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1.
Nat Hazards (Dordr) ; 119(1): 463-495, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37719282

RESUMO

The eruptions of Eyjafjallajökull volcano in 2010 (including its initial effusive phase at Fimmvörðuháls and its later explosive phase from the central volcano) and Bárðarbunga volcano in 2014-2015 (at Holuhraun) were widely reported. Here, we report on complementary, interdisciplinary observations made of the eruptive gases and lavas that shed light on the processes and atmospheric impacts of the eruptions, and afford an intercomparison of contrasting eruptive styles and hazards. We find that (i) consistent with other authors, there are substantial differences in the gas composition between the eruptions; namely that the deeper stored Eyjafjallajökull magmas led to greater enrichment in Cl relative to S; (ii) lava field SO2 degassing was measured to be 5-20% of the total emissions during Holuhraun, and the lava emissions were enriched in Cl at both fissure eruptions-particularly Fimmvörðuháls; and (iii) BrO is produced in Icelandic plumes in spite of the low UV levels. Supplementary Information: The online version contains supplementary material available at 10.1007/s11069-023-06114-7.

2.
Prog Hum Geogr ; 46(1): 121-138, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35125621

RESUMO

COVID-19 recovery is an opportunity to enhance life chances by Building Back Better, an objective promoted by the UN and deployed politically at national level. To help understand emergent and intentional opportunities to Build Back Better, we propose a research agenda drawing from geographical thinking on social contracts, assemblage theory and the politics of knowledge. This points research towards the ways in which everyday and professional knowledge cocreation constrains vision and action. Whose knowledge is legitimate, how legitimacy is ascribed and the place of science, the media and government in these processes become sites for progressive Building Back Better.

3.
J Med Radiat Sci ; 67(2): 159-163, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31950597

RESUMO

Urethral carcinoma is a rare urological cancer, accounting for only 1% of malignancies in Australia. The most common histology is transitional cell carcinoma (TCC). The majority of these cancers are treated with surgery. The main purpose of this case study is to describe a novel radiation treatment technique for treatment of this uncommon cancer. This report details organ-preserving treatment for a distal penile urethral cancer using definitive radiation therapy (RT). In May 2016 a 69-year-old male presented to Crown Princess Mary Cancer Centre (CPMCC) with a small TCC of the distal urethra. The patient was offered numerous treatment options, both radical and organ-preserving approaches, and came to a final decision of a course of radiation therapy despite the lack of randomised evidence to guide treatment in this setting. A dose of 66 Gy in 33 fractions from parallel opposed lateral beams was prescribed to the distal penile urethra. This case required an unusual approach to patient set up to allow access for accurate treatment delivery and to maintain patient comfort. The patient tolerated the full course of radiation therapy with expected skin side effects. He has maintained adequate penile function and is currently free from disease at 33 months with ongoing clinical follow-up.


Assuntos
Carcinoma de Células de Transição/radioterapia , Neoplasias Uretrais/radioterapia , Idoso , Carcinoma de Células de Transição/patologia , Humanos , Masculino , Dosagem Radioterapêutica , Resultado do Tratamento , Neoplasias Uretrais/patologia
7.
Contrib Mineral Petrol ; 173(1): 1, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-31983758

RESUMO

The 2011 eruption of Nabro volcano, Eritrea, produced one of the largest volcanic sulphur inputs to the atmosphere since the 1991 eruption of Mt. Pinatubo, yet has received comparatively little scientific attention. Nabro forms part of an off-axis alignment, broadly perpendicular to the Afar Rift, and has a history of large-magnitude explosive silicic eruptions, as well as smaller more mafic ones. Here, we present and analyse extensive petrological data obtained from samples of trachybasaltic tephra erupted during the 2011 eruption to assess the pre-eruptive magma storage system and explain the large sulphur emission. We show that the eruption involved two texturally distinct batches of magma, one of which was more primitive and richer in sulphur than the other, which was higher in water (up to 2.5 wt%). Modelling of the degassing and crystallisation histories demonstrates that the more primitive magma rose rapidly from depth and experienced degassing crystallisation, while the other experienced isobaric cooling in the crust at around 5 km depth. Interaction between the two batches occurred shortly before the eruption. The eruption itself was likely triggered by recharge-induced destabilisation of vertically extensive mush zone under the volcano. This could potentially account for the large volume of sulphur released. Some of the melt inclusions are volatile undersaturated, and suggest that the original water content of the magma was around 1.3 wt%, which is relatively high for an intraplate setting, but consistent with seismic studies of the Afar plume. This eruption was smaller than some geological eruptions at Nabro, but provides important insights into the plumbing systems and dynamics of off-axis volcanoes in Afar.

8.
Neurobiol Aging ; 49: 86-99, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27776266

RESUMO

Beta-amyloid (Aß) immunotherapy is a promising intervention to slow Alzheimer's disease. Aging dogs naturally accumulate Aß and show cognitive decline. An active vaccine against fibrillar Aß 1-42 (VAC) in aged beagles resulted in maintenance but not improvement of cognition along with reduced brain Aß. Behavioral enrichment (ENR) led to cognitive benefits but no reduction in Aß. We hypothesized cognitive outcomes could be improved by combining VAC with ENR in aged dogs. Aged dogs (11-12 years) were placed into 4 groups: (1) control/control (C/C); (2) control/VAC (C/V); (3) ENR/control (E/C); and (4) ENR/VAC (E/V) and treated for 20 months. VAC decreased brain Aß, pyroglutamate Aß, increased cerebrospinal fluid Aß 42 and brain-derived neurotrophic factor RNA levels but also increased microhemorrhages. ENR reduced brain Aß and prevented microhemorrhages. The combination treatment resulted in a significant maintenance of learning over time, reduced Aß, and increased brain-derived neurotrophic factor mRNA despite increased microhemorrhages; however, there were no benefits to memory. These results suggest that the combination of immunotherapy with behavioral enrichment leads to cognitive maintenance associated with reduced neuropathology that may benefit people with Alzheimer's disease.


Assuntos
Envelhecimento/metabolismo , Envelhecimento/psicologia , Doença de Alzheimer/terapia , Vacinas contra Alzheimer/uso terapêutico , Peptídeos beta-Amiloides/imunologia , Peptídeos beta-Amiloides/metabolismo , Hemorragia Cerebral/prevenção & controle , Cognição , Terapia Cognitivo-Comportamental/métodos , Imunoterapia , Fragmentos de Peptídeos/imunologia , Fragmentos de Peptídeos/metabolismo , Doença de Alzheimer/etiologia , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Cães , Desamparo Aprendido , Fragmentos de Peptídeos/líquido cefalorraquidiano , RNA Mensageiro/metabolismo
9.
Science ; 353(6296): aaf8988, 2016 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-27418515

RESUMO

Large volcanic eruptions on Earth commonly occur with a collapse of the roof of a crustal magma reservoir, forming a caldera. Only a few such collapses occur per century, and the lack of detailed observations has obscured insight into the mechanical interplay between collapse and eruption. We use multiparameter geophysical and geochemical data to show that the 110-square-kilometer and 65-meter-deep collapse of Bárdarbunga caldera in 2014-2015 was initiated through withdrawal of magma, and lateral migration through a 48-kilometers-long dike, from a 12-kilometers deep reservoir. Interaction between the pressure exerted by the subsiding reservoir roof and the physical properties of the subsurface flow path explain the gradual, near-exponential decline of both collapse rate and the intensity of the 180-day-long eruption.

10.
Sci Adv ; 2(11): e1600913, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28138521

RESUMO

Paektu volcano (Changbaishan) is a rhyolitic caldera that straddles the border between the Democratic People's Republic of Korea and China. Its most recent large eruption was the Millennium Eruption (ME; 23 km3 dense rock equivalent) circa 946 CE, which resulted in the release of copious magmatic volatiles (H2O, CO2, sulfur, and halogens). Accurate quantification of volatile yield and composition is critical in assessing volcanogenic climate impacts but is challenging, particularly for events before the satellite era. We use a geochemical technique to quantify volatile composition and upper bounds to yields for the ME by examining trends in incompatible trace and volatile element concentrations in crystal-hosted melt inclusions. We estimate that the ME could have emitted as much as 45 Tg of S to the atmosphere. This is greater than the quantity of S released by the 1815 eruption of Tambora, which contributed to the "year without a summer." Our maximum gas yield estimates place the ME among the strongest emitters of climate-forcing gases in the Common Era. However, ice cores from Greenland record only a relatively weak sulfate signal attributed to the ME. We suggest that other factors came into play in minimizing the glaciochemical signature. This paradoxical case in which high S emissions do not result in a strong glacial sulfate signal may present a way forward in building more generalized models for interpreting which volcanic eruptions have produced large climate impacts.

11.
Bull Volcanol ; 77(10): 85, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26379357

RESUMO

We present a synthesis of diverse observations of the first recorded eruption of Nabro volcano, Eritrea, which began on 12 June 2011. While no monitoring of the volcano was in effect at the time, it has been possible to reconstruct the nature and evolution of the eruption through analysis of regional seismological and infrasound data and satellite remote sensing data, supplemented by petrological analysis of erupted products and brief field surveys. The event is notable for the comparative rarity of recorded historical eruptions in the region and of caldera systems in general, for the prodigious quantity of SO2 emitted into the atmosphere and the significant human impacts that ensued notwithstanding the low population density of the Afar region. It is also relevant in understanding the broader magmatic and tectonic significance of the volcanic massif of which Nabro forms a part and which strikes obliquely to the principal rifting directions in the Red Sea and northern Afar. The whole-rock compositions of the erupted lavas and tephra range from trachybasaltic to trachybasaltic andesite, and crystal-hosted melt inclusions contain up to 3,000 ppm of sulphur by weight. The eruption was preceded by significant seismicity, detected by regional networks of sensors and accompanied by sustained tremor. Substantial infrasound was recorded at distances of hundreds to thousands of kilometres from the vent, beginning at the onset of the eruption and continuing for weeks. Analysis of ground deformation suggests the eruption was fed by a shallow, NW-SE-trending dike, which is consistent with field and satellite observations of vent distributions. Despite lack of prior planning and preparedness for volcanic events in the country, rapid coordination of the emergency response mitigated the human costs of the eruption.

12.
Biomed Mater ; 10(3): 035001, 2015 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-25953950

RESUMO

The aim of the study was to determine bone regeneration in a rabbit radius critical-size defect (CSD) model using a specific polymer composition (E1001(1k)) from a library of tyrosine-derived polycarbonate scaffolds coated with a calcium phosphate (CP) formulation (E1001(1k) + CP) supplemented with recombinant human bone morphogenetic protein-2 (rhBMP-2). Specific doses of rhBMP-2 (0, 17, and 35 µg/scaffold) were used. E1001(1k) + CP scaffolds were implanted in unilateral segmental defects (15 mm length) in the radial diaphyses of New Zealand White rabbits. At 4 and 8 weeks post-implantation, bone regeneration was determined using micro-computed tomography (µCT), histology, and histomorphometry. The quantitative outcome data suggest that E1001(1k) + CP scaffolds with rhBMP-2 were biocompatible and promoted bone regeneration in segmental bone defects. Histological examination of the implant sites showed that scaffolds made of E1001(1k) + CP did not elicit adverse cellular or tissue responses throughout test periods up to 8 weeks. Noteworthy is that the incorporation of a very small amount of rhBMP-2 into the scaffolds (as low as 17 µg/defect site) promoted significant bone regeneration compared to scaffolds consisting of E1001(1k) + CP alone. This finding indicates that E1001(1k) + CP may be an effective platform for bone regeneration in a critical size rabbit radius segmental defect model, requiring only a minimal dose of rhBMP-2.


Assuntos
Regeneração Óssea , Substitutos Ósseos/química , Cimento de Policarboxilato/química , Alicerces Teciduais/química , Animais , Proteína Morfogenética Óssea 2/administração & dosagem , Regeneração Óssea/efeitos dos fármacos , Regeneração Óssea/fisiologia , Fosfatos de Cálcio/química , Humanos , Teste de Materiais , Coelhos , Rádio (Anatomia)/lesões , Rádio (Anatomia)/patologia , Rádio (Anatomia)/fisiologia , Proteínas Recombinantes/administração & dosagem , Fator de Crescimento Transformador beta/administração & dosagem , Tirosina/química , Microtomografia por Raio-X
13.
Risk Anal ; 35(2): 332-43, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25263505

RESUMO

Eruptions at the Icelandic volcanoes of Eyjafjallajökull (2010) and Grimsvötn (2011) produced plumes of ash posing hazards to air traffic over northern Europe. In imposing restrictions on air traffic, regulators needed to balance the dangers of accidents or aircraft damage against the cost and inconvenience to travelers and industry. Two surveys examined how members of the public viewed the necessity of the imposed restrictions and their trust in different agencies as estimators of the level of risk. Study 1 was conducted with 213 British citizens (112 males, 101 females), who completed questionnaires while waiting for flights at London City Airport during May 2012. Study 2 involved an online survey of 301 Icelandic citizens (172 males, 127 females, 2 undeclared gender) during April 2012. In both samples, there was general support for the air traffic restrictions, especially among those who gave higher estimates of the likelihood of an air accident or mishap having otherwise happened. However, in both countries, the (minority of) respondents who had personally experienced travel disruption were less convinced that these restrictions were all necessary. Scientists, the International Civil Aviation Organization, and (in Iceland) the Icelandic Department of Civil Protection were all highly trusted, and seen as erring on the side of caution in their risk estimates. Airlines were seen as more likely to underestimate any risk. We conclude that perceptions of the balance between risk and caution in judgments under uncertainty are influenced by one's own motives and those attributed to others.


Assuntos
Risco , Erupções Vulcânicas/história , Viagem Aérea , Feminino , História do Século XXI , Humanos , Islândia , Masculino , Percepção , Medição de Risco , Inquéritos e Questionários , Confiança , Reino Unido , Erupções Vulcânicas/efeitos adversos
14.
Work ; 50(3): 433-42, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25248536

RESUMO

BACKGROUND: Increasing research suggests breastfeeding has many benfeits to mothers and children, yet breastfeeding duration rates remain well below Healthy People 2020 objectives. In order to increase breastfeeding rates, the complex role change in becoming a breastfeeding mother deserves closer examination. OBJECTIVE: This pilot study sought to explore the daily routines and supports experienced by primiparous breastfeeding mothers with the objective of using this information to design interventions to promote breastfeeding duration. METHODS: Surveys were conducted at 2-3, 6-8, and 10-12 weeks postpartum. Data were analyzed using quantitative and qualitative methods. PARTICIPANTS: Eleven primiparous mothers. RESULTS: None of the eleven mothers interviewed at 2-3 week had a daily routine; 5 out of 9 mothers described a 'hint of a routine' at 6-8 weeks, and 6 out of 7 mothers described an 'emerging routine' at 10-12 weeks. Despite wanting more support and better preparation, most mothers succeeded with exclusive breastfeeding for the 12-week period. CONCLUSIONS: These findings were viewed through the lens of non-linear dynamics and transition theory. Implications for occupational therapy and occupational science were discussed.


Assuntos
Aleitamento Materno , Promoção da Saúde , Mães , Adulto , Feminino , Hábitos , Humanos , Paridade , Projetos Piloto , Fatores de Tempo , Adulto Jovem
15.
Dalton Trans ; 42(37): 13706-14, 2013 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-23904037

RESUMO

Four molecular species chelated by edta have been synthesized from aqueous solutions and characterized by single-crystal X-ray diffraction, infrared spectroscopy, and thermogravimetric analysis. [Th(H2O)4(edta)] (Th1) crystallized in monoclinic space group P2(1)/c with unit cell parameters of a = 8.5275(5) Å, b = 12.0635(7) Å, c = 15.8825(9) Å, and ß = 105.340(2)°. Monoclinic space group C2 was identified for [Al2(edta)(OH)2(H2O)2] (Al2) with a = 11.1089(10) Å, b = 9.4830(8) Å, c = 7.6116(7) Å, and ß = 112.026(3)°. [Th4(H2O)4Al10(H2O)8(OH)28(edta)4]·Cl2(H2O)29 (Th4Al10) formed the triclinic space group P1 with a = 9.3172(8) Å, b = 16.6099(14) Å, c = 19.5080(14) Å, α = 102.314(3)°, ß = 95.615(3)°, and γ = 92.473(3)°. [Th2(H2O)2Al6(H2O)10(OH)14(edta)2]·(NO3)4(H2O)18 (Th2Al6) also crystallized in triclinic space group P1[combining macron] with unit cell parameters a = 10.9899(12) Å, b = 11.6107(12) Å, c = 14.3350(17) Å, α = 73.012(4)°, ß = 87.411(4)°, and γ = 75.717(4)°. Small molecular species are observed in the Th1 and Al2 compounds, while the metal cations hydrolyze to create nanometer-sized heterometallic clusters in the Th4Al10 and Th2Al6 materials. The topological characteristics of each species are described and related to aqueous speciation in Th(4+), Al(3+)-edta systems.


Assuntos
Alumínio/química , Ácido Edético/química , Compostos Organometálicos/química , Compostos Organometálicos/síntese química , Tório/química , Ligantes , Modelos Moleculares
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