371 resultados para isolating


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Doutoramento em Engenharia Florestal - Instituto Superior de Agronomia - UL

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Tese de dout. em Biologia, especialidade de Biologia Molecular, Unidade de Ciências e Tecnologias dos Recursos Aquáticos, Univ. do Algarve

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Themarine environment seems, at first sight, to be a homogeneousmediumlacking barriers to species dispersal. Nevertheless, populations of marine species show varying levels of gene flow and population differentiation, so barriers to gene flow can often be detected. Weaimto elucidate the role of oceanographical factors ingenerating connectivity among populations shaping the phylogeographical patterns in the marine realm, which is not only a topic of considerable interest for understanding the evolution ofmarine biodiversity but also formanagement and conservation of marine life. For this proposal,we investigate the genetic structure and connectivity between continental and insular populations ofwhite seabreamin North East Atlantic (NEA) and Mediterranean Sea (MS) aswell as the influence of historical and contemporary factors in this scenario using mitochondrial (cytochrome b) and nuclear (a set of 9 microsatellite) molecular markers. Azores population appeared genetically differentiated in a single cluster using Structure analysis. This result was corroborated by Principal Component Analysis (PCA) and Monmonier algorithm which suggested a boundary to gene flow, isolating this locality. Azorean population also shows the highest significant values of FST and genetic distances for both molecular markers (microsatellites and mtDNA). We suggest that the breakdown of effective genetic exchange between Azores and the others' samples could be explained simultaneously by hydrographic (deep water) and hydrodynamic (isolating current regimes) factors acting as barriers to the free dispersal of white seabream(adults and larvae) and by historical factors which could be favoured for the survival of Azorean white seabream population at the last glaciation. Mediterranean islands show similar genetic diversity to the neighbouring continental samples and nonsignificant genetic differences. Proximity to continental coasts and the current system could promote an optimal larval dispersion among Mediterranean islands (Mallorca and Castellamare) and coasts with high gene flow.

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Flat-lying Early and Middle Ordovician limestones exposed on the North margin of Estonia provide key insights into the early Paleozoic biosphere and climatic history of the Baltic Platform, and potentially offer a site for calibrating the duration of the proposed Moyero River Reversed Superchron. Past paleomagnetic analyses on these rocks have been focused primarily on determining paleomagnetic pole positions and have been hampered by relatively weak remanent magnetizations. We therefore applied techniques of the Rock and Paleomagnetic Instrument Development (RAPID) consortium using thin-walled, low-noise quartz glass sample holders on an automatic system to enhance magnetostratigraphic resolution. Our results, based on over 300 oriented core samples spanning the stratigraphic interval from the Volkhov stage, up through the Lasnamägi stage, confirm previous work isolating a stable characteristic magnetization of reversed polarity, and furthermore confirm the presence of an interval of magnetically Reversed polarity spanning an interval of at least 15 million year duration. In addition, we recognize a magnetic overprint of presumed Normal polarity held in antiferromagnetic phases, of presumed Permian age, based on the apparent polar wander path given by (Plado et al., 2010).

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The emotional bond that a mother feels towards her baby is critical to social, emotional and cognitive development. Maternal health and wellbeing through pregnancy and antenatal bonding also play a key role in determining bonding postnatally, but the extent to which these relationships may be disrupted by poor mental health or substance use is unclear. This study aimed to examine the extent to which mother-fetal bonding, substance use and mental health through pregnancy predicted postnatal mother-infant bonding at 8 weeks. Participants were 372 women recruited from three metropolitan hospitals in Australia. Data was collected during trimesters one, two and three of pregnancy and 8 weeks postnatal using the Maternal Antenatal Attachment Scale (MAAS), Maternal Postnatal Attachment Scale (MPAS), the Edinburgh Antenatal and Postnatal Depression Scale (EPDS), the Depression and Anxiety Scales (DASS-21), frequency and quantity of substance use (caffeine, alcohol and tobacco) as well as a range of demographic and postnatal information. Higher antenatal bonding predicted higher postnatal bonding at all pregnancy time-points in a fully adjusted regression model. Maternal depressive symptoms in trimesters two and three and stress in trimester two were inversely related to poorer mother-infant bonding 8 weeks postnatally. This study extends previous work on the mother’s felt bond to her developing child by drawing on a large sample of women and documenting the pattern of this bond at three time points in pregnancy and at 8 weeks postnatally. Utilising multiple antenatal waves allowed precision in isolating the relationships in pregnancy and at key intervention points. Investigating methods to enhance bonding and intervene in pregnancy is needed. It is also important to assess maternal mental health through pregnancy.

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This review discusses palliative care and end-of-life models of care for Aboriginal people in the Australian state New South Wales, and considers Aboriginal palliative care needs by reflecting on recent literature and lessons derived from Aboriginal consultation. Aboriginal people in Australia account for a very small proportion of the population, have poorer health outcomes and their culture demonstrates a clear resistance to accessing mainstream health services which are viewed as powerful, isolating and not relevant to their culture, way of life, family and belief systems. Aboriginal people regard their land as spiritual and their culture dictates that an Aboriginal person needs to know their origins, emphasising the value placed on kin and also demonstrating a strong desire to remain within their own country. Currently Aboriginal people tend to not access palliative care services in mainstream facilities; and there is very little data on Aboriginal admissions to palliative care centres. Over the last two decades only two models of palliative care focusing on and developed in Aboriginal communities have been implemented. The seminal contribution to Aboriginal Palliative Care was in the form of a resource kit developed to support palliative care providers to examine their practice for cultural appropriateness for Aboriginal and Torres Strait Islanders. The "living model" coming from this project is adaptive and flexible, enabling implementation in different Aboriginal country as a participative process with community input. The Australian government"s National Indigenous Palliative Care Needs Study similarly indicated that Australian empirical research on Aboriginal palliative care service provision is in its infancy, and comprehensive data on the rates of Aboriginal access to palliative care services did not exist. What literature does exist is drawn together in an argument for the development and need for culturally specific Aboriginal palliative care models, which are culturally appropriate, locally accessible and delivered in collaboration and partnership with Aboriginal controlled health services. This is essential because Aboriginal people are a minority cultural group who are disconnected from mainstream health service delivery, and have a sense of cultural isolation when accessing mainstream services. It is preferable that palliative care is delivered in a collaboration between Aboriginal Controlled Health Service and mainstream palliative care services to ensure a dignified end of life for the Aboriginal person. These collaborations and partnerships are fundamental to ensure that a critical mass of Aboriginal clinicians are trained and experienced in end of life care and palliation. Developing palliative care programs within Aboriginal communities and training Aboriginal Health Workers, promoted and developed in partnership with the Aboriginal community, are important strategies to enhance palliative care service provision. Further partnerships should be championed in this collaborative process, acknowledging a need for palliative care models that fit with Aboriginal peoples" community values, beliefs, cultural/ spiritual rituals, heritage and place.

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Introduced in this paper is a Bayesian model for isolating the resonant frequency from combustion chamber resonance. The model shown in this paper focused on characterising the initial rise in the resonant frequency to investigate the rise of in-cylinder bulk temperature associated with combustion. By resolving the model parameters, it is possible to determine: the start of pre-mixed combustion, the start of diffusion combustion, the initial resonant frequency, the resonant frequency as a function of crank angle, the in-cylinder bulk temperature as a function of crank angle and the trapped mass as a function of crank angle. The Bayesian method allows for individual cycles to be examined without cycle-averaging|allowing inter-cycle variability studies. Results are shown for a turbo-charged, common-rail compression ignition engine run at 2000 rpm and full load.

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This paper presents an application of Wavelet Transfonn (WT) for determination of stress wave velocity for Non-destructive Testing of timber utility poles in service. For surface Non-destructive Testing (NDT), the hammer impact, which produces generally broadband frequency excitation, is used to generate stress wave. Moreover, due to practicality the impact location for field testing of a utility pole is on the side of the pole and 1.5 m above ground level. And the geometry of utility pole could not guarantee non-dispersive longitudinal wave. All of these issues have resulted in lack of accuracy and reliability of results from surface NDT in field testing. In recognition of such problem, this research explores methods to reliably calculate desired wave velocity by isolating wave mode and studying dispersive nature of utility pole. Fast Fourier Transfonn (FFT) is firstly conducted to determine the suitable frequency from a stress wave data. Then WT is applied on the wave data mentioned to perfonn time-frequency analysis. Velocity can be detennined by time history data of desired frequency from WT results which will be compared with the available analytical solution for longitudinal wave velocity. The results of the investigation showed that wavelet transfonn analysis can be a reliable signal processing tool for non-destructive testing in tenns of velocity detennination, which in tum also helps to detennine the embedded length of the timber pole.

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This paper examines the design of minimal-order residual generators for the purpose of detecting and isolating actuator and/or component faults in dynamical systems. We first derive existence conditions and design residual generators using only first-order observers to detect and identify the faults. When the first-order functional observers do not exist, then based on a parametric approach to the solution of a generalized Sylvester matrix equation, we develop systematic procedures for designing residual generators utilizing minimal-order functional observers. Our design approach gives lower-order residual generators than existing results in the literature. The advantages for having such lower-order residual generators are obvious from the economical and practical points of view as cost saving and simplicity in implementation can be achieved, particularly when dealing with high-order complex systems. Numerical examples are given to illustrate the proposed fault detection and isolation schemes. In all of the numerical examples, we design minimum-order residual generators to effectively detect and isolate actuator and/or component faults in the system.

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Habitat loss and fragmentation are major threats to biodiversity and ecosystem processes. Our current understanding of the impacts of habitat loss and fragmentation is based largely on studies that focus on either short-term or long-term responses. Short-term responses are often used to predict long-term responses and make management decisions. The lack of studies comparing short- and long-term responses to fragmentation means we do not adequately understand when and how well short-term responses can be extrapolated to predict long-term responses, and when or why they cannot. To address this gap, we used data from one of the world's longest-running fragmentation experiments, The Wog Wog Habitat Fragmentation Experiment. Using data for carabid beetles, we found that responses in the long term (more than 22 years post-fragmentation ~ 22 generations) often contrasted markedly with those in the short term (five years post-fragmentation). The total abundance of all carabids, species richness and the occurrence of six species declined in the short term in the fragments but increased over the long term. The occurrence of three species declined initially and continued to decline, whilst another species was positively affected initially but decreased in the long term. Species' responses to the matrix that surrounds the fragments strongly predicted both the direction (increase/decline in occurrence) and magnitude of their responses to fragmentation. Additionally, species' responses to the matrix were somewhat predicted by their preferences for different types of native habitat (open vs. shaded). Our study highlights the degree of the matrix's influence in fragmented landscapes, and how this influence can change over time. We urge caution in using short-term responses to forecast long-term responses in cases where the matrix a) impacts species' responses to fragmentation (by isolating them, creating new habitat or altering fragment habitat) and b) is likely to change through time. This article is protected by copyright. All rights reserved.

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Introducción: Las guías de Tokyo de 2013 lograron un consenso respecto al manejo antibiótico de la infección biliar. Sus recomendaciones están sustentadas en estudios internacionales de la epidemiología bacteriana, pero también recalcan la importancia de conocer la microbiología local para ajustar las guías de manejo. Materiales y métodos: Se diseñó un estudio descriptivo tipo serie de casos de pacientes tratados por colecistitis aguda moderada y severa en Méderi Hospital Universitario Mayor (HUM), describiendo los aislamientos microbiológicos y perfiles de resistencia de los cultivos de bilis tomados durante la cirugía. Resultados: Se analizaron 131 pacientes con una edad promedio de 63 años, la mayoría sin comorbilidades médicas. Se encontró un 48% de positividad en los cultivos, predominantemente enterobacterias siendo la más frecuente Escherichia coli, seguida de especies de Klebsiella y de Enterococcus. Los perfiles de resistencia evidenciaron un 93% de multisensibilidad antibiótica y se aislaron 4 microorganismos multirresistentes. No se encontraron diferencias en comorbilidades, alteraciones paraclínicas, presencia de síndrome biliar obstrutivo, pancreatitis o instrumentación previa de la vía biliar entre los pacientes con cultivo positivo y negativo. Conclusiones: Los resultados concuerdan con los reportes internacionales en cuanto a la flora bacteriana aislada, pero los perfiles de resistencia evidenciados en esta serie son diferentes a los que sustentan las guías de manejo de Tokio revisadas en 2013. Este hallazgo obliga a ajustar las guías de manejo institucionales con base en la epidemiología local.