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A new nonlinear predictive control law for a class of multivariable nonlinear systems is presented in this paper. It is shown that the closed-loop dynamics under this nonlinear predictive controller explicitly depend on design parameters (prediction time and control order). The main features of this result are that an explicitly analytical form of the optimal predictive controller is given, on-line optimisation is not required, stability of the closed-loop system is guaranteed, the whole design procedure is transparent to designers and the resultant controller is easy to implement. By establishing the relationship between the design parameters and time-domain transient, it is shown that the design of an optimal generalised predictive controller to achieve desired time-domain specifications for nonlinear systems can be performed by...
Objective To examine the role of androgen receptor (AR) gene amplification and aneusomy of the X chromosome in the development of antiandrogen-resistant prostate cancer. Patients and methods Twenty patients with prostate cancer resistant to androgen-deprivation therapy were selected for study. The records of patients with tumours before and after antiandrogen therapy, and with a full clinical follow-up, were retrieved. AR gene amplification and X chromosome copy number were assessed by fluorescence in situ hybridization using a labelled probe at locus Xq11-13 for the AR gene and a labelled a-satellite probe for the X chromosome. At least 20 nuclei were scored over three tumour areas by two independent observers. Results Aneusomy of the X chromosome was reported respectively in seven (35%) and 11 (55%) tumours before and after hormone r...
Objective To relate the repeat length of the androgen-receptor CAG trinucleotide to the age of onset of prostate cancer, stage and grade of disease. Patients and methods After obtaining ethical approval, 265 patients with locally confined or locally advanced/metastatic prostate cancer were identified and evaluated for age at diagnosis (less than 65 years and greater than 75 years). DNA was extracted from peripheral blood lymphocytes and 1 mug aliquots subjected to polymerase chain reaction using fluorescently labelled primers. Samples were then run on an ABI 377 gene scan analysis gel with an internal molecular weight marker. The length of the CAG repeat was determined by comparing the gene scan product size to samples where the CAG repeat length had been quantified using direct sequencing. The Kruskal-Wallis, Mann-Whitney and Wilcox...
The predictive pole-placement control method introduced in this paper embeds the classical pole-placement state feedback design into a quadratic optimisation-based model-predictive formulation. This provides an alternative to model-predictive controllers which are based on linear–quadratic control. The theoretical properties of the controller in a linear continuous-time setting are presented and a number of illustrative examples are given. These results provide the foundation for novel linear and nonlinear constrained predictive control methods based on continuous-time models.
Objective To determine the frequency of HER2 genetic abnormalities in renal cell carcinoma (RCC) and hence assess the potential suitability of Herceptin(TM) immunotherapy. Patients and methods Tumours from 2 7 patients with RCC were assessed: all patients had undergone nephrectomy. Benign renal tissue from the nephrectomy specimens was studied in seven patients. Gene amplification was assessed using fluorescent in- situ hybridization, and protein over-expression using immunohistochemistry. Results Twenty-four patients had clear cell renal carcinoma, two had papillary renal carcinoma and one a sarcomatoid variant carcinoma. There was no HER2 amplification in the tumours or the benign renal tissue. Polysomy 17 was detected in 11 of 27 tumours (41%) and increased HER2 copy number in seven (26%). Both polysomy 17 and increased HER2 copy nu...
Samples from the Kola Superdeep Drillhole (12 262 m), a deep drillhole (1060 m), and from the surface, seaprated by only around 10 km, provided a unique opportunity for direct tracing of delta(13)C and delta(18)O changes through a low- to high-grade greenschist-facies transition within impure, C-13-rich Palaeoproterozoic dolostones. The least-altered dolostones have delta(13)C of +9 parts per thousand and delta(18)O of 22 parts per thousand. The metamorphic transition is expressed by dolomite + calcite, + quartz K-feldspar - tremolite + calcite(2) dolomite calcite, and defined by C-13 depletion of calcite(2) (c. 3.0 parts per thousand), calcite, (1.0-2.0 parts per thousand) and dolomite (<1 parts per thousand) which is associated with a Rayleigh distillation process. delta(18)O shows a considerable resetting in all carbonate compone...
The recently formed surface layers of peatlands are archives of past environmental conditions and can have a temporal resolution considerably greater than deeper layers. The low density and conditions of fluctuating water table have hindered attempts to construct chronologies for these peats. We tested the use of the radiocarbon bomb pulse to date recently accumulated peat in a blanket mire. The site was chosen because the peat profiles contained independent chronological markers in the form of charcoal-rich layers produced from known burning events. We compared chronologies derived from accelerator mass spectrometry C-14 analysis of plant macrofossils against these chronological markers. The bomb C-14-derived chronologies were in broad agreement with the charcoal dating evidence. However, there were uncertainties in the final interpre...
Although it has been suggested that structural adjustment policies have slowed Third World urban growth and have stimulated a spatial deconcentration of economic activity, this paper argues that African cities continue to grow and mainly through peri-urban development. This investment comes mainly from domestic sources and migrants' remittances, and tends to he in consumption rather than production. Reasons include cultural factors lack of confidence in the national economy and in the state's long-term economic objectives, an increasing demand for housing, improvements in intraurban transport, and a desire to spread investment risk among a range of alternatives including housing.
Lake sediments have the potential to preserve proxy records of past climate change. Organic material suitable for radiocarbon dating often provides age control of such proxy records. Six shallow freshwater lakes on the sub-Antarctic island of South Georgia were investigated for carbon reservoir effects that may influence age-depth profiles from lake sediment records in this important region. Paired samples of particulate organic matter (POM) from the water column and surface sediment (bulk organic carbon) were analyzed by accelerator mass spectrometry C-14. POM in 4 lakes was found to be in equilibrium with the atmosphere (similar to107% modern), whereas 2 lakes showed significant depletion of 14C. In each lake, the surface sediment ages were older than the paired POM age. Surface sediment ages showed a much greater range of ages compa...
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