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Search Results: 1 - 10 of 6766 matches for " Tom Pickles "
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The median non-prostate cancer survival is more than 10 years for men up to age 80 years who are selected and receive curative radiation treatment for prostate cancer
Paul A Blood, Tom Pickles
Radiation Oncology , 2007, DOI: 10.1186/1748-717x-2-17
Abstract: It is generally accepted that men with low and intermediate risk for prostate cancer should be treated with curative intent only if their life expectancy exceeds 10 years [1]. The average life expectancy of North American males is less than 10 years after age 75 [2], yet recent reports from the U.S. indicate that more than 35% of men with prostate cancer who are older than 75 are treated with radiation therapy [3]. Are these elderly men being treated inappropriately, or are radiation oncologists able to appropriately select for radiation treatment elderly men whose life expectancy is better than the average for their age?The objectives of this study were to determine the life expectancy from non-prostate cancer death for men aged 75 and older who are treated with curative radiotherapy for prostate cancer, and to compare their life expectancy with that of the general male population.The study included men who started curative radiotherapy for prostate cancer between 1984 and 2004, who were age 75 to 82 at the date of starting the therapy. Data was taken from the British Columbia Cancer Registry, which records all cancer diagnoses and treatments in the province of British Columbia (BC), Canada [4,5]. Mortality was determined from death certificates recorded in the Cancer Registry. Death certificates were available up to December 31, 2004.Between 1984 and 2004, 4,005 men aged 75 to 82 started radiation treatment for prostate cancer in BC. According to the risk criteria of the Canadian Consensus Guidelines [6], 56% of the men had high-risk prostate cancer, 33% had intermediate risk, and 11% had low risk. The median radiotherapy dose and fractionation was 66 Gy in 33 fractions (Range: 50 Gy in 16 fractions to 74 Gy in 37 fractions). One hundred and ten men were treated with brachytherapy.Figure 1 shows the Kaplan-Meier (K-M) survival curves for deaths from prostate cancer, non-prostate cancer deaths, and deaths from all causes. Survival is measured from the start date of
Expanded risk groups help determine which prostate radiotherapy sub-group may benefit from adjuvant androgen deprivation therapy
Matthew Beasley, Scott G Williams, Tom Pickles, The BCCA Prostate Outcomes Unit
Radiation Oncology , 2008, DOI: 10.1186/1748-717x-3-8
Abstract: Using a previously validated 5-risk group schema, a prospective non-randomized data set of 1423 men treated at the British Columbia Cancer Agency was assessed for the primary end point of biochemical control (bNED) with the RTOG-ASTRO "Phoenix" definition (lowest PSA to date + 2 ng/mL), both with and without adjuvant ADT. The median follow-up was 5 years.There was no bNED benefit for ADT in the low or low intermediate groups but there was a statistically significant bNED benefit in the high intermediate, high and extreme risk groups. The 5-year bNED rates with and without ADT were 70% and 73% respectively for the low intermediate group (p = non-significant) and 72% and 58% respectively for the high intermediate group (p = 0.002).There appears to be no advantage to ADT where the Gleason score is 6 or less and PSA is 15 or less. ADT is beneficial in patients treated to standard dose radiation with Gleason 6 disease and a PSA greater than 15 or where the Gleason score is 7 or higher.Androgen deprivation therapy (ADT) has a proven role in the treatment of metastatic prostate cancer. Some groups of patients undergoing external beam radiotherapy (EBRT) for localized prostate cancer also benefit from adjuvant ADT. An EORTC trial randomized patients with T1–2 high grade or T3–4 N0–1 prostate cancer to either radiotherapy alone or with 3 years of ADT and showed an improved overall survival at 5 years[1]. The Trans-Tasman Radiation Oncology Group 96.01 trial randomized patients with T2b-T4 N0 disease to radiotherapy alone or with 3 or 6 months ADT. There was an improvement in disease free survival for both ADT arms compared to EBRT alone [2].Sub-division of prostate cancer patients into risk groups can be used to guide management decisions based on their risk of relapse. The National Comprehensive Cancer Network (NCCN) classifies three risk groups: Low risk (T1-T2a, Gleason score ≤ 6 and PSA ≤ 10 ng/ml), Intermediate risk (T2b-T2c or Gleason score 7 or PSA 10.1–20 ng/ml) and
Termination-of-Pregnancy Rights and Foetal Interests in Continued Existence in South Africa: The Choice on Termination of Pregnancy Act 92 of 1996
C Pickles
Potchefstroom Electronic Law Journal/Potchefstroomse Elektroniese Regsblad , 2012,
Abstract: The aim of this article is to demonstrate that, although South Africa has permissive termination-of-pregnancy legislation, to the extent that women can terminate firstand second-trimester pregnancies on demand and for socio-economic reasons, foetal interests are in fact taken into account. The system of female reproductive rights progressively shelters foetal interests, albeit to a limited extent. South Africa is in the process of successfully balancing the conflicting notions of female reproductive rights and foetal interests. The article discusses the "right to terminate a pregnancy" with reference to the Constitution, the Choice on Termination of Pregnancy Act 92 of 1996 and relevant case law. On the topic of foetal interests, the article looks at the Choice on Termination of Pregnancy Act as legislative recognition of foetal interests since a woman's right to terminate her pregnancy is progressively limited as the pregnancy advances beyond the second trimester. The value of dignity justifies the recognition of foetal interests. Further, accepting that the Choice on Termination of Pregnancy Act limitedly protects foetal interests based on the value of dignity, the article questions why South Africa permits elective second trimester termination of pregnancies? Research indicates a need for second trimester terminations and the article discusses the position of a number of women seeking second trimester terminations. The article draws to an end by looking at the case of S v Mshumpa as an example of the balancing process that is needed when dealing with female reproductive rights and foetal interests. This article demonstrates the constitutional setting of women's termination-of-pregnancy rights on the one hand, and foetal interests on the other. Further, it illustrates that these conflicting positions, rather than being deepened, are in fact balanced by legislation and relevant case law. KEYWORDS: Choice on Termination of Pregnancy Act; female autonomy; foetal interests; value of dignity; second-trimester termination of pregnancy
TERMINATION-OF-PREGNANCY RIGHTS AND FOETAL INTERESTS IN CONTINUED EXISTENCE IN SOUTH AFRICA: THE CHOICE ON TERMINATION OF PREGNANCY ACT 92 OF 1996
Camilla Pickles
Potchefstroom Electronic Law Journal/Potchefstroomse Elektroniese Regsblad , 2012,
Abstract: The aim of this article is to demonstrate that, although South Africa has permissive termination-of-pregnancy legislation, to the extent that women can terminate first- and second-trimester pregnancies on demand and for socio-economic reasons, foetal interests are in fact taken into account. The system of female reproductive rights progressively shelters foetal interests, albeit to a limited extent. South Africa is in the process of successfully balancing the conflicting notions of female reproductive rights and foetal interests. The article discusses the "right to terminate a pregnancy" with reference to the Constitution, the Choice on Termination of Pregnancy Act 92 of 1996 and relevant case law. On the topic of foetal interests, the article looks at the Choice on Termination of Pregnancy Act as legislative recognition of foetal interests since a woman's right to terminate her pregnancy is progressively limited as the pregnancy advances beyond the second trimester. The value of dignity justifies the recognition of foetal interests. Further, accepting that the Choice on Termination of Pregnancy Act limitedly protects foetal interests based on the value of dignity, the article questions why South Africa permits elective second trimester termination of pregnancies? Research indicates a need for second trimester terminations and the article discusses the position of a number of women seeking second trimester terminations.The article draws to an end by looking at the case of S v Mshumpa as an example of the balancing process that is needed when dealing with female reproductive rights and foetal interests. This article demonstrates the constitutional setting of women's termination-of-pregnancy rights on the one hand, and foetal interests on the other. Further, it illustrates that these conflicting positions, rather than being deepened, are in fact balanced by legislation and relevant case law.
Thermodynamics of the Reduction Roasting of Nickeliferous Laterite Ores  [PDF]
R. Elliott, C. A. Pickles, J. Forster
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2016, DOI: 10.4236/jmmce.2016.46028
Abstract: The global nickel sulphide resources are becoming more difficult to mine and, as a result, there is increasing interest in the current and future development of the oxidic nickel laterite deposits. In comparison to the sulphide ores, the nickel laterites cannot be readily upgraded by conventional means and growing attention is being focused on the development of new methods for processing these ores. In this paper, firstly, brief overviews of laterite ore mineralogy and the conventional techniques used to extract the nickel from both the limonitic and the saprolitic nickeliferous laterites are provided. Secondly, previous research on the thermodynamic modelling of the reduction of the laterites is discussed. Thirdly, an improved thermodynamic model is used to predict the equilibrium products arising from the solid state reduction of both the limonitic and the saprolitic ores. Based on these thermodynamic predictions, the reduction behaviors of the two ore types are compared in terms of nickel recovery and grade in the ferronickel product. The effects of reduction temperature, ore composition and carbon additions were studied. Finally, the results from the simulations are compared to the experimental data available in the literature.
Joint modelling of longitudinal and multi-state processes: application to clinical progressions in prostate cancer
Lo?c Ferrer,Virginie Rondeau,James J. Dignam,Tom Pickles,Hélène Jacqmin-Gadda,Cécile Proust-Lima
Statistics , 2015,
Abstract: Joint modelling of longitudinal and survival data is increasingly used in clinical trials on cancer. In prostate cancer for example, these models permit to account for the link between longitudinal measures of prostate-specific antigen (PSA) and the time of clinical recurrence when studying the risk of relapse. In practice, multiple types of relapse may occur successively. Distinguishing these transitions between health states would allow to evaluate, for example, how PSA trajectory and classical covariates impact the risk of dying after a distant recurrence post-radiotherapy, or to predict the risk of one specific type of clinical recurrence post-radiotherapy, from the PSA history. In this context, we present a joint model for a longitudinal process and a multi-state process which is divided into two sub-models: a linear mixed sub-model for longitudinal data, and a multi-state sub-model with proportional hazards for transition times, both linked by shared random effects. Parameters of this joint multi-state model are estimated within the maximum likelihood framework using an EM algorithm coupled to a quasi-Newton algorithm in case of slow convergence. It is implemented under R, by combining and extending the mstate and JM packages. The estimation program is validated by simulations and applied on pooled data from two cohorts of men with localized prostate cancer and treated by radiotherapy. Thanks to the classical covariates available at baseline and the PSA measurements collected repeatedly during the follow-up, we are able to assess the biomarker's trajectory, define the risks of transitions between health states, and quantify the impact of the PSA dynamics on each transition intensity.
Nielsen-Olesen strings in Supersymmetric models
M. Pickles,J. Urrestilla
Physics , 2002, DOI: 10.1088/1126-6708/2003/01/052
Abstract: We investigate the behaviour of a model with two oppositely charged scalar fields. In the Bogomol'nyi limit this may be seen as the scalar sector of N=1 supersymmetric QED, and it has been shown that cosmic strings form. We examine numerically the model out of the Bogomol'nyi limit, and show that this remains the case. We then add supersymmetry-breaking mass terms to the supersymmetric model, and show that strings still survive. Finally we consider the extension to N=2 supersymmetry with supersymmetry-breaking mass terms, and show that this leads to the formation of stable cosmic strings, unlike in the unbroken case.
All-Sky spectrally matched UBVRI-ZY and u'g'r'i'z' magnitudes for stars in the Tycho2 catalog
Andrew Pickles,éric Depagne
Physics , 2010, DOI: 10.1086/657947
Abstract: We present fitted UBVRI-ZY and u'g'r'i'z' magnitudes, spectral types and distances for 2.4M stars, derived from synthetic photometry of a library spectrum that best matches the Tycho2 BtVt, NOMAD Rn and 2MASS JHK_{2/S} catalog magnitudes. We present similarly synthesized multi-filter magnitudes, types and distances for 4.8M stars with 2MASS and SDSS photometry to g<16 within the Sloan survey region, for Landolt and Sloan primary standards, and for Sloan Northern (PT) and Southern secondary standards. The synthetic magnitude zeropoints for BtVt, UBVRI, ZvYv, JHK_{2/S}, JHK_{MKO}, Stromgren uvby, Sloan u'g'r'i'z' and ugriz are calibrated on 20 calspec spectrophotometric standards. The UBVRI and ugriz zeropoints have dispersions of 1--3%, for standards covering a range of color from -0.3 < V-I < 4.6; those for other filters are in the range 2--5%. The spectrally matched fits to Tycho2 stars provide estimated 1-sigma errors per star of ~0.2, 0.15, 0.12, 0.10 and 0.08 mags respectively in either UBVRI or u'g'r'i'z'; those for at least 70% of the SDSS survey region to g<16 have estimated 1-sigma errors per star of ~0.2, 0.06, 0.04, 0.04, 0.05 in u'g'r'i'z' or UBVRI. The density of Tycho2 stars, averaging about 60 stars per square degree, provides sufficient stars to enable automatic flux calibrations for most digital images with fields of view of 0.5 degree or more. Using several such standards per field, automatic flux calibration can be achieved to a few percent in any filter, at any airmass, in most workable observing conditions, to facilitate inter-comparison of data from different sites, telescopes and instruments.
Block Algorithms for Quark Propagator Calculation
Stephen M. Pickles,UKQCD Collaboration
Physics , 1997, DOI: 10.1016/S0920-5632(97)00955-9
Abstract: Computing quark propagators in lattice QCD is equivalent to solving large, sparse linear systems with multiple right-hand sides. Block algorithms attempt to accelerate the convergence of iterative Krylov-subspace methods by solving the multiple systems simultaneously. This paper compares a block generalisation of the quasi-minimal residual method (QMR), Block Conjugate Gradient on the normal equation, Block Lanczos and ($\gamma_5$-symmetric) Block BiConjugate Gradient.
Dynamics and Properties of Chiral Cosmic Strings
M. Pickles,A. C. Davis
Physics , 2001, DOI: 10.1016/S0370-2693(01)01185-6
Abstract: Chiral cosmic strings naturally arise in many particle physics models, in particular in supersymmetric theories with a D-term. These strings have a single fermion zero mode in the core. We derive the general equation of motion for such strings. In Minkowski space we give the self-intersections for an arbitary varying current on the loop, showing that the self-intersection probability is dominated by the fraction of loop with maximal charge. We show how to relate the charge to the fermion condensation temperature, arguing that strings which become current carrying at formation will automatically have a maximal charge. Any daughter loops produced are likely to have the same charge as the parent loop. Possible models for chiral cosmic strings are also discussed and consequences for D-term inflation mentioned.
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