426215/2016-8 and CNPq-PQ308537/2019-0. GK received a master's scholarship from CAPES.info:eu-repo/semantics/submittedVersio

    Risk factors for physical disability in patients with leprosy: a systematic review and meta analysis

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    Abstract Importance: The World Health Organization (WHO) 2016–2020 Global Leprosy Strategy aims to reinvigorate efforts to control leprosy and avert leprosy disability to less than one per million population. Objective: This study aimed to identify systematically clinical factors associated with physical disability in patients with leprosy. Data source: Searches were performed in Scopus, PubMed and Web of Science databases to identify studies published up to May 2018, using the keywords leprosy and physical disability and related terms. Study selection: We included studies that evaluated patients using the WHO leprosy disability grading and reported the number of patients with and without disability by clinical characteristics. Data Extraction and Synthesis: The study was conducted following the Meta-Analysis of Observational Studies in Epidemiology (MOOSE) statement. We used the odds ratio (OR) as a measure of association between the clinical features and physical disability. Summary estimates were calculated using random-effects models. Main Outcome(s) and Measure(s): Our primary outcome was physical disability according the WHO disability classification. We evaluated the association between clinical features and physical disability. Results: Thirty-two studies were included in the systematic review. Males were more likely to have physical disability than females (pooled OR: 1.66; CI95% 1.43-1.93). Multibacillary (MB) leprosy were 4-fold more likely to have physical disability than paucibacillary (PB) leprosy 4 patients (pooled OR 4.32; CI95% 3.37-5.53). Patients having leprosy reactions were more likely to have disability (pooled OR 2.43, CI95% 1.35-4.36). Patients with lepromatous leprosy experienced 5- to 12-fold higher odds of disability. Conclusion and Relevance: This systematic review and meta-analysis confirms the strong association between the presence of physical disabilities and male gender, MB leprosy, leprosy reactions and lepromatous presentation. These findings can guide the development of targeted interventions to identify early individuals at greater risk of developing physical disabilities and education campaigns to promote early consultation to institute treatment for leprosy reactions and to prevent physical disability

    Skin color and severe maternal outcomes: evidence from the brazilian network for surveillance of severe maternal morbidity

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    Taking into account the probable role that race/skin color may have for determining outcomes in maternal health, the objective of this study was to assess whether maternal race/skin color is a predictor of severe maternal morbidity. This is a secondary analysis of the Brazilian Network for Surveillance of Severe Maternal Morbidity, a national multicenter cross-sectional study of 27 Brazilian referral maternity hospitals. A prospective surveillance was performed to identify cases of maternal death (MD), maternal near miss (MNM) events, and potentially life-threatening conditions (PLTC), according to standard WHO definition and criteria. Among 9,555 women with severe maternal morbidity, data on race/skin color was available for 7,139 women, who were further divided into two groups: 4,108 nonwhite women (2,253 black and 1,855 from other races/skin color) and 3,031 white women. Indicators of severe maternal morbidity according to WHO definition are shown by skin color group. Adjusted Prevalence Ratios (PRadj - 95%CI) for Severe Maternal Outcome (SMO=MNM+MD) were estimated according to sociodemographic/obstetric characteristics, pregnancy outcomes, and perinatal results considering race. Results. Among 7,139 women with severe maternal morbidity evaluated, 90.5% were classified as PLTC, 8.5% as MNM, and 1.6% as MD. There was a significantly higher prevalence of MNM and MD among white women. MNMR (maternal near miss ratio) was 9.37 per thousand live births (LB). SMOR (severe maternal outcome ratio) was 11.08 per 1000 LB, and MMR (maternal mortality ratio) was 170.4 per 100,000 LB. Maternal mortality to maternal near miss ratio was 1 to 5.2, irrespective of maternal skin color. Hypertension, the main cause of maternal complications, affected mostly nonwhite women. Hemorrhage, the second more common cause of maternal complication, predominated among white women. Nonwhite skin color was associated with a reduced risk of SMO in multivariate analysis. Nonwhite skin color was associated with a lower risk for severe maternal outcomes. This result could be due to confounding factors linked to a high rate of Brazilian miscegenation.2019CNPQ - Conselho Nacional de Desenvolvimento Científico e Tecnológico402702/2008-

    The footprint of continental-scale ocean currents on the biogeography of seaweeds

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    Explaining spatial patterns of biological organisation remains a central challenge for biogeographic studies. In marine systems, large-scale ocean currents can modify broad-scale biological patterns by simultaneously connecting environmental (e.g. temperature, salinity and nutrients) and biological (e.g. amounts and types of dispersed propagules) properties of adjacent and distant regions. For example, steep environmental gradients and highly variable, disrupted flow should lead to heterogeneity in regional communities and high species turnover. In this study, we investigated the possible imprint of the Leeuwin (LC) and East Australia (EAC) Currents on seaweed communities across ~7,000 km of coastline in temperate Australia. These currents flow poleward along the west and east coasts of Australia, respectively, but have markedly different characteristics. We tested the hypothesis that, regional seaweed communities show serial change in the direction of current flow and that, because the LC is characterised by a weaker temperature gradient and more un-interrupted along-shore flow compared to the EAC, then coasts influenced by the LC have less variable seaweed communities and lower species turnover across regions than the EAC. This hypothesis was supported. We suggest that this pattern is likely caused by a combination of seaweed temperature tolerances and current-driven dispersal. In conclusion, our findings support the idea that the characteristics of continental-scale currents can influence regional community organisation, and that the coupling of ocean currents and marine biological structure is a general feature that transcends taxa and spatial scales.Thomas Wernberg, Mads S. Thomsen, Sean D. Connell, Bayden D. Russell, Jonathan M. Waters, Giuseppe C. Zuccarello, Gerald T. Kraft, Craig Sanderson, John A. West, Carlos F. D. Gurge

    Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

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    Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt
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