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1.
J Phycol ; 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38558363

RESUMO

Crustose coralline algae (CCA) are a highly diverse group of habitat-forming, calcifying red macroalgae (Rhodophyta) with unique adaptations to diverse irradiance regimes. A distinctive CCA phenotype adaptation, which allows them to maximize photosynthetic performance in low light, is their content of a specific group of light-harvesting pigments called phycobilins. In this study, we assessed the potential of noninvasive hyperspectral imaging (HSI) in the visible spectrum (400-800 nm) to describe the phenotypic variability in phycobilin content of an Antarctic coralline, Tethysphytum antarcticum (Hapalidiales), from two distinct locations. We validated our measurements with pigment extractions and spectrophotometry analysis, in addition to DNA barcoding using the psbA marker. Targeted spectral indices were developed and correlated with phycobilin content using linear mixed models (R2 = 0.64-0.7). Once applied to the HSI, the models revealed the distinct phycoerythrin spatial distribution in the two site-specific CCA phenotypes, with thin and thick crusts, respectively. This study advances the capabilities of hyperspectral imaging as a tool to quantitatively study CCA pigmentation in relation to their phenotypic plasticity, which can be applied in laboratory studies and potentially in situ surveys using underwater hyperspectral imaging systems.

2.
J Phycol ; 60(1): 195-202, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37864777

RESUMO

To examine the potential for the autogenic ecosystem engineers, crustose coralline algae (CCA), to serve as seed banks or refugia for life stages of other species, it is critical to develop sampling protocols that reflect the diversity of life present. In this pilot study on two shallow water species of CCA collected from Raoul Island (Kermadec Islands; Rangitahua) New Zealand, we investigated two preservation methods (ethanol vs. silica gel), sampled inner and outer regions of the crusts, and used DNA metabarcoding and seven genes/gene regions (16S rRNA, 18S rRNA, 23S rRNA, cox1, rbcL, and tufA genes and the ITS rRNA region) to develop a protocol for taxa identification. The results revealed immense diversity, with typically more taxa identified within the inner layers than the outer layers. As highlighted in other metabarcoding studies and in earlier work on rhodoliths (nodose coralline algae), reference databases are incomplete, and to some extent, the use of multiple markers mitigates this issue. Specifically, the 23S rRNA and rbcL genes are currently more suitable for identifying algae, while the cox1 gene fares better at capturing the diversity present inclusive of algae. Further investigation of these autogenic ecosystem engineers that likely act as marine seed banks is needed.


Assuntos
Ecossistema , Rodófitas , Rodófitas/genética , RNA Ribossômico 16S , Código de Barras de DNA Taxonômico , Projetos Piloto , RNA Ribossômico 23S , Banco de Sementes
3.
Harmful Algae ; 128: 102494, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37714580

RESUMO

Temperatures and temperature anomalies have been increasing in the sub-tropical regions of Aotearoa New Zealand and these changes may impact on harmful algal bloom (HAB) events. Benthic and epiphytic dinoflagellates, particularly the toxin producers, are the focus of this study as it is predicted that under future climate conditions they may produce more toxins or marine animals may become more susceptible to them. The results of past expeditions to Rangitahua Kermadec Islands and sampling trips to Northland, Aotearoa New Zealand, are summarised and the results of the most recent trips to both regions are presented. The macroalgal habitats of the dinoflagellates are also characterised. Dinoflagellate species not previously identified in Rangitahua include Coolia canariensis, C. palmyrensis, and C. tropicalis, all identified by DNA sequencing of the large subunit ribosomal RNA region. Gambierdiscus polynesiensis was again isolated and produced 44-methylgambierone and gambierone, and one isolate produced ciguatoxins, the cause of Ciguatera Poisoning. An Ostreopsis tairoto isolate, as analysed by the oxidative cleavage method, produced a palytoxin (PLTX)-like amine oxidation fragment, but when analysed for PLTX-like analogues using a new intact method none were detected indicating an 'unknown' PLTX-like compound is produced by this isolate. Isolates of O. cf. siamensis (Ostreopsis sp. 9), collected in Northland, were also analysed using the oxidative cleavage method, with the common PLTX-like amine fragment and the amide fragment corresponding to bishomoPLTX detected in all isolates. Again, the intact method indicated no detections in the isolates, again suggesting an unknown compound was being produced by these isolates. Prorocentrum hoffmannianum isolates produced okadaic acid (OA) and isoDTX-1 and P. lima isolates produced OA, DTX-1, and isoDTX-1. It is expected that new species of potentially harmful, benthic dinoflagellates will continue to be recorded in Aotearoa New Zealand and the results from Rangitahua provide a guide to the HAB species to expect in sub-tropical Northland as the oceans continue to warm.


Assuntos
Dinoflagellida , Animais , Ilhas , Nova Zelândia , Proliferação Nociva de Algas , Aminas
4.
Sci Total Environ ; 892: 164818, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37315600

RESUMO

Global marine conservation remains fractured by an imbalance in research efforts and policy actions, limiting progression towards sustainability. Rhodolith beds represent a prime example, as they have ecological importance on a global scale, provide a wealth of ecosystem functions and services, including biodiversity provision and potential climate change mitigation, but remain disproportionately understudied, compared to other coastal ecosystems (tropical coral reefs, kelp forests, mangroves, seagrasses). Although rhodolith beds have gained some recognition, as important and sensitive habitats at national/regional levels during the last decade, there is still a notable lack of information and, consequently, specific conservation efforts. We argue that the lack of information about these habitats, and the significant ecosystem services they provide, is hindering the development of effective conservation measures and limiting wider marine conservation success. This is becoming a pressing issue, considering the multiple severe pressures and threats these habitats are exposed to (e.g., pollution, fishing activities, climate change), which may lead to an erosion of their ecological function and ecosystem services. By synthesizing the current knowledge, we provide arguments to highlight the importance and urgency of levelling-up research efforts focused on rhodolith beds, combating rhodolith bed degradation and avoiding the loss of associated biodiversity, thus ensuring the sustainability of future conservation programs.


Assuntos
Biodiversidade , Ecossistema , Recifes de Corais , Poluição Ambiental , Florestas , Conservação dos Recursos Naturais
5.
J Phycol ; 59(3): 603-618, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37070822

RESUMO

Introduced seaweeds and undescribed species often remain undetected because marine regional floras are as yet poorly understood. DNA sequencing facilitates their detection, but databases are incomplete, so their improvement will continue to lead the discovery of these species. Here we aim to clarify the taxonomy of two turf-forming red algal Australian species that morphologically resemble the European Aphanocladia stichidiosa. We also aim to elucidate whether either of these species could have been introduced in Europe or Australia. We studied their morphology, analyzed 17 rbcL sequences of European and Australian specimens, examined their generic assignment using a phylogeny based on 24 plastid genomes, and investigated their biogeography using a taxon-rich phylogeny including 52 rbcL sequences of species in the Pterosiphonieae. The rbcL sequences of one of the Australian species were identical to A. stichidiosa from Europe, considerably expanding its known distribution. Unexpectedly, our phylogenetic analyses resolved this species in the Lophurella clade rather than in Aphanocladia and the new combination L. stichidiosa is proposed. The other Australian species is described as L. pseudocorticata sp. nov. Although L. stichidiosa was originally described in the Mediterranean ca. 70 years ago, our phylogenetic analyses placed it in a lineage restricted to the southern hemisphere, showing that it is native to Australia and introduced to Europe. This study confirms that further work using molecular tools is needed to characterize seaweed diversity, especially among the poorly explored algal turfs, and showcases the usefulness of phylogenetic approaches to uncover introduced species and to determine their native ranges.


Assuntos
Rodófitas , Alga Marinha , Filogenia , Austrália , Rodófitas/genética , Alga Marinha/genética , Análise de Sequência de DNA
6.
Bull Environ Contam Toxicol ; 110(3): 62, 2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-36913053

RESUMO

Coastal ecosystems in the Caribbean are vulnerable to pollution from land-based activities with possible impacts to human health. Ten heavy metals in the blue land crab, Cardisoma guanhumi, harvested from the Caroni Swamp, Trinidad, were investigated in the wet and dry seasons. Metal concentrations (µg g-1 dry weight) in crab tissue were: As (0.15-6.46), Ba (0.69-19.64), Cd (< 0.001-3.36), Cr (0.63-3.64), Cu (26.64-120.31), Hg (0.09-1.83), Ni (1.21-9.33), Se (0.19-1.55), V (0.16-0.69) and Zn (121.06-494.3). There were seasonal differences in the concentration of some heavy metals and, Cu and Zn exceeded the local maximum permissible levels for fish and shellfish at several sites in either one or both seasons. Health risk assessment based on estimated daily intake, target hazard quotient and hazard index revealed that Cardisoma guanhumi harvested from the Caroni Swamp, does not pose a health risk to consumers.


Assuntos
Braquiúros , Metais Pesados , Animais , Humanos , Áreas Alagadas , Ecossistema , Monitoramento Ambiental , Metais Pesados/análise , Medição de Risco
7.
Mol Ecol ; 31(21): 5506-5523, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36029170

RESUMO

Gracilaria chilensis is the main cultivated seaweed in Chile. The low genetic diversity observed in the Chilean populations has been associated with the over-exploitation of natural beds and/or the founder effect that occurred during post-glacial colonization from New Zealand. How these processes have affected its evolutionary trajectory before farming and incipient domestication is poorly understood. In this study, we used 2232 single nucleotide polymorphisms (SNPs) to assess how the species' evolutionary history in New Zealand (its region of origin), the founder effect linked to transoceanic dispersion and colonization of South America, and the recent over-exploitation of natural populations have influenced the genetic architecture of G. chilensis in Chile. The contrasting patterns of genetic diversity and structure observed between the two main islands in New Zealand attest to the important effects of Quaternary glacial cycles on G. chilensis. Approximate Bayesian Computation (ABC) analyses indicated that Chatham Island and South America were colonized independently near the end of the Last Glacial Maximum and emphasized the importance of coastal and oceanic currents during that period. Furthermore, ABC analyses inferred the existence of a recent and strong genetic bottleneck in Chile, matching the period of over-exploitation of the natural beds during the 1970s, followed by rapid demographic expansion linked to active clonal propagation used in farming. Recurrent genetic bottlenecks strongly eroded the genetic diversity of G. chilensis prior to its cultivation, raising important challenges for the management of genetic resources in this incipiently domesticated species.


Assuntos
Gracilaria , Rodófitas , Alga Marinha , Filogeografia , Alga Marinha/genética , Gracilaria/genética , Domesticação , Variação Genética/genética , Teorema de Bayes , Chile , Filogenia
8.
J Phycol ; 58(1): 161-178, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34862980

RESUMO

A multigene (psbA, rbcL, 18S rDNA) molecular phylogeny of the genus Phymatolithon showed a polyphyletic grouping of two monophyletic clades within the Hapalidiales. DNA sequence data integrated with morpho-anatomical comparisons of type material and of recently collected specimens were used to establish Phymatolithopsis gen. nov. with three species, P. prolixa comb. nov., the generitype, P. repanda comb. nov. and P. donghaensis sp. nov. Phymatolithopsis is sister to Mesophyllum and occurs in a clade distinct from Phymatolithon and boreal species currently assigned to Lithothamnion. Morpho-anatomically, Phymatolithopsis is comprised of species that are non-geniculate and encrusting, bear epithallial cells with rounded walls (not flared), subepithallial initials that are usually as short as or shorter than their immediate inward derivatives, conceptacle primordia from all stages forming superficially directly from subepithallial initials, mature carposporangial conceptacles with a discontinuous fusion cell, gonimoblast filaments that develop at the margins of the fusion cell around the periphery of the carposporangial conceptacle chambers, and multiporate tetra/bisporangial conceptacles. Phymatolithopsis can be distinguished from Phymatolithon by the origin of its conceptacle primordia, which are initiated superficially, directly from the layer of subepithallial initials below the epithallial cells and the distribution of gonimoblast filaments in carposporangial conceptacles, that are at the margins of the fusion cells.


Assuntos
Rodófitas , Sequência de Bases , DNA Ribossômico , Filogenia , RNA Ribossômico 16S , Rodófitas/genética , Análise de Sequência de DNA
9.
Healthc Q ; 24(3): 48-52, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34792448

RESUMO

During crises, leaders must address fear, give people a role and purpose and emphasize experimentation, learning and self-care. A survey of emerging health leaders rated the frequency with which they observed their organizational leaders and themselves engage in these crisis leadership functions during the COVID-19 pandemic. Findings revealed significant differences between emerging and more experienced leaders' behaviours in acknowledging fears and providing reassurance, managing individual health and role modelling good self-care and encouraging others to practise good self-care. Emerging leaders rated themselves as engaging in these behaviours more frequently. Barriers preventing these practices included heavy workloads and communication issues. Enablers included good team dynamics, clear communication and incorporating technology. Implications for leadership are presented.


Assuntos
COVID-19 , Pandemias , Comunicação , Humanos , Liderança , Pandemias/prevenção & controle , SARS-CoV-2
10.
Nat Ecol Evol ; 5(3): 360-368, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33495590

RESUMO

Human activity is an important driver of ecological and evolutionary change on our planet. In particular, domestication and biological introductions have important and long-lasting effects on species' genomic architecture and diversity. However, genome-wide analysis of independent domestication and introduction events within a single species has not previously been performed. The Pacific kelp Undaria pinnatifida provides such an opportunity because it has been cultivated in its native range in Northeast Asia but also introduced to four other continents in the past 50 years. Here we present the results of a genome-wide analysis of natural, cultivated and introduced populations of U. pinnatifida to elucidate human-driven evolutionary change. We demonstrate that these three categories of origin can be distinguished at the genome level, reflecting the combined influence of neutral (demography and migration) and non-neutral (selection) processes.


Assuntos
Kelp , Alga Marinha , Undaria , Agricultura , Humanos , Kelp/genética
11.
J Phycol ; 57(3): 849-862, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33305368

RESUMO

The coralline algal genus Corallinapetra is currently monospecific and was established on the species Corallinapetra novaezelandiae, known from a single collection from north-eastern New Zealand. On the basis of multi-gene phylogenetic analyses, Corallinapetra has been resolved apart from all currently recognized families and orders within the Corallinophycidae. We analyzed DNA sequence data from the holotype of Lithothamnion gabrielii, which has been considered a heterotypic synonym of L. muelleri, and an unidentified sample collected from Stewart Island in New Zealand, using psbA, rbcL, and COI-5P genes. We also observed detailed morpho-anatomical characters with light and scanning electron microscopy. Our phylogenetic analyses showed that L. gabrielii and the sample from New Zealand belonged to the same clade as Corallinapetra, distinct from other families and orders in the Corallinophycidae. Members of this clade are distinguishable from other families and orders in the Corallinophycidae by possessing sporangia that are surrounded by remnant sterile filaments that are weakly calcified in mature multiporate sporangial conceptacles that produce zonately divided tetrasporangia. Therefore, we propose that Corallinapetra be placed in its own family, Corallinapetraceae and order, Corallinapetrales, and that L. gabrielii should be assigned to Corallinapetra, as C. gabrielii, to reflect their phylogenetic relationships. We also obtained a partial rbcL sequence data from the lectotype of L. muelleri, the generitype of Lithothamnion. Comparison of the L. muelleri type sequence with L. gabrielii unambiguously demonstrated that these two species are not conspecific, and confirm the placement of L. muelleri within the Hapalidiales.


Assuntos
Rodófitas , Nova Zelândia , Filogenia , Rodófitas/genética , Análise de Sequência de DNA
12.
Environ Pollut ; 266(Pt 1): 115344, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32829170

RESUMO

Fish farming in coastal areas has become an important source of food to support the world's increasing population. However, intensive and unregulated mariculture activities have contributed to changing seawater carbonate chemistry through the production of high levels of respiratory CO2. This additional CO2, i.e. in addition to atmospheric inputs, intensifies the effects of global ocean acidification resulting in localized extreme low pH levels. Marine calcifying macroalgae are susceptible to such changes due to their CaCO3 skeleton. Their physiological response to CO2-driven acidification is dependent on their carbon physiology. In this study, we used the pH drift experiment to determine the capability of 9 calcifying macroalgae to use one or more inorganic carbon (Ci) species. From the 9 species, we selected the rhodolith Sporolithon sp. as a model organism to investigate the long-term effects of extreme low pH on the physiology and biochemistry of calcifying macroalgae. Samples were incubated under two pH treatments (pH 7.9 = ambient and pH 7.5 = extreme acidification) in a temperature-controlled (26 ± 0.02 °C) room provided with saturating light intensity (98.3 ± 2.50 µmol photons m-2 s-1). After the experimental treatment period (40 d), growth rate, calcification rate, nutrient uptake rate, organic content, skeletal CO3-2, pigments, and tissue C, N and P of Sporolithon samples were compared. The pH drift experiment revealed species-specific Ci use mechanisms, even between congenerics, among tropical calcifying macroalgae. Furthermore, long-term extreme low pH significantly reduced the growth rate, calcification rate and skeletal CO3-2 content by 79%, 66% and 18%, respectively. On the other hand, nutrient uptake rates, organic matter, pigments and tissue C, N and P were not affected by the low pH treatments. Our results suggest that the rhodolith Sporolithon sp. is susceptible to the negative effects of extreme low pH resulting from intensive mariculture-driven coastal acidification.


Assuntos
Alga Marinha , Animais , Carbono , Dióxido de Carbono , Carbonatos , Concentração de Íons de Hidrogênio , Oceanos e Mares , Água do Mar
13.
J Phycol ; 56(6): 1575-1590, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32609871

RESUMO

Molecular studies have reported the coexistence of two species of Agarophyton in New Zealand: the newly described A.transtasmanicum with an apparently restricted distribution to some sites in the North Island, and the more widespread A.chilense. Here, we compared the distribution, genetic diversity, and structure of both Agarophyton species throughout the archipelago using sequences of the nuclear Internal Transcribed Spacer 2 (ITS2) marker. Agarophyton chilense's distribution was continuous and extensive along the North and South Islands, Stewart Island, and Chatham Island, and the genetic clusters were mostly concordant with boundaries between biogeographic regions. In contrast, specimens of A.transtasmanicum were collected in four sites broadly distributed in both the North and South Islands, with no clear spatial structure of the genetic diversity. Populations, where the species co-occurred, tended to display similar levels in genetic diversity for the two species. Demographic inferences supported a postglacial demographic expansion for two A.chilense genetic clusters, one present in the South Island and the eastern coast of the North Island, and the other present in northern South Island. A third genetic cluster located on the western coast of the North Island had a signature of long-term demographic stability. For A.transtasmanicum, the skyline plot also suggested a postglacial demographic expansion. Last, we developed a new molecular tool to quickly and easily distinguish between the two Agarophyton species, which could be used to ease future fine-scale population studies, especially in areas where the two species coexist.


Assuntos
DNA Mitocondrial , Variação Genética , Haplótipos , Ilhas , Nova Zelândia , Filogenia , Filogeografia
14.
Healthc Q ; 22(4): 55-58, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32073392

RESUMO

A key goal of programs in health management, policy and research is to transform students into effective leaders. Academic experience can impart knowledge about the skills or competencies required but may not be sufficient to transform students into leaders of health system change.


Assuntos
Educação de Pós-Graduação/métodos , Ocupações em Saúde/educação , Liderança , Feminino , Humanos , Masculino
15.
J Phycol ; 56(1): 23-36, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31642057

RESUMO

Long-distance dispersal plays a key role in evolution, facilitating allopatric divergence, range expansions, and species movement in response to environmental change. Even species that seem poorly suited to dispersal can sometimes travel long distances, for example via hitchhiking with other, more intrinsically dispersive species. In marine macroalgae, buoyancy can enable adults-and diverse hitchhikers-to drift long distances, but the evolution and role of this trait are poorly understood. The southern bull-kelp genus Durvillaea includes several non-buoyant and buoyant species, including some that have only recently been recognized. In revising the genus, we not only provide updated identification tools and describe two new species (D. incurvata comb. nov. from Chile and D. fenestrata sp. nov. from the Antipodes Islands), but also carry out biogeographic analyses to determine the evolutionary history of buoyancy in the genus. Although the ancestral state was resolved as non-buoyant, the distribution of species suggests that this trait has been both gained and lost, possibly more than once. We conclude that although buoyancy is a trait that can be useful for dispersal (creating evolutionary pressure for its gain), there is also evolutionary pressure for its loss as it restricts species to narrow environmental ranges (i.e., shallow depths).


Assuntos
Kelp , Alga Marinha , Animais , Bovinos , Chile , Masculino , Filogenia
16.
Mar Pollut Bull ; 150: 110774, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31785846

RESUMO

Sequential extraction was used to determine the geochemical distribution of trace metals in coastal sediments from Trinidad and Tobago. The results showed that there was considerable variation in the bioavailability, mobility and ecological risk of the metals determined. Cadmium had very high ecological risk: 57-88% of cadmium was associated with the exchangeable and carbonate bound metal fraction (F1). Ecological risk decreased in the order manganese> nickel> lead> zinc. Copper had the lowest ecological risk: lowest percentages of copper were associated with F1 (1-15%) and F2 (3-15%), while considerable percentages (48-55%) were associated with the residual fraction. Management of the risks posed by these metals in the marine environment requires a holistic approach including reduction in trace metal inputs from point and non-point sources of pollution, particularly off the west coast of Trinidad, and public education on the impacts of trace metals in the environment and on human health.


Assuntos
Monitoramento Ambiental , Metais/análise , Oligoelementos/análise , Poluentes Químicos da Água/análise , Sedimentos Geológicos , Humanos , Trinidad e Tobago
17.
PLoS One ; 14(12): e0225645, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31790447

RESUMO

Coralline algae (Corallinophycideae) are calcifying red algae that are foundation species in euphotic marine habitats globally. In recent years, corallines have received increasing attention due to their vulnerability to global climate change, in particular ocean acidification and warming, and because of the range of ecological functions that coralline algae provide, including provisioning habitat, influencing settlement of invertebrate and other algal species, and stabilising reef structures. Many of the ecological roles corallines perform, as well as their responses to stressors, have been demonstrated to be species-specific. In order to understand the roles and responses of coralline algae, it is essential to be able to reliably distinguish individual species, which are frequently morphologically cryptic. The aim of this study was to document the diversity and distribution of coralline algae in the New Zealand region using DNA based phylogenetic methods, and examine this diversity in a broader global context, discussing the implications and direction for future coralline algal research. Using three independent species delimitation methods, a total of 122 species of coralline algae were identified across the New Zealand region with high diversity found both regionally and also when sampling at small local spatial scales. While high diversity identified using molecular methods mirrors recent global discoveries, what distinguishes the results reported here is the large number of taxa (115) that do not resolve with type material from any genus and/or species. The ability to consistently and accurately distinguish species, and the application of authoritative names, are essential to ensure reproducible science in all areas of research into ecologically important yet vulnerable coralline algae taxa.


Assuntos
Biodiversidade , Recifes de Corais , Monitorização de Parâmetros Ecológicos/métodos , Rodófitas/fisiologia , Mudança Climática , Geografia , Concentração de Íons de Hidrogênio , Nova Zelândia , Oceanos e Mares , Filogenia , Água do Mar/química , Temperatura
18.
Geochem Geophys Geosyst ; 20(1): 314-338, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30853858

RESUMO

The Izu-Bonin-Mariana (IBM) fore arc preserves igneous rock assemblages that formed during subduction initiation circa 52 Ma. International Ocean Discovery Program (IODP) Expedition 352 cored four sites in the fore arc near the Ogasawara Plateau in order to document the magmatic response to subduction initiation and the physical, petrologic, and chemical stratigraphy of a nascent subduction zone. Two of these sites (U1440 and U1441) are underlain by fore-arc basalt (FAB). FABs have mid-ocean ridge basalt (MORB)-like compositions, however, FAB are consistently lower in the high-field strength elements (TiO2, P2O5, Zr) and Ni compared to MORB, with Na2O at the low end of the MORB field and FeO* at the high end. Almost all FABs are light rare earth element depleted, with low total REE, and have low ratios of highly incompatible to less incompatible elements (Ti/V, Zr/Y, Ce/Yb, and Zr/Sm) relative to MORB. Chemostratigraphic trends in Hole U1440B are consistent with the uppermost lavas forming off axis, whereas the lower lavas formed beneath a spreading center axis. Axial magma of U1440B becomes more fractionated upsection; overlying off-axis magmas return to more primitive compositions. Melt models require a two-stage process, with early garnet field melts extracted prior to later spinel field melts, with up to 23% melting to form the most depleted compositions. Mantle equilibration temperatures are higher than normal MORB (1,400 °C-1,480 °C) at relatively low pressures (1-2 GPa), which may reflect an influence of the Manus plume during subduction initiation. Our data support previous models of FAB origin by decompression melting but imply a source more depleted than normal MORB source mantle.

19.
J Pain Symptom Manage ; 57(6): 1151-1165, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30794937

RESUMO

CONTEXT: Being diagnosed with cancer often forces patients and families to make difficult medical decisions. How patients think they and others will feel in the future, termed affective predictions, may influence these decisions. These affective predictions are often biased, which may contribute to suboptimal care outcomes by influencing decisions related to palliative care and advance care planning. OBJECTIVES: This study aimed to translate perspectives from the decision sciences to inform future research about when and how affective predictions may influence decisions about palliative care and advance care planning. METHODS: A systematic search of two databases to evaluate the extent to which affective predictions have been examined in the palliative care and advance care planning context yielded 35 relevant articles. Over half utilized qualitative methodologies (n = 21). Most studies were conducted in the U.S. (n = 12), Canada (n = 7), or European countries (n = 10). Study contexts included end of life (n = 10), early treatment decisions (n = 10), pain and symptom management (n = 7), and patient-provider communication (n = 6). The affective processes of patients (n = 20), caregivers (n = 16), and/or providers (n = 12) were examined. RESULTS: Three features of the palliative care and advance care planning context may contribute to biased affective predictions: 1) early treatment decisions are made under heightened emotional states and with insufficient information; 2) palliative care decisions influence life domains beyond physical health; and 3) palliative care decisions involve multiple people. CONCLUSION: Biases in affective predictions may serve as a barrier to optimal palliative care delivery. Predictions are complicated by intense emotions, inadequate prognostic information, involvement of many individuals, and cancer's effect on non-health life domains. Applying decision science frameworks may generate insights about affective predictions that can be harnessed to solve challenges associated with optimal delivery of palliative care.


Assuntos
Planejamento Antecipado de Cuidados/organização & administração , Afeto , Modelos Organizacionais , Cuidados Paliativos/organização & administração , Previsões , Humanos , Neoplasias/terapia
20.
Ann Behav Med ; 53(2): 158-168, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29746628

RESUMO

Background: Poor physical and mental health is common among cancer survivors, but little is known about how cancer influences life satisfaction and expectations about one's future, both of which may subsequently influence health decisions and outcomes. Purpose: The current study examined how a cancer diagnosis influences current and predicted future life satisfaction in seven domains, including family, finances, work, and health. Methods: We leveraged data from three waves of the Midlife in the United States study (N = 6,389) and examined the relation between new and past cancer diagnoses on satisfaction using generalized estimating equations. We also compared participants' predicted satisfaction to the actual satisfaction they reported at later waves of data collection, and examined whether concordance between the two differed by cancer history. Results: A cancer diagnosis was associated with a decline in satisfaction about one's present health and sex life, ps < .05, but satisfaction with all other domains remained steady or improved. In contrast, predictions about the future became and remained less optimistic than the predictions of those without cancer across all life domains except relationships with children, ps < .05. Within-subjects comparisons of predicted and actual satisfaction suggest those without a cancer history were optimistic in their predictions across all life domains except health whereas survivors were more accurate in their predictions. Conclusions: Given the many ways in which expectations about the future can influence decision making, behavior, and health, survivors' attenuated optimistic outlooks may influence their health and well-being.


Assuntos
Neoplasias/diagnóstico , Neoplasias/psicologia , Satisfação Pessoal , Qualidade de Vida , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Otimismo/psicologia , Comportamento Sexual , Fatores de Tempo
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