14 resultados para Pre-Mesozoic basement of Iberia
em University of Queensland eSpace - Australia
Resumo:
New K-Ar and Ar-40/Ar-39 data of tholeiitic and alkaline dike swarms from the onshore basement of the Santos Basin (SE Brazil) reveal Mesozoic and Tertiary magmatic pulses. The tholeiitic rocks (basalt, dolerite, and microgabbro) display high TiO2 contents (average 3.65 wt%) and comprise two magmatic groups. The NW-oriented samples of Group A have (La/Yb)N ratios between 15 and 32.3 and range in age from 192.9 +/- 2.2 to 160.9 +/- 1.9 Ma. The NNW-NNE Group B samples, with (La/Yb)(N) ratios between 7 and 16, range from 148.3 +/- 3 to 133.9 +/- 0.5 Ma. The alkaline rocks (syenite, trachyte, phonolite, alkaline basalts, and lamprophyre) display intermediate-K contents and comprise dikes, plugs, and stocks. Ages of approximately 82 Ma were obtained for the lamprophyre dikes, 70 Ma for the syenite plutons, and 64-59 Ma for felsic dikes. Because Jurassic-Early Cretaceous basic dikes have not been reported in SE Brazil, we might speculate that, during the emplacement of Group A dikes, extensional stresses were active in the region before the opening of the south Atlantic Ocean and coeval with the Karoo magmatism described in South Africa. Group B dikes yield ages compatible with those obtained for Serra Geral and Ponta Grossa magmatism in the Parana Basin and are directly related to the breakup of western Gondwana. Alkaline magmatism is associated with several tectonic episodes that postdate the opening of the Atlantic Ocean and related to the upwelling of the Trindade plume and the generation of Tertiary basins southeast of Brazil. In the studied region, alkaline magmatism can be subdivided in two episodes: the first one represented by lamprophyre dykes of approximately 82 Ma and the second comprised of felsic alkaline stocks of approximately 70 Ma and associated dikes ranging from 64 to 59 Ma. (c) 2005 Elsevier Ltd. All rights reserved.
Resumo:
The morphology of the exine of Late Cretaceous and Tertiary specimens of Tricolpites reticulatus previously documented from Kerguelen, the Antarctic Peninsula, and the Otway Basin of southeastern Australia has been re-examined and compared with the three pollen types identified in the genus Gunnera. An Antarctic specimen of T reticulatus (Maastrichtian) has a uniform reticulum with elongated lumina, similar to that characterising pollen type 3a of Gunnera macrophylla (subgenus Pseudogunnera). Late Cretaceous (Maastrichtian) Australian specimens of T reticulatus differ; specimens from McNamara resemble pollen of subgenera Pseudogunnera and Milligania of type 3a or type 3b, while specimens of T reticulatus from Princes show more rounded and equidimensional lumina and are therefore tentatively attributed to pollen type 2 found in subgenera Gunnera, Misandra and Panke. Kerguelen Island T reticulatus (Miocene) are distinct from Vega Island specimens: a closer resemblance of Kerguelen T reticulatus and pollen type 2 of extant Gunnera is hypothesised. A comparison between specimens of the North American Tricolpites reticulatus/microreticulatus and pollen of Gunnera is also made. The clear similarity of the North American specimens of Tricolpites microreticulatus and pollen of Gunnera in shape and in the exine surface features of pollen suggests that this taxon should not be separated from T reticulatus but should be treated as a synonym of this species. (C) 2004 Elsevier B.V. All rights reserved.
Resumo:
Background: The results from previous studies have indicated that a pre-attentive component of the event-related potential (ERP), the mismatch negativity (MMN), may be an objective measure of the automatic auditory processing of phonemes and words. Aims: This article reviews the relationship between the MMN data and psycholinguistic models of spoken word processing, in order to determine whether the MMN may be used to objectively pinpoint spoken word processing deficits in individuals with aphasia. Main Contribution: This article outlines the ways in which the MMN data support psycholinguistic models currently used in the clinical management of aphasic individuals. Furthermore, the cell assembly model of the neurophysiological mechanisms underlying spoken word processing is discussed in relation to the MMN and psycholinguistic models. Conclusions: The MMN data support current theoretical psycholinguistic and neurophysiological models of spoken word processing. Future MMN studies that include normal and aphasic populations will further elucidate the role that the MMN may play in the clinical management of aphasic individuals.
Resumo:
After providing background on Dendrolagus species in Australia, two consecutive surveys of Brisbane's residents are used to assess public knowledge of tree-kangaroos and the stated degree of support for their conservation in Australia. The responses of participants in Survey I are based on their pre-survey knowledge of wildlife. The same set of participants completed Survey II after being provided with additional information on all the wildlife species mentioned in Survey I. Changes in the attitudes of respondents and their degree of support for the protection and conservation of Australia's tree-kangaroos are measured, including changes in their contingent valuations and stated willingness to provide financial support for such conservation. Reasons for wanting to protect tree-kangaroos are specified and analysed. Furthermore, changes that occur in the relative importance of these reasons with increased knowledge are also examined. Support for the conservation of tree-kangaroos is found to rise with the additional knowledge supplied about all species and is compared with variations in support for protection of other mammals. Support for the conservation of Australia's less well known tropical mammals is found to increase relative to better known mammals (icons) present in temperate areas, such as koalas and red kangaroos. Possible implications of the results for government conservation policies in Australia are examined.
Resumo:
Adult mosquitoes (Diptera: Culicidae) were collected in January and February 2000 from Saibai Island in the Torres Strait of northern Australia, and processed for arbovirus isolation during a period of Japanese encephalitis (JE) virus activity on nearby Badu Island. A total of 84 2 10 mosquitoes were processed for virus isolation, yielding six flavivirus isolates. Viruses obtained were single isolates of JE and Kokobera (KOK) and four of Kunjin (KUN). All virus isolates were from members of the Culex sitiens Weidemann subgroup, which comprised 53.1 % of mosquitoes processed. Nucleotide sequencing and phylogenetic analysis of the pre-membrane region of the genome of JE isolate TS5313 indicated that it was closely related to other isolates from a sentinel pig and a pool of Cx. gelidus Theobald from Badu Island during the same period. Also molecular analyses of part of the envelope gene of KUN virus isolates showed that they were closely related to other KUN virus strains from Cape York Peninsula. The results indicate that flaviviruses are dynamic in the area, and suggest patterns of movement south from New Guinea and north from the Australian mainland.
Resumo:
A new, fast, continuous flow technique is described for the simultaneous determination of 633 S and delta(34)S using SO masses 48, 49 and 50. Analysis time is similar to5min/sample with measurement precision and accuracy better than +/-0.3parts per thousand. This technique, which has been set up using IAEA Ag2S standards S-1, S-2 and S-3, allows for the fast determination of mass-dependent or mass-independent fractionation (MIF) effects in sulfide, organic sulfur samples and possibly sulfate. Small sample sizes can be analysed directly, without chemical pre-treatment. Robustness of the technique for natural versus artificial standards was demonstrated by analysis of a Canon Diablo troilite, which gave a delta(33)S of 0.04parts per thousand and a delta(34)S of -0.06parts per thousand compared to the values obtained for S-1 of 0.07parts per thousand and -0.20parts per thousand, respectively. Two pyrite samples from a banded-iron formation from the 3710 Ma Isua Greenstone Belt were analysed using this technique and yielded MIF (Delta(33)S of 2.45 and 3.31parts per thousand) comparable to pyrite previously analysed by secondary ion probe. Copyright (C) 2004 John Wiley Sons, Ltd.
Resumo:
It was hypothesized that employees' perceptions of an organizational culture strong in human relations values and open systems values would be associated with heightened levels of readiness for change which, in turn, would be predictive of change implementation success. Similarly, it was predicted that reshaping capabilities would lead to change implementation success, via its effects on employees' perceptions of readiness for change. Using a temporal research design, these propositions were tested for 67 employees working in a state government department who were about to undergo the implementation of a new end-user computing system in their workplace. Change implementation success was operationalized as user satisfaction and system usage. There was evidence to suggest that employees who perceived strong human relations values in their division at Time 1 reported higher levels of readiness for change at pre-implementation which, in turn, predicted system usage at Time 2. In addition, readiness for change mediated the relationship between reshaping capabilities and system usage. Analyses also revealed that pre-implementation levels of readiness for change exerted a positive main effect on employees' satisfaction with the system's accuracy, user friendliness, and formatting functions at post-implementation. These findings are discussed in terms of their theoretical contribution to the readiness for change literature, and in relation to the practical importance of developing positive change attitudes among employees if change initiatives are to be successful.
Resumo:
Pre-settlement events play an important role in determining larval success in marine invertebrates with bentho-pelagic life histories, yet the consequences of these events typically are not well understood. The purpose of this study was to examine the pre-settlement impacts of different seawater temperatures on the size and population density of dinoflagellate symbionts in brooded larvae of the Caribbean coral Porites astreoides. Larvae were collected from P. astreoides at 14-20 m depth on Conch Reef (Florida) in June 2002, and incubated for 24 h at 15 temperatures spanning the range 25.1 degrees-30.0 degrees C in mean increments of 0.4 +/- 0.1 degrees C (+/- SD). The most striking feature of the larval responses was the magnitude of change in both parameters across this 5 degrees C temperature range within 24 h. In general, larvae were largest and had the highest population densities of Symbiodinium sp. between 26.4 degrees-27.7 degrees C, and were smallest and had the lowest population densities at 25.8 degrees C and 28.8 degrees C. Larval size and symbiont population density were elevated slightly (relative to the minimal values) at the temperature extremes of 25.1 degrees C and 30 degrees C. These data demonstrate that coral larvae are highly sensitive to seawater temperature during their pelagic phase, and respond through changes in size and the population densities of Symbiodinium sp. to ecologically relevant temperature signals within 24 h. The extent to which these changes are biologically meaningful will depend on the duration and frequency of exposure of coral larvae to spatio-temporal variability in seawater temperature, and whether the responses have cascading effects on larval success and their entry to the post-settlement and recruitment phase.
Resumo:
Aim. The paper presents a study assessing the rate of adoption of a sedation scoring system and sedation guideline. Background. Clinical practice guidelines including sedation guidelines have been shown to improve patient outcomes by standardizing care. In particular sedation guidelines have been shown to be beneficial for intensive care patients by reducing the duration of ventilation. Despite the acceptance that clinical practice guidelines are beneficial, adoption rates are rarely measured. Adoption data may reveal other factors which contribute to improved outcomes. Therefore, the usefulness of the guideline may be more appropriately assessed by collecting adoption data. Method. A quasi-experimental pre-intervention and postintervention quality improvement design was used. Adoption was operationalized as documentation of sedation score every 4 hours and use of the sedation and analgesic medications suggested in the guideline. Adoption data were collected from patients' charts on a random day of the month; all patients in the intensive care unit on that day were assigned an adoption category. Sedation scoring system adoption data were collected before implementation of a sedation guideline, which was implemented using an intensive information-giving strategy, and guideline adoption data were fed back to bedside nurses. After implementation of the guideline, adoption data were collected for both the sedation scoring system and the guideline. The data were collected in the years 2002-2004. Findings. The sedation scoring system was not used extensively in the pre-intervention phase of the study; however, this improved in the postintervention phase. The findings suggest that the sedation guideline was gradually adopted following implementation in the postintervention phase of the study. Field notes taken during the implementation of the sedation scoring system and the guideline reveal widespread acceptance of both. Conclusion. Measurement of adoption is a complex process. Appropriate operationalization contributes to greater accuracy. Further investigation is warranted to establish the intensity and extent of implementation required to positively affect patient outcomes.
Resumo:
Fires are integral to the healthy functioning of most ecosystems and are often poorly understood in policy and management, however, the relationship between floristic composition and habitat structure is intrinsically linked, particularly after fire. The aim of this study was to test whether the variability of habitat structure or floristic composition and abundance in forests at a regional scale can be explained in terms of fire frequency using historical data and experimental prescribed burns. We tested this hypothesis in open eucalypt forests of Fraser Island off the east coast of Australia. Fraser Island dunes show progressive stages in plant succession as access to nutrients decreases across the Island. We found that fire frequency was not a good predictor of floristic composition or abundance across dune systems; rather, its affects were dune specific. In contrast, habitat structure was strongly influenced by fire frequency, independent of dune system. A dense understorey occurred in frequently burnt areas, whereas infrequently burnt areas had a more even distribution of plant heights. Plant communities returned to pre-burn levels of composition and abundances within 6 months of a fire and frequently burnt areas were dominated by early successional species of plant. These ecosystems were characterized by low diversity and frequently burnt areas on the east coast were dominated by Pteridium. Greater midstorey canopy cover in low frequency areas reduces light penetration and allows other species to compete more effectively with Pteridium. Our results strongly indicate that frequent fires on the Island have resulted in a decrease in relative diversity through dominance of several species. Prescribed fire represents a powerful management tool to shape habitat structure and complexity of Fraser Island forests.
Resumo:
Objective: Mitral repair is increasingly performed in asymptomatic mitral regurgitation (MR). Previous work showed that pre-operative documentation of loss of contractile reserve (Cr) by exercise echo (ExE) may predict LV dysfunction early after repair. We sought the value of Cr in predicting late post-op LV dysfunction and clinical outcome. Methods: Pre-op ExE was performed in 41 pts with isolated MR without coronary disease undergoing repair. LV end-systolic and end-diastolic volumes were measured at rest and post-stress and EF was calculated using modified Simpson’s rule. Intact Cr was defined by >4% increment of stress compared with rest EF. During follow up (3±1 years), EF was serially assessed and occurrence of cardiac events was documented. Results: Cr was present in 19 pts (Cr+)(peak EF 76±7%) and absent in 22 pts (Cr-)(peak EF 56±11%, p
Resumo:
A major task of traditional temporal event sequence mining is to predict the occurrences of a special type of event (called target event) in a long temporal sequence. Our previous work has defined a new type of pattern, called event-oriented pattern, which can potentially predict the target event within a certain period of time. However, in the event-oriented pattern discovery, because the size of interval for prediction is pre-defined, the mining results could be inaccurate and carry misleading information. In this paper, we introduce a new concept, called temporal feature, to rectify this shortcoming. Generally, for any event-oriented pattern discovered under the pre-given size of interval, the temporal feature is the minimal size of interval that makes the pattern interesting. Thus, by further investigating the temporal features of discovered event-oriented patterns, we can refine the knowledge for the target event prediction.
Resumo:
This study examined the effectiveness of the Triple P-Positive Parenting Program in a government child health service delivery context with Chinese parents in Hong Kong. Specifically, the study sought to identify pre-intervention variables that might predict programme outcomes such as, level of clinical improvement and programme completion. Participants were 661 parents of pre-school and primary aged children participating in a group version of the Triple P-Positive Parenting Program. There were significant decreases in disruptive child behaviours, levels of parenting stress, general stress and anxiety and an increase in parenting sense of competence. Greater change in reports of child behaviour problems was related to lower levels of family income, new immigrant family status, and higher pre-intervention levels of parenting stress. The present study provides a profile of parents who are most likely to benefit from parent training programmes.