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1.
J Environ Manage ; 351: 119622, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38042079

RESUMO

Vegetation is a critical boundary condition for the stability of coastal dunes. Globally, vegetation cover is increasing on the coast with many dunes being stabilised in the past decades. This pattern is driven by site-specific (e.g., coastal management) and global (e.g., climatic changes) factors. This study examines changes in dune vegetation during the past six decades at the regional scale along the southeast coast of Australia to understand the relative importance of the climate and human interventions in vegetation cover change. A total area of >31,000 ha, comprising 53% of the open coast of Victoria was studied. Since the 1960's, a general trend of dune stabilisation and coastal greening has occurred with total vegetation cover increasing from 61% to 84% coverage until 2020. At the regional scale, the increase in vegetation cover has been primarily driven by both climatic-related drivers, such as rising temperature, elevating CO2 concentrations and declining windiness, and state-wide coastal management interventions (e.g., marram grass planting, fencing, fire control, grazing removal). The only areas where there was a decline in total area of vegetation was where substantial coastal recession had occurred. The decrease in vegetation is a result of a loss of land area rather than a loss of plant biomass over the dunefields. Therefore, it is considered that the overall decadal changes in both climate and coastal management are forcing the dunes toward a more stabilised state at the regional scale. At the same time, compelling local drivers (e.g., storms and local sediment deficiency) can be the most crucial factor to regulate vegetation change and shift dune mobility at the site-specific scale.


Assuntos
Ecossistema , Plantas , Humanos , Vitória , Biomassa
2.
Sci Rep ; 11(1): 3935, 2021 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-33594157

RESUMO

Sandy beaches are highly dynamic systems which provide natural protection from the impact of waves to coastal communities. With coastal erosion hazards predicted to increase globally, data to inform decision making on erosion mitigation and adaptation strategies is becoming critical. However, multi-temporal topographic data over wide geographical areas is expensive and time consuming and often requires highly trained professionals. In this study we demonstrate a novel approach combining citizen science with low-cost unmanned aerial vehicles that reliably produces survey-grade morphological data able to model sediment dynamics from event to annual scales. The high-energy wave-dominated coast of south-eastern Australia, in Victoria, is used as a field laboratory to test the reliability of our protocol and develop a set of indices to study multi-scale erosional dynamics. We found that citizen scientists provide unbiased data as accurate as professional researchers. We then observed that open-ocean beaches mobilise three times as much sediment as embayed beaches and distinguished between slowed and accelerated erosional modes. The data was also able to assess the efficiency of sand nourishment for shore protection. Our citizen science protocol provides high quality monitoring capabilities, which although subject to important legislative preconditions, it is applicable in other parts of the world and transferable to other landscape systems where the understanding of sediment dynamics is critical for management of natural or anthropogenic processes.

3.
Sci Total Environ ; 731: 139123, 2020 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-32417479

RESUMO

Beaches that are geologically controlled by rock and coral formations are the rule, not the exception. This paper reviews the current understanding of geologically controlled beaches, bringing together a range of terminologies (including embayed beaches, shore platform beaches, relict beaches, and perched beaches, among others) and processes, with the aim of exploring the multiple ways in which geology influences beach morphology and morphodynamics. We show how in addition to sediment supply, the basement geology influences where beaches will form by providing accommodation, and in the cross-shore, aspects of rock platform morphology such as elevation and slope are also important. Geologically controlled beaches can have significant variations in sediment coverage with seasons and storms, and geological controls have fundamental influences on their contemporary morphodynamics. This includes wave shadowing by headlands and rock/coral formations inducing strong alongshore gradients in wave energy, resulting in corresponding variations in morphodynamic beach state and storm response. Geologically-induced rip currents including shadow rips, deflection rips and mega-rips that can develop on embayed beaches during storms, are an integral feature of the nearshore circulation and morphodynamics of geologically controlled beaches. We bring these processes together by presenting a conceptual model of alongshore and cross-shore levels of geological control. In the longshore dimension, this ranges from beaches that are slightly embayed, through to highly embayed beaches where headlands dominate the entire beach morphodynamic response. In the cross-shore dimension, this ranges from beaches without discernible geological controls, through to relict beaches above the influence of the contemporary littoral zone. Given the prevalence of geologically controlled beaches along the world's coasts, it is paramount for coastal management to consider how these beaches differ from unconstrained beaches and avoid applying inappropriate models and tools, especially with our uncertain future climate.

4.
Sci Rep ; 4: 4997, 2014 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-24845540

RESUMO

In 1842 Charles Darwin claimed that vertical growth on a subsiding foundation caused fringing reefs to transform into barrier reefs then atolls. Yet historically no transition between reef types has been discovered and they are widely considered to develop independently from antecedent foundations during glacio-eustatic sea-level rise. Here we reconstruct reef development from cores recovered by IODP Expedition 310 to Tahiti, and show that a fringing reef retreated upslope during postglacial sea-level rise and transformed into a barrier reef when it encountered a Pleistocene reef-flat platform. The reef became stranded on the platform edge, creating a lagoon that isolated it from coastal sediment and facilitated a switch to a faster-growing coral assemblage dominated by acroporids. The switch increased the reef's accretion rate, allowing it to keep pace with rising sea level, and transform into a barrier reef. This retreat mechanism not only links Darwin's reef types, but explains the re-occupation of reefs during Pleistocene glacio-eustacy.

5.
J Ren Care ; 39 Suppl 2: 23-9, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23941701

RESUMO

BACKGROUND: Some patients with chronic kidney disease are still referred late for specialist care despite the evidence that earlier detection and intervention can halt or delay progression to end-stage kidney disease (ESKD). OBJECTIVES: To develop a population surveillance system using existing laboratory data to enable early detection of patients at high risk of ESKD by reviewing cumulative graphs of estimated glomerular filtration rate (eGFR). METHODS: A database was developed, updated daily with data from the laboratory computer. Cumulative eGFR graphs containing up to five years of data are reviewed by clinical scientists for all primary care patients or out-patients with a low eGFR for their age. For those with a declining trend, a report containing the eGFR graph is sent to the requesting doctor. A retrospective audit was performed using historical data to assess the predictive value of the graphs. RESULTS: In nine months, we reported 370,000 eGFR results, reviewing 12,000 eGFR graphs. On average 60 graphs per week were flagged as 'high' or 'intermediate' risk. Patients with graphs flagged as high risk had a significantly higher mortality after 3.5 years and a significantly greater chance of requiring renal replacement therapy after 4.5 years of follow-up. Five patients (7%) with graphs flagged as high risk had a sustained >25% fall in eGFR without evidence of secondary care referral. Feedback about the service from requesting clinicians was 73% positive. CONCLUSIONS: We have developed a system for laboratory staff to review cumulative eGFR graphs for a large population and identify patients at highest risk of developing ESKD. Further research is needed to measure the impact of this service on patient outcomes.


Assuntos
Falência Renal Crônica/diagnóstico , Vigilância da População , Melhoria de Qualidade/organização & administração , Idoso , Sistemas de Informação em Laboratório Clínico , Gráficos por Computador , Estudos Transversais , Progressão da Doença , Diagnóstico Precoce , Inglaterra , Feminino , Taxa de Filtração Glomerular , Humanos , Falência Renal Crônica/mortalidade , Falência Renal Crônica/prevenção & controle , Masculino , Programas de Rastreamento , Pessoa de Meia-Idade , Estudos Retrospectivos , Medição de Risco , Medicina Estatal , Taxa de Sobrevida
6.
Proc Natl Acad Sci U S A ; 109(50): 20222-8, 2012 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-23213225

RESUMO

The unprecedented engagement of scientists from government, academia, and industry enabled multiple unanticipated and unique problems to be addressed during the Deepwater Horizon oil spill. During the months between the initial blowout on April 20, 2010, and the final well kill on September 19, 2010, researchers prepared options, analyses of tradeoffs, assessments, and calculations of uncertainties associated with the flow rate of the well, well shut in, killing the well, and determination of the location of oil released into the environment. This information was used in near real time by the National Incident Commander and other government decision-makers. It increased transparency into BP's proposed actions and gave the government confidence that, at each stage proposed, courses of action had been thoroughly vetted to reduce risk to human life and the environment and improve chances of success.

7.
Proc Natl Acad Sci U S A ; 109(50): 20212-21, 2012 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-23213250

RESUMO

This introduction to the Special Feature presents the context for science during the Deepwater Horizon oil spill response, summarizes how scientific knowledge was integrated across disciplines and statutory responsibilities, identifies areas where scientific information was accurate and where it was not, and considers lessons learned and recommendations for future research and response. Scientific information was integrated within and across federal and state agencies, with input from nongovernmental scientists, across a diverse portfolio of needs--stopping the flow of oil, estimating the amount of oil, capturing and recovering the oil, tracking and forecasting surface oil, protecting coastal and oceanic wildlife and habitat, managing fisheries, and protecting the safety of seafood. Disciplines involved included atmospheric, oceanographic, biogeochemical, ecological, health, biological, and chemical sciences, physics, geology, and mechanical and chemical engineering. Platforms ranged from satellites and planes to ships, buoys, gliders, and remotely operated vehicles to laboratories and computer simulations. The unprecedented response effort depended directly on intense and extensive scientific and engineering data, information, and advice. Many valuable lessons were learned that should be applied to future events.

9.
Angiology ; 59(1): 72-6, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18319225

RESUMO

Flight-related deep vein thrombosis (DVT) is well recognized. Reduced venous return occurs during immobility. This alteration in venous hemodynamics may contribute to DVT development. A prototype design of an in-flight exercise device to stimulate ambulatory bloodflow while seated has been developed, consisting of a foot pedal attached to a base by a hinge mechanism. Four devices of differing resistance were evaluated. Calf muscle pump function was assessed by air plethysmography in 10 healthy volunteers. Ejection volume fraction and RVF were determined in the standing position (control values) and were compared with those achieved by depression of the 4 devices while seated. Similar EVF and RVF values were achieved by the control and 2 of the devices. Plantar flexion against a predetermined resistance can effectively activate the calf muscle pump while seated and may reduce the incidence of flight-related DVT.


Assuntos
Aeronaves , Exercício Físico , Imobilização/efeitos adversos , Contração Muscular , Músculo Esquelético , Viagem , Trombose Venosa/prevenção & controle , Adulto , Idoso , Método Duplo-Cego , Desenho de Equipamento , Feminino , Humanos , Perna (Membro) , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/irrigação sanguínea , Músculo Esquelético/fisiopatologia , Fluxo Sanguíneo Regional , Trombose Venosa/etiologia , Trombose Venosa/fisiopatologia
10.
Time ; 166(5): 50, 2005 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-16107078
11.
Nurse Educ Today ; 25(1): 23-30, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15607244

RESUMO

Online teaching is a growing, but not a new, phenomenon. It is most associated with distance education, but it also features in classroom education, in the form of blended learning. During this period of growth in online teaching, there has been time for the development of standards to ensure its quality. Yet the standards that have emerged tend to be derivatives of the standards for conventional, classroom teaching. They do not adequately address the specific demands of online education. Is this acceptable for online teachers? Is it supportive of online students? This contribution to the debate outlines how nurse educators can generate--and are generating--credible standards for their online practice. It identifies flaws in the current guidance for online teachers. It points out that knowledge of standard setting in the health service can support standard setting in higher education. And it highlights that the most useful guidance for the online teacher comes not from the education sector but from the industrial sector, specifically from the IT industry. It finishes on a practical note, describing how nurse educators in the University of Paisley are using these findings to develop standards for their online teaching practice.


Assuntos
Instrução por Computador/normas , Educação a Distância/normas , Educação em Enfermagem/métodos , Educação em Enfermagem/normas , Sistemas On-Line , Humanos , Comunicação Interdisciplinar , Internacionalidade , Formulação de Políticas , Reino Unido
12.
Nurse Educ Today ; 22(5): 409-16, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12383741

RESUMO

Distance is obviously a core issue in distance education. But distance is a factor in classroom-based education as well. Classroom-based teachers and distance educators have a common interest in the dynamics of distance. The focus of much discussion in distance education is on geographical distance and how it may be bridged. However, this focus obscures the more fundamental issue of educational distance. Educational distance includes cognitive distance, role distance and access distance. This form of distance is as potent in the classroom environment as it is in a virtual learning environment. The writer explores this theme by his analysis of the communication patterns between teacher and students in one module in a BSc Health Studies degree programme. The writer has taught this module in both distance education format and in traditional classroom-based format. His finding is that the communication time between the teacher and students in the distance education form of the module is 29% greater than the communication time in the classroom-based form. The most significant feature of the communication pattern is the greater quantity of individual communication between student and teacher in the distance education format. Both the quantity and type of the communication in each of these modes suggest that the more communication-rich distance education format has greater potential for overcoming the problems of educational distance within this module.


Assuntos
Educação a Distância/normas , Bacharelado em Enfermagem/normas , Reeducação Profissional/normas , Ensino/normas , Comunicação , Docentes de Enfermagem , Humanos , Relações Interprofissionais , Descrição de Cargo , Papel do Profissional de Enfermagem , Pesquisa em Educação em Enfermagem , Avaliação de Programas e Projetos de Saúde , Escócia , Estudantes de Enfermagem/psicologia , Ensino/métodos , Fatores de Tempo
13.
Ann Clin Biochem ; 39(Pt 5): 502-8, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12227857

RESUMO

BACKGROUND: We evaluated the use of the glucose biosensor on the Bayer Rapidlab 860 (BR 860) blood gas analyser for neonates and compared it with two laboratory-based methods for measuring blood glucose using the Yellow Springs Instruments 2300 STAT PLUS (YSI) analyser and the Vitros 750 XRC (Vitros) analyser. METHODS: Arterial, capillary and venous blood samples were taken from 50 neonates, and blood glucose was measured using all three instruments. Blood pH, PO(2), haematocrit and plasma albumin data were also recorded. The effect of varying the degree of haemolysis and the haematocrit was examined using cord blood samples prepared in vitro. RESULTS: Day-to-day imprecision of the BR 860 was 4.90% at a mean glucose concentration of 2.55 mmol/L (n = 60), compared with 3.03% at 2.33 mmol/L (n = 34) for the YSI and 2.64% at 3.52 mmol/L for the Vitros (n = 59). Using Deming regression, the BR 860 results correlated well with results produced on both the YSI (r = 0.962, n = 47, P < 0.001) and Vitros (r = 0.980, n = 46, P < 0.001) analysers. Bland-Altman difference plots showed that the BR 860 had a mean of the differences of 0.30 mmol/L compared with the YSI and 0.09 mmol/L compared with the Vitros. The Bland-Altman standard deviation of the differences was 0.46 mmol/L when the BR 860 was compared with the YSI and 0.31 mmol/L when the BR 860 was compared with the Vitros. No significant correlation was found between the BR 860 glucose measurements and haematocrit, degree of sample haemolysis, plasma albumin, blood pH or PO(2). CONCLUSIONS: The BR 860 analyser provides neonatal blood glucose measurements in the clinical setting of a neonatal unit that compare well with results obtained using laboratory-based methods.


Assuntos
Técnicas Biossensoriais/métodos , Glicemia/análise , Recém-Nascido/sangue , Sistemas Automatizados de Assistência Junto ao Leito/normas , Técnicas Biossensoriais/instrumentação , Dióxido de Carbono/sangue , Hematócrito , Hemólise , Humanos , Concentração de Íons de Hidrogênio , Unidades de Terapia Intensiva Neonatal , Oxigênio/sangue , Pressão Parcial , Controle de Qualidade , Análise de Regressão , Sensibilidade e Especificidade
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