193 resultados para 145-885
Resumo:
Carbonatites are known to contain the highest concentrations of rare-earth elements (REE) among all igneous rocks. The REE distribution of carbonatites is commonly believed to be controlled by that of the rock forming Ca minerals (i.e., calcite, dolomite, and ankerite) and apatite because of their high modal content and tolerance for the substitution of Ca by light REE (LREE). Contrary to this conjecture, calcite from the Miaoya carbonatite (China), analyzed in situ by laser-ablation inductively-coupled-plasma mass-spectrometry, is characterized by low REE contents (100–260 ppm) and relatively !at chondrite-normalized REE distribution patterns [average (La/Yb)CN=1.6]. The carbonatite contains abundant REE-rich minerals, including monazite and !uorapatite, both precipitated earlier than the REE-poor calcite, and REE-fluorocarbonates that postdated the calcite. Hydrothermal REE-bearing !uorite and barite veins are not observed at Miaoya. The textural and analytical evidence indicates that the initially high concentrations of REE and P in the carbonatitic magma facilitated early precipitation of REE-rich phosphates. Subsequent crystallization of REE-poor calcite led to enrichment of the residual liquid in REE, particularly LREE. This implies that REE are generally incompatible with respect to calcite and the calcite/melt partition coefficients for heavy REE (HREE) are significantly greater than those for LREE. Precipitation of REE-fluorocarbonates late in the evolutionary history resulted in depletion of the residual liquid in LREE, as manifested by the development of HREE-enriched late-stage calcite [(La/Yb)CN=0.7] in syenites associated with the carbonatite. The observed variations of REE distribution between calcite and whole rocks are interpreted to arise from multistage fractional crystallization (phosphates!calcite!REE-!uorocarbonates) from an initially REE-rich carbonatitic liquid.
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In our rejoinder to Don Weatherburn's paper,"Law and Order Blues", we do not take issue with his advocacy of the need to take crime seriously and to foster a more rational approach to the problems it poses. Where differences do emerge is (1) with his claim that he is willing to do so whilst we (in our different ways) are not; and (2) on the question of what this involves. Of particular concern is the way in which his argument proceeds by a combination of simple misrepresentation of the positions it seeks to disparage, and silence concerning issues of real substance where intellectual debate and exchange would be welcome and useful. Our paper challenges, in turn, the misrepresentation of Indermaur's analysis of trends in violent crime, the misrepresentation of Hogg and Brown's Rethinking Law and Order, the misrepresentation of the findings of some of the research into the effectiveness of punitive policies and the silence on sexual assault in "Law and Order Blues". We suggest that his silence on sexual assault reflects a more widespread unwillingness to acknowledge the methodological problems that arise in the measurement of crime because such problems severely limit the extent to which confident assertions can be made about prevalence and trends.
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CD151, a member of the tetraspanin family, is associated with regulation of migration of normal and tumour cells via cell surface microdomain formation. CD151 was found in our laboratory to have a prognostic value in prostate cancer and is a promoter of prostate cancer migration and invasion. These roles involve association with integrins on both cell-cell and cell-stroma levels. Furthermore, CD151 plays a role in endothelial cell motility. CD151 expression was examined in three commonly used prostate cancer cell lines. We investigated CD151 expression, angiogenesis (microvessel density; MVD) and lymphangiogenesis (lymphatic vessel density; LVD) in an orthotopic xenograft model of prostate cancer in matched tumours from primary and secondary sites. CD151 was found to be heterogeneously expressed across different prostate cancer cell lines and the levels of CD151 expression were significantly higher in the highly tumorigenic, androgen-insensitive cells PC-3 and DU-145 compared to the androgen-sensitive cell line LNCaP (P<0.05). The majority of in vivo xenografts developed pelvic lymph node metastases. Importantly, primary tumours that developed metastasis had significantly higher CD151 expression and MVD compared to those which did not develop metastasis (P<0.05). We identified, for the first time, that CD151 expression is associated with LVD in prostate cancer. These findings underscore the potential role of CD151 and angiogenesis in the metastatic potential of prostate cancer. CD151 has a prognostic value in this mouse model of prostate cancer and may play a role in lymphangiogenesis. CD151 is likely an important regulator of cancer cell communication with the surrounding microenvironment.
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Diabetic peripheral neuropathy (DPN) is one of the most common long-term complications of diabetes. The accurate detection and quantification of DPN are important for defining at-risk patients, anticipating deterioration, and assessing new therapies. Current methods of detecting and quantifying DPN, such as neurophysiology, lack sensitivity, require expert assessment and focus primarily on large nerve fibers. However, the earliest damage to nerve fibers in diabetic neuropathy is to the small nerve fibers. At present, small nerve fiber damage is currently assessed using skin/nerve biopsy; both are invasive technique and are not suitable for repeated investigations.
Resumo:
In our rejoinder to Don Weatherburn's paper, “Law and Order Blues”, we do not take issue with his advocacy of the need to take crime seriously and to foster a more rational approach to the problems it poses. Where differences do emerge is (1) with his claim that he is willing to do so whilst we (in our different ways) are not; and (2) on the question of what this involves. Of particular concern is the way in which his argument proceeds by a combination of simple misrepresentation of the positions it seeks to disparage, and silence concerning issues of real substance where intellectual debate and exchange would be welcome and useful. Our paper challenges, in turn, the misrepresentation of Indermaur's analysis of trends in violent crime, the misrepresentation of Hogg and Brown's Rethinking Law and Order, the misrepresentation of the findings of some of the research into the effectiveness of punitive policies and the silence on sexual assault in “Law and Order Blues”. We suggest that his silence on sexual assault reflects a more widespread unwillingness to acknowledge the methodological problems that arise in the measurement of crime because such problems severely limit the extent to which confident assertions can be made about prevalence and trends.
Resumo:
Articular cartilage has a limited intrinsic repair capacity, and thus defects are more likely to further degrade rather than undergo spontaneous self-repair. Whilst a number of surgical techniques have been developed to repair cartilage defects, their efficacy is generally poor and total joint replacement remains the gold standard, albeit last resort, treatment option. Cell-based therapies hold the greatest promise, as they appear uniquely capable of generating de novo cartilage tissue. Two approved therapies (ACI and MACI) are based on the premise that the transplantation of ex vivo expanded autologous chondrocyte populations, harvested from a non-load bearing region of the same joint, could be utilized to effectively regenerate cartilage tissue in the primary defect site. These therapeutic strategies are partially limited by our inability to harvest and expand adequate numbers of autologous chondrocytes that retain the appropriate phenotype. By contrast, the harvest and expansion of large numbers of mesenchymal stem/stromal cells (MSC) derived from tissues such as bone marrow and adipose is comparatively straightforward and has become routine in laboratories worldwide. Additionally, our understanding of the biochemical and biophysical signals required to drive the chondrogenic differentiation of MSC is rapidly increasing. It is conceivable that in the near future MSC expansion and differentiation technologies will offer a means to generate sufficient cell numbers, of an appropriate phenotype, for use in cartilage defect repair. In this chapter we review the relative potential of MSC and their likely contribution to cartilage regeneration.
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AIM The aim of this paper was to review the current discourse in relation to intensive care unit (ICU) delirium. In particular, it will discuss the predisposing and contributory factors associated with delirium's development as well as effects of delirium on patients, staff and family members. BACKGROUND Critically ill patients are at greater risk of developing delirium and, with an ageing population and increased patient acuity permitted by medical advances, delirium is a growing problem in the ICU. However, there is a universal consensus that the definition of ICU delirium needs improvement to aid its recognition and to ensure both hypoalert-hypoactive and hyperalert-hyperactive variants are easily and readily identified. RELEVANCE TO CLINICAL PRACTICE The effects of ICU delirium have cost implications to the National Health Service in terms of prolonged ventilation and length of hospital stay. The causes of delirium can be readily classified as either predisposing or precipitating factors, which are organic in nature and commonly reversible. However, contributory factors also exist to exacerbate delirium and having an awareness of all these factors promises to aid prevention and expedite treatment. This will avoid or limit the host of adverse physiological and psychological consequences that delirium can provoke and directly enhance both patient and staff safety. CONCLUSIONS Routine screening of all patients in the ICU for the presence of delirium is crucial to its successful management. Nurses are on the front line to detect, manage and even prevent delirium.
Resumo:
Creative Development: The Body and Light. Within the current cultural climate, the independent choreographer struggles to pursue and establish their artistic career outside the infrastructure of mainstream dance companies. The independent choreographer is challenged to articulate alternative choreographic models without the support of that infrastructure. My research examines that challenge by exploring my own independent choreographic practice through a number of performance-based dance projects. This exploration will be underpinned by theoretical research to enable clarification of the tacit understandings of an embodied practice and the point of intersection between practice and theory so as to articulate alternative choreographic models. As a starting point for that enquiry, an example is provided of how questions that emerge from within the choreographic practice can be discussed in terms of research through an initial investigation exploring light in relation to the moving body and the implications of atmospheres.
Resumo:
The Brain Research Institute (BRI) uses various types of indirect measurements, including EEG and fMRI, to understand and assess brain activity and function. As well as the recovery of generic information about brain function, research also focuses on the utilisation of such data and understanding to study the initiation, dynamics, spread and suppression of epileptic seizures. To assist with the future focussing of this aspect of their research, the BRI asked the MISG 2010 participants to examine how the available EEG and fMRI data and current knowledge about epilepsy should be analysed and interpreted to yield an enhanced understanding about brain activity occurring before, at commencement of, during, and after a seizure. Though the deliberations of the study group were wide ranging in terms of the related matters considered and discussed, considerable progress was made with the following three aspects. (1) The science behind brain activity investigations depends crucially on the quality of the analysis and interpretation of, as well as the recovery of information from, EEG and fMRI measurements. A number of specific methodologies were discussed and formalised, including independent component analysis, principal component analysis, profile monitoring and change point analysis (hidden Markov modelling, time series analysis, discontinuity identification). (2) Even though EEG measurements accurately and very sensitively record the onset of an epileptic event or seizure, they are, from the perspective of understanding the internal initiation and localisation, of limited utility. They only record neuronal activity in the cortical (surface layer) neurons of the brain, which is a direct reflection of the type of electrical activity they have been designed to record. Because fMRI records, through the monitoring of blood flow activity, the location of localised brain activity within the brain, the possibility of combining fMRI measurements with EEG, as a joint inversion activity, was discussed and examined in detail. (3) A major goal for the BRI is to improve understanding about ``when'' (at what time) an epileptic seizure actually commenced before it is identified on an eeg recording, ``where'' the source of this initiation is located in the brain, and ``what'' is the initiator. Because of the general agreement in the literature that, in one way or another, epileptic events and seizures represent abnormal synchronisations of localised and/or global brain activity the modelling of synchronisations was examined in some detail. References C. M. Michel, G. Thut, S. Morand, A. Khateb, A. J. Pegna, R. Grave de Peralta, S. Gonzalez, M. Seeck and T. Landis, Electric source imaging of human brain functions, Brain Res. 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Objective Evaluate the effectiveness and robustness of Anonym, a tool for de-identifying free-text health records based on conditional random fields classifiers informed by linguistic and lexical features, as well as features extracted by pattern matching techniques. De-identification of personal health information in electronic health records is essential for the sharing and secondary usage of clinical data. De-identification tools that adapt to different sources of clinical data are attractive as they would require minimal intervention to guarantee high effectiveness. Methods and Materials The effectiveness and robustness of Anonym are evaluated across multiple datasets, including the widely adopted Integrating Biology and the Bedside (i2b2) dataset, used for evaluation in a de-identification challenge. The datasets used here vary in type of health records, source of data, and their quality, with one of the datasets containing optical character recognition errors. Results Anonym identifies and removes up to 96.6% of personal health identifiers (recall) with a precision of up to 98.2% on the i2b2 dataset, outperforming the best system proposed in the i2b2 challenge. The effectiveness of Anonym across datasets is found to depend on the amount of information available for training. Conclusion Findings show that Anonym compares to the best approach from the 2006 i2b2 shared task. It is easy to retrain Anonym with new datasets; if retrained, the system is robust to variations of training size, data type and quality in presence of sufficient training data.
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We consider the following problem: members in a dynamic group retrieve their encrypted data from an untrusted server based on keywords and without any loss of data confidentiality and member’s privacy. In this paper, we investigate common secure indices for conjunctive keyword-based retrieval over encrypted data, and construct an efficient scheme from Wang et al. dynamic accumulator, Nyberg combinatorial accumulator and Kiayias et al. public-key encryption system. The proposed scheme is trapdoorless and keyword-field free. The security is proved under the random oracle, decisional composite residuosity and extended strong RSA assumptions.
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Robust facial expression recognition (FER) under occluded face conditions is challenging. It requires robust algorithms of feature extraction and investigations into the effects of different types of occlusion on the recognition performance to gain insight. Previous FER studies in this area have been limited. They have spanned recovery strategies for loss of local texture information and testing limited to only a few types of occlusion and predominantly a matched train-test strategy. This paper proposes a robust approach that employs a Monte Carlo algorithm to extract a set of Gabor based part-face templates from gallery images and converts these templates into template match distance features. The resulting feature vectors are robust to occlusion because occluded parts are covered by some but not all of the random templates. The method is evaluated using facial images with occluded regions around the eyes and the mouth, randomly placed occlusion patches of different sizes, and near-realistic occlusion of eyes with clear and solid glasses. Both matched and mis-matched train and test strategies are adopted to analyze the effects of such occlusion. Overall recognition performance and the performance for each facial expression are investigated. Experimental results on the Cohn-Kanade and JAFFE databases demonstrate the high robustness and fast processing speed of our approach, and provide useful insight into the effects of occlusion on FER. The results on the parameter sensitivity demonstrate a certain level of robustness of the approach to changes in the orientation and scale of Gabor filters, the size of templates, and occlusions ratios. Performance comparisons with previous approaches show that the proposed method is more robust to occlusion with lower reductions in accuracy from occlusion of eyes or mouth.
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Plant microRNAs (miRNAs) are a class of endogenous small RNAs that are essential for plant development and survival. They arise from larger precursor RNAs with a characteristic hairpin structure and regulate gene activity by targeting mRNA transcripts for cleavage or translational repression. Efficient and reliable detection and quantification of miRNA expression has become an essential step in understanding their specific roles. The expression levels of miRNAs can vary dramatically between samples and they often escape detection by conventional technologies such as cloning, northern hybridization and microarray analysis. The stem-loop RT-PCR method described here is designed to detect and quantify mature miRNAs in a fast, specific, accurate and reliable manner. First, a miRNA-specific stem-loop RT primer is hybridized to the miRNA and then reverse transcribed. Next, the RT product is amplified and monitored in real time using a miRNA-specific forward primer and the universal reverse primer. This method enables miRNA expression profiling from as little as 10 pg of total RNA and is suitable for high-throughput miRNA expression analysis.
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Introduction Older people recovering from cardiac events requiring an acute hospital admission may experience a decline in physical function limiting their ability to return home to their previous accommodation. Subacute inpatient rehabilitation therapies have potential to assist recovery of physical functioning. However, it is unknown whether age influences the length of stay or physical functioning at discharge from subacute inpatient rehabilitation for this population. Objectives This study examined the outcomes of a cohort of older patients recovering from a cardiac event requiring hospitalisation to investigate the association between age and physical function at discharge, as well as age and length of rehabilitation stay. Methods Participants included 145 consecutive inpatient admissions to a subacute geriatric assessment and rehabilitation unit with a cardiac condition as their primary reason for hospital admission. Participants were required to complete a multi-disciplinary physical functioning assessment within 72 hours of admission to the unit, and again within 72 hours prior to discharge from the unit. The primary outcome measure was the Functional Independence Measure motor score. Demographic and clinical information, including length of stay and discharge destination, were also recorded. Results A total n=126 (87%) participants, with a mean (standard deviation) age of 79 (10) years, had both assessments completed and were included in analyses. Participants who had passed away (n=4, 3%), or did not have both assessments completed per protocol were excluded from analyses. Discharge destinations included home (n=101, 80%), residential aged care (n=17, 13%) and another hospital (n=8, 6%). The (median, interquartile range) Functional Independence Measure motor score was higher at discharge (79, 71 to 84) than admission (61, 48 to 71); z=7.75 p<0.001. Age was not associated with Functional Independence Measure motor score at discharge (t= -0.18, p=0.86), or length of stay in the rehabilitation unit (t= -0.52, 0.60). Conclusion Any perception that age may be associated with longer lengths of stay and reduced physical function outcomes among patients with cardiac conditions admitted for subacute inpatient rehabilitation for older adults is not supported data from this investigation. Older age should not be considered a disincentive when considering the suitability of patients with cardiac diagnoses for this type of inpatient rehabilitation or their potential physical functioning outcome.