NEXP-completeness and Universal Hardness Results for Justification Logic

We provide a lower complexity bound for the satisfiability problem of a multi-agent justification logic, establishing that the general NEXP upper bound from our previous work is tight. We then use a simple modification of the corresponding reduction to prove that satisfiability for all multi-agent justification logics from there is hard for the Sigma 2 p class of the second level of the polynomial hierarchy - given certain reasonable conditions. Our methods improve on these required conditions for the same lower bound for the single-agent justification logics, proven by Buss and Kuznets in 2009, thus answering one of their open questions.Comment: Shorter version has been accepted for publication by CSR 201

Bone mineral density in Jamaican men on androgen deprivation therapy for prostate cancer

<p>Abstract</p> <p>Background</p> <p>Androgen deprivation therapy (ADT) has been reported to reduce the bone mineral density (BMD) in men with prostate cancer (CaP). However, Afro-Caribbeans are under-represented in most studies. The aim was to determine the effect of androgen deprivation therapy (ADT) on the bone mineral density (BMD) of men with prostate cancer in Jamaica.</p> <p>Methods</p> <p>The study consisted of 346 Jamaican men, over 40 years of age: 133 ADT treated CaP cases (group 1), 43 hormone-naïve CaP controls (group 2) and 170 hormone naïve controls without CaP (group 3). Exclusion criteria included metastatic disease, bisphosphonate therapy or metabolic disease affecting BMD. BMD was measured with a calcaneal ultrasound and expressed in S.D. units relative to young adult men (T score), according to the World Health Organization definition. Patient weight, height and BMI were assessed.</p> <p>Results</p> <p>Mean ± sd, age of patients in group 1 (75± 7.4 yrs) was significantly greater than groups 2 and 3 (67 ± 8.1 yrs; 65±12.0 yrs). There was no significant difference in weight and BMI between the 3 groups. . The types of ADT (% of cases, median duration in months with IQR) included LHRH (Luteinizing hormone releasing hormone) analogues (28.6%, 17.9, IQR 20.4), oestrogens (9.8%, 60.5, IQR 45.6) anti-androgens (11.3%, 3.3, IQR 15.2) and orchiectomy (15.7%, 43.4, IQR 63.9). Unadjusted t score of group 1, mean ± sd, (-1.6± 1.5) was significantly less than group 2 (-0.9±1.1) and group 3 (-0.7±1.4), p <0.001. Ninety three (69.9%), 20 (45%) and 75 (42%) of patients in groups 1, 2 and 3 respectively were classified as either osteopenic or osteoporotic (p<0.001). Adjusting for age, there was a significant difference in t scores between groups 1 and 2 as well as between groups 1 and 3 (p<0.001). Compared with oestrogen therapy and adjusting for duration of therapy, the odds of low bone mineral density (osteopenia or osteoporosis) with LHRH analogue was 4.5 (95%CI, 14.3 to 3.4); with anti-androgens was 5.9 (95%CI, 32.7 to 5); with orchiectomy was 7.3 (95%CI, 30 to 5.8) and multiple drugs was 9.2 ((95%CI, 31 to 7.1).</p> <p>Conclusions</p> <p>ADT is associated with lower BMD in Jamaican men on hormonal therapy for prostate cancer.</p

Spatial variation in prostate cancer survival in the Northern and Yorkshire region of England using Bayesian relative survival smoothing

Primary Care Trust (PCT) estimates of survival lack robustness as there are small numbers of deaths per year in each area, even when incidence is high. We assess PCT-level spatial variation in prostate cancer survival using Bayesian spatial models of excess mortality. We extracted data on men diagnosed with prostate cancer between 1990 and 1999 from the Northern and Yorkshire Cancer Registry and Information Service database. Models were adjusted for age at diagnosis, period of diagnosis and deprivation. All covariates had a significant association with excess mortality; men from more deprived areas, older age at diagnosis and diagnosed in 1990–1994 had higher excess mortality. The unadjusted relative excess risks (RER) of death by PCT ranged from 0.75 to 1.66. After adjustment, areas of high and low excess mortality were smoothed towards the mean, and the RERs ranged from 0.74 to 1.49. Using Bayesian smoothing techniques to model cancer survival by geographic area offers many advantages over traditional methods; estimates in areas with small populations or low incidence rates are stabilised and shrunk towards local and global risk estimates improving reliability and precision, complex models are easily handled and adjustment for covariates can be made

Clinical significance of altered nm23-H1, EGFR, RB and p53 expression in bilharzial bladder cancer

<p>Abstract</p> <p>Background</p> <p>Clinical characterization of bladder carcinomas is still inadequate using the standard clinico-pathological prognostic markers. We assessed the correlation between <it>nm23-H1</it>, <it>Rb, EGFR </it>and <it>p53 </it>in relation to the clinical outcome of patients with muscle invasive bilharzial bladder cancer (MI-BBC).</p> <p>Methods</p> <p><it>nm23-H1</it>, <it>Rb, EGFR and p53 </it>expression was assessed in 59 MI-BBC patients using immunohistochemistry and reverse transcription (RT-PCR) and was correlated to the standard clinico-pathological prognostic factors, patient's outcome and the overall survival (OS) rate.</p> <p>Results</p> <p>Overexpression of <it>EGFR </it>and <it>p53 </it>proteins was detected in 66.1% and 35.6%; respectively. Loss of <it>nm23-H1</it>and <it>Rb </it>proteins was detected in 42.4% and 57.6%; respectively. Increased <it>EGFR and </it>loss of <it>nm23-H1 </it>RNA were detected in 61.5% and 36.5%; respectively. There was a statistically significant correlation between <it>p53 </it>and <it>EGFR </it>overexpression (<it>p </it>< 0.0001), <it>nm23 </it>loss (protein and RNA), lymph node status (<it>p </it>< 0.0001); between the incidence of local recurrence and <it>EGFR </it>RNA overexpression (p= 0.003) as well as between the incidence of metastasis and altered <it>Rb </it>expression (<it>p </it>= 0.026), <it>p53 </it>overexpression (<it>p </it>< 0.0001) and mutation (<it>p </it>= 0.04). Advanced disease stage correlated significantly with increased <it>EGFR </it>(protein and RNA) (<it>p </it>= 0.003 & 0.01), reduced <it>nm23-H1 </it>RNA (<it>p </it>= 0.02), altered <it>Rb </it>(<it>p </it>= 0.023), and <it>p53 </it>overexpression (<it>p </it>= 0.004). OS rates correlated significantly, in univariate analysis, with <it>p53 </it>overexpression (<it>p </it>= 0.011), increased <it>EGFR </it>(protein and RNA, <it>p </it>= 0.034&0.031), <it>nm23-H1 RNA </it>loss (<it>p </it>= 0.021) and aberrations of ≥ 2 genes. However, multivariate analysis showed that only high <it>EGFR </it>overexpression, metastatic recurrence, high tumor grade and the combination of ≥ 2 affected markers were independent prognostic factors.</p> <p>Conclusion</p> <p><it>nm23-H1, EGFR </it>and <it>p53 </it>could be used as prognostic biomarkers in MI-BBC patients. In addition to the standard pathological prognostic factors, a combination of these markers (≥ 2) has synergistic effects in stratifying patients into variable risk groups. The higher is the number of altered biomarkers, the higher will be the risk of disease progression and death.</p

Prognostic factors in prostate cancer

Prognostic factors in organ confined prostate cancer will reflect survival after surgical radical prostatectomy. Gleason score, tumour volume, surgical margins and Ki-67 index have the most significant prognosticators. Also the origins from the transitional zone, p53 status in cancer tissue, stage, and aneuploidy have shown prognostic significance. Progression-associated features include Gleason score, stage, and capsular invasion, but PSA is also highly significant. Progression can also be predicted with biological markers (E-cadherin, microvessel density, and aneuploidy) with high level of significance. Other prognostic features of clinical or PSA-associated progression include age, IGF-1, p27, and Ki-67. In patients who were treated with radiotherapy the survival was potentially predictable with age, race and p53, but available research on other markers is limited. The most significant published survival-associated prognosticators of prostate cancer with extension outside prostate are microvessel density and total blood PSA. However, survival can potentially be predicted by other markers like androgen receptor, and Ki-67-positive cell fraction. In advanced prostate cancer nuclear morphometry and Gleason score are the most highly significant progression-associated prognosticators. In conclusion, Gleason score, capsular invasion, blood PSA, stage, and aneuploidy are the best markers of progression in organ confined disease. Other biological markers are less important. In advanced disease Gleason score and nuclear morphometry can be used as predictors of progression. Compound prognostic factors based on combinations of single prognosticators, or on gene expression profiles (tested by DNA arrays) are promising, but clinically relevant data is still lacking

Growth morphology of ultrathin Pb layers on Ni(001)

The atomic structure and morphology of ultrathin Pb layers deposited on the Ni(001) face in ultrahigh vacuum at the substrate temperature, ranging from 145 K to 900 K, were investigated with the use of the Auger electron spectroscopy and low-energy electron diffraction. The analysis of the Auger electron spectroscopy measurements indicates that the Volmer-Weber growth of the Pb takes place for substrate temperature T < 300 K. Between 300 and 600 K, the Stranski-Krastanov growth mode is observed. For 600 K ≤ T ≤ 700 K, only first two-dimensional Pb layer formation is found. Above 700 K desorption of lead atoms from the first layer is observed. The ordered low-energy electron diffraction patterns corresponding to p(1 × 1) and c(2 × 2) structures are observed