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6.
Nat Ecol Evol ; 3(10): 1438-1444, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31558830

RESUMO

Climate change is causing major changes to marine ecosystems globally, with ocean acidification of particular concern for coral reefs. Using a 200 d in situ carbon dioxide enrichment study on Heron Island, Australia, we simulated future ocean acidification conditions, and found reduced pH led to a drastic decline in net calcification of living corals to no net growth, and accelerated disintegration of dead corals. Net calcification declined more severely than in previous studies due to exposure to the natural community of bioeroding organisms in this in situ study and to a longer experimental duration. Our data suggest that reef flat corals reach net dissolution at an aragonite saturation state (ΩAR) of 2.3 (95% confidence interval: 1.8-2.8) with 100% living coral cover and at ΩAR > 3.5 with 30% living coral cover. This model suggests that areas of the reef with relatively low coral mortality, where living coral cover is high, are likely to be resistant to carbon dioxide-induced reef dissolution.


Assuntos
Antozoários , Animais , Austrália , Ecossistema , Concentração de Íons de Hidrogênio , Água do Mar , Solubilidade
7.
World J Microbiol Biotechnol ; 35(5): 78, 2019 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-31087167

RESUMO

The increase in the CO2 concentration in the Earth's atmosphere has been a topic of worldwide concern since anthropogenic emissions of greenhouse gases began increasing considerably during the industrial period. The effects of these mass emissions are probably the main cause of global warming, which has been observed over recent decades. Among the various techniques of CO2 capture, microalgal biofixation by photosynthesis is considered a promising technology due to the efficiency of these microorganisms in converting this gas into organic compounds through its use as a nutrient in the culture medium. Over the years, several research centers have developed studies on this subject, which have focused on mainly the development of bioreactors, the growth conditions that increase the efficiency of the process and the production of biomass with applicability in several areas. The biological mitigation of CO2 by microalgae has many advantages, including reductions in the concentration of an industrially sourced greenhouse gas and the energy or food obtained from the produced photosynthetic biomass. This versatility allows for the cultivation of economically useful biomass while reducing the environmental impacts of industrial facilities. In this context, this mini-review aims to discuss new technologies and strategies along with the main challenges and future prospects in the field and the ecological and economic impacts of CO2 biofixation by microalgae.


Assuntos
Ciclo do Carbono , Dióxido de Carbono/metabolismo , Microalgas/crescimento & desenvolvimento , Microalgas/metabolismo , Biomassa , Reatores Biológicos , Ecologia , Economia , Aquecimento Global , Gases de Efeito Estufa
8.
Nature ; 565(7738): 222-225, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30568300

RESUMO

Increasing human populations around the global coastline have caused extensive loss, degradation and fragmentation of coastal ecosystems, threatening the delivery of important ecosystem services1. As a result, alarming losses of mangrove, coral reef, seagrass, kelp forest and coastal marsh ecosystems have occurred1-6. However, owing to the difficulty of mapping intertidal areas globally, the distribution and status of tidal flats-one of the most extensive coastal ecosystems-remain unknown7. Here we present an analysis of over 700,000 satellite images that maps the global extent of and change in tidal flats over the course of 33 years (1984-2016). We find that tidal flats, defined as sand, rock or mud flats that undergo regular tidal inundation7, occupy at least 127,921 km2 (124,286-131,821 km2, 95% confidence interval). About 70% of the global extent of tidal flats is found in three continents (Asia (44% of total), North America (15.5% of total) and South America (11% of total)), with 49.2% being concentrated in just eight countries (Indonesia, China, Australia, the United States, Canada, India, Brazil and Myanmar). For regions with sufficient data to develop a consistent multi-decadal time series-which included East Asia, the Middle East and North America-we estimate that 16.02% (15.62-16.47%, 95% confidence interval) of tidal flats were lost between 1984 and 2016. Extensive degradation from coastal development1, reduced sediment delivery from major rivers8,9, sinking of riverine deltas8,10, increased coastal erosion and sea-level rise11 signal a continuing negative trajectory for tidal flat ecosystems around the world. Our high-spatial-resolution dataset delivers global maps of tidal flats, which substantially advances our understanding of the distribution, trajectory and status of these poorly known coastal ecosystems.


Assuntos
Ecossistema , Mapeamento Geográfico , Sedimentos Geológicos/análise , Ondas de Maré , Ásia , América do Norte , Reprodutibilidade dos Testes , Imagens de Satélites , América do Sul
9.
J Pediatr ; 167(6): 1196-201, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26340879

RESUMO

For over 25 years, with medical advances increasing the lifespan of YYASHCN, we have been aware of the need to improve health care transition to adult-based care services. Barriers to health care transition have been identified and in a number of settings, recognition of the problem and preliminary success has been achieved for pilot programs. Evidence-based solutions to improve health care transition for YYASHCN are needed. There are barriers at the patient, family, pediatric, and adult provider, and insurance system levels that must be overcome.


Assuntos
Acessibilidade aos Serviços de Saúde , Necessidades e Demandas de Serviços de Saúde , Transição para Assistência do Adulto , Adolescente , Adulto , Criança , Humanos , Pediatria , Adulto Jovem
10.
Sci Rep ; 5: 7694, 2015 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-25582836

RESUMO

Coral reefs globally are declining rapidly because of both local and global stressors. Improved monitoring tools are urgently needed to understand the changes that are occurring at appropriate temporal and spatial scales. Coral fluorescence imaging tools have the potential to improve both ecological and physiological assessments. Although fluorescence imaging is regularly used for laboratory studies of corals, it has not yet been used for large-scale in situ assessments. Current obstacles to effective underwater fluorescence surveying include limited field-of-view due to low camera sensitivity, the need for nighttime deployment because of ambient light contamination, and the need for custom multispectral narrow band imaging systems to separate the signal into meaningful fluorescence bands. Here we describe the Fluorescence Imaging System (FluorIS), based on a consumer camera modified for greatly increased sensitivity to chlorophyll-a fluorescence, and we show high spectral correlation between acquired images and in situ spectrometer measurements. This system greatly facilitates underwater wide field-of-view fluorophore surveying during both night and day, and potentially enables improvements in semi-automated segmentation of live corals in coral reef photographs and juvenile coral surveys.


Assuntos
Recifes de Corais , Imageamento Tridimensional , Espectrometria de Fluorescência/métodos , Animais , Automação , Luz , Panamá , Polinésia
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