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1.
Sci Total Environ ; 917: 170363, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38308900

RESUMEN

Living shorelines aim to enhance the resilience of coastlines to hazards while simultaneously delivering co-benefits such as carbon sequestration. Despite the potential ecological and socio-economic benefits of living shorelines over conventional engineered coastal protection structures, application is limited globally. Australia has a long and diverse coastline that provides prime opportunities for living shorelines using beaches and dunes, vegetation, and biogenic reefs, which may be either natural ('soft' approach) or with an engineered structural component ('hybrid' approach). Published scientific studies, however, have indicated limited use of living shorelines for coastal protection in Australia. In response, we combined a national survey and interviews of coastal practitioners and a grey and peer-reviewed literature search to (1) identify barriers to living shoreline implementation; and (2) create a database of living shoreline projects in Australia based on sources other than scientific literature. Projects included were those that had either a primary or secondary goal of protection of coastal assets from erosion and/or flooding. We identified 138 living shoreline projects in Australia through the means sampled starting in 1970; with the number of projects increasing through time particularly since 2000. Over half of the total projects (59 %) were considered to be successful according to their initial stated objective (i.e., reducing hazard risk) and 18 % of projects could not be assessed for their success based on the information available. Seventy percent of projects received formal or informal monitoring. Even in the absence of peer-reviewed support for living shoreline construction in Australia, we discovered local and regional increases in their use. This suggests that coastal practitioners are learning on-the-ground, however more generally it was stated that few examples of living shorelines are being made available, suggesting a barrier in information sharing among agencies at a broader scale. A database of living shoreline projects can increase knowledge among practitioners globally to develop best practice that informs technical guidelines for different approaches and helps focus attention on areas for further research.


Asunto(s)
Secuestro de Carbono , Inundaciones , Australia
2.
Reg Environ Change ; 23(2): 66, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37125023

RESUMEN

Nearly a billion people depend on tropical seascapes. The need to ensure sustainable use of these vital areas is recognised, as one of 17 policy commitments made by world leaders, in Sustainable Development Goal (SDG) 14 ('Life below Water') of the United Nations. SDG 14 seeks to secure marine sustainability by 2030. In a time of increasing social-ecological unpredictability and risk, scientists and policymakers working towards SDG 14 in the Asia-Pacific region need to know: (1) How are seascapes changing? (2) What can global society do about these changes? and (3) How can science and society together achieve sustainable seascape futures? Through a horizon scan, we identified nine emerging research priorities that clarify potential research contributions to marine sustainability in locations with high coral reef abundance. They include research on seascape geological and biological evolution and adaptation; elucidating drivers and mechanisms of change; understanding how seascape functions and services are produced, and how people depend on them; costs, benefits, and trade-offs to people in changing seascapes; improving seascape technologies and practices; learning to govern and manage seascapes for all; sustainable use, justice, and human well-being; bridging communities and epistemologies for innovative, equitable, and scale-crossing solutions; and informing resilient seascape futures through modelling and synthesis. Researchers can contribute to the sustainability of tropical seascapes by co-developing transdisciplinary understandings of people and ecosystems, emphasising the importance of equity and justice, and improving knowledge of key cross-scale and cross-level processes, feedbacks, and thresholds.

3.
J Cachexia Sarcopenia Muscle ; 13(6): 2608-2615, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35945660

RESUMEN

Sarcopenia is an increasingly recognized complication of cirrhosis that is associated with morbidity and mortality. Differences in the prevalence and prognosis of sarcopenia between men and women have been reported in other patient groups, but there is insufficient understanding of how sex impacts the prognostic value of sarcopenia in cirrhosis. A search of MEDLINE and Embase was conducted from earliest entries to April 2021. Studies were included if they examined sex-stratified mortality impact of reduced muscle function or mass in outpatient populations with cirrhosis. We identified 700 studies of which 6 were deemed relevant for inclusion in this narrative review. Studies of interest were heterogeneous, precluding pooling of data and making interpretation of the literature challenging. Muscle mass was assessed in five studies (n = 2566, 1730 men, 836 women) and was reduced in 36-50% of men and 24-43% of women. All five studies found that reduced muscle mass determined by computed tomography, dual-energy X-ray absorptiometry, and bioelectrical impedance analysis was associated with increased mortality in men. Of these, two studies identified a corresponding relationship in women; reduced muscle mass defined by computed tomography was associated with increased mortality [hazard ratio (HR) 2.82, P = 0.001], while increasing muscle mass by bioelectrical impedance analysis likewise conferred a survival benefit (HR 0.45, P = 0.0016). Only one study assessed the relationship of muscle function with sex-stratified mortality (n = 1405, 827 men, 578 women), concluding that reduced muscle function predicted mortality in both men and women (HR 1.65, P < 0.001 and HR 1.54, P < 0.001, respectively). Reduced muscle mass in cirrhosis is consistently associated with mortality in men, but lack of sex-stratification of mortality analyses limits the ability to make strong conclusions about the impact of sarcopenia specifically in women, with even fewer data available for analysing muscle function. Improved understanding of the sex-specific impacts of sarcopenia may help address patient deterioration and mortality while awaiting liver transplantation and allow for early intervention to mitigate mortality risk. Large, multicentre studies with adequate female participation and sex-stratified mortality analyses are warranted.


Asunto(s)
Trasplante de Hígado , Sarcopenia , Masculino , Femenino , Humanos , Pronóstico , Sarcopenia/diagnóstico , Sarcopenia/epidemiología , Sarcopenia/etiología , Cirrosis Hepática/complicaciones , Cirrosis Hepática/diagnóstico , Absorciometría de Fotón/efectos adversos
4.
ANZ J Surg ; 92(10): 2571-2576, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35642258

RESUMEN

BACKGROUND: Repeat colonoscopy may be required for tumour localisation. The aim of the study is to explore the clinical settings it was used and benchmark the quality of initial colonoscopy against standardized guidelines for tumour localisation, tattooing and colonoscopy reporting amongst clinicians. METHODS: A retrospective study from 2016 to 2021 has been performed on patients who underwent elective colorectal cancer resections at the Northern Hospital. Patient demographics, colonoscopic and operative details were retrieved from the Bi-National Colorectal Cancer Audit (BCCA) Registry database and hospital medical records. PRIMARY OUTCOMES: changes in operative approach and delays to operation. SECONDARY OUTCOMES: reasons for a repeat colonoscopy and complications from repeat colonoscopy. RESULTS: A total of 339 patients were included in this study. 94 (28.6%) underwent a repeat colonoscopy. Re-scoping rate was 29.6% for surgeons, and 26.2% for non-operating endoscopists. Surgeons had a 5.9% localisation error rate, and non-operating endoscopist 6.95% (p = 0.673). Surgeons did not have a lower rate of repeat colonoscopy (p = 0.462). Repeat endoscopy was associated with a longer time to definitive operation (p < 0.001). No complications were associated with a repeat colonoscopy. CONCLUSION: There was no difference in localisation error rates or repeat colonoscopy amongst surgeons (29.6%) and non-operating endoscopists (26.2%) (p = 0.462). This could be explained by the standardized endoscopy training in Australia governed by a common training board. Lack of tattooing at index colonoscopy and inadequate documentation often led to a repeat endoscopy, which was associated with a longer time to definitive operation. Standardized guidelines in tattooing of lesions and colonoscopy reporting should be implemented.


Asunto(s)
Neoplasias Colorrectales , Tatuaje , Colonoscopía , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/cirugía , Endoscopía Gastrointestinal , Humanos , Estudios Retrospectivos
5.
Cont Shelf Res ; 245: 104794, 2022 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-35719127

RESUMEN

The global COVID-19 pandemic has seen extended lockdowns, isolation periods and travel restrictions across many countries around the world since early 2020. Some countries, such as Australia and New Zealand, closed their international borders in early 2020 preventing researchers travelling to other parts of the world. To facilitate the exposure of our students' work, and for them to meet international researchers, as well as foster a sense of coastal community, we started a zoominar series (seminars via Zoom) in April 2020. The Coast2Coast zoominar series had therefore humble origins but we soon discovered that there was an appetite for more widely sharing science across the coastal research disciplines. The Coast2Coast zoominar grew rapidly, attracting researchers from many countries around the world who presented and attended fortnightly online seminars. In just one year and a half we had 38 presentations with roughly 1900 attendees, creating a sense of community and belonging for the researchers involved. In early 2021, two of the co-authors, Giovanni (GC) and Ana (AVC) decided to expand and take this sense of community further creating the Coast2Cast podcast series, where researchers are asked research and non-research questions. In only 7 months, the podcasts have attracted more than 3700 listeners. Importantly, while the main prerequisite was high-quality and impactful research, diversity and inclusion were also a priority in selecting and inviting speakers for the zoominars and guests for the podcast. Importantly, our survey results suggest that there is a place for online events similar to Coast2Coast and Coast2Cast in a pandemic-free future, and that the coastal community involved has greatly benefited from such initiatives.

6.
Philos Trans R Soc Lond B Biol Sci ; 377(1854): 20210124, 2022 07 04.
Artículo en Inglés | MEDLINE | ID: mdl-35574851

RESUMEN

Atoll societies have adapted their environments and social systems for thousands of years, but the rapid pace of climate change may bring conditions that exceed their adaptive capacities. There is growing interest in the use of 'nature-based solutions' to facilitate the continuation of dignified and meaningful lives on atolls through a changing climate. However, there remains insufficient evidence to conclude that these can make a significant contribution to adaptation on atolls, let alone to develop standards and guidelines for their implementation. A sustained programme of research to clarify the potential of nature-based solutions to support the habitability of atolls is therefore vital. In this paper, we provide a prospectus to guide this research programme: we explain the challenge climate change poses to atoll societies, discuss past and potential future applications of nature-based solutions and outline an agenda for transdisciplinary research to advance knowledge of the efficacy and feasibility of nature-based solutions to sustain the habitability of atolls. This article is part of the theme issue 'Nurturing resilient marine ecosystems'.


Asunto(s)
Cambio Climático , Ecosistema , Aclimatación
7.
Proc Natl Acad Sci U S A ; 118(21)2021 05 25.
Artículo en Inglés | MEDLINE | ID: mdl-33972407

RESUMEN

Ocean warming and acidification threaten the future growth of coral reefs. This is because the calcifying coral reef taxa that construct the calcium carbonate frameworks and cement the reef together are highly sensitive to ocean warming and acidification. However, the global-scale effects of ocean warming and acidification on rates of coral reef net carbonate production remain poorly constrained despite a wealth of studies assessing their effects on the calcification of individual organisms. Here, we present global estimates of projected future changes in coral reef net carbonate production under ocean warming and acidification. We apply a meta-analysis of responses of coral reef taxa calcification and bioerosion rates to predicted changes in coral cover driven by climate change to estimate the net carbonate production rates of 183 reefs worldwide by 2050 and 2100. We forecast mean global reef net carbonate production under representative concentration pathways (RCP) 2.6, 4.5, and 8.5 will decline by 76, 149, and 156%, respectively, by 2100. While 63% of reefs are projected to continue to accrete by 2100 under RCP2.6, 94% will be eroding by 2050 under RCP8.5, and no reefs will continue to accrete at rates matching projected sea level rise under RCP4.5 or 8.5 by 2100. Projected reduced coral cover due to bleaching events predominately drives these declines rather than the direct physiological impacts of ocean warming and acidification on calcification or bioerosion. Presently degraded reefs were also more sensitive in our analysis. These findings highlight the low likelihood that the world's coral reefs will maintain their functional roles without near-term stabilization of atmospheric CO2 emissions.


Asunto(s)
Antozoos/fisiología , Carbonato de Calcio/metabolismo , Cambio Climático , Arrecifes de Coral , Animales , Antozoos/química , Carbonato de Calcio/química , Humanos , Concentración de Iones de Hidrógeno , Océanos y Mares , Agua de Mar/química
8.
PLoS One ; 15(10): e0239978, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33079939

RESUMEN

Coral bleaching driven by ocean warming is one of the most visible ecological impacts of climate change and perhaps the greatest threat to the persistence of reefs in the coming decades. In the absence of returning atmospheric greenhouse gas concentrations to those compatible with ocean temperatures below the mass coral bleaching temperature thresholds, the most straightforward means to reduce thermal-stress induced bleaching is to cool water at the seabed. The feasibility of reducing the seabed temperature through cool-water injections is considered first by analysing the feasibility of doing so on 19 reefs with differing physical environments using a simple residence time metric in 200 m resolution hydrodynamic model configurations. We then concentrate on the reefs around Lizard Island, the most promising candidate of the 19 locations, and develop a 40 m hydrodynamic model to investigate the effect of the injection of cool water at differing volumetric rates. Injecting 27°C seawater at a rate of 5 m3 s-1 at 4 sites in early 2017 cooled 97 ha of the reef by 0.15°C or more. The power required to pump 5 m3 s-1 through a set of pipes over a distance of 3 km from a nearby channel is ∼466 kW. This power applied at 4 sites for 3 months achieves a 2 Degree Heating Weeks (DHWs) reduction on 97 ha of reef. A more precise energy costing will require further expert engineering design of the pumping equipment and energy sources. Even for the most physically favourable reefs, cool-water transported through pipes and injected at a reef site is energy expensive and cannot be scaled up to any meaningful fraction of the 3,100 reefs of the GBR. Should priority be given to reducing thermal stress on one or a few high value reefs, this paper provides a framework to identify the most promising sites.


Asunto(s)
Antozoos/fisiología , Arrecifes de Coral , Estrés Fisiológico , Animales , Frío , Ecosistema , Hidrodinámica , Agua de Mar/química
9.
J Environ Manage ; 268: 110666, 2020 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-32510431

RESUMEN

The worlds' coral reefs are declining due to the combined effects of natural disturbances and anthropogenic pressures including thermal coral bleaching associated with global climate change. Nearshore corals are receiving increased anthropogenic stress from coastal development and nutrient run-off. Considering forecast increases in global temperatures, greater understanding of drivers of recovery on nearshore coral reefs following widespread bleaching events is required to inform management of local stressors. The west Pilbara coral reefs, with cross-shelf turbidity gradients coupled with a large nearby dredging program and recent history of repeated coral bleaching due to heat stress, represent an opportune location to study recovery from multiple disturbances. Mean coral cover at west Pilbara reefs was monitored from 2009 to 2018 and declined from 45% in 2009 to 5% in 2014 following three heat waves. Recruitment and juvenile abundance of corals were monitored from 2014 to 2018 and were combined with biological and physical data to identify which variables enhanced or hindered early-stage coral recovery of all hard corals and separately for the acroporids, the genera principally responsible for recovery in the short-term (<7 years). From 2014 to 2018, coral cover increased from 5 to 10% but recovery varied widely among sites (0-13%). Hard coral cover typically recovered most at shallower sites that had higher abundance of herbivorous fish, less macroalgae, and lower turbidity. Similarly, acroporid corals recovered most at sites with lower turbidity and macroalgal cover. Juvenile acroporid densities were a good indicator of recovery at least two years after they were recorded. However, recruitment to settlement tiles was not a good predictor of total coral or acroporid recovery. This study shows that coral recovery can be slower in areas of high turbidity and the rate may be reduced by local pressures, such as dredging. Management should focus on improving or maintaining local water quality to increase the likelihood of coral recovery under climate stress. Further, in turbid environments, juvenile coral density predicts early coral recovery better than recruits on tiles and may be a more cost-effective technique for monitoring recovery potential.


Asunto(s)
Antozoos , Algas Marinas , Animales , Cambio Climático , Arrecifes de Coral , Peces
10.
Glob Chang Biol ; 26(8): 4302-4315, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32459881

RESUMEN

Tropical cyclones generate extreme waves that can damage coral reef communities. Recovery typically requires up to a decade, driving the trajectory of coral community structure. Coral reefs have evolved over millennia with cyclones. Increasingly, however, processes of recovery are interrupted and compromised by additional pressures (thermal stress, pollution, diseases, predators). Understanding how cyclones interact with other pressures to threaten coral reefs underpins spatial prioritization of conservation and management interventions. Models that simulate coral responses to cumulative pressures often assume that the worst cyclone wave damage occurs within ~100 km of the track. However, we show major coral loss at exposed sites up to 800 km from a cyclone that was both strong (high sustained wind speeds >=33 m/s) and big (widespread circulation >~300 km), using numerical wave models and field data from northwest Australia. We then calculate the return time of big and strong cyclones, big cyclones of any strength and strong cyclones of any size, for each of 150 coral reef ecoregions using a global data set of past cyclones from 1985 to 2015. For the coral ecoregions that regularly were exposed to cyclones during that time, we find that 75% of them were exposed to at least one cyclone that was both big and strong. Return intervals of big and strong cyclones are already less than 5 years for 13 ecoregions, primarily in the cyclone-prone NW Pacific, and less than 10 years for an additional 14 ecoregions. We identify ecoregions likely at higher risk in future given projected changes in cyclone activity. Robust quantification of the spatial distribution of likely cyclone wave damage is vital not only for understanding past coral response to pressures, but also for predicting how this may change as the climate continues to warm and the relative frequency of the strongest cyclones rises.


Asunto(s)
Antozoos , Tormentas Ciclónicas , Animales , Australia , Clima , Arrecifes de Coral
11.
Abdom Radiol (NY) ; 45(1): 45-54, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31705250

RESUMEN

PURPOSE: Prior iterative reconstruction (PIR) spatially registers CT image data from multiple phases of enhancement to reduce image noise. We evaluated PIR in contrast-enhanced multiphase liver CT. METHODS: Patients with archived projection CT data with proven malignant or benign liver lesions, or without lesions, by reference criteria were included. Lower-dose PIR images were reconstructed using validated noise insertion from multiphase CT exams (50% dose in 2 phases, 25% dose in 1 phase). The phase of enhancement most relevant to the diagnostic task was selected for evaluation. Four radiologists reviewed routine-dose and lower-dose PIR images, circumscribing liver lesions and rating confidence for malignancy (0 to 100) and image quality. JAFROC Figures of Merit (FOM) were calculated. RESULTS: 31 patients had 60 liver lesions (28 primary hepatic malignancies, 6 hepatic metastases, 26 benign lesions). Pooled JAFROC FOM for malignancy for routine-dose CT was 0.615 (95% CI 0.464, 0.767) compared to 0.662 for PIR (95% CI 0.527, 0.797). The estimated FOM difference between the routine-dose and lower-dose PIR images was + 0.047 (95% CI - 0.023, + 0.116). Pooled sensitivity/specificity for routine-dose images was 70%/68% compared to 73%/66% for lower-dose PIR. Lower-dose PIR had lower diagnostic image quality (mean 3.8 vs. 4.2, p = 0.0009) and sharpness (mean 2.3 vs. 2.0, p = 0.0071). CONCLUSIONS: PIR is a promising method to reduce radiation dose for multiphase abdominal CT, preserving observer performance despite small reductions in image quality. Further work is warranted.


Asunto(s)
Competencia Clínica/estadística & datos numéricos , Neoplasias Hepáticas/diagnóstico por imagen , Dosis de Radiación , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Anciano de 80 o más Años , Medios de Contraste , Femenino , Humanos , Hígado/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Proyectos Piloto , Intensificación de Imagen Radiográfica/métodos , Sensibilidad y Especificidad
12.
Sci Rep ; 9(1): 19693, 2019 12 23.
Artículo en Inglés | MEDLINE | ID: mdl-31873181

RESUMEN

Seeds of Australian species of the seagrass genus Posidonia are covered by a membranous wing that we hypothesize plays a fundamental role in seed establishment in sandy, wave swept marine environments. Dimensions of the seed and membrane were quantified under electron microscopy and micro-CT scans, and used to model rotational, drag and lift forces. Seeds maintain contact with the seabed in the presence of strong turbulence: the larger the wing, the more stable the seed. Wing surface area increases from P. sinuosa < P. australis < P.coriacea correlating with their ability to establish in increasingly energetic environments. This unique seed trait in a marine angiosperm corresponds to adaptive pressures imposed on seagrass species along 7,500 km of Australia's coastline, from open, high energy coasts to calmer environments in bays and estuaries.


Asunto(s)
Alismatales/fisiología , Semillas/fisiología , Adaptación Fisiológica , Alismatales/anatomía & histología , Organismos Acuáticos/fisiología , Australia , Bahías , Simulación por Computador , Ecosistema , Estuarios , Hidrodinámica , Microscopía Electrónica de Rastreo , Modelos Biológicos , Semillas/anatomía & histología , Microtomografía por Rayos X
13.
Mol Ecol ; 27(24): 5019-5034, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30427083

RESUMEN

Movement is fundamental to the ecology and evolutionary dynamics within species. Understanding movement through seed dispersal in the marine environment can be difficult due to the high spatial and temporal variability of ocean currents. We employed a mutually enriching approach of population genetic assignment procedures and dispersal predictions from a hydrodynamic model to overcome this difficulty and quantify the movement of dispersing floating fruit of the temperate seagrass Posidonia australis Hook.f. across coastal waters in south-western Australia. Dispersing fruit cohorts were collected from the water surface over two consecutive years, and seeds were genotyped using microsatellite DNA markers. Likelihood-based genetic assignment tests were used to infer the meadow of origin for seed cohorts and individuals. A three-dimensional hydrodynamic model was coupled with a particle transport model to simulate the movement of fruit at the water surface. Floating fruit cohorts were mainly assigned genetically to the nearest meadow, but significant genetic differentiation between cohort and most likely meadow of origin suggested a mixed origin. This was confirmed by genetic assignment of individual seeds from the same cohort to multiple meadows. The hydrodynamic model predicted 60% of fruit dispersed within 20 km, but that fruit was physically capable of dispersing beyond the study region. Concordance between these two independent measures of dispersal provides insight into the role of physical transport for long distance dispersal of fruit and the consequences for spatial genetic structuring of seagrass meadows.


Asunto(s)
Alismatales/genética , Genética de Población , Hidrodinámica , Dispersión de Semillas , Australia , Frutas , Genotipo , Funciones de Verosimilitud , Repeticiones de Microsatélite , Modelos Teóricos , Océanos y Mares , Movimientos del Agua
14.
Science ; 359(6371): 80-83, 2018 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-29302011

RESUMEN

Tropical reef systems are transitioning to a new era in which the interval between recurrent bouts of coral bleaching is too short for a full recovery of mature assemblages. We analyzed bleaching records at 100 globally distributed reef locations from 1980 to 2016. The median return time between pairs of severe bleaching events has diminished steadily since 1980 and is now only 6 years. As global warming has progressed, tropical sea surface temperatures are warmer now during current La Niña conditions than they were during El Niño events three decades ago. Consequently, as we transition to the Anthropocene, coral bleaching is occurring more frequently in all El Niño-Southern Oscillation phases, increasing the likelihood of annual bleaching in the coming decades.


Asunto(s)
Antozoos , Arrecifes de Coral , El Niño Oscilación del Sur , Calentamiento Global , Animales , Agua de Mar
15.
Front Plant Sci ; 8: 2026, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29259609

RESUMEN

Clonality is common in many aquatic plant species, including seagrasses, where populations are maintained through a combination of asexual and sexual reproduction. One common measure used to describe the clonal structure of populations is clonal richness. Clonal richness is strongly dependent on the biological characteristics of the species, and how these interact with the environment but can also reflect evolutionary scale processes especially at the edge of species ranges. However, little is known about the spatial patterns and drivers of clonal richness in tropical seagrasses. This study assessed the spatial patterns of clonal richness in meadows of three tropical seagrass species, Thalassia hemprichii, Halodule uninervis, and Halophila ovalis, spanning a range of life-history strategies and spatial scales (2.5-4,711 km) in Indonesia and NW Australia. We further investigated the drivers of clonal richness using general additive mixed models for two of the species, H. uninervis and H. ovalis, over 8° latitude. No significant patterns were observed in clonal richness with latitude, yet disturbance combined with sea surface temperature strongly predicted spatial patterns of clonal richness. Sites with a high probability of cyclone disturbance had low clonal richness, whereas an intermediate probability of cyclone disturbance and the presence of dugong grazing combined with higher sea surface temperatures resulted in higher levels of clonal richness. We propose potential mechanisms for these patterns related to the recruitment and mortality rates of individuals as well as reproductive effort. Under a changing climate, increased severity of tropical cyclones and the decline in populations of mega-grazers have the potential to reduce clonal richness leading to less genetically diverse populations.

16.
Sci Rep ; 7(1): 14999, 2017 11 03.
Artículo en Inglés | MEDLINE | ID: mdl-29101362

RESUMEN

In 2015/16, a marine heatwave associated with a record El Niño led to the third global mass bleaching event documented to date. This event impacted coral reefs around the world, including in Western Australia (WA), although WA reefs had largely escaped bleaching during previous strong El Niño years. Coral health surveys were conducted during the austral summer of 2016 in four bioregions along the WA coast (~17 degrees of latitude), ranging from tropical to temperate locations. Here we report the first El Niño-related regional-scale mass bleaching event in WA. The heatwave primarily affected the macrotidal Kimberley region in northwest WA (~16°S), where 4.5-9.3 degree heating weeks (DHW) resulted in 56.6-80.6% bleaching, demonstrating that even heat-tolerant corals from naturally extreme, thermally variable reef environments are threatened by heatwaves. Some heat stress (2.4 DHW) and bleaching (<30%) also occurred at Rottnest Island (32°01'S), whereas coral communities at Ningaloo Reef (23°9'S) and Bremer Bay (34°25'S) were not impacted. The only other major mass bleaching in WA occurred during a strong La Niña event in 2010/11 and primarily affected reefs along the central-to-southern coast. This suggests that WA reefs are now at risk of severe bleaching during both El Niño and La Niña years.


Asunto(s)
Antozoos , Arrecifes de Coral , Calentamiento Global , Respuesta al Choque Térmico/fisiología , Animales , Australia , Temperatura
17.
Nature ; 543(7645): 373-377, 2017 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-28300113

RESUMEN

During 2015-2016, record temperatures triggered a pan-tropical episode of coral bleaching, the third global-scale event since mass bleaching was first documented in the 1980s. Here we examine how and why the severity of recurrent major bleaching events has varied at multiple scales, using aerial and underwater surveys of Australian reefs combined with satellite-derived sea surface temperatures. The distinctive geographic footprints of recurrent bleaching on the Great Barrier Reef in 1998, 2002 and 2016 were determined by the spatial pattern of sea temperatures in each year. Water quality and fishing pressure had minimal effect on the unprecedented bleaching in 2016, suggesting that local protection of reefs affords little or no resistance to extreme heat. Similarly, past exposure to bleaching in 1998 and 2002 did not lessen the severity of bleaching in 2016. Consequently, immediate global action to curb future warming is essential to secure a future for coral reefs.


Asunto(s)
Antozoos/metabolismo , Arrecifes de Coral , Calentamiento Global/estadística & datos numéricos , Animales , Australia , Clorofila/metabolismo , Clorofila A , Conservación de los Recursos Naturales/tendencias , Calentamiento Global/prevención & control , Agua de Mar/análisis , Temperatura
18.
Biol Rev Camb Philos Soc ; 92(2): 921-938, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-27010433

RESUMEN

Accurate estimation of connectivity among populations is fundamental for determining the drivers of population resilience, genetic diversity, adaptation and speciation. However the separation and quantification of contemporary versus historical connectivity remains a major challenge. This review focuses on marine angiosperms, seagrasses, that are fundamental to the health and productivity of temperate and tropical coastal marine environments globally. Our objective is to understand better the role of sexual reproduction and recruitment in influencing demographic and genetic connectivity among seagrass populations through an integrated multidisciplinary assessment of our present ecological, genetic, and demographic understanding, with hydrodynamic modelling of transport. We investigate (i) the demographic consequences of sexual reproduction, dispersal and recruitment in seagrasses, (ii) contemporary transport of seagrass pollen, fruits and seed, and vegetative fragments with a focus on hydrodynamic and particle transport models, and (iii) contemporary genetic connectivity among seagrass meadows as inferred through the application of genetic markers. New approaches are reviewed, followed by a summary outlining future directions for research: integrating seascape genetic approaches; incorporating hydrodynamic modelling for dispersal of pollen, seeds and vegetative fragments; integrating studies across broader geographic ranges; and incorporating non-equilibrium modelling. These approaches will lead to a more integrated understanding of the role of contemporary dispersal and recruitment in the persistence and evolution of seagrasses.


Asunto(s)
Variación Genética , Magnoliopsida/fisiología , Flujo Génico , Genética de Población , Reproducción , Semillas
19.
J Asthma ; 54(1): 105-110, 2017 01 02.
Artículo en Inglés | MEDLINE | ID: mdl-27383130

RESUMEN

OBJECTIVE: The goal of this study was to examine the impact of a multidisciplinary intervention designed to improve appropriate albuterol inhaler utilization among patients with asthma. METHODS: This was a pre-post retrospective analysis. The study intervention included written information sent directly to patients, educated prescribers, and enhanced pharmacist training on appropriate albuterol inhaler utilization. Eligible study patients had a diagnosis of asthma and purchased at least two albuterol inhalers between 07/12/2012 and 06/30/2013 (pre-period) and 7/01/2013 to 06/30/2014 (post-period). The primary outcome was a comparison between study periods of the count of albuterol inhalers purchased per patient per month (PPPM). RESULTS: The median age of included patients was 41 years, 53% were females, and allergic rhinitis was the most common comorbidity. The median albuterol inhalers purchased PPPM decreased from 0.60 (interquartile range [IQR] = 0.39-0.87) to 0.37 (IQR = 0.26-0.53) from the pre- to post-period (p < 0.001). The proportion of patients with at least one systemic corticosteroid purchase decreased (36% vs. 31%) and >1 albuterol inhaler purchased on the same day increased (3.1% vs. 5.7%) from the pre- to post-period (p < 0.001). Numerically, the proportion of participants who experienced an acute asthma exacerbation decreased and asthma controller inhalers purchased PPPM increased but these did not reach statistical significance (both p > 0.05). CONCLUSIONS: A multidisciplinary approach to increasing appropriate albuterol inhaler use was associated with a decrease in albuterol inhalers purchased PPPM while not increasing acute asthma exacerbations. Future study is needed to evaluate patient perspectives on this intervention and assess its economic impact.


Asunto(s)
Albuterol/uso terapéutico , Asma/tratamiento farmacológico , Broncodilatadores/uso terapéutico , Cumplimiento de la Medicación , Educación del Paciente como Asunto/organización & administración , Servicios Farmacéuticos/organización & administración , Administración por Inhalación , Adolescente , Adulto , Albuterol/administración & dosificación , Broncodilatadores/administración & dosificación , Femenino , Humanos , Capacitación en Servicio/organización & administración , Masculino , Inhaladores de Dosis Medida , Persona de Mediana Edad , Estudios Retrospectivos , Adulto Joven
20.
Sci Adv ; 2(8): e1600825, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27540589

RESUMEN

Temperatures within shallow reefs often differ substantially from those in the surrounding ocean; therefore, predicting future patterns of thermal stresses and bleaching at the scale of reefs depends on accurately predicting reef heat budgets. We present a new framework for quantifying how tidal and solar heating cycles interact with reef morphology to control diurnal temperature extremes within shallow, tidally forced reefs. Using data from northwestern Australia, we construct a heat budget model to investigate how frequency differences between the dominant lunar semidiurnal tide and diurnal solar cycle drive ~15-day modulations in diurnal temperature extremes. The model is extended to show how reefs with tidal amplitudes comparable to their depth, relative to mean sea level, tend to experience the largest temperature extremes globally. As a consequence, we reveal how even a modest sea level rise can substantially reduce temperature extremes within tide-dominated reefs, thereby partially offsetting the local effects of future ocean warming.


Asunto(s)
Cambio Climático , Arrecifes de Coral , Ecosistema , Olas de Marea , Australia , Agua de Mar , Luz Solar , Temperatura
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